JP2004505180A - Cloth with altered surface properties - Google Patents

Abstract

Excellent liquid handling properties and / or repellency wherein the multi-component thermoplastic polymer fibers have exposed first and second components that form the outer surface of the multi-component fibers and extend substantially continuously in the longitudinal direction of the fibers. Multicomponent fibrous nonwoven webs having liquid properties are described. The first component includes a thermoplastic polymer and an activator, such as a liquid repellent, and the second component includes a thermoplastic polymer, and 100% to 50% less activator by weight than the first component. Including.

Description

【００４２】
上に示す実施例は、繊維の外表面上に露出した全成分内に、殆んど又は全く活性剤を有しないにもかかわらず、優れた撥液性を提供する低レベルの活性剤を有する布を得ることができることを示している。更に、アルコール撥性度は、繊維の外表面を形成する全ての成分内に分配された活性剤を有する繊維を含む布と比較可能である。
【００４３】
種々の特許及び他の引用材料が、引用により本明細書に組み込まれてきたが、引用した材料と記載された明細書との間に不一致が存在する場合、その範囲内でそれがいかなるものであっても、記載された明細書が支配するものとする。更に、本発明をその具体的な実施形態に関して詳細に説明してきたが、本発明の技術的思想及び範囲から逸脱することなく、様々な変更、修正、及び他の変形が成され得ることは当業者には明らかであろう。従って、全てのそのような変更、修正、及び、他の変形は、添付の特許請求の範囲により包含されることが意図されている。
【図面の簡単な説明】
【図１】
本発明と共に使用するのに適した、縞状配列の重合体成分Ａ及びＢを有する多成分繊維の断面を示す図である。
【図２】
本発明と共に使用するのに適した、楔形配列のポリマー成分Ａ及びＢを有する多成分繊維の断面を示す図である。
【図３】
本発明と共に使用するのに適した、複数の楔様成分が放射状に延びるアームを有する中央の成分により分離された配列のポリマー成分Ａ及びＢを有する多成分繊維の断面を示す図である。
【図４】
多成分繊維を含むメルトブローン繊維ウェブを組み込んだ多層不織ラミネートの一部を剥がした図である。[0001]
(Technical field)
The present invention relates to fabrics having modified surface properties, and more particularly, to fabrics having improved liquid barrier and / or liquid repellency properties.
[0002]
(Background technology)
It is known in the art that the physical properties of fabrics can be modified by applying one or more chemical compositions to them. As some examples, fabrics have heretofore been modified to improve and / or impart properties such as strength, wettability, absorbency, antistatic (electrostatic decay), flame retardancy, alcohol repellency, etc. to the fabric. Has been treated with various chemical compositions. Generally, the chemical composition is applied in such a way as to modify the surface properties of the fibers that make up the fabric. In this regard, it is often preferred that the chemical composition be applied throughout the thickness of the fabric. By applying the chemical composition in such a manner, the desired physical properties can be imparted throughout the fabric as well as the outer portions. This can significantly increase the desired properties of the treated fabric and / or improve the efficiency of the treatment. However, it is difficult to apply the local treatment agent uniformly over the entire thickness of the thick and / or fine fiber base material. Existing methods of applying chemical compositions locally do not often provide a method for applying the composition evenly across the thickness of the fabric in an efficient and economical manner.
[0003]
As an example, conventionally, the activator has been applied to a fabric by applying the chemical composition to one surface of the fabric and then applying vacuum from the opposite surface of the fabric. The suction of the vacuum is intended to draw the active agent into the fabric and help treat the fibers inside the fabric. By way of example only, topical coating of fiber surfaces with a chemical composition is described in U.S. Pat. No. 4,266,976 to Gegorian et al. And U.S. Pat. No. 954. Another method of treating the fabric with an activator is to completely impregnate the sheet. One such method is the "dip and squeeze" method, in which the fabric is first completely immersed in a solution of the activator, and then the fabric is "squeezed" to remove excess activator. That is, it is passed through a pair of compression rollers that serve to compress. This and other similar processes are generally described in EP 0 472 942. However, such processes can result in undesirable amounts of waste because significant amounts of the chemical composition are often removed from the fabric. Further, for dense and / or thicker fabrics, such processes often cannot produce a uniformly treated web, and reduce the desirable physical properties of the fabric. there is a possibility. Still further, such a process facilitates the transfer of the chemical composition to the adjacent surface, along with many chemical compositions, on the outer surface of the fabric, leaving an excess amount of treating agent that can give the fabric an oily feel. There is a possibility. This is highly undesirable for fabrics that will be touched and / or utilized in articles proximate human skin. Still further, such uneven processing may require the use of higher levels of activator to achieve the desired physical properties.
