HK1065978B - Condrapable hydrophobic nonwoven web and method of making same - Google Patents

Description

Drapable hydrophobic nonwoven web and method of making same

Background

The present invention relates to a condrapable hydrophobic nonwoven web of continuous fibers and a method of making the same, and more particularly, the present invention relates to a method of making the same using a fiber surface modifier.

Nonwoven webs of continuous fibers are well known in the fiber art and are commonly referred to as "meltspun fibers," a term derived from a primary member of this class, i.e., meltblown webs, spunbond fibers, and combinations thereof. While other nonwoven webs are known in the art, they contain staple fibers (that is, staple fibers rather than continuous fibers), with carded webs being a well-known example of nonwoven webs of such discontinuous fibers.

Melt-spun webs have utility in a wide variety of different fields. Some of these areas (e.g., as liner sheets and cuffs for paper diapers) result from the hydrophobic nature and barrier properties of melt-spun webs due to the nature of the materials used in the webs. For example, webs formed from polypropylene fibers typically exhibit the high degree of hydrophobicity required for use in liner sheets and cuffs for paper diapers, surgical gowns, and the like (in which case it is undesirable to absorb water through a fabric formed from continuous fibers), but exhibit inferior hand and drape. On the other hand, meltspun webs formed from other materials such as polyethylene and polyethylene/polypropylene copolymers either exhibit an unsatisfactorily low degree of hydrophobicity for particular applications or are even hydrophilic in nature, but exhibit excellent relative softness and drape. In this case, the material may be made hydrophobic or more hydrophobic by using a hydrophobic material such as polydimethylsiloxane (hereinafter referred to as "PDMS"). The PDMS may be incorporated into the polymer mixture from which the fibers are made, or applied to the web after the web is formed.

The particular web additives are typically economically applied to the web by dispersing the additives in an aqueous medium so that the additive-containing aqueous medium can thereafter be conveniently sprayed, coated or otherwise applied to the web, and thereafter removing the aqueous medium from the web by simple drying in order to leave the additives on the fiber surfaces of the web. Some of these additives are hydrophilic in nature and therefore readily disperse in aqueous media. Other additives are hydrophobic additives and therefore hydrophilic emulsifiers (such as long chain fatty acids) are required to disperse the additive in the aqueous medium. In the latter case, removal of the aqueous medium leaves not only the desired additives on the fibers, but also the hydrophilic emulsifier, so that the treated web either becomes hydrophilic or at least less hydrophobic than before treatment with the additives. Examples of additives are surfactants and emulsifiers which are commonly used to improve aesthetic tactile properties such as softness, smoothness and feel. The use of surfactants to provide softness to the web reduces the hydrophobic nature of the web and, of course, often results in unacceptable hydrophilic products for certain specific applications requiring a hydrophobic nature. See, for example, U.S. patent No. 3973068.

More particularly, it is known to provide hydrophobic nonwoven webs of continuous fibers formed from polypropylene. It is known to apply hydrophilic additives dispersed in an aqueous medium to the fibers of such a web as a softener or lubricant (to facilitate economical application of the additives to the web), and then to dry the web to remove the aqueous medium and leave a treated web. However, the resulting treated web is typically no longer sufficiently hydrophobic for its intended use, either because the additives treating the web are themselves primarily hydrophilic or because a large amount of hydrophilic emulsifier is used to disperse the non-hydrophilic additives within the aqueous medium.

Summary of The Invention

It is therefore an object of the present invention to provide a process for making a flexible, hydrophobic nonwoven web of continuous fibers. It is another object to provide such a method which uses a fiber surface modifying agent dispersed in an aqueous medium as an additive wherein the web substantially retains its hydrophobic nature. It is a further object to provide such a process wherein the modifying agent is dispersed in the aqueous medium using a hydrophilic emulsifier in an amount that does not adversely affect the hydrophobic nature of the web. It is a further object of the invention to provide a product manufactured by the method.

In particular, the present invention relates to a process for making a flexible, hydrophobic nonwoven web of continuous fibers, comprising the steps of: (A) providing a hydrophobic nonwoven web of continuous fibers having an initial drape; (B) applying to the web a fiber surface modifying agent dispersed in an aqueous medium, said modifying agent consisting essentially of an amino-modified polydimethylsiloxane; and (C) drying the web to remove the aqueous medium and obtain a flexible hydrophobic web.

The present invention also relates to a flexible, hydrophobic nonwoven web of continuous fibers comprising: (A) a hydrophobic nonwoven web of continuous fibers having initial drape; and (B) a fibrous surface modifying agent on said fibrous web which forms a condrapable hydrophobic fibrous web with the fibrous web, wherein said modifying agent consists essentially of an amino-modified polydimethylsiloxane; the drapeable hydrophobic fibers are characterized by a significant improvement in hydrophobicity, as measured by a strike through time of greater than 180 seconds, and drape, as measured using a textile hand tester, which decreases by at least 15% on average in the MD and CD directions.

It has now been found that the above and related objects of the invention are obtained in a process for making a drapeable hydrophobic nonwoven web of continuous fibers having an initial drapeability, the process comprising the steps of: providing a hydrophobic nonwoven web of continuous fibers, and applying to the web a fiber surface modifying agent dispersed in an aqueous medium. Finally, the web is dried to remove the aqueous medium and to obtain a flexible hydrophobic web. In one aspect of the invention, the modifier consists essentially of an amino-modified polydimethylsiloxane. In another aspect of the invention, the dried web is characterized by a significant hydrophobicity (as measured by a strike through time of more than 300 seconds) and a significant improvement in drape (as measured by using a hand of fabric tester, with an average decrease (measured in the direction of force) in the MD and CD directions of at least 15% (and preferably at least 20%)). The web is preferably a melt-spun nonwoven fiber.

In a preferred embodiment, the amino modification is the substitution of the methyl group on the PDMS with an aminoalkyl group. Thus, amino modified PDMS is:

wherein Y, X are independently terminal groups; r ═ R₁-NH-R₂(R₁＝-(CH₂)_p-, where p is greater than 0; r₂H, alkyl, cycloalkyl, aryl, aminoalkyl, alkylaminoalkyl, cycloalkylaminoalkyl or aminoaryl); and n, m are independently greater than 0. Preferably, R ═ CH₂-CH₂-CH₂-NH-R₂。

In the preferred amino-modified PDMS, the sum of n + m is 400-1500 (preferably about 1100); a degree of amino modification of 2 to 5 (preferably about 3.5); and the number of amino groups is 0.1 to 0.3 (preferably about 0.12 to 0.15). The molecular weight of the amino-modified PDMS when applied to the web is about 30000-150000 (preferably 70000-100000).

