JP2003534466A - Uptake system for personal care products - Google Patents

Abstract

  (57) [Summary] An uptake system material is provided for a personal care product made from a nonwoven web and having a hydrophobic upper surface and an increasing capillary attractive gradient in the Z direction perpendicular to the upper surface. The uptake system material can be formed from a single layer or multiple layers, and is useful for personal care products such as diapers, training pants, incontinence clothing, and feminine hygiene products. .

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention relates to an uptake system for primarily personal care products such as diapers, training pants, swimwear, absorbent underwear, adult incontinence products, and feminine hygiene products. The material may also be used in applications such as, for example, bandages and wound dressings, nursing pads, and veterinary fields.

BACKGROUND ART Personal care articles such as diapers generally consist of a number of components including a liner, an absorbent core, and baffles (also called backsheets). Liners with one or more absorbent layers provide flexibility and comfort, visual discrimination, absorbency,
It is often necessary to provide cleanliness and dryness. The liner is sometimes referred to as the bodyside liner or topsheet. In the thickness direction of the article, the liner material is the layer that faces the wearer's skin, and is therefore the layer that first contacts liquid or other exudates from the wearer. The liner should also serve to isolate the wearer's skin from the liquid retained in the absorbent structure and be compliant, soft feeling and non-irritating to the skin. Conventional materials used as liners are of light weight, fine fiber monolayer construction for cost efficiency and good appearance. Although some fibers are hydrophobic in nature, they are usually treated with surface chemicals (ie surfactants) to improve the uptake of liquids. Surfactants cause the web to become hydrophilic by changing the surface tension of the web, resulting in the liquid "wetting" or spreading across the surface of the web. This moisturizing action causes the liner to become liquid saturated, prolonging the contact time of the liquid with the skin and increasing skin hydration. However, it is desirable to design personal care articles to minimize skin hydration since skin hydration causes diaper rash, for example during use of diapers. If the liner has poor liquid uptake, remains saturated, or is fluid diffusive, hydration of the skin will increase.

Modern product designs incorporate one or more layers of material to help prevent leaks. This layer acts as a very temporary storage area, distribution medium or both. The layer below this liner layer, referred to herein as the "surge" layer, has traditionally been a relatively highly permeable material that allows liquids to quickly pass to the absorbent core.
However, the rapid passage of liquid to the absorbent core results in a large amount of liquid accumulating in the target area, leaving much of the absorbent core unused, resulting in excessive hydration of the target area or crotch. Therefore, it has good uptake on the surface, low saturation, and minimal fluid diffusion, further utilizes more of the absorbent core and reduces skin hydration, which reduces diaper rash There is still a need for a capture system that allows it.

DISCLOSURE OF THE INVENTION It is an object of the present invention that the upper portion of the material, ie, the surface that contacts the wearer, is hydrophobic (ie, has a liquid contact angle of 90 degrees or greater) and the capillary attraction of the material is Achieved by an uptake system material for personal care products that increases in the Z direction away from the surface that contacts the.

Definitions "Disposable" includes single use, disposal, and is not intended to be laundered or reused. "Front" and "rear" are used throughout this specification to describe the relationship to the garment itself, rather than to any position the garment assumes when worn by the wearer. The Y direction is the anteroposterior direction of the product, the Z direction is perpendicular to the Y direction and passes through the product, and the X direction is perpendicular to both the Y and Z directions. By "liquid communication" is meant that liquid can be transferred from one layer to another, or within a layer from one location to another. "Hydrophilic" refers to a fiber or surface of a fiber that is wetted by an aqueous liquid that contacts the fiber. The wettability of a material can be described by the contact angle and surface tension of the liquid and the material involved. Suitable equipment and techniques for measuring the wettability of a particular fibrous material or blend of fibrous materials are provided by the Cahn SFA-222 surface tension analyzer system or a system substantially equivalent thereto. Fibers having a contact angle of less than 90 degrees are "wettable" or hydrophilic and fibers having a contact angle of greater than 90 degrees are "non-wettable" or hydrophobic as measured by this system.

As used herein, the term “nonwoven or web” is a web in which individual fibers or threads have an interstitial structure, rather than in a manner recognizable as a knitted fabric. . Nonwoven fabrics or webs have been formed by many processes, such as, for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The basis weight of a nonwoven is usually the number of ounces per square yard of material (o
sy), or grams per square meter (gsm), useful fiber diameters are usually expressed in microns. (To convert osy to gsm, multiply osy by 33.91.)

