MXPA00000714A - Method and composition for treating substrates for wettability - Google Patents

Abstract

A surfactant composition useful for imparting durability and wettability to a substrate includes first and second surfactants in combination. The first surfactant includes a compound selected from ethoxylated hydrogenated fatty oils, monosaccharides, monosaccharide derivatives, polysaccharides, polysaccharide derivatives, and combinations thereof. The second surfactant includes an organosilicon compound. The surfactant composition can be applied as an aqueous emulsion to a substrate such as a nonwoven web, to provide enhanced wettability after repeated washing cycles.

Description

METHOD AND COMPOSITION TO TREAT SUBSTRATES FOR HUMANTABILITY BACKGROUND OF THE INVENTION The non-woven fabrics and their manufacture have been the object of an extensive development that has resulted in a wide variety of materials for numerous applications. For example, non-woven fabrics with a light weight and open structure used in personal care items such as disposable diapers, such as lining fabrics that provide contact with dry skin but that readily transmit fluid to more absorbent materials which may also be of a different composition and / or structure . Nonwoven of heavier weights can be designed with structures that make them more suitable for filtration, absorbent and barrier applications such as wraps for article to be sterilized, garments for protective cleaners for medical, veterinary uses or industrial Still what heavier nonwovens have been developed for recreational, agricultural and construction use. These are not without a few of the practically limitless examples of the types of nonwovens and their uses that will be known to those experts in the art who will recognize that new nonwovens and their uses are constantly identified. Different ways _T have also been developed. _ > % equipment for making nonwovens having the desired structures and compositions suitable for these uses. Examples of such processes include spinning, melting, carding and others which will be described in greater detail below. The present invention generally has application to nonwovens as will be apparent to one skilled in the art and is not limited by reference or examples in relation to specific nonwovens which are merely illustrative. It is not always possible to efficiently produce a nonwoven having all the desired properties when it is formed, and it is often necessary to treat non-woven to improve xz > alter such properties' as the wettability by one or more fluids, the repellency to one or more fluids, the electrostatic characteristics, -the conductivity, and the softness to only name a few examples. Conventional treatments involve steps such as the embedding of the non-woven in a treatment bath, the coating or spraying the non-woven with the treatment composition, and printing the non-woven composition of the treatment. For cost and other reasons it is usually desired to use the minimum amount of treatment composition that will produce the desired effect with an acceptable degree of uniformity. It is known, for example, that the heat of an additional drying step to remove the water applied with the treatment composition can deleteriously affect the non-woven resistance properties as well as add cost to the process. It is therefore desirable to provide an improved treatment process and / or composition for nonwovens that can effectively and efficiently apply the desired treatment if it adversely affects the desired physical properties of the non-woven fabric and achieve the desired results.

Also known are the more conventional surfactants which are dispersible in water and which are not likely to form stable mixtures of high solids (> 10% po weight), low viscosity (> 100 centipoises) with water. An additional desire, therefore, is to provide a high solids treatment bath that is stable without phase separation, over an extended period and exhibits a low viscosity profile at room temperature "as well as means to effectively apply to the treatment of surfactant to impart a durable hydrophilic character to the substrate such as a nonwoven.

SYNTHESIS OF THE INVENTION The present invention is directed to a composition Improved and a method for effectively and efficiently treating non-wovens to impart one or more desired properties such as durable wettability and resulting improved non-wovens. The process and composition include at least one surfactant in combination with a viscosity modifier and includes subjecting one or both of the nonwovens to a pure high solids treatment composition. Drying and its deleter effects are essentially completely unnecessary and the process provides means to uniformly treat one or both sides of the nonwoven in a desired grad without adversely affecting the duration of the result., for example the wettability of the fabric. According to the process of the invention, a non-woven fabric is directed to a treatment station wherein the treatment composition which is preferably less than about 90% solvent is applied to the fabric by means of a coating, embedded, sprayed, or the like, in an amount to effectively treat the area of the fabric contacted by the composition. The untreated fabric can be subjected to a similar treatment on the same or the opposite side and a minimum drying, if necessary, or However, the process of the invention greatly facilitates any cleaning steps that may be required. The resulting treated non-wovens have been shown to be uniformly, durably and effectively treated with reduced composition requirements and minimal adverse effects or without such effects. Preferred treatments include a combination of a surfactant which, in itself is a mixture of hydrogenated and ethoxylated castor oil and sorbitan monoleate, and a viscosity modifier, an alkyl polyglycoside. These treatments for non-wovens are of particular use for medical personal care and other applications such as cleaning cloths, protective garments, applicators and others where the compositions are desirably applied to a substrate at high solids.

The present invention is also directed to a composition and method for treating nonwovens to impart a relatively high rewet performance (durability) to accept multiple fluid discharges and fast fluid absorption rates. For this application, preferred treatments include a combination which in turn includes at least two surfactants. A first surfactant includes a compound selected from a hydrogenated and ethoxylated fatty oil, - a monosaccharide, or a monosaccharide derivative, a polysaccharide, a polysaccharide derivative and combinations thereof. A second surfactant includes an organosilicon compound. The surfactant combination can be prepared in the form of an aqueous emulsion which is then homogenized. In this embodiment, the second surfactant acts as a powerful emulsifier, flux / viscosity modifier and aid leveler. Non-wovens treated in this way are especially useful for signs, underpants, incontinence garments, and other applications that require possible exposure to multiple fluid discharges.

-. The foregoing and other features and advantages of the invention will become more apparent from the following detailed description of the currently preferred embodiments, read in conjunction with the examples and drawings. The detailed description, the examples and the drawings are merely illustrative rather than limiting, the scope of the invention being defined by the appended claims and the equivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a treatment process of the present invention useful for the application to one or both sides of a non-woven fabric substrate.

Figure 2 is a similar schematic illustration showing an alternative treatment system.

Figure 3 is a schematic showing the time of absorption against the cycle for non-wovens treated with different proportions of a surfactant combination of the invention, as discussed in Examples 81-85.

Figure 4 is a schematic showing the time of Absorption against the cycle for non-wovens treated with different levels of a surfactant combination of the invention, as discussed in Examples 83 and 86-88.

DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS As used herein the term "non-woven fabric or fabric" means a fabric having a structure of individual fibers or threads which are interleaved, but not in a regular or identifiable form as in a non-woven fabric. Also included are foams and films that have been fibrillated, punched or otherwise treated to impart fabric-like properties to them. Non-woven fabrics or fabrics that have been formed from many processes such as for example meltblowing processes, spinning processes, and carded and bonded weaving processes. The basis weight of non-woven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and useful fiber diameters are usually expressed in microns (note that to convert ounces per yard square to grams per square meter, multiply ounces per square yard by 33.91).