The liquid absorption rate of the fiber web is 20-200% based on the dry fiber web; the aqueous medium contains 0.5 to 20% of the modifying agent therein, based on the weight of the aqueous medium; and the dried web has 0.005 to 0.5% of a modifying agent thereon, based on the weight of the dried web.

The fibers are selected from the group consisting of polyolefins, polyesters, polyamides, copolymers thereof, and blends thereof. Preferably, the fibers are a polyolefin selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof, such as a blend of polypropylene/polyethylene copolymer containing about 4% polyethylene. Most preferably the fiber is polypropylene. The fibers are set by a process selected from the group consisting of thermal bonding (melt bonding), chemical bonding (resin bonding), hydroentanglement (hydroentangling) and needling, preferably by thermal bonding.

The modifier may be dispersed in the aqueous medium by at least one hydrophilic emulsifier. Preferably the hydrophilic emulsifier is a nonionic emulsifier and most preferably it is at least one ethoxylated fatty alcohol. The hydrophilic emulsifier has an HLB value of from 8 to 17 and is present in an amount of from 3 to 30 percent, based on the weight of the modifier. The hydrophilic emulsifier may comprise a nonionic or cationic co-emulsifier.

The present invention also includes a drapeable hydrophobic nonwoven web of continuous fibers comprising a hydrophobic nonwoven web of continuous fibers and a fibrous surface modifying agent on the web to form a drapeable hydrophobic web therewith. The modifier consists essentially of an amino-modified polydimethylsiloxane, and the drapeable hydrophobic web is characterized by significant hydrophobicity (as measured by a strike through time of more than (over)180 seconds) and a significant improvement in drapeability (as measured by using a textile hand tester, an average reduction of at least 15% in the MD and CD directions relative to the initial drapeability).

Description of The Preferred Embodiment

Briefly, the present invention is a flexible, hydrophobic nonwoven web of continuous fibers and a method of making the same. The method comprises the following steps: providing a hydrophobic nonwoven web of continuous fibers, and applying to the web a fiber surface modifying agent dispersed in an aqueous medium, and then drying the web to remove the aqueous medium and obtain a flexible hydrophobic web (which contains the modifying agent). Thus, the fibrous surface modifying agent must be capable of improving the initial drape of the web while still maintaining the hydrophobicity of the web. It has now been found that amino modified polydimethylsiloxanes, by virtue of their highly hydrophobic PDMS nature, maintain and possibly even improve the desired hydrophobicity of the web, while making the web more drapeable due to the amino modification. The modifying agent is sufficiently hydrophobic in nature that even when it is desired to use a hydrophilic emulsifier for dispersion in an aqueous medium, the inherently hydrophobic nature of the modifying agent predominates and the web hydrophobicity is maintained despite the presence of the hydrophilic emulsifier.

The term "hydrophobicity" denotes a property related to three different and quantifiable parameters: hydrohead (EDANA 120.1-80 for hydrostatic head), strike-through (EDANA 1503-96 for penetration time or acquisition speed) and contact angle (FIBRO DAT (dynamic absorption tester-version 2.6) 1100). Depending on the context in which the term is used in the prior art and the particular application for which the prior art is concerned, the prior art can quantitatively determine hydrophobicity using only one or two of these parameters as a test or standard in any given case. A web as used herein and in the claims may be said to have "significant hydrophobicity" only if it has a strike through time in excess of 180 seconds. This high transmission is typically (but not necessarily) associated with a hydrohead of at least 5cm and a contact angle of at least 90 °.

As used herein and in the claims, the term "drape" means the characteristic of an aesthetic tactile parameter that combines hand feel and drape. "hand" relates to the sensory feel of a fabric when the hand is moved parallel over the fabric surface, typically with the fingers touching it. Since a material such as glass may be very smooth but have a poor hand feel, it is not truly smooth. Since a material such as a polypropylene film may be quite soft, but has a poor hand feel, it is not truly soft. On the other hand, "drapeability" relates to the ability of a fabric to fold or crease. Conveniently, hand may be considered to relate to the external or surface friction of the fabric, and drape may be considered to relate to the internal or fibre-to-fibre friction of the fabric.

The well-known hand-feel tester test method for fabrics (INDA IST 90.3-95) provides a reliable quantitative measure of drape, which correlates well with the results of the sensory test panel. It relates variously to the measurement in the art of hand, softness, drapability, flexibility, etc. In practice, however, it measures both hand or external friction effects and drape or internal friction effects. The hand of the fabric meter measures the force required to pass the fabric through a slit opening with a blade (blade) of substantially the same length as the opening. A fabric sample of a given size was placed on the platform of the instrument, which consisted of two thin metal plates forming a slit with a width of 0.25 inch (6.4mm) for the passage of a web of 5-100gsm basis weight. The midline (MD or CD) of the fabric sample is aligned with the slit and/or through the blade used to force the sample into the slit. The force required to perform this step was measured and reported in grams. The test was repeated with the fabric sample reverse-oriented 90 °. Unless otherwise indicated, the reported results are the average results of the fabric extending through the slit in both the Machine Direction (MD) and the Cross Direction (CD). The test is usually performed on all two sides of the material having two sides, but in the case of the present invention, the test is performed on only one side, because it is considered that the material does not have two sides. Variations in structure or formation uniformity affect the test results of the hand of the fabric tester, so the results should be averaged over several (about 10) readings.

The more drapable the fabric, the easier it will move through the slit under the influence of the blade. The test results reflect both the drapability of the material (that is, the ease with which it is folded or creased across the slit by the blade) and the feel of the material (that is, the ease with which the friction generated between the moving web and the stationary slit is overcome). The lower the force required for the fabric to pass through the slit, the lower the test reading and the more drapable the fabric.

The web may comprise a single layer (e.g., meltblown layer M or spunbond layer S), a two layer composite (e.g., SS, MM or SM web), or even a three or more layer composite (e.g., SMs or SMMS web). In SMS or SMMS webs, the outer layers may be selected to provide a desired hand or feel, while the middle layer is selected for specific liquid or gas barrier properties. Thus, a particular web is by weight (g/m)²) Can vary widely and this variation in weight of course has a significant effect on the drapability and hence the flexibility of the web. Therefore, in determining drape, the hand-feel tester test method must be modified so that different weight webs are tested using slits of different widths, the heavier the basis weight of the fabric, the wider the slits are required, or the test must be performed on a web of comparable weight for comparative purposes only. Thus, as used herein, a "web" can be said to have a "significant improvement in drape" only if the average is reduced by at least 15% in the MD and CD directions relative to the initial drape as measured by using a hand of fabric tester, with the slit width appropriately selected to suit the weight of the web.