The term “spunbond fiber” refers to a small diameter fiber formed by extruding a molten thermoplastic material as filaments from a plurality of fine capillaries of a spinneret. Such a process is described, for example, in U.S. Pat. No. 4,340,563 to Appel et al. This fiber is also described, for example, in US Pat. No. 5,277,9 to Hogle et al., Which describes a fiber having a non-conventional shape.
It may have a shape as described in No. 76. "Bonded carded web" means that staple fibers are fed into a combing or carding device and unraveled or chopped to align them in the machine direction to form a non-woven fiber oriented in a generally machine direction. It refers to the web created from that. The materials will be bonded together by methods including point bonding, through air bonding, ultrasonic bonding, adhesive bonding and the like.

“Air deposition” is a known process by which a fibrous nonwoven layer can be formed. In the air deposition process, bundles of fibrils with typical lengths ranging from about 3 to about 52 millimeters are separated and mixed into an air supply, which is then deposited on a forming screen, usually with the aid of a vacuum supply. To be done. The randomly deposited fibers are then bonded together using, for example, hot air or spray adhesive. Air accumulation is, for example, L
Aursen et al., U.S. Pat. No. 4,640,810.

As used herein, "hot spot bonding" refers to bonding a cloth or web of fibers through a heated calender roll and anvil roll. Calendar rolls are usually, but not always, patterned to some extent so that the fabric is not bonded across the entire surface of the fabric and the anvil roll is usually flat. is there. Therefore, various patterns of calendar rolls have been developed for functional and aesthetic reasons. An example of a pattern is one having dots, about 30% of which is about 200 bonds / inch 2 bond area, as taught in US Pat. No. 3,855,046 to Hansen and Pennings. , Hansen Pennings or "H &P" pattern. The H & P pattern has square dots or pin bond areas, each pin having a side dimension of 0.038 inch (0.9
65 mm), the spacing between each pin is 0.070 inch (1.778 mm), and the bond depth is 0.023 inch (0.584 mm). The resulting pattern is about 29.
It has a binding area of 5%. Another typical point bond pattern has a side dimension of 0.037.
Inch (0.94 mm), pin spacing is 0.097 inch (2.464 mm),
And 15% with a square pin having a depth of 0.039 inches (0.991 mm)
Is an extended Hansen-Pennings or "EHP" binding pattern that gives a binding zone of Another common pattern is a diamond pattern with repeated, slightly offset, bond areas of about 16% and, as the name implies, about 19% bond areas reminiscent of screen doors, for example. A wire weave pattern is included. Yet another common pattern is the C-Star pattern, which has a bond area of about 16.9%. The C-Star pattern has a horizontal bar or "corduroy" design interrupted by shooting stars. Typically, the percentage of bond area varies from about 10% to about 30% of the area of the fabric laminate web. As is well known in the art, point bonding not only holds the laminate layers together, but also adds integrity to each of the individual layers by bonding filaments and / or fibers within each layer. .

Various processes are known for bonding nonwoven webs. These processes include through air bonding, stitch bonding, ultrasonic bonding, point bonding, and pattern (or point) unbonding. An example of these binding processes is St
US Pat. No. 4,891,957 to Rack et al., US Pat. No. 4,374,888 to Bornslaeger, US Pat. No. 3,855,046 to Hansen and Pennings, and US Pat. No. 5,858 to Stokes et al. Seen at No. 515. "Personal Care Products" means diapers, training pants, swimwear, absorbent underwear, adult incontinence products, bandages and feminine hygiene products. "Target area" means the area or location of a personal care product that is normally subject to release by the wearer.

Test method and material basis weight : A circular sample having a diameter of 3 inches (7.6 cm) is cut out and weighed using a balance. Weights are recorded in grams. Divide weight by sample area. Measure and average 5 samples. Material caliper (thickness) : Material caliper is a measure of thickness, STARRE
Measured in millimeters at 0.05 psi (3.5 g / cm ² ) with a T® Bulk Tester. Sample 4 inches x 4 inches (10.2 cm
Cut out in 10.4 cm squares, test 5 samples and average the results. Density : The density of a material is calculated by dividing the weight per unit area of the material expressed in grams per square meter (gsm) by the caliper of the material expressed in millimeters. This caliper should be measured at 0.05 psi (3.5 g / cm ² ) as described above. Gram per cubic centimeter (g / cc)
Multiply the resulting value by 0.001 to convert to To get the density value,
A total of 5 samples are evaluated and averaged.