As used herein, "microfibers" means small diameter fibers having an average diameter of no more than about 75 microns, for example, having an average diameter of from about 0.5 microns to about 50 microns, or more particularly, Microfibers can have an average diameter of from about 2 microns to about 40 microns. Another frequently used expression of fiber diameter is denier, which is defined as grams per 9,000 meters of a fiber and can be calculated as fiber diameter in square microns, multiplied by the density in grams / cc, multiplied by 0.00707. A lower denier indicates a finer fiber and a higher denier indicates a thicker or heavier fiber. For example, the diameter of a polypropylene fiber given as 15 microns can be converted to denier by placing the square, multiplying the result by .89 g / cc and multiplying by .00707. Therefore, a polypropylene fiber of 15 microns has a denier of about 1.42 (152 x 0.89 x .00707 = 1.415). Outside the United States of America the unit of measurement is more commonly the "tex" which is defined as the grains per kilometer of fiber. The tex can be calculated as denier / 9.

As used herein, the term "spunbond fibers" refers to fibers of small diameter which are formed by extruding the molten thermoplastic material as filaments from a plurality of usually circular and thin capillaries of a spinning organ with the diameter of the extruded filaments then being rapidly reduced as by, for example, is indicated in U.S. Patent No. 4,340,563 issued Appel et al., and in U.S. Patent No. 3,592,618 issued to Améric. Dorschner et al., In U.S. Patent No. 3,802,817 issued to Matsuk et al., In U.S. Patent Nos. 3,338,992 and 3,341,394 issued to Kinney, the U.S. Patent. of America number 3,502,763 granted to Hartmann, the United States of America patent number 3,502,538 granted to Levy, and the United States patent of Am. éric number 3,542,615 granted to Dobo and others. The fibers bound together are cooled and are generally not sticky when they are deposited on a collection surface. Spunbonded fibers are generally continuous and have larger average diameters of 7 microns, more particularly, of between about 10 and 20 microns.

As used herein, the term "meltblown fibers" means fibers formed by extruding a melted thermoplastic material through a plurality of usually circular and thin capillary matrix vessels such as melted threads or filaments into high velocity gas streams ( for example air) which attenuate the filaments of melted thermoplastic material to reduce its diameter which can be to a microfiber diameter. Then, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a meltblown fabric and randomly disbursed. Such process is described, for example, in the patent of the United States of America number 3,849,241 granted to Butin. Melt blown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in average diameter and are generally sticky when deposited on a collecting surface.

As used herein the term "polymer" generally includes but is not limited to homopolymers, copolymers, such as, for example, block, graft, random and alternating copolymers, terpolymers, etc. and the mixtures and modifications thereof. In addition, unless specifically limited in another way, the term "polymer" will include all possible geometric configurations of the material. These configurations include but are not limited. to isotactic, syndiotactic, atactic and random symmetries.

As used herein, the term "machine direction" or MD means the length of a fabric in the direction in which it is produced. The term "cross machine direction" or CD means the width of the fabric, for example in a direction generally perpendicular to the machine direction.

As used herein, the term "monocomponent fiber" refers to a fiber formed from one or more extruders using only one polymer. This does not mean that the fibers formed from a polymer to which small amounts of color additives, antistatic properties, lubrication, hydrophilicity, etc. have been added are excluded. These additives, for example titanium dioxide for color, are generally present in an amount of less than 5 percent by weight and more typically of about 2 percent by weight.

As used herein, the term "conjugated fibers" refers to fibers which have been formed from at least two extruded polymers of separate extruders but which have been spun together to form a fiber. The fibers conjugates are also sometimes referred to as multicomponent or bicomponent fibers. The polymers are usually different from each other even though the conjugated fibers can be monocomponent fibers. The polymers are arranged in areas placed essentially constant across the cross section of the conjugated fibers and extend continuously along the length of the conjugated fibers. The configuration of such conjugated fiber can be, for example, a pod / core arrangement where one polymer is surrounded by another or can be a side-by-side arrangement or an arrangement of "islands in the sea". Conjugated fibers are shown in U.S. Patent Nos. 5,108,820 issued to Kaneko et al., 5,336,552 issued to Strack et al. And 5,382,400 issued to Pike et al. For fibers of component components, the polymers may be present in proportions of 75/25, 50/50, 25/75 or any other desired proportions.

As used herein the term "biconstituent fibers" refers to fibers which have formed at least two polymers extruded from the same extruder as a mixture. The term "mixture" is defined below. The biconstituent fibers do not have the various polymer components arranged in different zones placed relatively constant across the cross-sectional area of the fiber. The various polymers are usually not continuous along the full length of the fiber, instead of this usually forms fibrils or protofibrils which start and end at random. The biconstituent fibers are sometimes also referred to as multi-constituent fibers. The fibers of this general type are discussed in, for example, US Pat. No. 5,108,827 issued to Gessner. Bicomponent and biconstituent fibers are also discussed in the text "Mixtures and Compounds of Polymers" by John A. Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of New York, IBSN 0 -306-30831-2, pages 273 to 277.

As the term "mixture" is used herein as applied to polymers, it means a combination of two or more polymers even when the term "alloy" means a subclass of mixtures wherein the components are immiscible but have been compatibilized. The "miscibility" and the "immiscibility" are defined as mixtures that have negative and positive values, respectively, for the free energy of mixing. In addition, "compatibilization" is defined as the process of modifying the interfacial properties of an immiscible polymer mixture in order to make an alloy.

As used here, the binding through air or " " means a process of joining a nonwoven, for example, a two-component fiber fabric in which the air which is hot enough to melt one of the polymers from which the fibers of the fabric are made is forced to through the tissue. The air speed is frequently between 100 and 500 feet per minute and the dwell time can be so. prolonged about 6 seconds. The melting and resolidification of the polymer provides the bond. The binding through air to restricted variability and is generally seen as a second step joining process. Bonding through air requires the melting of at least one component to achieve bonding, this is restricted to fabrics with two components such as bicomponent fiber fabrics or fabrics containing an adhesive fiber or powder.