The process of the present invention starts from a hydrophobic nonwoven web of continuous fibers formed by methods well known in the art. The web is preferably a "meltspun fiber," i.e., a meltblown nonwoven, spunbond, or combination thereof. It is formed substantially of continuous fibers, rather than staple fibers, and therefore it does not include a carded nonwoven web.

In a preferred embodiment, the fibers are thermoplastic or spinnable polymers selected from the group consisting of polyolefins, polyesters, polyamides, copolymers thereof (with olefins, esters, amides or other monomers) and blends thereof. The term "blend" as used herein includes a homogeneous mixture of at least two polymers or a non-homogeneous mixture of at least two physically distinct polymers, such as bicomponent fibers. Preferably the fibers are polyolefins selected from the group consisting of polyethylene, polypropylene, copolymers thereof and blends thereof including, for example, ethylene/propylene copolymers and polyethylene/polypropylene blends. Most preferably, the fibers are polypropylene due to the natural hydrophobicity of the fibers alone or with small amounts of less hydrophobic polyethylene.

The fibers are consolidated into the form of a nonwoven web of continuous fibers by any of a variety of methods well known in the art, such as those selected from the group consisting of thermal bonding (melt bonding), chemical bonding (resin bonding), hydroentanglement, and needlepunching. The fibers are preferably set by thermal bonding or similar methods of exposing the individual fibers to the additives.

The method includes the step of applying a fiber surface modifying agent dispersed in an aqueous medium to the web. The modifying agent is dispersed within the aqueous medium so as to facilitate economical application of the modifying agent to the fibrous web by any of a variety of methods well known in the art for applying additives or modifying agents to fibrous webs, such as spraying, coating, foaming, pasting, screen printing, or even using a saturated bath or a nipped double lick-up roll. In the preferred "dip and nip" process for applying the modifying agent to the web, the web is passed through an aqueous solution containing the medium ("dip") and then through nip rolls ("nip") which force the solution into the interior of the web while removing excess solution from the surface of the web. To create drapability, static fiber-to-fiber friction must be reduced to enable deformation of the fabric. This requires that the modifying agent not only stay on the surface of the fabric, but also penetrate into the pores of the fabric and theoretically reach the surface of the individual fibers of the fabric.

The wet pick-up (that is, the wet pick-up of the web to aqueous media including the modifying agent) is preferably from 20 to 200% on a dry web basis. Lower wet pick-up levels tend to result in non-uniform low levels of modifier added to the web, while higher web wet pick-up levels require longer web drying times. The aqueous medium preferably contains 0.5 to 20% of the modifying agent therein, based on the weight of the aqueous medium. Lower levels of modifier in the aqueous medium tend to result in non-uniform low levels of modifier being added to the web, while higher levels of modifier in the aqueous medium potentially result in undesirable viscosity changes in the aqueous medium. The dried web preferably has 0.005 to 0.5% of the modifying agent thereon, based on the weight of the dried web. While tight control of uniformity is difficult to achieve at lower levels of modifier on the dried web, higher levels of modifier on the dried web are not only unnecessary and expensive, but can also negatively impact the degree of hydrophobicity of the web.

Drying of the web with the modifying agent to remove the aqueous medium and obtain a pliable hydrophobic web can be accomplished by conventional means such as by hot air in a dryer, steam drum, hot air drum, infrared oven, or the like. The heated air is maintained at a temperature suitable for the particular web material, typically 110 ℃ and 125 ℃ for a 130 ℃ softening temperature polypropylene.

As previously mentioned, PDMS or polydimethylsiloxane are well known additives for increasing the hydrophobicity of webs. PDMS has the following formula:

wherein

m is greater than 0.

Typically, m is in the range of 400-²Sec).

The amino modification of the present invention is the substitution of a methyl group with an aminoalkyl group. Thus the amino modified PDMS is:

wherein

Y, X are independently terminal groups;

R＝R₁-NH-R₂；

R₁＝-(CH₂)_p-, where p is greater than 0;

R₂h, alkyl, cycloalkyl, aryl, aminoalkyl, alkylaminoalkyl, cycloalkylaminoalkyl or aminoaryl; and

n, m are independently greater than 0.

Terminal groups for Y and X include H, OH, methyl, ethyl, acetyl, methoxy, ethoxy, and the like.

R₁Is a polymethylene group such as methylene, dimethylene, trimethylene, etc. Particularly preferred amino modification uses trimethylene as R₁And having the following aminopropyl formula:

R＝CH₂-CH₂-CH₂-NH-R₂

R₂preferably the nonionic group and is H, alkyl, cycloalkyl or aryl, or preferably an amino derivative thereof (i.e. aminoalkyl, alkylaminoalkyl, cycloalkylaminoalkyl or aminoaryl), in order to achieve the additional flexibility provided by the additional amino group modified by each amino group.

In the preferred amino-modified PDMS, n is 120-1500, preferably about 150, and the sum of n and m is 400-1500 (preferably about 1100). The molecular weight of the amino-modified PDMS when applied to the web is about 30000-150000 (preferably 70000-100000). In general, an increase in the n/m ratio produces a more drapeable web, although its hydrophobicity is slightly lower than without the amino modification of the PDMS. Also generally, increasing the molecular weight of the amino-modified PDMS results in a slight increase in the drape of the web, while not significantly reducing the hydrophobicity of the web. This is probably because an increase in the n/m ratio not only increases the number of amino groups in each molecule but also decreases the relative number of unmodified PDMS groups, whereas increasing the molecular weight of amino-modified PDMS increases the total number of amino groups in each molecule but does not decrease the relative number of unmodified PDMS groups.

The degree of modification of the amino group is 2 to 5 (preferably about 3.5), and the number of amino groups is 0.1 to 0.3 (preferably 0.12 to 0.15). The degree of amino modification represents the total fraction of methyl groups that can be substituted by amino modifying groups within the PDMS molecule. The number of amino groups represents the number of milligrams of potassium hydroxide (KOH) equivalent to neutralizing 1g of amino-modified PDMS. Thus, both the degree of amino modification and the number of amino groups are indicative of the number of amino groups added to the PDMS molecule. It will be appreciated that as a statistical case, there must be unmodified PDMS mixed with amino-modified PDMS, but typically less than 1 wt%.