Permeability : Permeability is obtained by measuring the resistance of a material to the flow of liquid. Forcing a liquid of known viscosity through a material of defined thickness at a constant flow rate,
Monitor the flow resistance, which is measured as the pressure drop. To obtain the transmittance, the following Darcy's law is used. Permeability = (Flow velocity × Thickness × Viscosity / Pressure drop) (Equation 1) However, the unit is as follows. Transmittance: cm ² , or Darcy, 1 Darcy = 9.87 × 10 ^-9 cm ² Flow rate: cm / sec Viscosity: Pascal sec Pressure drop: Pascal

The device consists of a piston in a cylinder that pushes a liquid through a sample to be measured. The sample is clamped between two vertically oriented aluminum cylinders. Both cylinders have an outer diameter of 3.5 inches (8.9 cm), an inner diameter of 2.5 inches (6.35 cm), and a length of about 6 inches (15.2 cm). A 3-inch diameter web sample is held in place by its outer edge so that it is completely contained within the device. The bottom cylinder has a piston that is vertically movable at a constant speed inside the cylinder, which piston is connected to a pressure transducer capable of monitoring the pressure experienced by the liquid column supported by the piston. Since the transducer is arranged to move with the piston, no additional pressure is measured until the liquid column contacts the sample and is pushed into the sample. The additional pressure measured at this point is due to the resistance of the material to the flow of liquid through the material. The piston is moved by a sliding assembly driven by a stepper motor. The test is started by moving the piston at a constant speed until the liquid is pushed into the sample. The piston is then stopped and the baseline pressure is recorded. This compensates for the effects of sample buoyancy. The movement is then resumed for a time sufficient to measure the new pressure. The difference between the two pressures is the pressure due to the material's resistance to liquid flow, the pressure drop used in Eq. The velocity of the piston is the flow velocity. Although any liquid of known viscosity can be used, a liquid that wets the material is preferred as it ensures that a saturated flow is achieved. This measurement is a mineral oil with a viscosity of 6 centipoise (Penetec Technical Mineral Oil manufactured by Penreco, Los Angeles, CA, USA).
Was used at a piston speed of 20 cm / min.

Conductance : Conductance is calculated as the permeability per unit thickness and gives a measure of the openness of a particular structure, thereby giving an indication of the relative ease with which a material can transfer a liquid. Transepidermal water loss (TEWL) : Skin hydration value is transepidermal water loss (TEWL)
Can be measured by using the following test procedure. The test is performed on the adult forearm. Any drugs should be investigated to ensure that they do not affect the test results, and the subject's forearms should be free of skin conditions such as rashes or abrasions. Subject has humidity of about 40%
The test environment should be relaxed for about 15 minutes prior to testing in a test environment at about 22 ° C (72 ° F) with minimal movement during the test. Subjects must wear short-sleeved shirts, no bathing or showering for approximately 2 hours prior to the test, and no perfume, lotion, or powder applied to their forearms.

The measurements are based on DERMALA distributed by Cortex Technology of Hadsund 19590 Textilvaenget, Denmark.
It is performed by an evaporation meter such as B (registered trademark). Baseline reading must be performed on subject's forearm, 10 g / m ² / h
must be less than r. Each test measurement is performed over 2 minutes and the TEWL value is measured once per second (120 TEWL values total). Evaporator EP
The digital output from one device gives the rate of water loss by evaporation (TEWL) expressed in g / m ² / hr. To perform the test, place the end of the dosing tube in the center of the forearm. The hole in the tube should face the target load area. The product to be tested is placed on the subject's forearm with the tube end directly covered. Products may vary depending on the type of material being tested and the usefulness of the material, and care should be taken to ensure that test results are comparable. To help hold the product in place, a stretchable net, such as that available from Zens Industrial Knit Products, Milwaukee, Wis., USA, is placed over the product.

By means of a pump such as the MASTERFLEX® Digistatic Batch Dosing Pump, VWR Scientific Products (800-932)
-5000), 3 equivalent loads of 70 ml of saline, about 95 °
Product is given at 45 seconds intervals at F (35 ° C). After 60 minutes the product is removed from the subject's forearm and an evaporometer reading is taken immediately on the skin where the product was. The value of transepidermal water loss was g / m ² / as the difference between the 1-hour value and the baseline value.
Reported in hr.

Capillarity : Capillarity is defined as the tendency of a liquid to be absorbed by and retained within a porous structure. This tendency, represented by capillary attraction, is
And Kapur, “The Textile and Research J.
“Aurnal”, Volume 37 (May 1967) p. 356-366 by the application of the porous plate method. This method relies on balancing the capillary pressure to equal opposing hydrostatic pressures (h) and determining the amount of liquid that the sample has gained or lost as the hydrostatic pressure increases and decreases. This device is designed to measure the liquid content of the sample at various hydrostatic pressures as well as the simultaneous changes in bulk volume of the fiber mass.

The test apparatus includes a calibrated height gauge, a programmable stepper motor,
It consists of a UNISLIDE (R) vertical transfer platform with a funnel and filter plate assembly, a reservoir, several tubes, and an electronic balance controlled by a microprocessor. A funnel with a horizontal filter plate of known pore size inside is placed on a UNISLIDE® stand. Below the funnel, a TYGON® tube is attached to the reservoir, which is placed on the electronic balance, and the reservoir, tube and funnel (down to the filter plate) are filled with liquid. U used here
The NISLIDE (R) platform is available from Velmex Inc. of Bloomfield, NY, USA. Model No. manufactured by MB4045P1
It was 0J-S4. The funnel and filter plate unit is a Pyrex Corp. Model No. manufactured by 36060 and the filter plate had 10-15 micron holes.