[0004]
In addition to topical treatment of fibers, surfactants and other activators have been included in the polymer being melt processed. By way of example only, U.S. Patent Nos. 3,973,068 and 4,070,218 to Weber disclose mixing a surfactant with a polymer and then dissolving the mixture to provide the desired fabric. Are taught. The fabric is then treated to push the surfactant to the surface of the fiber. This is often done by heating the web on a series of heated rolls, often referred to as "blooming". As a further example, U.S. Pat. No. 4,578,414 to Sawyer et al. Describes wettable olefin polymer fibers formed from a composition comprising a polyolefin and one or more surfactants. I have. The surfactant is said to bloom to the fiber surface, where at least one of the surfactants remains partially embedded within the polymer matrix. In this regard, wetting performance can be better controlled by the composition and concentration of the additive package. Still further, U.S. Pat. No. 4,923,914 to Nohr et al. Discloses that fibers treated by melt extrusion have different and increased concentrations of additives from the center of the fiber or film to its surface. Or teach a surface separable and melt extrudable thermoplastic composition suitable for forming a film. This different and increased concentration gives the fiber surface the desired properties, for example hydrophilicity. As a specific example in the Nohr patent, a polyolefin fiber nonwoven web having improved wettability utilizing various polysiloxanes is provided.
[0005]
Various methods for improving or modifying the surface properties of polymer fibers are known in the art, but provide fabrics with desired physical properties that can be more efficiently and / or economically manufactured. There is a continuing need for that. This is particularly relevant where the product is intended to be used or used in disposable articles such as, for example, wipes, absorbents, medical cloths, personal care products, and the like.
[0006]
(Disclosure of the Invention)
At least one component A disposed in substantially discrete areas across the cross-section of the fiber and extending substantially continuously in the longitudinal direction of the fiber, each having an exposed portion forming an outer surface of the multicomponent fiber The foregoing needs are met and / or the disadvantages of the prior art are overcome by the nonwoven fabric of the present invention comprising a web of multicomponent thermoplastic polymer fibers having at least one component B. The exposed portion of component A comprises at least about 25% of the peripheral surface of the fiber. In addition, component A comprises a thermoplastic polymer and an activator, with the activator on exposed portions thereof. Component B comprises a thermoplastic polymer and comprises 100% to 50% less activator by weight than Component A.
[0007]
In particular embodiments, component A comprises at least about 50% of the outer surface of the multicomponent fiber. As one example of a suitable cross-sectional arrangement, component A can include at least two separate components separated by one or more B components. In another aspect, the multicomponent fibers preferably have an average fiber diameter of less than about 25 microns, and more preferably have an average fiber diameter of less than about 10 microns. By way of example, the activator may include a wetting agent or a liquid repellent. Further, it is desirable that none of the single or continuous exposed portions of Component B constitute more than about 35% of the peripheral surface of the multicomponent fiber. In another aspect, component B preferably comprises at least about 45% by volume of the fiber cross-section. Further, a nonwoven fabric having good liquid barrier and / or liquid repellency properties can be provided wherein the activator comprises a liquid repellent and the multicomponent fibers have an average denier less than about 1. Further, the activator may comprise less than 0.75% of the multicomponent fibers by weight, and the nonwoven web has a weight of about 50 g / m²It may have a smaller basis weight. Despite having a relatively low basis weight, a nonwoven fabric having an alcohol repellency of 50 or more can be provided.
[0008]
Definition
The word "comprising", used in the claims and herein, can be interpreted in a comprehensive or broad sense, and does not exclude the addition of unlisted elements, components, or method steps. Thus, the term "comprising" encompasses the more restrictive terms "consisting essentially of" and "consisting of."