As used herein, "thermal point bonding" involves passing a fabric or fabric of fibers that are to be bonded between a heated calender roll and an anvil roll. The calendering roll usually has, although not always, a pattern in some way so that the complete fabric is not bonded through its entire surface. As a result of this, several calendering roller patterns have been developed for functional reasons as well as aesthetics. An example of a pattern has points and is the Hansen Pennings or "H &P" pattern with around a 30% co-area around 200 joints / square inch as taught in the United States of America patent number 3,855 .046 granted to Hansen and Pennings. The H &P pattern has bolt-joint or square-point areas where each bolt has a side dimension of 0.965 millimeters, a spacing of 1,778 millimeters between the bolts, and a joint depth of 0.584 millimeters. The resulting pattern has a bound area of about 29.5%. Another typical point union pattern is the Hansen and Pennings junction pattern or "EHP" which produces a 15% joint area with a square bolt that has a side dimension of 0.94 millimeters, a bolt spacing of 2,464 millimeters and a depth of 0.991 millimeters. Another typical point union pattern designated "714" has square bolt joint areas where each bolt has a side dimension of 0.023 inches, a spacing of 1,575 mm between the bolts and a joint depth of 0.838 mm. The resulting pattern has a bound area of about 15%. Yet another common pattern is the C-Star pattern which has a united area of about 16.9%. The C-Star pattern has a bar in the transverse direction or "corduroy" design interrupted by shooting stars. Another common pattern includes a diamond pattern with repetitive and slightly off-center diamonds and a woven wire pattern that looks like the name suggests, like a window grid. Typically, the percent of bonded area ranges from about 10% to about 30% of the area of the fabric laminated fabric. As is well known in the art, point bonding holds laminated layers together as well as one that imparts integrity to each individual layer by joining the filaments and / or fibers within each layer.

As used herein, the term "personal care product" means diapers, training underpants, absorbent garments, adult incontinence products, and women's hygiene products.

As used herein the term "durable wettability" or "durably wettable" means the ability to withstand at least two and advantageously at least three discharges using the run-off test described below.

As used herein, the term "hydrophilic" means that the polymeric material has a surface of free energy so that the polymeric material is wettable by an aqueous medium, for example a liquid medium of which water is the main component. That is, an aqueous medium moistens non-woven fabric that has been treated with a surfactant bath. The surfactant bath is made of at least 10% by weight of surfactant or mixtures of surfactant and of no more than about 90% solvent such as water, for example.

TEST METHODS The runoff test (exposure) and the washing / drying process are described in U.S. Patent No. 5,258,221 issued to Meirowitz et al., Which is hereby incorporated by reference in its entirety. Typically, a generally rectangular sample of about 20 centimeters by 38 centimeters of a fibrous web, such as a non-woven fabric, is mounted on the top of an absorbent core composed of polypropylene, wood pulp fibers, and / or a superabsorbent material. The resulting test set is centered on the sloped surface and held in place with tape at each corner of the assembly. The inclined surface angle is 45% instead of the 30% angle described in the patent. The funnel is located approximately 7.8 inches (about 200 millimeters) from the bottom or bottom edge of the test set. The funnel valve is located approximately 10 millimeters above the upper surface of the test set. About 100 milliliters of water that have a temperature of 35 degrees centigrade are placed in the funnel. The funnel valve is open to supply the water over a period of about 15 seconds. The amount of water (grams) drained and collected in the collection media was determined and recorded. A fibrous tissue is typically considered to pass the modified runoff test if the amount of water collected in the collection means is less than an amount considered appropriate for a given type of fibrous fabric. For example, when the fabric is fibrous it is a woven fabric knitted together with lightweight yarn (for example having a basis weight of 0.6 ounces per square yard or about 2 grams per square meter), the amount of water- : collected should be less than 20 ml.

The washing / drying cycle was modified by using 500 milliliters, rather than 1 liter of water at room temperature (around 23. degrees centigrade). Thus, the generally rectangular sample of the coated porous substrate described above was placed in 500 milliliters of water. The sample was allowed to remain in the water for one minute while being stirred at 15-20 revolutions per minute with a mechanical stirrer. The sample was removed from the water and the excess liquid was squeezed back into the wash water container. The sample was allowed to air dry overnight or was dried in an oven (Blue M model 0V-475A-3 from General Signal, of Blue Island, Illinois) at 80 degrees centigrade for 20 minutes and then subjected to the test modified runoff described above. This process was repeated a desired number of times.

The strip tension test is a measure of the breaking strength and elongation or tension of a fabric when subjected to a unidirectional tension. This test is a modified version of the standard test method ASTM D882 (the Test Method for the Tension Properties of the Thin Plastic Sheet).

To measure peak resistance for the purposes of the present invention, the following modifications were made to the standard procedure: the separation rate imparted to the grip members of the test apparatus was maintained at a rate of 50 mm / minute for all samples.

The initial separation between the handle members was varied from 1 inch to 3 inches depending on the type of sample tested. The initial separation when testing the tape backing material is 1.5 inches, and the initial separation when testing outer cover materials and belay area materials is 3 inches.

The peak resistance was calculated by dividing the maximum load of the cross-head-load displacement curve by the sample width.

The results are expressed in pounds at break and percent stretch before breaking. The upper numbers indicate a stronger and more stretchable fabric. The term "load" means the maximum load or force, expressed in units of weight, required to break or tear the sample in a stress test. The term "tension" or "total energy" means the total energy under a load curve against elongation, as expressed in units of weight-length. The term "elongation" means the increase in length of a specimen during a stress test. - The values for elongation and elongation grip strength are obtained using a specified fabric width, usually 4 inches (102 millimeters), the handle width and a constant extension rate. The sample is wider than the handle to give representative results of effective resistance of the fibers in the grasped width combined with additional strength contributed by the adjacent fibers in the fabric. The specimen is attached to, for example, an Instron Model TM apparatus, available from Instron Corporation, 2500 Washington Street, Canto MA 02021, or a Thwing-Albert Model INTELLECT II apparatus available from thwing-Albert Instrument Company, 10960 Dutton Road, Philadelphia, Pennsylvania 19154, which has parallel grab bars 76 mm long. This is very close to simulate the tension conditions of the fabric in actual use.

Liquid transfer time: This test is identified as EDANA 150.1-90 and measures the time taken for a volume of liquid (simulated urine) applied to the surface of a non-woven test sample in contact with the underlying absorbent pad to pass to through the non-woven. In general, a 50 ml test piece is placed on a ring holder with the tip inside a funnel. A standard 5-layer absorbent pad. Specified filter paper (482% absorbency) was placed on an acrylic glass base plate under the funnel, and a non-woven sample was placed on top of the absorbent. A transfer plate of acrylic glass 25 millimeters thick and weighing 500 g was placed on the sample with the cavity centered 5 millimeters below the funnel. The specimen was filled with liquid holding the funnel closed, and a quantity of liquid (for example 5 ml or 10 ml) was run into the funnel. The 5 milliliters or 10 milliliters were allowed to discharge starting a chronometer which is when the liquid penetrated in the pad has already fallen down from a set of electrodes, and the time elapsed is recorded. For the examples given below, this test was repeated 5 times for each sample using the same test pieces at each repetition, and the times were averaged. Examples 1-80 were tested using 10 milliliters of liquid. Examples 81-88 were tested using 5 milliliters of liquid. The liquid was saltwater from the blood bank available from Stephens Scientific Company, catalog number 8504.