Pore size is calculated from the LaPlace equation (Equation 2), which relates to hydrostatic pressure or height (h), pore size, and wettability expressed as contact angle. h = 2γCos (θ) / (ρ _l gr) (Equation 2) where h = height, cm, γ = surface tension of liquid used, dyne / cm, θ = contact angle, degree, ρ _l = Liquid density, g / cc, g = gravitational acceleration, 980.665 cm / sec ² , r = pore size, cm Therefore there is a correspondence between equal pore size and height.

The control program moves the platform to the desired height, collects data at a particular sampling rate until equilibrium is reached, and moves to the next calculated height corresponding to the next pore size. Controllable parameters include sampling rate, equilibrium criteria, number of absorption / emission cycles. The filter plate is filled with liquid so that an unbroken column of liquid extends from the lower surface of the filter plate into the capillary tube to the reservoir. When a dry sample of absorbent material is placed on the filter plate, liquid will be sucked into the pore system. The filling of the pore system depends on the height of the filter plate above the position of the reservoir,
In other words, it depends on the hydrostatic pressure at which absorption occurs. Therefore, this device can be used to raise or lower the hydrostatic pressure at which absorption occurs in small steps. Concurrent liquid uptake and loss is measured by measuring the amount of liquid remaining in the reservoir. Therefore, the capillary attraction of the absorbent medium can be characterized by the filling of the pores when the hydrostatic pressure conditions are systematically changed.

In the test procedure, a sample of known height is placed on a porous filter plate on a UNISLIDE® platform. A typical sample size is 3 inches in diameter. Place a small 47 gram plastic disc on top of the sample to hold it in place. The plastic disc has 57 pins for weight distribution, each pin carrying a weight of 0.82 grams so that the sample does not collapse.
Liquid is supplied to the filter plate from a reservoir on the electronic balance to equilibrate the system.
By lowering the filter plate step by step at predetermined intervals, the hydrostatic height h is reduced. The spacing is chosen to be equally spaced pore size (eg, 20 microns to 520 microns at 20 micron spacing). Therefore, the sample begins to absorb liquid, which is reflected in the volume and weight loss of the reservoir. At each of the pore size or h values, the system is equilibrated. When no further decrease is seen, the weight of the reservoir is recorded and the web thickness is measured. This procedure is repeated until the largest pore size has been scanned (h is almost 0) and in this approach the amount of absorbed liquid at each pore size is measured. At this stage, the sample is transferred from the dry state to one of the fully saturated states. This process can be reversed by raising the filter plate step-by-step at predetermined height intervals with a UNISLIDE® platform. The resulting increase in hydrostatic pressure causes liquid to drain from the web. The absorption cycle is then repeated.

The pore size is plotted against the amount of liquid absorbed or released at each height to obtain the pore size distribution of the sample. The peak of the distribution is expressed as the mode pore size, which is the pore size containing most liquids. If the liquid used is one that completely wets the sample, the pore size distribution reflects the structure of the sample. Typical liquids used are hexadecane, mineral oil, or aqueous surfactant solutions. Equation 2 can be used to calculate the capillarity of the structure if the wettability or contact angle of the sample is known.

If the wettability or contact angle of the sample is unknown, it can be derived by determining the mode pore size of the sample using a liquid that completely wets it and then using water to determine the mode pore size of the sample. In both cases, the instrument scans the sample with the pore size calculated assuming complete wetting. The modal pore size of the sample with water will be the same as the modal pore size of the fully wetting fluid if the sample is completely wetted with water, and will shift to a larger pore size if only partially wetted. Will be done.
The ratio of the mode pore size of water to that of the fluid wetting represents the wettability of the sample and is equal to the cosine of the contact angle. Cos (θ) = (modal pore size) _{Wetting fluid} / (modal pore size) _water This value is then used in Equation 2 to determine the capillarity of the sample. The first absorption cycle is used in all capillarity measurements.