[0009]
All percentages, ratios and ratios used herein are by weight unless otherwise specified.
[0010]
As used herein, the term "activator" refers to any compound or chemical composition that imparts or improves at least one physical or functional property on the fiber surface.
[0011]
As used herein, the term "wetting agent" refers to any compound or chemical composition that has the property of exhibiting increased hydrophilicity on a fiber surface, such as by reducing the contact angle of an aqueous liquid in contact with the fiber surface.
[0012]
As used herein, the term "lyophobic agent" refers to any property of a fiber surface that exhibits increased barrier or lyophobic properties to a particular liquid, such as by increasing the contact angle for a particular liquid in contact with the fiber surface. Or a chemical composition of
[0013]
As used herein, the term "fabric" refers to a material comprising a network fiber, including, but not limited to, woven or knitted materials, tufted or tufted-like materials, nonwoven webs, and the like.
[0014]
As used herein, the term "non-woven" fabric or web refers to a web having a structure of individual fibers or yarns that are superposed in layers but are not in an identifiable manner as in a knitted or woven fabric. . Nonwovens or webs are formed in a number of processes, such as, for example, melt blown processes, spunbond processes, hydraulic entanglement processes, air deposition processes, and bonded carded web processes.
[0015]
"Polymer" as used herein generally includes, but is not limited to, homopolymers and copolymers, such as block, graft, random, and alternating copolymers, terpolymers and the like, and mixtures and modifications thereof. Further, unless otherwise specifically limited, the term "polymer" includes all possible geometric or spatial arrangements of the molecule. These configurations include, but are not limited to, isotactic, syndiotactic and random symmetries.
[0016]
As used herein, the term "medical cloth" refers to surgical gowns and drapes, face masks, buffan caps, surgical caps and hoods, shoe covers, slippers, wound dressings, bandages, sterile wraps, wipes, and lab coats. , Coveralls, aprons, clothing such as jackets, and medical items such as patient bedding.
[0017]
The term "personal care product" as used herein refers to personal hygiene items such as wipes, diapers, training pants, absorbent underpants, adult incontinence products, feminine hygiene products and the like.
[0018]
The term "protective cover" as used herein means vehicle covers, outdoor equipment and furniture covers, garden and garden equipment covers, floor covers, tablecloths, tents, tarpaulins, and the like.
[0019]
(Best Mode for Carrying Out the Invention)
The fabric of the present invention comprises an integrated layer of multi-component fibers, having at least two components, wherein the surface properties of the fibers have been modified by an activator predominantly located within less than all of the components. Including sheet. The term "multi-component" refers to a fiber formed from at least two polymer streams and extruded to form a single fiber. The individual components of the multicomponent fiber are arranged in discrete areas in the cross section of the fiber and extend substantially continuously in the longitudinal direction of the fiber. The cross-sectional array of multicomponent fibers has at least two distinct components that include a portion of the outer surface of the fiber. The multicomponent fibers preferably have three, four or more exposed sections that form the outer surface of the fiber. As mentioned above, each section of the individual polymer components collectively forms the outer surface of the multicomponent fiber. The multicomponent fiber includes at least a first and a second component, the second component including significantly less active agent than the first component. Preferably, the second component comprises at least about 50% (by weight) less activator than the first component, more preferably at least about 75% less activator than the first component. , About 95% less active agent than the first component. In another aspect, the second component can have 100% less, ie, zero weight percent, of the active agent therein than the first component.
[0020]
Referring to FIG. 1 as a specific example, the individual components of the fiber are striped parallel, where the individual components A and B are adjacent to each other and each component occupies at least a portion of the periphery or outer surface of the fiber. Can be arranged in an array. Referring to FIG. 2 as another example, a wedge or "pie" arrangement including alternating wedge sections A and B is also suitable for use with the present invention. Referring to FIG. 3 as yet another example, the plurality of components A may be separated by a central B component having radially extending arms or protrusions. If only two polymer compositions are used to form the individual components of the multicomponent fiber, the respective polymer components A and B should be present in a proportion (volume ratio) of about 90/10 to about 10/90. With a range between about 75/25 and about 25/75 being preferred. A ratio of approximately 50/50 is often particularly preferred, but the specific ratio employed can be varied as needed.