It is also possible to have other materials mixed with the polymer used to produce a non-woven according to this invention as fire retardants for an increased resistance to fire and / or pigments to give each layer the same or different colors. Also additives for odors, odor control, antibacterials, lubricants and the like can also be used. Such components for thermoplastic polymers linked with spinning and meltblowing are known in the art "and are often internal additives." A pigment, if used, is generally present in an amount of less than 5 percent by weight of the layer while other materials may be present in a cumulative amount of less than about 25 percent by weight, for example.

The fibers of which the fabric of this invention is made can be produced, for example, by meltblowing or spin-bonding processes which are well known in the art. These processes generally use an extruder to deliver the melted thermoplastic polymer to a spinner where the polymer is fibrillated to give fibers which may be of basic length or longer. The fibers are then pulled, usually pneumatically, and deposited on a mat or perforated band to form the non-woven fabric. The fibers produced in the spinning and meltblowing processes are microfibers as defined above.

The manufacture of meltblown fabrics is generally discussed above and in the references.

The fabric of this invention can be a multilayer laminate. An example of a multi-layer laminate is an embodiment wherein some of the layers are spin-bonded and some are meltblown such as a laminate bonded with spinning / meltblowing / spinning (SMS) as described in FIG. U.S. Patent No. 4,041,203 issued to Brock et al., in U.S. Patent No. 5,169,706 Collier et al., in U.S. Patent No. 5,540,979 granted to Yahiaoui et al., and in U.S. Patent No. 4,374,888 issued to Bornslaeger. Such lamination can be done by depositing in a sequence on a movable forming web first a layer of spin-linked fabric, then a layer of meltblown fabric and finally another layer linked with spinning and then joining the laminate in a manner as described down. Alternatively, the fabric layers can be made individually, collected in rolls and combined in a separate bonding step. Such fabrics usually have a basis weight of from about 0.1 to 12 ounces per square yard (6 to 400 grams per square meter) more particularly from about 0.75 to about 3 ounces per square yard.

Spunbond non-woven fabrics are generally joined in some way as they are produced in order to give them sufficient structural integrity to withstand the rigors of further processing in a finished product. Bonding can be achieved in a number of ways such as by hydroentanglement, perforation, ultrasonic bonding, adhesive bonding, stitch bonding, air bonding and thermal bonding.

As alluded to above, an important parameter for treating nonwovens for many applications is the durability of wettability or the ability to withstand multiple discharges in use. For diaper liner applications, for example, the ability to maintain wettability properties after 3 or more discharges is extremely desirable. Some available treatments such as the mixture of ethoxylated hydrogenated castor oil and sorbitan monooleate (Base Ahcovel N-62 available from Hodgsen Chemical Company, manufactured by ICI (also referred to as simply "Ahcovel")) have been shown to be durable according to to this standard.

The chemical formulas for these components are as follows: Sorbitan Ethoxylated Hydrogenated Monooleate Castor Oil However, this treatment is very viscous and difficult to apply to high solids using conventional treatment methods. Traditional viscosity modifying additives or surfactant mixtures may reduce the treatment viscosities but these may adversely affect the durability of the treated fabric as discussed below with reference to Tables 3 and 4. According to this invention, it has been found that the use of the specific alkyl polyglycosides not only reduces the viscosity of this treatment but also maintains the desirable durability. For the best results the alkyl polyglycoside is one with 8 to 1 carbon atoms in the alkyl chain (for example Glucopo 220UP) and is included in an amount of about 5% about 80%, advantageously about 5% to about 10% based on the weight of the total composition and the weight of the alkyl polyglycoside composition, which may be aqueous, containing about 40% water, for example.

Glucopon 220UP is an octiIpolyglycoside that has the following chemical formula: Table 1 below illustrates the effect on the viscosity of Ahcovel Base N-62 of the addition of Glucopon 220UP a solution of 60% alkyl polyglycoside in 40% water by weight available from Henkel Corporation (also referred to as simply "Glucopon" ). Determinations of the viscosity were made on 20% of global solid compositions and at a cut-off rate of 20 (l / sec) using a Brockfield DV 11+ viscometer, CP41 spindle in each case.

Table 1. Effect of Glucopon on the Viscosity * of Ahcovel at 20% Solids * Measurements with Brockfield DVII + viscometer, CP-41 spindle.

For the purposes of this invention, "achieving a viscosity of less than about 100 centipoise under application conditions, preferably at room temperature, is desirable so that conventional high solids application systems and methods such as WEKO Rotor Dampening System available from Weko Other such brush spray applicators and coating and printing applicators can be used as will be apparent to those skilled in the art As shown above, the surfactant also fails to fill this one requirement, but also as a part in 20 of the addition of an alkyl polyglycoside such as Glucopon 220UP dramatically reduces its viscosity.

The present invention is believed to be applicable to reduced viscosity treatment with a wide variety of compositions even when combination with surfactant compositions such as the Ahcovel series is highly preferred due to the durability of such treatments. Where this degree of durability is not critical, however, it is only essential that the composition contain effective amounts of the surfactant combination and the viscosity modifier to treat the nonwoven. To determine the adequacy, the composition can be tested by the Brockfield viscosity. Preferred compositions are those having a viscosity of about 2000 centipoise or less. Specific examples include Triton x-102, an alkyl phenol ethoxylate surfactant available from Union Carbide, Y12488 and Y12734, series of ethoxylated polydimethyl siloxanes available from OSI, Masil SF-19, an ethoxylated trisiloxane available from PPG, PEG 200 series, 400 and 600 polyethylene glycol monostearates, and stearates and monolaurates available from PPG, GEMTEX SM-33 'SC75 series, and dialkyl sulfosuccinates available from Finetex as well as water soluble polymers such as polyvinyl pylorridone, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose , starch, agar and other natural water soluble polymers. Other surfactants include the ethoxylated terephthalates such as Milease T from ICI, Alcohol ethoxylates such as Mazawet 77 from PPG and block copolymers PEO-PPO such as Pluronic L 101 from BASF. Examples of the viscosity modifier include Glucopon 220 or 225, both alkyl polyglycosides having 8-18 carbon atoms in the alkyl chain and available from Henkel Corporation. The resulting mixture will have a viscosity as an emulsion of less than 100 CP, preferably and even more desirably, less than 50 Cp- under application conditions.