Horizontal wicking : This test measures how much liquid moves in the fabric when only one end of the fabric is immersed in the liquid and the fabric is leveled. Prepare the fabric to be tested by cutting the fabric in the machine direction into 1 inch (2.5 cm) x 8 inch (20.3 cm) strips. The fabric is compressed by any suitable means to a thickness of 0.06 inches (1.52 mm). Weigh the sample and mark every 0.5 inch (13 mm) in the length direction. Sample 5 inches (12.7c
m) x 10 inches (25.4 cm) on a horizontal wire grid and apply a slight weight to flatten on the wire. 0.5 inch at one end of the sample
0.5 inch depth x 0.5 width containing 10 ml of colored 8.5 g / l saline solution
Immerse in inch by 5 inch long reservoir. The end of the sample in the reservoir was fixed with a cylindrical glass stir bar 1.5 inch (3.8 cm) long and 5/16 inch (7.9 mm) in diameter submerged in the same saline solution. Keep in position. One end of the sample remains in the reservoir for 20 minutes, then is carefully pulled horizontally out of the reservoir, cut at 0.5 inch marks, and each portion is weighed. To obtain the grams of fluid reached, subtract the weight of the dry sample from the weight of the wet sample and do not take into account 0.5 inches immersed in the reservoir. Record the total distance wicked, as well as the total grams of fluid wicked.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an uptake system used in absorbent articles to provide an improved dryness to the skin. This uptake system consists of a material containing one or more layers. The surface of the uptake system material should have uptake characteristics such that it rapidly transports an incoming stream of liquid into the material, thereby minimizing liquid spillage at the top surface. In addition, the top of this system material should have minimal saturation so that skin hydration is not increased. This can be accomplished by providing a structure with desirably zero or negative capillary attraction. Another way to express this in a desirable way is that the contact angle of the surface is 90 degrees or more, that is, the surface is hydrophobic.

The hydrophobic surface does not wick liquid along the fibers, but instead forces the liquid, for example in the form of droplets, until sufficient pressure is exerted on the liquid to force it into the material. Stay in one place. Since the force required to do this is minimal, the time the liquid is on the surface is also very short. The system material must have an increasing capillary attraction in the Z direction, farther from the wearer. As the liquid travels from the wearer through the material, the capillary attraction that increases in the Z direction slows the travel of the liquid in the Z direction and allows it to diffuse horizontally (XY direction) within the system material. Become. This horizontal diffusion within the system material results in a larger wetted contact area between the system material and the absorbent core, which distributes the load on the absorbent body, thus allowing the core to be used more effectively. it can.

The system material is preferably a non-woven fibrous web, and a number of variables can be adjusted to control the capillary attraction of the non-woven web. Fiber size, density, hydrophobicity, pore size, and fiber orientation are some of these variables. The actual route chosen by one wishing to practice the present invention will depend on the desired end product properties and economics and manufacturing constraints encountered at the time, which are major selection events in the capillarity of the art. Is. However, whatever method or combination of methods is used, in order to produce an effective product according to the invention, the surface contacting the wearer must be hydrophobic and the capillary attraction must be far from the wearer. Must be increased in the Z direction.

In the most preferred embodiment, the uptake system material is about 13.6 gsm.
To about 200 gsm and manufactured as a single layer having a basis weight of between 0.2 mm and 15.0 mm. This material has the hydrophobic surface and capillary attraction gradient needed to function ideally. However, the economy of modern manufacturing makes this ideal single layer material unattainable at this time. An alternative to this is to use a number of layers with different capillary attraction and assemble them according to the requirements of the invention. When multiple layers are used, the top layer closest to the wearer is called the liner or facesheet and the layer below it is called the surge layer. The liner and surge layers can be made from multiple layers as well.

An example of the top of the system material is, for example, published on December 9, 1998, where the upper surface of the web is porous and ideally hydrophobic and the lower surface of the web is porous and hydrophilic. , A multi-layer liner made in accordance with commonly assigned US patent application Ser. No. 09 / 209,177. The capillarity of the upper layer should be lower than the other layers. The hydrophilic underlayer helps draw the liquid from the hydrophobic layer into the next layer in the absorbent article. Fluid communication should be provided between the layers and between the liner and the next layer in the absorbent structure. This ensures that the upper layers have the proper emissions to minimize saturation. The combined basis weight of the liner web is from about 5 gsm to about 50 gsm
Up to, or more specifically, about 0.4 osy (13.6 gsm) to about 0.7
It can be up to osy (23.7 gsm).

The following are control liners that do not meet the requirements of the present invention and suitable multilayer liners. These materials were made according to steps known to those skilled in the art, each of which reproduced a minimal amount of experimentation.

Control Liner The control liner was a single spunbond web of 0.5 osy (17 gsm) 2.2 denier polypropylene fiber with a high density diamond point bond pattern having a bond area of about 15 percent. It was a layer. The polypropylene used was Exxon Chemical's 3155 Ziegler-Natta type polymer with a melt flow rate of about 35. The control liner also had 0.3 weight percent AHC.
The top surface had been treated with OVEL® surfactant. The control liner had a bulk thickness of 0.27 mm, a density of 0.062 g / cc, and a permeability of about 920 Darcy. This layer was tested for capillary attraction according to the procedure given above,
It was found to be between 8 cm and 11 cm.