[0021]
Further, the individual components of the multicomponent fiber may be such that, in the cross-section of the fiber, the amount of active agent therein is low or the component having no active agent therein comprises only about 70% of the perimeter or outer surface of the fiber. Are located in Preferably, the component containing the higher amount of active agent comprises more than 30% of the outer surface of the fiber, more preferably at least about 50% of the outer surface of the fiber, and from about 55% to about 55% of the outer surface of the fiber. More preferably between about 85%. In addition, for fabrics having improved barrier and / or liquid repellency properties, the exposed portion of the component with low or no active agent inside may have about 35% of the outer surface of the fiber. Preferably, it does not form more single or continuous sections, and even more preferably, does not form single or continuous exposed sections that extend beyond about 25% of the outer surface of the fiber. Referring to the striped cross-sectional arrangement depicted in FIG. 1 as a specific example, component B may include approximately 50% fiber by weight, and the two separate exposed portions are each It may comprise approximately 10-15% of the outer surface of the component fibers. Referring to FIG. 2 as another example, the exposed sections of the B component can collectively include approximately 50% of the outer surface of the multicomponent fiber, while each of the exposed sections or portions is outside the fiber. It contains only about 12.5% of the surface.
[0022]
Preferably, the fibers are less than about 4 denier (g / 9000 meters), more preferably less than about 1 denier, and even more preferably less than about 0.5 denier. In another embodiment, the fibers can have an average cross-sectional diameter of less than about 25 microns, and preferably have an average cross-sectional diameter of between about 0.5 microns and about 10 microns, and between about 1 and about 5 microns. Even more preferred is between. The average fiber size used here is measured using the largest dimension in the fiber cross section. Although the fibers are generally manufactured as solid, circular structures, the multicomponent fibers of the present invention can be prepared using, for example, hollow fibers, multilobal fibers, or flat (eg, ribbon-shaped) fibers, and the like. It will be appreciated that various fiber shapes other than solid circular fibers can be provided.
[0023]
The fiber-forming components can include one or more melt-processable polymers. The individual components can include the same polymer, similar and / or different polymers. However, at least two of the individual components are distinguishable in that each has a distinguishable amount of the active agent selected therein. The polymer component of the multicomponent fiber includes, but is not limited to, polyolefins (eg, polypropylene and polyethylene), polycondensates (eg, polyamide, polyester, polycarbonate and polyarylate), polyols, polydienes, polyurethanes, polyethers, polyacrylates, It is preferably selected from thermoplastic polymers including polyacetals, polyimides, cellulose esters, polystyrene and the like. As specific examples, the polymer component is polyethylene, polypropylene, poly (1-butene), poly (2-butene), poly (1-pentene), poly (2-pentene), poly (1-methyl). -1-pentene), poly (3-methyl-1-pentene), poly (4-methyl-1-pentene), and the like. Furthermore, mixtures and / or copolymers of the aforementioned polymers are likewise suitable for use with one or more multicomponent fibers. The individual components or sections that make up the multicomponent fiber can include the same polymer or different polymers. By way of example only, desirable polymer segment combinations may include polyolefin / polyamide, polyolefin / polyester, polyolefin / polyolefin, and the like. More specifically, examples of suitable polymer component combinations include, but are not limited to, polypropylene / polyethylene, polypropylene / polypropylene, polyethylene / nylon, polyethylene / polyester, and the like. Referring to FIGS. 1 and 2 for specific examples, component A can include a mixture of a propylene polymer and an activator, and component B can include a propylene polymer. As another specific example, component A can include an activator and a mixture of polypropylene and polybutylene, and component B can include polypropylene. Still further, component A can include an activator and polypropylene, and component B can include a mixture of polypropylene and polybutylene. Exemplary blends of polypropylene and polybutylene include, but are not limited to, those described in U.S. Patent Nos. 5,204,174 and 5,482,765.