In a preferred embodiment, a first surfactant includes a compound selected from the group consisting of an ethoxylated hydrogenated fatty oil, a monosaccharide, a monosaccharide derivative, a polysaccharide, a polysaccharide derivative, and combinations thereof. The first surfactant is combined with a second surfactant which includes an organosilicon compound. The first surfactant may include a mixture of hydrogenated and ethoxylated castor oil and sorbitan monooleate, and may be combined with a second surfactant including an alkoxylated polysiloxane. For example, the Ahcovel Base N-62, which is a mixture of a hydrogenated and ethoxylated fatty oil and a monosaccharide derivative, can also be combined with a Masil SF-19. Said Masil SF-19 is an alkoxylated polysiloxane having the following chemical formula: CH3 I (CH3) 3SiO - Si-O - Si (CH3) 3 I CH, where R is defined as: • CH2CH2CH20- (CH2CH20) P- (CH2CH [CH3] O) Q-R1 (R * = H or alkyl) and X, Y, P and Q are positive integers, The first and second surfactants may be initially prepared in the form of an aqueous emulsion. The aqueous emulsion may include about 1-60% by weight of the total surfactant solids and about 40-99% by weight of water. Desirably, the aqueous emulsion may include about 10-40% by weight of total surfactant solids and about 60-90% by weight of water. More suitably, the aqueous emulsion may contain about 15-35 percent by weight of total surfactant solids and about 65-85% by weight of water. The surfactant combination can be dispersed in water in the form of small drops or microdroplets using vigorous agitation or other suitable mixing / emulsification process known to those skilled in the art.

The emulsion can then be homogenized by mixing at an elevated temperature of about 130 degrees F or more. When the emulsion is homogenized, the aqueous system including the first and second surfactants exhibits a much lower viscosity than a similarly prepared system which contains the first surfactant without the second surfactant. The second surfactant which is preferably present at lower levels relative to the first surfactant, acts as a powerful emulsifier, a flow modifier / viscosity, and a leveling agent.

The combination of the first and second surfactants should include, on a dry weight basis, about 50-99.5 parts by weight of the first surfactant and about 0.5-50 parts by weight of the second surfactant. Desirably, the combination includes about 65-95 parts by weight of the first surfactant and about 5-35 parts by weight of the second surfactant. Preferably, the combination should include about 70-85 parts by weight of the first surfactant and about 15-30 parts by weight of the second surfactant.

The above combination of the first and second surfactants is particularly useful for applications that require high rewet performance (durability), which involve exposure to multiple fluid insults and / or rapid fluid absorption rates. The advantages of this surfactant mixture further include excellent processability (eg low viscosity) at a relatively high solids content in water, and excellent processability at high temperatures (eg 130 degrees F or higher) which inhibit bacterial growth without the addition of chemical preservatives. Also, the wetting of the non-woven fabric results from a uniform treatment of the non-woven fabric at fairly low levels.

For example, the fabric can be effectively treated with the combination of surfactant at levels below about 2.0% by weight of dry surfactant solids in relation to the basis weight of the fabric, such as, for example, levels of about 0.1- 1.5% by weight in relation to the base weight of the fabric. Desirably, the fabric is treated at levels of about 0.1-1.0% by weight of surfactant solids in relation to the basis weight of the fabric. Preferably, the fabric is treated at levels of about 0.1-0.5% by weight of surfactant solids in relation to the basis weight of the fabric.

Another advantage of using the combination of the first and second surfactants is that there is an apparent synergy between the durable character (rewetting) of the prime surfactant and the strength of emulsification and surface activity of the second surfactant. This synergy causes the non-woven fabric to have significantly improved fluid handling properties, including an improved rewet rate of fluid absorption.

Although the present invention is suitable for treating nonwovens widely, it is more effective, and is therefore preferred, for non-wovens that have properties that lend themselves to efficient high speed processing. These properties include the basis weight, for example, from 5 to 500 grams per square meter, thickness, for example from 0. to 10 millimeters and the like.

In order to maximize the advantages of the present invention, the selection of the nonwoven and the treatment composition are preferably made so that the composition can be applied with no more than about 80% preferably less water.

Referring to Figure 1, a process for the application to one or both sides of a moving fabric will be described. It will be appreciated by those skilled in the art that the invention is equally applicable to on-line treatment or to a separate off-line treatment step. The fabric 12, for example, a nonwoven bonded with spinning or melt blowing is directed under the support roll 15, to a treatment station including the rotating spray heads 22 for application to a side 14 of the fabric 12. an optional treatment station 18 (shown in phantom) which may include the rotating spray heads (not shown) may also be used to apply to the opposite side 23 of the fabric 12 directed over the support rollers 17 and 19. Each treatment station receives a supply of treatment liquid 30 from a reservoir (not shown). The treated fabric can then be dried if required by passing over the driers (not shown) or other drying means and then under e? roll of support 25 to be rolled cpmo-un-- roll-p converted to the use for which this was attempted ... Alternating drying means include ovens, air dryers, infrared dryers, and air blowers and the like.

Figure 2 illustrates an alternating arrangement that employs a tightening and embedding application step. As shown, the fabric 100 passes over the guide roller 102 and into the bath 104 with the treatment time controlled by the guide rollers 106. The pressure point between the squeeze rollers 108 removes the excess of the treatment composition. which is returned to the bath by the trapping tray 109. The drying cans 110 remove the remaining moisture.

It is also understood that the method and the hydrophilic surface treatment of nonwoven materials with topical application of surfactants of this invention can incorporate not only multiple surfactants for improved wettability with aqueous fluids (eg urine), or facilitate the handling of other body fluids (blood, menstrual fluid, feces, etc.) but can also be used to incorporate bioactive compounds and macromolecules, which can provide biofunctional attributes to the surface treatments of this invention (eg antibacterial activity, condoms, anti-inflammatory , odor control, skin comfort and the like).

The present invention is further illustrated by the following examples which are representative of the invention even when other examples will be apparent to those skilled in the art and are intended to be covered by the claims.