Liner Example A two-layer spunbond web was prepared. The basis weight of this web was 0.5 osy and the basis weight ratio of the upper layer to the lower layer was 33:67. The upper layer fibers were approximately 2.5 denier and were made from Exxon Chemical's 3155 polypropylene. The underlying fiber is approximately 5 denier and was made from 3155 polypropylene, also from Exxon Chemical. The bottom layer is 0.3 weight percent AHCOV available from ICI Chemicals
It was treated with EL® surfactant and contained 2 weight percent TiO ₂ colorant as an internal additive to the fiber. The layers were bonded using the EHP pattern described above.

The web thus produced was tested according to the bulk, density, and permeability test methods. The web had a bulk of about 0.28 mm. Density is about 0.061g / c
It was c. The permeability was about 1450 Darcy. The web was tested for capillary attraction according to the procedure given above and the average of the two layers was 3 cm to 4 cm.
It was found to be between. The surface of the web was hydrophobic.

In the approach of the multilayer embodiment of the present invention, the layer immediately below the liner is the surge layer. In most cases, the surge layer is sandwiched between and in intimate fluid communication therewith between the bodyside liner and the underlying layer, such as the distribution layer or absorbent core layer. To further enhance liquid transfer, it may be desirable to attach the upper and / or lower surface of the surge layer to the liner and the underlying layer, respectively. Adhesive bonding (water-based,
Solvent base and heat activated adhesive), heat bond, ultrasonic bond, needling,
Suitable conventional mounting techniques can be used, including pin and pin drilling, and combinations of the above, or other suitable mounting methods.

The surge layer is provided to quickly receive inflowing emissions, reduce spillage and outflow at the top surface, and maintain liquid once entrapped within the structure. For example, the surge layer of a diaper should normally be able to handle inflowing emissions of between about 60 cc and about 100 cc with a volumetric flow rate of about 5 cc / sec to about 20 cc / sec, for example for babies. An example of a surge layer according to the prior art is Elli.
US Pat. No. 5,490,846, et al., and Latimer US Pat.
See 364,382. As mentioned above, multiple layers of surge material can also be used in the practice of the invention.

The surge layer of the present invention is preferably a single fiber layer having a higher capillarity than the liner layer. The surge layer can have fibers with diameters from about 10 microns to about 30 microns, and the layer can be made from a blend of fibers of various diameters or can be made from fibers of uniform diameter. Is also good. When not inherently hydrophilic, the surge layer fibers are loaded with a surfactant loading of 0.05 to 3.0 weight percent, more specifically about 0.1 to 1.0 weight percent. It can be made hydrophilic with agents. The surfactant treatment may be internal,
It may be local. A surge layer suitable for use in the present invention has a saline solution of at least 100 mm when tested according to the horizontal wicking test provided above.
It is preferred to wick and absorb at least 2 grams of saline.

The following are control surges that do not meet the requirements of the invention and suitable surge layers. These materials were made according to steps known to those skilled in the art, each of which reproduced a minimal amount of experimentation.

A control surge -bonded carded web was prepared. The basis weight of this web is 2.5 os
It was y. The web was a mixture of 3 denier T-256 bicomponent fibers and 6 denier T-295 polyester fibers in a 60/40 ratio, respectively.
Both fibers are manufactured by KoSa Inc. Is commercially available from. These fibers were treated by the manufacturer with 0.3 weight percent of a proprietary surfactant to render them hydrophilic. The layers were created by a carding process and then through air bonded. The web thus produced was tested according to several tests given above. The bulk or caliper of this web is 3.7 mm and the density is 0.0
22g / cc, transmission is 5350 darcy, horizontal wicking is 1
． At 5 inches (38 mm), the fluid absorbed was 0.95 gms. This layer was tested for capillary attraction according to the procedure given above, 3 cm to 4 cm.
It was found to be in between.

Example of Surge A bonded carded web was prepared. The basis weight of this web is 2.5 os
It was y. The web was a mixture of 2 denier T-256 bicomponent fibers and 3 denier T-244 polyester fibers in a 60/40 ratio, respectively.
Both fibers are manufactured by KoSa Inc. Is commercially available from. These fibers were treated by the manufacturer with 0.5 weight percent of a proprietary surfactant to render them hydrophilic. The layers were created by a carding process and then through air bonded. The web thus produced was tested according to several tests given above. The web or caliper of this web is 3.2 mm and the density is 0.0
28 g / cc, permeability 3300 d'arcy, horizontal wicking 8
In inches (203 mm), the fluid absorbed was 4.28 gms. Note that this horizontal wicking distance is more than five times that of the control surge. This layer was tested for capillary attraction according to the procedure given above, 5 cm
Was found to be between 8 cm and 8 cm.