Amino-modified PDMS such as SILASTOL SJKN and UKANOL in the form of a crude emulsion is available from Schill&Seilacher Aktiengesellschaft of Boeblingen, Germany, in which the amino modification is aminoethyl-aminopropyl (i.e. R₁Is propyl and R₂Is aminoethyl, an aminoalkyl group). Such amino-modified PDMS has been used to provide softness to woven textiles, but is often replaced by improved products that soften and maintain the woven textiles more hydrophobic.

As previously mentioned, PDMS is highly hydrophobic. Whether used as such or in amino-modified form (i.e., as a modifier of the invention), it is typically dispersible in aqueous media only by the intervention of a hydrophilic emulsifier. Preferred hydrophilic emulsifiers are in nonionic form, such as at least one ethoxylated fatty alcohol, and preferably a mixture of ethoxylated fatty alcohols. It may also include nonionic or cationic co-emulsifiers. The HLB (hydrophilic/lipophilic balance) of the hydrophilic emulsifier is from 8 to 17, preferably from 10 to 15 and most preferably 13. It is typically used in amounts of 3 to 30% based on the weight of the modifier. It is natural to use hydrophilic emulsifiers at a minimum level to minimize the effect of the hydrophilic effect of the added emulsifier on the hydrophobic nature of the web. The modified or unmodified PDMS is itself somewhat more hydrophobic than polypropylene, but when mixed with a hydrophilic emulsifier required to enable it to form an emulsion, it is substantially the same hydrophobicity as polypropylene.

After drying the web to remove the aqueous medium, the remaining web, which includes the modifying agent and any emulsifier remaining thereon, is characterized by a significant hydrophobicity (as measured by a strike through time of more than (over)300 seconds) and a significant improvement in drape (as measured by using a hand-of-fabric tester, an average reduction of at least 15% (and preferably at least 20% on average) in the MD and CD directions relative to the initial drape).

Surprisingly, it has been found that the minimal improvement in final drape (measured as a percentage of the initial drape) is independent of the initial drape level. Thus, not only those webs that initially lack any significant drape, but also those that initially exhibit significant drape, will exhibit improved drape under the action of the modifying agent.

The product of the present invention is a hydrophobic nonwoven web of continuous fibers having a fiber surface modifier on the fibers, thereby forming a pliable hydrophobic nonwoven web of continuous fibers. The modifier comprises essentially the aforementioned amino-modified PDMS, and as previously mentioned, the drapable hydrophobic fibers are characterized by a significant improvement in hydrophobicity and drapability of at least 15%.

The following examples illustrate the effects of the present invention.

Example I

The fiber surface modifier of the present invention (silatol SJKN) was dispersed in the aqueous medium (water) at a content of 3% based on the weight of water. The modifier was applied to a thermally bonded SS polypropylene nonwoven web (15gsm) having a 19% bond area using two lick-roll applicators, one roll on each side of the web, to ensure complete saturation of the web, and thus complete wetting of the surface of the fibers. The web speed was 250m/min and the lick roll speed was 8 rpm. The web was dried with an IR-dryer to "absolute dry" and then conditioned for 24 hours. The following test results (average of 10 samples) were obtained:

the dried web contained 0.18% modifier based on the weight of the dried web.

The dried web showed a strike through time of greater than 300 seconds (untreated control: over 300 seconds). The test was terminated at 350 seconds.

The dried web showed a contact angle of 123 ° (untreated control: 128 °).

The dried web showed an average sag (mN) of 9.3 in the MD and an average sag (compliance) of 4.5 in the CD using a hand-of-fabric tester (untreated control: average 12.3 in the MD and 5.5 in the CD). See table 1.

These test results show that the drapeable hydrophobic nonwoven web exhibits significantly improved drapeability compared to the untreated control, i.e., an average of 25% improvement in the MD direction and 19% improvement in the CD direction (overall average: 22%).

Example II

The procedure of example I was carried out on a thermally bonded polypropylene nonwoven SMMS web (15.5gsm, which included 3.5gsm meltspun fibers) having a bond area of 19%.

The dry web contained 0.24% modifier, based on the weight of the dry web, with a bond area of 19%.

The dried web showed a strike through time of greater than 300 seconds (untreated control: over 300 seconds). The test was terminated at 350 seconds.

The dried web showed a contact angle of 124 ° (untreated control: 127 °).

The dried webs exhibited sag (mN) averaging over (over)12.5 in the MD and sag averaging 4.9 in the CD as determined using a hand-of-fabric tester (untreated control: 16 averaging in the MD and 6.6 averaging in the CD). See table 1.

These test results show that the drapeable hydrophobic nonwoven web exhibits significantly improved drapeability compared to the untreated control, i.e., an average of 22% improvement in the MD direction and 26% improvement in the CD direction (overall average: 24%).

Example III

The procedure of example I was carried out on a thermally bonded polypropylene nonwoven SS web (15gsm) having a bond area of 17%.

The dried web contained 0.17% modifier based on the weight of the dried web.

The dried web showed a strike through time of greater than 300 seconds (untreated control: over 300 seconds). The test was terminated at 350 seconds.

The dried web showed a contact angle of 123 ° (untreated control: 123 °).

The dried webs exhibited sag (mN) averaging over (over)8.4 in the MD and 3.6 in the CD as measured using a hand-of-fabric tester (untreated control: 12.6 averaged in the MD and 5.6 averaged in the CD). See table 1.

These test results show that the drapeable hydrophobic nonwoven web exhibits significantly improved drapeability compared to the control, i.e., an average of 33% improvement in the MD direction and an average of 35% improvement in the CD direction (overall average: 34%).

Example IV

The procedure of example I was carried out on a thermally bonded polypropylene nonwoven SMMS web (15.5gsm, which included 3.5gsm meltspun fibers) having a bond area of 17%.

The dried web contained 0.26% modifier based on the weight of the dried web.

The dried web showed a strike through time of greater than 300 seconds (untreated control: over 300 seconds). The test was terminated at 350 seconds.

The dried web showed a contact angle of 122 ° (untreated control: 125 °).

The dried webs exhibited an average sag (mN) in the MD of more than (over)14.5 and an average sag in the CD of 5.4 as measured using a hand-of-fabric tester (untreated control: average 18 in MD and average 7.7 in CD). See table 1.