E M EXAMPLES 1-43 LOW VISCOSITY / HIGH SOLID SURFACTANT FORMULAS Many methods of hydrophilic treatment of non-woven materials with surfactants from baths at low solids contents are known and are commonly used. However, due to the high solvent content, a drying step is required. It is known that the heat effects of the drying process have a negative impact on the mechanical properties of the non-woven materials. The surface treatment (Table 2). Therefore, employing a high solids bath minimizes or alleviates the need for a drying requirement, thereby retaining the inherent tensile strength of the fabric. Other obvious advantages of a high solids treatment system include: lower cost for surfactant formula, shipping and storage, conserved energy and lower treatment cost and better treatment uniformity. As used herein, "high solids" means a concentration of at least 10% solids, and advantageously such compositions are at least about 20% solids. - " Table 2. Comparative Data on the Effect of Drying on the Mechanical Properties of United Fabrics with 0.6 Oz Polyethylene Yarn per Square Yard * Fabric 1: treated with 0.9% Ahcovel / Glucopon with the WEKO process of high solids, where no drying is applied. ** Fabric 2: treated with 0.9% dß Ahcovel / Glucopon with a low solids saturation process, where drying at 220 degrees F is applied.

On the other hand, the compositions of surfactant treatment at higher solid contents have also presented disadvantages such as poor rheology, emulsion instability, gelation and variability of treatment. Other challenges related to the topical application of surfactant for the treatment of non-woven materials include durability or the ability to maintain and operate with water wettability during multiple exposures to aqueous fluids.

Then, the object of this invention is of the following kind: 1) to provide high solids / low viscosity treatment compositions applicable to the ambient temperature, 2) to provide high solids treatment compositions without drying requirements or minimum drying requirements , 3) to provide treatment compositions that impart a durable wettability to non-woven fabrics.

The following procedure is typical of the general method employed when using the low viscosity / high solids treatment compositions of the present invention.

Nonwoven Typically, rolls of 14 inches wide of cloth bound with 0.6 oz yarn per square yard (osy) made of polypropylene fibers (ca. 2.2 denier per fiber).

Surfactant Formula Typically, an aqueous treatment bath containing at least 0.075% antifoam (Dow 2210 from Dow Corning) and 20% by weight of surfactant formula (Table 3) was prepared. After thorough mixing at room temperature, the surfactant formula is poured into it. treatment tank where mixing is continued at room temperature, unless otherwise indicated (Table 3).

Table 3. Experimental Data and Comparison of Durability of Various Non Woven Hydrophilic Treatments (WEKO dß High Solids Process) Treatment Composition at 20% Solids Very high viscosity for high solids applications.

Application process The high solids low viscosity surfactant treatment compositions of this invention have been applied using a WEKO treater (WEKO, from Biel AG, Switzerland). The general WEKO configuration is a centrifugal dipping application system using a single double rotocarrier as shown in Figure 1. The surfactant formula is pumped to the WEKO headboard through a gear pump where it is fed to the wetting rotors. through tube restrictors. The WEKO pilot equipment used in this invention is equipped with 6 rotors which spin at a speed of 450 revolutions per minute. Under the effect of a centrifugal force generated by the spinning rotors, the chemical is supplied to the non-woven fabric in the form of small drops.

The production (gram / minute) is controlled and adjusted with restrictor tubes of different diameter, head pressure and bath parameters (temperature and viscosity). A finer production control can be achieved by adding optional needle valves to the header exit ports.

Drying All fabrics treated in Examples 1-43 n required no drying.

Aggregate level The level of aggregate on the fabric was measured by low resolution solid state nuclear magnetic resonance (NMR) spectroscopy using a Brucker Minispec 120 nuclear magnetic resonance (by Brucke Spectrospin, of Canada Limited). Additional information about this analytical technique can also be found in the following reference: "Broad Line Nuclear Magnetic Resonance in Finishing Measurements on Textile Fiber", by J. E. Rodgers, Espectroscopia, 9 (8), 40 (1994).

A preferred surfactant treatment composition is described in Examples 1 to 6. As shown in Table 3, the fabrics of Examples 1-6 were treated from an aqueous emulsion of relatively high viscosity relatively low solids of Ahcovel and Glucopon to proportions varying from 10: 1 to 20: 1. It is notable to mention that the treated fabrics do not require any subsequent drying after their surface treatment with the WEKO process. The unusual finding in Examples 1-6 compared to other treatments reported in Table 3 is the duration of the viscosity modifier / surfactant treatment as described herein. The special feature of the treatment compositions lies in their simultaneous compliance with the following attributes: 1) high solids, low viscosity, stable aqueous emulsion applicable at room temperature; 2) no drying was required; 3) improved durability treatment as assessed by the runoff test described herein.

Table 4. Experimental Data and Comparison of Durability of Various Non-Woven Hydrophilic Treatments Using Various Surfactants and Applied Cosurfactant Systems from Low Solids Baths (Low Solids Saturation Process) Treatment Composition The runoff test provides clear evidence that durable treatments are achieved in Examples 1-11 and Examples 27-29 of Table 3, and in Examples 44-46, 59-61 of Table 4. Runoff test results suggest that the surfactant type Ahcovel only and only certain co-formulations is surfactant without other surfactants pass the durability test. The results of the durability (of the draining test) also suggest that there is a direct correlation between the level of aggregate and the extension of durability (or number of running cycles) only with the Ahcovel-type surfactant and certain co-formulations such as Ahcovel / Glucopon, Ahcovel / Glucopon / SF 19 and Ahcovel / Glucopon / Y 12488. Such a correlation is not virtually existent with other types of single surfactant treatment as well as with certain co-formulations of Ahcovel type such as Ahcovel / PEG 400 ML, Ahcovel / TL 2119, Ahcovel / G2109. In this last co-formulation, the addition of a secondary surfactant to Ahcovel seems to be detrimental to the durability treatment.

The EDANA fluid transfer data provides information on the fluid absorption rate of a treated fabric, but also provides information on the durability of the treatment when the same fabric is exposed 5 times to 10 ml of salt water. The data presented in Table 6, clearly show that while the initial fluid absorption time is around the same of all the treated fabrics, and a difference in the operation of the fabrics as they are exposed to multiple insults of fluid. For example, the time of fluid intake of the fabrics treated with Triton X-102 seems to deteriorate over a cycle of 4 and 5, the performance of Ahcovel and Ahcovel / Glucopon, Ahcovel / Glucopon / SF 19 seemed less affected by 5 exposures to salt water. Therefore, the EDANA fluid transfer data are consistent with the durability of the treatment and the results are consistent with the results of the runoff test.