System materials made from separate layers should have the layers sufficiently bonded to hold the materials together and to provide fluid communication between the layers. Adhesive bonding (using water-based, solvent-based, and heat-activatable adhesives), thermal bonding, ultrasonic bonding, needling, and pin drilling, and combinations of the above, or other suitable attachment methods Any suitable conventional attachment technique can be used. For example, if the surge layer is adhesively bonded to the bodyside liner, the amount of adhesive applied is sufficient to provide the desired bonding level without unduly obstructing the flow of liquid from the liner to the surge layer. It should be

In the TEWL test referred to below, as a product, about 12.8 grams of Stock, mixed with 18 grams of pulp fluff, placed in an area about 94 mm wide.
FAVOR® 8 from Hausen (Charlotte, NC)
Modified HUGGIES® ULTRATR with 80 superabsorbents
An IM step 4 diaper was used. The liner to be tested covers the inside of the diaper with the surface sheet and surge of the standard liner, and the surge to be tested has a width of 7
The system under test was replaced with a 3 mm and 220 mm length. There is a spacer layer between the outer cover and the absorber layer, the spacer layer being 0.6 osy (20.
3 gsm) of an elongated shaped spunbond / meltblown / spunbond laminate measuring 104 mm × 419 mm with a wire woven pattern.
The outer cover was a 0.6 osy spunbond polypropylene web with a wire woven pattern that was heat bonded to a film having a Mocon breathability of 12,000 using a C-star pattern.

Control Liner Surge The control surge of the control liner obtained as a laminate with the control layer having a capillarity attraction between 8 and 11 for the upper layer and a capillarity force between 3 and 4 for the lower layer. I placed it below. The web was manually adhesively bonded in a swirl pattern with about 0.03 grams of adhesive. The liner surge laminate was tested for TEWL according to the test method above and the result was 25 g / m ² / hr.

Example of Liner Surge An example of a surge is a laminate in which the upper layer has a capillary attraction between 3 and 4 and the lower layer has a capillary attraction between 5 and 8, ie about twice that of the liner. Placed below the example of the liner obtained as. The web was manually adhesively bonded in a swirl pattern with about 0.03 grams of adhesive. The liner surge laminate was tested for TEWL according to the test method above and the result was 17 g / m ² / hr. Thus, the liner surge of the present invention provides a significantly improved TEWL over the control liner surge. We have found that such an improvement results in a TEWL of between 25 percent and 60 percent compared to a liner that does not have a hydrophobic top surface and does not have an increasing capillary attraction gradient in a direction perpendicular to the top surface. Believe to give a reduction. These improvements in TEWL will improve skin health when using diapers and reduce the frequency of diaper rashes.

Suitable system materials are nonwoven webs made by a variety of processes known in the art including spunbonding, bonding and carding, and air deposition. The web can also be bonded by known processes including through air bonding, stitch bonding, ultrasonic bonding, point bonding, and pattern (or point) unbonding. Polymers useful in making the system materials of the present invention include, for example, thermoplastic polymers such as polyolefins, polyesters and polyamides. An elastic polymer may be used, and the elastic polymer may be polyurethane, copolyether ester, polyamide polyether block copolymer, ethylene vinyl acetate (
EVA) and copoly (styrene / ethylene-butylene), styrene-poly (
Ethylene-propylene) -styrene, styrene-poly (ethylene-butylene)-
Styrene, polystyrene / poly (ethylene-butylene) / polystyrene, poly (
Styrene / ethylene-butylene / styrene) and the like, and block copolymers such as block copolymers having the general chemical formula of AB-A 'or AB.

It is also possible to use polyolefins with single-point catalysts, sometimes called metallocene catalysts. Many polyolefins are available for fiber production, such as Dow Chemical's ASPUN® 6811A linear low density polyethylene, 2553LLDPE, and polyethylene such as 25355 and 12350 high density polyethylene. Suitable polymer. The above polyethylenes have melt flow indices of about 26, 40, 25, and 12, respectively. Fiber forming polypropylenes include 3155 polypropylene from Exxon Chemical Company and PF-304 from Montel Chemical Company. Many other polyolefins are commercially available.

Biodegradable polymers are also available for making fibers, and suitable polymers include polylactic acid (PLA) and BIONOLLE®, adipic acid, and UNITOX®. Formulation (BAU). PLA is not a blend, but is a pure polymer such as polypropylene. BAU is B
FIG. 3 represents a formulation containing IONOLE®, adipic acid and UNITHOX® in different proportions. Typically, the formulation for staple fiber is 44.1 percent BIONOLLE® 1020, 44.1 percent BIONOLLE® 3020, 9.8 percent adipic acid, 2 percent UNITHOX®. ) 480, but about 15 percent adipic acid is typically used for spunbond BAU fibers. BION
OLELE® 1020 is a polybutylene succinate and is
LLE® 3020 is a polybutylene succinate adipate copolymer and UNITHOX® 480 is an ethoxylated alcohol. BIONALLE is a registered trademark of Showa High Polymer Co., Ltd. in Japan. UNITHOX
Is a registered trademark of Baker Petrolite, a subsidiary of Baker Hughes International. Note that these biodegradable polymers are hydrophilic and therefore preferably not used on the surface of the inventive uptake system materials.