These test results show that the drapeable hydrophobic nonwoven web exhibits significantly improved drapeability compared to the untreated control, i.e., an average of 22% improvement in the MD direction and 26% improvement in the CD direction (overall average: 25%).

Example V

The procedure of example I was carried out on a thermally bonded nonwoven SS web (15gsm) of a polypropylene/polyethylene copolymer obtained as experimental resin from Exxon and a copolymer in a proportion 97/3 similar to that commercially available under the trade name ESCORENE PP9355 from Exxon at a weight ratio of 96/4 (which had a bond area of 17%).

The dried web contained 0.38% modifier based on the weight of the dried web.

The dried web showed a strike through time of about 300 seconds (untreated control: 240-. The test was terminated at 350 seconds.

The dried web showed a contact angle of 121 °.

The dried webs exhibited sag (mN) averaging over (over)4 in the MD and sag averaging 1 in the CD as measured using a hand-of-fabric tester (untreated control: 7 averaging in the MD and 4 averaging in the CD). See table 1.

These test results show that the drapeable hydrophobic nonwoven web exhibits significantly improved drapeability compared to the untreated control, i.e., an average of 43% improvement in the MD direction and 75% improvement in the CD direction (overall average: 59%).

Example VI

As a treated control, a fiber surface modifier (a macroemulsion of unmodified PDMS available from Schill & Seilacher under the trade designation SILASTOL E35) was dispersed in an aqueous medium at a level of 0.15%, based on the weight of water. The modifier was applied to a laboratory hand sample (15gsm) of a thermally bonded SS nonwoven web of polypropylene having a 19% bond area. An impregnation bath (similar to a saturation bath) with a pair of pressure-adjustable nip rolls (available under the trade name laborary front # VFH-35594 from mathis company, germany) was used to ensure complete saturation of the web and thus complete wetting of the surface of the fibers. The web speed was 0.5m/min and the nip pressure was 50 at a scale of 1-100 units. The web was dried to an "absolute dry" state using a laboratory type forced-air-oven dryer and then conditioned for 24 hours. The following test results (average of 10 samples) were obtained:

the dried web contained 0.25% dry add-on (dry add-on) of the modifier, based on the weight of the dried web.

The dried web showed a strike through time of 185.2 seconds (untreated control: 197.7 seconds).

The dried web showed a contact angle of 130.2 ° (untreated control: 129.2 °).

The dried webs showed an average sag (mN) of 9.7 in the MD and an average sag of 4.2 in the CD as determined using a hand-of-fabric tester (untreated control: 12.4 on average in the MD and 5.5 on average in the CD). See table II.

These experimental results show that the drapeable hydrophobic nonwoven web shows a significant improvement in drapeability, but a slight decrease in hydrophobicity, compared to the untreated control.

Example VII

The fiber surface modifier of the present invention (a macroemulsion of amino-modified PDMS obtained under the trade name SILASTOL SJKN) was dispersed in an aqueous medium at a content of 0.4% based on the weight of water. The procedure of example VI was followed.

The following experimental results (average of 10 samples) were obtained:

the dried web contained 0.15% dry add-on of modifier based on the weight of the dried web.

The dried web showed a strike through time of 231.8 seconds (untreated control: more than 197.7 seconds).

The dried web showed a contact angle of 129.6 deg. (untreated control: 129.2 deg.).

The dried webs showed an average sag (mN) of 8.4 in the MD and an average sag of 3.5 in the CD as determined using a hand-of-fabric tester (untreated control: 12.4 on average in the MD and 5.5 on average in the CD). See table II.

These experimental results show that the drapeable hydrophobic nonwoven web shows a more significant improvement than the PDMS treated control, and shows an increase in hydrophobicity, compared to the untreated control.

Example VIII

As a treated control, a fiber surface modifier (a macroemulsion of unmodified PDMS obtained under the trade name SILASTOL E35) was dispersed in an aqueous medium at a level of 0.15%, based on the weight of water. The modifier was applied to a laboratory hand sample (15gsm) of a thermally bonded SMMS nonwoven web of polypropylene having a 19% bond area. The procedure of example VI was followed.

The following experimental results (average of 10 samples) were obtained:

the dried web contained 0.25% dry add-on of modifier based on the weight of the dried web.

The dried web showed a strike through time of greater than 300 seconds (untreated control: over 300 seconds).

The dried web showed a contact angle of 129.6 deg. (untreated control: 128.1 deg.).

The dried webs showed an average sag (mN) of 14.9 in the MD and an average sag of 5.1 in the CD as determined using a hand-of-fabric tester (untreated control: 16 on average in the MD and 6.5 on average in the CD). See table II.

These experimental results show that the drapeable hydrophobic nonwoven web shows an improvement in drapeability without decreasing hydrophobicity as compared to the untreated control.

Example IX

The fiber surface modifier of the present invention (a macroemulsion of amino-modified PDMS obtained under the trade name SILASTOL SJKN) was dispersed in an aqueous medium at a content of 0.4% based on the weight of water. The modifier was applied to a thermally bonded SMMS nonwoven web of polypropylene (15gsm) having a bond area of 19%. The procedure of example VI was followed.

The following experimental results (average of 10 samples) were obtained:

the dried web contained 0.21% dry add-on of modifier based on the weight of the dried web.

The dried web showed a strike through time of greater than 300 seconds (untreated control: over 300 seconds).

The dried web showed a contact angle of 127.9 ° (untreated control: 128.1 °).

The dried webs showed an average sag (mN) of 12.8 in the MD and an average sag of 4.3 in the CD as determined using a hand-of-fabric tester (untreated control: 16 on average in the MD and 6.5 on average in the CD). See table II.

These experimental results show that the drapeable hydrophobic nonwoven web shows a more significant improvement in drapeability than the PDMS treated control without decreasing hydrophobicity compared to the untreated control.

* * *

While the copolymer web (of example V) showed higher initial drape than any of the neat polypropylene webs (of examples I to IV), it also showed a surprisingly large increase in drape (59% overall, and particularly in the CD direction) relative to the neat polypropylene web. This may be associated with a relatively high addition or percentage of the modifier (0.17-0.26% relative to the neat polypropylene web, 0.38%).

Although the treated copolymeric web (of example V) exhibits the ambiguous (borderline) defined herein of "pronounced hydrophobicity", the treated hydrophobicity is still sufficiently high for many practical applications, particularly where drape is more important than hydrophobicity.