[0024]
The fibers that make up the fabric can be manufactured by various melt processing techniques. Generally, multicomponent fibers direct two or more molten polymer streams simultaneously, immediately before or immediately after extruding the polymer from a die or other extrusion device, such that the polymer streams merge to form a single filament. It can be made by doing Preferably, the polymer is fed to the die via a separate conduit and kept separate until just before extrusion. In another aspect, a divider can be used to maintain separation of the polymer stream until the polymer reaches the die capillaries. In addition, multicomponent fibers can be made using a spin pack assembly. Generally speaking, a spin pack assembly comprises a housing and a superimposed plurality of pattern openings arranged to create flow paths for separately orienting polymer components A and B through the spin pack assembly. Distribution plate. The distribution plate is connected to a spinning plate, or spinneret, which often has a plurality of openings arranged in one or more rows. Exemplary methods and apparatus for making multicomponent nonwoven webs are described in U.S. Pat. No. 3,425,091 to Ueda et al., U.S. Pat. No. 3,981,650 to Page, Terakawa et al. U.S. Patent No. 5,601,851 to Cook, U.S. Patent No. 5,989,004 to Cook, U.S. Patent No. 5,344,297 to Hills, and U.S. Patent to Pike et al. No. 5,382,400.
[0025]
The fibers and / or fabrics of the present invention can be made using conventional melt processing equipment that has been modified to form multicomponent fibers. Exemplary fiber forming steps include, but are not limited to, a melt blown step and a spunbond step. The fibers can be substantially long fibers or short fibers, ie, staple fibers. As a specific example, the fibers and fabrics of the present invention can be made using meltblown fiber equipment. Thus, multi-component meltblown fiber nonwoven webs are described, for example, in U.S. Pat. No. 3,849,241 to Butin et al., U.S. Pat. No. 5,160,746 to Dodge et al., Lau. U.S. Patent No. 4,526,733; U.S. Patent No. 5,652,048 to Haynes et al., U.S. Patent No. 5,366,793 to Fitts et al. Wante, E.L. Boone and C.I. Fluharty, Naval Research Laboratory Report No. entitled "Munfactory of Superfine Organic Fibers". No. 4364, the entire content of which is incorporated herein by reference. When using conventional meltblown equipment, the primary or damped air often has a temperature above the melting point of each polymer, including the individual polymer components. However, the primary or damped air can optionally have a temperature below the melting point of one or more of the extruded polymers. A detailed description of an apparatus and method suitable for forming a meltblown fibrous web utilizing cold air is provided in US Patent Application Serial No. 08 / 994,373, filed December 19, 1997 by Haynes et al. And the entire contents of which are incorporated herein by reference. Further, as described above, multi-component spunbond fiber nonwoven webs can be similarly made using conventional melt spinning equipment. In this regard, and by way of example only, spunbond fiber nonwoven webs and methods for making the same are disclosed in U.S. Pat. No. 4,340,563 to Appel et al., And U.S. Pat. No. 692,618; U.S. Pat. No. 3,802,817 to Matsuki et al .; U.S. Pat. No. 3,502,763 to Harman; U.S. Pat. No. 3,542,615 to Dobo et al. And U.S. Patent No. 5,382,400 to Pike et al., The entire contents of which are incorporated herein by reference.
[0026]
The particular activator or activators contained within one or more components may be any desired choice to impart or improve specific surface properties to the fibers and alter the properties of the fabric made therefrom. It can be performed. To impart or improve various surface properties including, but not limited to, absorbency, wettability, antistatic properties, antibacterial properties, antifungal properties, liquid repellency (eg, alcohol or water), etc. Activators or compounds have been utilized. Regarding the wettability or absorbency of a particular fabric, many fabrics exhibit essentially good affinity or absorption properties only for certain liquids. For example, polyolefin nonwoven webs have traditionally been used to absorb oil or hydrocarbon liquids. In this regard, polyolefin nonwoven wipes are inherently lipophilic and hydrophobic. Therefore, polyolefin nonwovens need to be treated in a particular way to impart good wetting or absorbing properties to water or aqueous solutions or emulsions. As an example, exemplary wetting agents that can be melt processed in a section to impart improved wetting to fibers include, but are not limited to, ethoxylated silicon surfactants, Ethoxylated hydrocarbon surfactants, ethoxylated fluorocarbon surfactants and the like are included. In addition, exemplary chemistries useful for making more hydrophilic melt-processed thermoplastic fibers are disclosed in U.S. Patent Nos. 3,973,068 and 4,070,218 to Weber et al. And U.S. Patent No. 5,696,191 to Nohr et al., The entire contents of the above-cited references are incorporated herein by reference.