EXAMPLES 44-76 BASS SOLUTION SATURATION PROCESS The following procedure is typical of the general method employed when using the low solids saturation process of the present invention: Typically, an aqueous treatment bath was prepared containing 0.15% antifoam (Dow 2210 from Do Corning), 0.5% hexanol and a desired amount of surfactant or cosurfactant is added to the conditions indicated in Table 4. After mixing At room temperature, the surfactant formula is poured into the tank of the treatment station (Figure 2). Typically the 14-inch-wide rolls of a 0.6-ounce fabric per square yard of fibers bonded with polypropylene yarn (ca. 2.2 denier per fiber) were treated with surfactant treatment compositions as shown in Table 4. The level of aggregate is determined by measuring the wet pick-up percentage (% WPU) after the fabric is saturated and subjected to a pressure point between the rubber rolls. The percent of WPU is gravimetrically determined and is calculated using the following formula: (Ww-Wd)% WPU = x 100 Wd where Ww and Wd are wet and dry weights, respectively, of a piece of cloth approximately 12 inches by 12 inches. For example, as measured with 100% wet pickup measured on a fabric treated from a 0.3% solids bath, it will be achieved that an aggregate level of 0.3% is achieved on the fabric. The level of aggregate is controlled predominantly by the chemical concentration in the bath, the line speed and the pressure of the clamping point (Table 5).

Table 5. Process Conditions for the Low Solids Saturation Application System + 5% After the target aggregate level was verified and the fabrics treated were run on a series of steam-heated cans for drying (Figure 2). The treated and dried cloth was then tested in the bank for durability (draining / washing / drying test) and fluid absorption rate (EDANA fluid transfer time).

Table 6. Experimental Data and Comparison of Transfer Time of EDANA Fluid of Various Nonwoven Hydrophilic Treatments (WEKO High Solids process) Transfer Time of EDANA Fluid (second) Cycle EXAMPLE 77 A sheet of metallocene polyolefin foam (OPCELL LC31 foam from Sentinel Products Corporation, Hyannis, MA) was cut to a thickness of 0.25 inches (ca. 0.6 centimeters).

The foam samples were saturated with 1% Ahcovel / Glucopon solution mixed at a weight ratio of 15: 1 with 1% Triton X-102. The treated foams were then dried in the oven at 60 degrees centigrade for 30 minutes. The fluid absorption time of the treated foams was measured for a discharge using the EDAN fluid transfer test described herein, and the results are reported in Table 7.

Table 7. Comparison of Polyolefin Foam Fluid Collection Rate Substrate too hydrophobic, the fluid did not penetrate, tom time could not be measured. The fluid intake time was only measured for a "discharge.

EXAMPLE 78 The same treatments described in Example 77 were applied to a different metallocene polyolefin foam (OPCELL LC33 foam from Sentinel Products Corporation). The rate of fluid absorption was mediated as described in Example 77 and the results are presented in Table 7.

The present invention is further described by the following Examples.

EXAMPLE 79 The fabric employed in Example 79 was a woven n-woven fabric bonded with yarn of 2.5 ounces per square yard (about 85 grams per square meter) in which the fibers were bicomponent fibers side by side. The components, which were present in approximately equal amounts, consisted of polyethylene and polypropylene. The tel was cut by 8 inches by 10 inches. The test sample was submerged for about 30 seconds in a 3% by weight compound solution of Ahcovel / Glucopon at a ratio of 3: 1. The average WPU, as described here, was around 200, thus yielding a surfactant treatment of the fabric about 6% by weight of "aggregate level." The treated -fu fabric tested for wettability of the water by placing 10 water droplets (ca. 0.1 ml) through the "width" of the cloth All 10 drops of water were instantly absorbed into the fabric indicating that the applied treatment imparted a uniform and highly hydrophilic character to the fabric. Control treated fabric subjected to the same water drop test showed that none of the 10 drops of water penetrated absorbed into the nonwoven fabric.

EXAMPLE 80 The fabric used in Example 80 was 100 grams per square meter of bonded and carded fabric (BCW) in which the fibers were 3 denier per fiber and were made of polyethylene / polypropylene bicomponent in a sheath / core configuration, respectively . The fabric was cut in 8 inches by 10 inches. The fabric sample was submerged for about 30 seconds in a solution composed of 3% by weight of Ahcovel / Glucopon at a ratio of 3: 1. The measured WPU, as described here was around 100%, thus giving a surfactant treatment of the fabric at about an aggregate level of 3% by weight. The treated fabric was tested for wettability with water by placing 10 drops of water (ca. 0.1 ml) across the width of the fabric. All 10 drops of water were absorbed instantaneously into the fabric indicating that the applied treatment imparted a uniform and highly hydrophilic character to the fabric of carded and bonded fabric. The untreated control fabric <; free 'of finished spinning} 'subjected to the same water drop test showed that none of the 10 drops of water penetrated or were absorbed inside the nonwoven fabric.

EXAMPLES 81-88 The surfactant formulas were prepared by combining a first surfactant (Ahcovel Base N-62, with a second surfactant, Masil SF-19, in various proportions ranging from 100% Ahcovel Base N-62 to 100% Masil SF-19). In each case, the surfactants were combined in an aqueous emulsion that contained 20% by weight of total surfactant solids and 80% by weight of water.The emulsions were homogenized by mixing at a temperature of 130 degrees F. The resulting surfactant were then applied at various levels to a tel linked with polypropylene yarn having a basis weight of 0-6 ounces per square yard as described above.

The following Table 8 shows the proportion of Ahcovel Base N-62 to Masil SF-19 in each surfactant combination, and the amount applied to the base weight of the non-woven fabric.

Table The treated non-woven fabric samples were measured for transfer of liquid using the test identified as EDANA 150.1-90 described above. The measurements were taken after the non-woven fabrics were exposed to 1-5 wash cycles, where the treated tissues were washed and dried according to the procedure described above.

Table 9 (given below) shows the absorption time of the liners treated with the various surfactant combinations at a constant coating of 0.3% by weight after 1-5 wash cycles. The results of this comparison are plotted in Figure 3.

Table As shown above, and in Figure 3, the samples treated with the combined surfactants would have lower fluid absorption times after 2-5 wash cycles than the samples treated with pure Ahcovel Base N-62 or Masil SF-19 pure. This indicates that the samples treated with the surfactant combinations had an improved wettability (for example lower absorption times) and improved durability (ability to withstand washing and repeated drying). The lowest fluid intake after repeated wash cycles consistently occurred for the samples treated with the combination of 75 parts by weight of 7? Hcovel per 25 parts by weight of Masil SF-19.

Table 10 (given below) shows the take-up time of the treated liners with various coating weights of the preferred combined surfactant having 75 parts by weight of 7? Hcovel N-62 per 25 parts by weight of Masil SF-19, after 1-5 wash cycles. The results of this comparison are plotted in Figure 4.