Comparison of examples I-II with examples III-V generally demonstrates the increased sagging effect of the inventive process with a reduced bond area (e.g., to about 17%) relative to a standard bond area (e.g., about 19%). Therefore, a bonding area of 12 to 18%, optimally 13 to 17%, is preferred.

Examples VI-IX generally show that while unmodified PDMS improves sag relative to the untreated control, it may reduce hydrophobicity. On the other hand, amino-modified PDMS improves the drape more than unmodified PDMS without significantly decreasing or actually increasing the hydrophobicity.

The materials of the present invention can be used in a wide variety of industrial applications. For example, the material may be used as air filtration, automotive filtration, liquid filtration and filter bags. The material can also be used in industrial protective clothing, such as room cleaning appliances, consumer goods clothing, dust protection and chemical protection. The material is further useful as a surface protection for industrial wipes such as room cleaning wipes, oil absorbing wipes, lens cleaning wipes, and low friction and/or non-scratching surfaces. Other industrial applications of the material include the wrapping of housings, packaging, furniture and bedding, automotive coverings, insulation, wrapping of insulated cables, battery separators, shoe components and the like.

The material is useful as a wrap and packaging for both domestic and industrial applications.

Furthermore, the materials of the present invention can be used in a wide variety of hygiene applications. For example, the material is useful as a gasketing sheet or outer covering, leg cuffs (leg cuffs), waist bands, stretch tabs, and elastic or stretchable side panels.

Finally, the materials of the present invention can also be used in a wide variety of medical applications. For example, the material is useful as a surgical drape, surgical gown, field cut gown, shoe upper, hood, and sterilization wrap.

The above description of a specific application is illustrative only and not limiting. The uses other than the industrial, sanitary and medical applications described above are naturally derived from the physical and chemical properties of the material according to the invention.

The materials of the present invention provide high drape, high hydrophobicity, low surface-to-surface friction and high slip/low tack and are therefore particularly useful in the hygiene field (particularly for use as gasketing sheets or outer coverings, leg covers, stretch tabs and elastic or stretchable side panels), in the furniture and bedding industry (such as seat covers, spring covers and furniture covers), in general for wrapping and packaging applications and as insulated cable wraps.

* * *

Although the present invention is described in the context of the above described webs, which are hydrophobic both initially and after processing, the principles of the present invention are also applicable to webs which are initially of a hydrophilic nature (i.e. exhibit a strike through time of significantly less than 10 seconds, preferably less than 3 seconds), such as the biodegradable polymers PLA (polylactic acid) or PCL (polycaprolactone). Thus, if the web is initially hydrophilic, the treated web will be less hydrophilic, or may even be weakly or moderately hydrophobic. This is because the modifier of the invention covers the surface of the web fibers to some extent, thereby masking, hiding or converting the surface (depending on how one would look at it) so that it is effectively either less hydrophilic or even hydrophobic. As a practical matter, the modifier does not cover 100% of the fiber surface, so that it is not possible to ignore the initial hydrophilicity/hydrophobicity of the fibers altogether, and it will affect whether the treated web is only less hydrophilic or indeed hydrophobic. However, for the purposes of the present invention, the treated web should have a strike through time of at least 10 seconds.

In summary, the present invention provides a method for making a flexible, hydrophobic nonwoven web of continuous fibers that substantially retains its hydrophobic nature using a fiber surface modifier dispersed in an aqueous medium as an additive. The hydrophilic emulsifier may be used to disperse the modifying agent in the aqueous medium in an amount that does not adversely affect the hydrophobic nature of the web. The invention also provides products made by the method.

While the preferred embodiments of the invention have been shown and described in detail, various modifications and improvements thereto will become apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention should be construed broadly and limited only by the appended claims, and not by the foregoing specification.

TABLE 1

Examples		Flexibility and drapability
						Control, mN	Treated fibrous web, mN	Increase in sag,% (average)
			Polypropylene
I	SS-bond area*19 percent to the adding amount of 0.18 percent
							MD	12.4	9.3	25	(22％)
	CD	5.5	4.5	19
					II	SMMS-area of adhesion*19 percent to the adding amount of 0.24 percent
	MD	16.0	12.5	22							(24％)
						CD	6.6	4.9	26
III	SS-bond area**17 percent to the adding amount of 0.17 percent
							MD	12.6	8.4	33	(34％)
	CD	5.6	3.6	35
					IV	SMMS-area of adhesion**17 percent to the adding amount of 0.26 percent
	MD	18	14.5	19							(25％)
						CD	7.7	5.4	30
	PP/PE copolymer
						V	SS-bond area**17 percent to the adding amount of 0.38 percent
	MD	7	4	43	(59％)
							CD	4	1	75

Remarking:

standard bond area: 19 percent of

The addition amount SS: 0.18% SMMS: 0.24 percent

Reduced bond area: 17 percent of

The addition amount SS: 0.17% SMMS: 0.26% SS blend: 0.38 percent

TABLE II

Comparison of untreated control with PDMS and amino-modified PDMS

Examples	Product(s)	Dry addition amount	Penetration time	Contact angle	Degree of drapability (mN)
									(％)	(second)	(degree)	MD	CD
-	15 gsmSS/control	0.00％	197.7	129.2	12.4	5.5
							VI	15gsmSS/PDMS	0.25％	185.2	130.2	9.7	4.2
VII	15 gsmSS/modified PDMS	0.15％	231.8	129.6	8.4	3.5
							-	15.5 gsmSMMS/control	0.00％	300.0	128.1	16	6.5
VIII	15.5gsmSMMS/PDMS	0.25％	300.0	129.6	14.9	5.1
							IX	15.5 gsmSMMS/modified PDMS	0.21％	300.0	127.9	12.8	4.3

Claims (86)

1. A process for making a flexible, hydrophobic nonwoven web of continuous fibers, the process comprising the steps of:

(A) providing a hydrophobic nonwoven web of continuous fibers having an initial drape;

(B) applying to the web a fiber surface modifying agent dispersed in an aqueous medium, said modifying agent consisting essentially of an amino-modified polydimethylsiloxane; and

(C) the web is dried to remove the aqueous medium and to obtain a flexible hydrophobic web.

2. The method of claim 1, wherein the modifying agent is dispersed in the aqueous medium by a hydrophilic emulsifier.

3. The method of claim 1 wherein the amino modification is the substitution of a methyl group with an aminoalkyl group.

4. The method of claim 1, wherein the amino-modified PDMS is:

wherein

Y, X are independently terminal groups;

R＝R₁-NH-R₂；

R₁＝-(CH₂)_p-, where p is greater than 0;

R₂h, alkyl, cycloalkyl, aryl, aminoalkyl, alkylaminoalkyl, cycloalkylaminoalkyl or aminoaryl; and

n, m are independently greater than 0.