[0027]
In another aspect, it is often desirable to improve the fiber's barrier or repellency to a particular liquid. As a specific example, it is often desirable to provide a fabric that has good barrier or repellency properties to both water and alcohol in infection control products and medical garments. In this regard, the function of thermoplastic fibers to better repel alcohol is to mix a compound having the desired repellency with the thermoplastic polymer resin prior to extrusion and then melt treat the mixture to form one or more It can be given by dividing into sections. The activator migrates to the surface of the polymer component, thereby changing the surface properties of the polymer component. Further, the distance or gap between the components exposed on the outer surface of the fiber containing significant levels of the active agent can substantially alter the functional properties of the entire fiber because the active agent is sufficiently small to thereby reduce the desired properties. It is believed that a cloth having the following characteristics can be obtained. Alcohol repellency enhancing chemical compositions suitable for use in the melt extrusion process include, but are not limited to, fluorochemicals. Exemplary melt processable liquid repellents include those available from DuPont under the ZONYL Fluorochemical trade name and those available from 3M under the trade name FX-1801. Various activators suitable for imparting alcohol repellency to thermoplastic fibers are described in US Pat. No. 5,145,727 to Potts et al. And US Pat. No. 4,855,360 to Duchesne et al. U.S. Pat. No. 4,863,983 to Johnson et al., U.S. Pat. No. 5,798,402, U.S. Pat. No. 5,459,188 and U.S. Pat. No. 5,025 to Fizzgerald et al. No., 052, the entire contents of the aforementioned cited references are incorporated herein by reference. In addition to alcohol repellency, the chemical composition can be used to similarly improve the repellency or barrier properties to other low surface tension liquids.
[0028]
Preferably, the activator comprises less than about 5% of the total multicomponent fiber, more preferably between about 0.1% and about 3% of the total multicomponent fiber. Even more preferably, it comprises between about 0.2% and about 2% of the total. When treating the activator in one or more components, the activator and polymer are extruded in a mixture wherein the activator is present in a weight ratio of about 0.1% to about 5% of the extrudate. Preferably, it comprises from about 0.2% to about 1% of the extrudate. In another aspect, good alcohol repellency, wherein the multicomponent fiber comprises less than 0.8% liquid repellent by weight, and even more preferably comprises about 0.6% or less liquid repellent. Can be provided.
[0029]
Additional materials that are compatible and do not substantially degrade the performance of the particular active agent can optionally be added to one or more of the polymer components and extruded together. As an example, one or more individual components of the multicomponent fiber can optionally include additional surfactants, dyes, stabilizers, pigments, fragrances, and the like.
[0030]
The fabric of the present invention is about 7 g / m²~ About 340g / m²Of about 14 g / m²~ About 68g / m²More preferably, the basis weight is In another aspect, the fabric can have an alcohol repellency of at least 30, preferably has an alcohol repellency of at least about 50, and even more preferably has an alcohol repellency of at least about 65. . As a specific example, about 14 g / m²~ About 50g / m²And a multi-component meltblown cloth having an alcohol repellency of more than 50.