The fibers used to make the webs useful in the present invention can be single component fibers, conjugate (bicomponent) fibers, or bicomponent fibers. In the case of conjugates, they can have a side-by-side configuration, a sheath / core configuration, or an "islands in the ocean current" configuration. Fibers are described, for example, in US Pat.
It may be pleated or crimped according to No. 400. Modifications and variations of the present invention are deemed to be within the utility of one of ordinary skill in the art, as will be apparent to those skilled in the art. Such modifications and variations are intended to be included within the scope of the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) A61F 13/49 A61F 5/44 H 13/511 T 13/53 A61J 13/00 A // A61D 9/00 A61F 13/18 310Z A61F 5/44 310A A41B 13/02 B A61J 13/00 (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, TR), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR , LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW (72) Inventor Fenwick Christopher Dale, Georgia, USA 30022 Alpharetta Virginia Pine Lane 10545 (72) Inventor Nelson Dennis Jager Net United States Wisconsin 54942 Greenville Ridgeway Drive North 1654 (72) Inventor Paul Susan Carroll Georgia United States 30022 Alpharetta Turners Crossing 310 (72) Inventor Smith Roland Columbus Junia United States Georgia 30507 Gainesville Pierce Road 2771 F Terms (reference) 3B029 BA05 BA14 BA17 4C003 BA04 BA06 BA09 HA05 4C098 AA09 CC02 CC03 DD02 DD03 DD04 DD05 DD06 DD10 DD12 DD13 DD21 DD23 DD24 DD25 DD26 4L047 AA14 AA28 AB02 AB03 BA03 BA09 BA12 BA23 CA02 CA19 CB07 CC05 CB10 CC05 CC03 CC03

Claims (20)

[Claims] 1. An uptake system material for a personal care product, comprising a non-woven fibrous web having a hydrophobic upper surface and a lower surface and having an increasing capillary attraction gradient in a direction perpendicular to said upper surface. 2. A TEWL level that is between about 25 percent and about 60 percent less than an entrapment material that does not have a hydrophobic top surface and does not have an increasing capillary attraction gradient in a direction perpendicular to the top surface. An intake system material for personal care products according to claim 1, characterized in that 3. The intake system material comprises from about 13.6 gsm to about 20.
The intake system material of claim 1, having a basis weight of up to 0 gsm. 4. The uptake system material of claim 1, wherein the lower surface is hydrophilic. 5. The intake system material of claim 1, having a thickness of between 0.2 mm and 15.0 mm. 6. The uptake system material of claim 1, wherein the web comprises fibers formed from a polyolefin. 7. The intake system material of claim 6, wherein the polyolefin is selected from the group consisting of polyethylene, polypropylene, polybutylene, and copolymers thereof, and blends thereof. 8. A horizontal wicking test to obtain at least 100 saline solutions.
The intake system material of claim 1, wherein the intake system material absorbs mm and absorbs at least 2 grams. 9. A liner surge system for personal care products, comprising: at least a first liner layer having an upper surface and a lower surface; and a surge layer, wherein the upper surface of the liner is hydrophobic and the surge. A liner surge system, wherein the layer has a greater capillary attraction than the liner and the surge layer and the liner layer are joined together. 10. The liner of claim 9, further comprising a second liner layer between the first liner layer and the surge layer that has a greater capillary attraction than the first liner layer. Surge system. 11. A TEWL level that is less than about 25 percent to about 60 percent less than an entrapment material that does not have a hydrophobic top surface and that does not have an increasing capillary attraction gradient in a direction perpendicular to the top surface. 11. The method according to claim 10, wherein
Intake system materials for personal care products as described in. 12. The liner surge system of claim 10, wherein the surge layer has about twice the capillary attraction of the liner. 13. The liner layer and the surge layer are bonded together by a method selected from the group consisting of adhesive bonding, thermal bonding, ultrasonic bonding, needling, and pin drilling, and combinations thereof. The liner surge system of claim 9, wherein: 14. A fiber denier having a basis weight of between about 5 gsm and about 50 gsm and comprising a hydrophobic upper layer and a lower layer facing the wearer, the upper layer having a lower fiber denier than the lower layer. A liner surge system for a personal care product comprising: a liner having: and a surge layer having a capillary attraction greater than the liner layer. 15. A diaper comprising the system of claim 1. 16. The diaper of claim 14, further comprising a breathable outer cover. 17. Training pants comprising the system of claim 1. 18. An incontinence product comprising the system of claim 1. 19. A bandage comprising the system of claim 1. 20. A sanitary napkin comprising the system of claim 1.