5. The method of claim 4, wherein R ═ CH₂-CH₂-CH₂-NH-R₂。

6. The method of claim 5, wherein R₂Is aminoalkyl.

7. The method of claim 6, wherein R is aminoethyl-aminopropyl.

8. The method of claim 4, wherein:

(A) n is 120-; and n + m is 400-;

(B) the amino modification degree is 2-5; and

(C) the number of amino groups is 0.1-0.3.

9. The method of claim 8, wherein:

(D) n is 150; and n + m is 1100;

(E) the degree of amino modification was 3.5; and

(F) the number of amino groups is 0.12-0.15.

10. The method of claim 4, wherein the molecular weight of the amino modified PDMS is 30000-150000.

11. The method of claim 10 wherein the amino modified PDMS has a molecular weight of 70000-.

12. The method of claim 1, wherein the web has a wet pick-up of 20 to 200% based on dry web.

13. The method of claim 12, wherein the aqueous medium contains 0.5 to 20% of the modifying agent therein, based on the weight of the aqueous medium.

14. The method of claim 1, wherein the dried web has 0.005 to 0.5 percent of the modifying agent thereon, based on the weight of the dried web.

15. The method of claim 1 wherein the fibers are selected from the group consisting of polyolefins, polyesters, polyamides, copolymers thereof, and blends thereof.

16. The method of claim 15 wherein the fibers are a polyolefin selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof.

17. The method of claim 16, wherein the fiber is polypropylene.

18. The method of claim 16 wherein the fibers are a polypropylene/polyethylene copolymer blend containing 4% polyethylene.

19. The method of claim 1, wherein the web is a melt-spun nonwoven web.

20. The method of claim 1, wherein the fibers are coagulated by a process selected from the group consisting of thermal bonding, chemical bonding, hydroentanglement, and needlepunching.

21. The method of claim 20, wherein the fibers are set by thermal bonding.

22. The method of claim 1, wherein the web has a bond area of 12 to 18 percent based on the total area of the web.

23. The method of claim 2 wherein the hydrophilic emulsifier is a nonionic emulsifier.

24. The method of claim 23 wherein the hydrophilic emulsifier is at least one ethoxylated fatty alcohol.

25. The method of claim 23, wherein the hydrophilic emulsifier comprises a nonionic or cationic co-emulsifier.

26. The method of claim 23 wherein the hydrophilic emulsifier has an HLB value of from 8 to 17.

27. The method of claim 23 wherein the hydrophilic emulsifier is present in an amount of 3 to 30% based on the weight of the modifier.

28. A process for making a flexible, hydrophobic nonwoven web of continuous fibers, the process comprising the steps of:

(A) providing a hydrophobic nonwoven web of continuous fibers having an initial drape;

(B) applying to the web a fiber surface modifying agent dispersed in an aqueous medium, wherein the modifying agent comprises an amino-modified polydimethylsiloxane; and

(C) drying the web to remove the aqueous medium and to obtain a dried web characterized by a significant improvement in hydrophobicity and drape, wherein hydrophobicity is measured by a strike through time of at least 180 seconds and drape is reduced by an average of at least 15% in the MD and CD directions relative to initial drape, as measured using a textile hand tester.

29. The method of claim 28, wherein the modifying agent is dispersed in the aqueous medium by a hydrophilic emulsifier.

30. The method of claim 28, wherein the amino modification is the substitution of a methyl group with an aminoalkyl group.

31. The method of claim 28, wherein the modifier is an amino-modified PDMS:

wherein

Y, X are independently terminal groups;

R＝R₁-NH-R₂；

R₁＝-(CH₂)_p-, where p is greater than 0;

R₂h, alkyl, cycloalkyl, aryl, aminoalkyl, alkylaminoalkyl, cycloalkylaminoalkyl or aminoaryl; and

n, m are independently greater than 0.

32. The method of claim 31, wherein R ═ CH₂-CH₂-CH₂-NH-R₂。

33. The method of claim 32, wherein R₂Is aminoalkyl.

34. The method of claim 33, wherein R is aminoethyl-aminopropyl.

35. The method of claim 31, wherein:

(A) n is 120-; and n + m is 400-;

(B) the amino modification degree is 2-5; and

(C) the number of amino groups is 0.1-0.3.

36. The method of claim 35, wherein:

(D) n is 150; and n + m is 1100;

(E) the degree of amino modification was 3.5; and

(F) the number of amino groups is 0.12-0.15.

37. The method of claim 31, wherein the amino modified PDMS has a molecular weight of 30000-150000.

38. The method of claim 37 wherein the amino modified PDMS has a molecular weight of 70000-.

39. The method of claim 28, wherein the web has a wet pick-up of 20 to 200% based on dry web.

40. The method of claim 39, wherein the aqueous medium contains 0.5 to 20% of the modifying agent therein, based on the weight of the aqueous medium.

41. The method of claim 28, wherein the dried web has 0.005 to 0.5 percent of the modifying agent thereon, based on the weight of the dried web.

42. The method of claim 28, wherein the fibers are selected from the group consisting of polyolefins, polyesters, polyamides, copolymers thereof, and blends thereof.

43. The method of claim 42, wherein the fibers are a polyolefin selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof.

44. The method of claim 43, wherein the fiber is polypropylene.

45. The method of claim 43, wherein the fibers are a polypropylene/polyethylene copolymer blend containing 4% polyethylene.

46. The method of claim 28, wherein the web is a melt-spun nonwoven web.

47. The method of claim 28, wherein the fibers are coagulated by a process selected from the group consisting of thermal bonding, chemical bonding, hydroentanglement, and needlepunching.

48. The method of claim 47, wherein the fiber is set by thermal bonding.

49. The method of claim 28, wherein the web has a bond area of 12 to 18 percent, based on the total area of the web.

50. The method of claim 29, wherein the hydrophilic emulsifier is a nonionic emulsifier.

51. The method of claim 50 wherein the hydrophilic emulsifier is at least one ethoxylated fatty alcohol.

52. The method of claim 50, wherein the hydrophilic emulsifier comprises a nonionic or cationic co-emulsifier.

53. The method of claim 50 wherein the hydrophilic emulsifier has an HLB value of from 8 to 17.

54. The method of claim 50 wherein the hydrophilic emulsifier is present in an amount of 3 to 30% based on the weight of the modifier.