Table 10 Absorption time, Seconds As shown above, and in Figure 4, the absorption time improved only slightly as the coating level was raised from 0.3% to 1.5% of the basis weight of the non-woven fabric. Therefore, coating weights of less than 0.5% (eg 0.3%) gave excellent results in terms of low fluid absorption times and long durability.

Therefore, according to the invention, an improved treatment process and the resulting woven fabrics providing the benefits described above have been provided. Although the invention has been illustrated by the specific embodiments, it is not limited thereto and an attempt is made to cover all equivalents that fall within the broad scope of the claims.

Claims (36)

R E I V I N D I C A C I O N S

1. A treatment composition for imparting durability and wettability to a substrate, comprising a first and a second surfactant in combination; the first surfactant includes a hydrogenated and ethoxylated fatty oil and a compound selected from the group consisting of monosaccharides, monosaccharide derivatives, polysaccharides, polysaccharide derivatives, and combinations thereof; the second surfactant includes an organosilicon compound.

2. "The" "composition of" treatment: at and as claimed in clause 1, characterized in that the first and second surfactants are combined in an aqueous emulsion.

3. The treatment composition as claimed in clause 1 characterized in that the first surfactant comprises a hydrogenated and ethoxylated castor oil.

4. The treatment composition as claimed in clause 1 characterized in that the first surfactant comprises a compound selected from the group consisting of monosaccharides, monosaccharide derivatives and combinations thereof.

5. The treatment composition as claimed in clause 1, characterized in that the first surfactant comprises sorbitan monooleate.

6. The treatment composition as claimed in clause 1 characterized in that the first surfactant comprises hydrogenated and ethoxylated castor oil and sorbitan monooleate.

7. The treatment composition as claimed in clause 1 characterized in that, the second surfactant comprises an alkoxylated polysiloxane.

8. The treatment composition as claimed in clause 7 characterized in that the second surfactant comprises an alkoxylated trisiloxane.

9. The treatment composition as claimed in clause 1 characterized in that the first and second surfactants are present in a weight ratio of from about 50-99.5 parts by weight of the first surfactant to about 0.5-50 parts by weight of the second surfactant.

10. The treatment composition as claimed in clause 1 characterized in that the first and second surfactants are present in a weight ratio of about 65-95 parts by weight of the first surfactant and about 5-35 parts by weight of the second surfactant

11. The treatment composition as claimed in clause 1 characterized in that the first and second surfactants are present at a weight ratio of about 70-85 parts by weight of the first surfactant and about 15-30 parts by weight of the second surfactant

12. A substrate treated with a composition comprising the first and second surfactants; the first surfactant includes a hydrogenated and ethoxylated fatty oil and a compound selected from the group consisting of monosaccharides, monosaccharide derivatives, polysaccharides, polysaccharide derivatives, and combinations thereof; the second surfactant includes an organosilicon compound,

13. The substrate treated as claimed in clause 12 characterized in that said substrate comprises a non-woven fabric.

14. The treated substrate as claimed in clause 13, characterized in that the non-woven fabric comprises a fabric bonded with yarn.

15. The treated substrate as claimed in clause 13 characterized in that the non-woven fabric comprises a meltblown fabric.

16. The substrate treated as claimed in clause 12 characterized in that the substrate comprises a multiple layer laminate.

17. The treated substrate as claimed in clause 12 characterized in that the first surfactant comprises a compound selected from the group consisting of monosaccharides, monosaccharide derivatives, and combinations thereof.

18. The treated substrate as claimed in clause 12 characterized in that the first surfactant comprises hydrogenated and ethoxylated castor oil.

19. The treated substrate as claimed in clause 12 characterized in that the first surfactant comprises sorbitan monooleate.

20. The treated substrate as claimed in clause 12 characterized in that the second surfactant comprises an alkoxylated polysiloxane.

21. The treated substrate as claimed in clause 17 characterized in that the second surfactant comprises an alkoxylated polysiloxane.

22. The treated substrate as claimed in clause 12 characterized in that the surfactant composition is applied at a level of about 0.1-1-5% .. per. weight, of surfactant solids in relation to the base weight of the substrate.

23. The substrate treated as claimed in clause 12, characterized in that the surfactant composition is applied at a level of about 0.1-1-0% by weight of surfactant solids in relation to the base weight of the substrate.

24. The treated substrate as claimed in clause 12 characterized in that the surfactant composition is applied at a level of about 0.1-0.5% by weight of surfactant solids in relation to the base weight of the substrate.

25. A non-woven fabric treated on the surface that has an absorption time of less than 3.0 seconds, tested according to EDANA 150.1-90, after four wash cycles.

26. A non-woven fabric treated on the surface as claimed in clause 25 characterized in that the absorption time remains less than 3.0 seconds after five wash cycles.

27. A non-woven fabric treated on the surface as claimed in clause 25 characterized in that the non-woven fabric comprises a fabric bonded with yarn.

28. A non-woven fabric treated on the surface as claimed in clause 27 characterized in that the yarn-bound fabric comprises polypropylene.

29. A non-woven fabric treated on the surface as claimed in clause 25 characterized in that it is treated with less than 0.5% by weight of a surfactant combination.

30. A non-woven fabric treated on the surface as claimed in clause 25 characterized in that the absorption time is less than 2.8 seconds after five wash cycles.

31. A non-woven fabric treated on the surface as claimed in clause 25 characterized in that the absorption time is less than 2.6 seconds after five wash cycles.

32. A non-woven fabric treated on the surface as claimed in clause 25 characterized in that the absorption time is less than 2.4 seconds after five wash cycles.

33. The treatment composition as claimed in clause 1 further characterized in that it comprises a biofunctional additive.

34. The treatment composition as claimed in clause 33 characterized in that the biofunctional additive comprises a skin welfare additive.

35. The treated substrate as claimed in clause 12 characterized in that the composition further comprises a biofunctional additive.

36. The treated substrate as claimed in clause 35 characterized in that the biofunctional additive comprises a skin welfare additive. SUMMARY A surfactant composition useful for imparting durability and wettability to a substrate includes the first and second surfactants in combination. The first surfactant includes a compound selected from hydrogenated and ethoxylated fatty oils, monosaccharides, monosaccharide derivatives, polysaccharides, polysaccharide derivatives, and combinations thereof. The second surfactant includes an organosilicon compound. The surfactant composition can be applied as an aqueous emulsion to a substrate such as a non-woven fabric to provide increased wettability after repeated wash cycles.