55. The method of claim 28, wherein the reduction is an average of at least 20% in the MD and CD directions.

56. A flexible, hydrophobic nonwoven web of continuous fibers comprising:

(A) a hydrophobic nonwoven web of continuous fibers having initial drape; and

(B) a fibrous surface modifying agent on said fibrous web which forms a condrapable hydrophobic fibrous web with said fibrous web, wherein said modifying agent consists essentially of an amino-modified polydimethylsiloxane;

the drapeable hydrophobic fibers are characterized by a significant improvement in hydrophobicity, as measured by a strike through time of greater than 180 seconds, and drape, as measured using a textile hand tester, which decreases by at least 15% on average in the MD and CD directions.

57. The web of claim 56, comprising a hydrophilic emulsifier.

58. The web of claim 56, wherein the amino modification is a substitution of a methyl group with an aminoalkyl group.

59. The web of claim 56, wherein the amino-modified PDMS is:

wherein

Y, X are independently terminal groups;

R＝R₁-NH-R₂；

R₁＝-(CH₂)_p-, where p is greater than 0;

R₂h, alkyl, cycloalkyl, aryl, aminoalkyl, alkylaminoalkyl, cycloalkylamino

Alkyl or aminoaryl; and

n, m are independently greater than 0.

60. The web of claim 59, wherein R ═ CH₂-CH₂-CH₂-NH-R₂。

61. The fiber web of claim 60, wherein R₂Is aminoalkyl.

62. The web of claim 61, wherein R is aminoethyl-aminopropyl.

63. The fiber web of claim 59, wherein:

(C) n is 20 to 500; and n + m is from 00 to 1500;

(D) the amino modification degree is 2-5; and

(E) the number of amino groups is 0.1-0.3.

64. The fiber web of claim 63, wherein:

(F) n is 150; and n + m is 1100;

(G) the degree of amino modification was 3.5; and

(H) the number of amino groups is 0.12-0.15.

65. The web of claim 59 in which the amino modified PDMS has a molecular weight of 30000-150000.

66. The web of claim 65 in which the amino modified PDMS has a molecular weight of 70000-100000.

67. The fiber web of claim 56, wherein the fiber web has 0.005 to 0.5 percent of the modifying agent thereon, based on the weight of the fiber web.

68. The fiber web of claim 56, wherein the fibers are selected from the group consisting of polyolefins, polyesters, polyamides, copolymers thereof, and blends thereof.

69. The fiber web of claim 68, wherein the fibers are a polyolefin selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof.

70. The fiber web of claim 69, wherein the fibers are polypropylene.

71. The fiber web of claim 69, wherein the fibers are polypropylene/polyethylene copolymer containing 4% polyethylene.

72. The web of claim 56, wherein the web is a meltspun nonwoven web.

73. The web of claim 56, wherein the fibers are consolidated by a process selected from the group consisting of thermal bonding, chemical bonding, hydroentanglement, and needlepunching.

74. The fiber web of claim 73, wherein the fibers are consolidated by thermal bonding.

75. The web of claim 56, wherein the web has a bond area of 12 to 18 percent, based on the total area of the web.

76. The web of claim 57, wherein the hydrophilic emulsifier is a nonionic emulsifier.

77. The web of claim 76, wherein the hydrophilic emulsifier is at least one ethoxylated fatty alcohol.

78. The web of claim 76, wherein the hydrophilic emulsifier comprises a nonionic or cationic co-emulsifier.

79. The web of claim 76, wherein the hydrophilic emulsifier has an HLB value of from 8 to 17.

80. The web of claim 76, wherein the hydrophilic emulsifier is present in an amount of 3 to 30 percent based on the weight of the modifier.

81. The web of claim 56, wherein the reduction is an average of at least 20% in the MD and CD directions.

82. A method of making a flexible nonwoven web of continuous fibers, the method comprising the steps of:

(A) providing a hydrophilic nonwoven web of continuous fibers having initial drape;

(B) applying to the web a fiber surface modifying agent dispersed in an aqueous medium, said modifying agent consisting essentially of an amino-modified polydimethylsiloxane; and

(C) the web is dried to remove the aqueous medium and to obtain a pliable web having reduced hydrophilicity.

83. A process for making a flexible, hydrophobic nonwoven web of continuous fibers, the process comprising the steps of:

(A) providing a non-hydrophobic nonwoven web of continuous fibers having an initial drape;

(B) applying to the web a fiber surface modifying agent dispersed in an aqueous medium; and

(C) drying the web to remove the aqueous medium and to obtain a dried web characterized by a significant improvement in hydrophobicity and drape, wherein hydrophobicity is measured by a strike through time of at least 180 seconds and drape is reduced by an average of at least 15% in the MD and CD directions relative to initial drape, as measured using a textile hand tester.

84. A method of making a flexible nonwoven web of continuous fibers, the method comprising the steps of:

(A) providing a nonwoven web of continuous fibers having an initial drape;

(B) applying to the web a fiber surface modifying agent dispersed in an aqueous medium; and

(C) drying the web to remove the aqueous medium and to obtain a dried web characterized by a significant improvement in hydrophilicity and drape, wherein hydrophobicity is measured by a strike through time of at least 10 seconds and drape is reduced by an average of at least 15% in the MD and CD directions relative to initial drape, as measured using a textile hand tester.

85. A flexible, hydrophobic nonwoven web of continuous fibers comprising:

(A) a non-hydrophobic nonwoven web of continuous fibers having initial drape; and

(B) a fibrous surface modifying agent on said fibrous web which forms a condrapable hydrophobic fibrous web with said fibrous web, wherein said modifying agent consists essentially of an amino-modified polydimethylsiloxane;

the drapeable hydrophobic web is characterized by a significant improvement in hydrophobicity, as measured by a strike through time of greater than 180 seconds, and drapeability, as measured by use of a textile hand tester, which is reduced by an average of at least 15% in the MD and CD directions relative to the initial drapeability.

86. A flexible, nonwoven web of continuous fibers comprising:

(A) a hydrophilic nonwoven web of continuous fibers having initial drape; and

(B) a fibrous surface modifying agent on said web which forms a flexible, drapeable web of reduced hydrophilicity with the web, wherein said modifying agent consists essentially of an amino-modified polydimethylsiloxane;

the drapable web is characterized by a penetration time of at least 10 seconds and a significant improvement in drapability with an average reduction in MD and CD relative to initial drapability of at least 15% as measured by use of a textile hand tester.