[0031]
The fabric of the present invention can be used alone or as part of a multilayer structure. Referring to FIG. 4 as an example, a multi-layer nonwoven laminate 20 is provided that includes a multi-component meltblown fibrous web 22 laminated to a sheet-like layer or fabric 24, such as, for example, a nonwoven web of spunbond fibers. ing. In a specific embodiment, referring to FIG. 4, the multi-layer laminate comprises, for example, an intermediate layer of multicomponent meltblown fibers 22 disposed between a first spunbond fiber web 24 and a second spunbond fiber web 26. A three layer laminate 20 may be included, such as to form a spunbond / meltblown / spunbond (SMS) nonwoven web laminate. In this regard, the individual layers can be attached to one another by one or more means known in the art, such as by bonding the layers with heat, ultrasound, and / or an adhesive. As an example, the individual layers can be pattern bonded, for example, by point bonding. As used herein, "point bond" refers to the bonding of one or more layers of a fabric at a number of small, discrete bonding points, such as bonding point 28 depicted in FIG. As a specific example, generally, hot point bonding involves passing one or more layers to be bonded between heated rolls, for example, between an engraving or pattern roll and a second roll. . The engraved roll is patterned in a particular way so that the fabric is not bonded over its entire surface, and the second roll can be either flat or patterned. As a result, various engraving roll patterns have been developed for aesthetic reasons in addition to function. The multi-layer laminate is preferably pattern bonded such that the bonding area includes less than 50% of the fabric surface area, and the bonding area includes an area between about 5% to about 30% of the fabric surface area. Even more preferred. Exemplary bonding patterns and / or bonding steps suitable for use with the present invention include, but are not limited to, U.S. Pat. No. 4,374,888 to Bornslaeger, and U.S. Pat. No. 3 to Hansen et al. No. 5,855,046, U.S. Pat. No. 5,635,134 to Bourne et al., And PCT Application No. US94 / 03412 (publication number WO95 / 09261).
[0032]
The fabrics of the present invention are suitable for use in a variety of end uses and applications, including, but not limited to, medical fabrics, personal care products, protective fabrics, absorbents, wipes, and the like. . In this regard, the fabrics of the present invention are particularly suitable for use in surgical gowns, surgical drapes, tarps, and other liquid barrier fabrics.
[0033]
test
Alcohol repellency: The alcohol repellency can be measured by placing a few drops of isopropyl alcohol (IPA) / water solution on the cloth surface. The solution may contain between 20% and 100% IPA in 5% increments by volume of IPA in water. The surface tension decreases as the IPA level in the solution increases. Therefore, solutions with high IPA levels are more difficult to be repellent. Eight drops of each solution are placed parallel to the cross machine direction of the cloth and after 5 minutes repellency is obtained. The repellency is a solution having a maximum% of IPA which is not drawn into the cloth and does not pass through by observing the back surface of the cloth. If one in eight drops penetrates, the fabric is considered to have lost a particular IPA level.
[0034]
Example
The materials cited in the following examples were made using a melt blown process. Both monocomponent and multicomponent fibers have a solid circular cross section. For multicomponent fibers, the polymer components were melted and each molten polymer stream was directed separately through the die apparatus until just before the die capillary inlet. The molten polymer stream was directed into a die to form fibers having an A / B / A cross-sectional arrangement similar to that depicted in FIG. It contained almost 50%. The melting temperature was 282 ° C and the primary suction air was also 282 ° C. The activator for imparting alcohol repellency was premixed with the resin before the melt treatment. For the data described herein below, the alcohol repellency test was performed using only 10% increments (20%, 30%, 40%, etc.).
[0035]
Example 1: About 17 g / m²A multicomponent fiber meltblown nonwoven web was formed having a basis weight of 3 and an average fiber diameter of 3-5 microns. The A component comprises 1% by weight of an alcohol repellent (a fluorochemical available from 3M under the trade name FX1801), 8.3% polybutylene (DP-8911 available from Montell), and 90. It contained a mixture of 7% polypropylene (3746G available from Exxon Chemical Company). The B component contained about 15% polybutylene (DP-8911 available from Montell) and about 85% polypropylene (3746G available from Exxon Chemical Company).
[0036]
Example 2: 17 g / m²A multicomponent fiber meltblown non-woven web having a basis weight of 3-5 microns and an average fiber diameter of 3-5 microns was formed. The A component comprises 1% by weight of an alcohol repellent (a fluorochemical available from 3M under the trade name FX1801), 2.1% pigment, 8.3% polybutylene (DP available from Montell) -8911), and 88.6% of polypropylene (3746G available from Exxon Chemical Company). Component B comprises 0.5% by weight of a fluorochemical (FX-1801 available from 3M), 2.1% pigment, 8.3% polybutylene (DP-8911 available from Montell) and 89% 0.1% polypropylene (3746G available from Exxon Chemical Company).
[0037]
Example 3: 17 g / m²A multicomponent fiber meltblown non-woven web having a basis weight of 3-5 microns and an average fiber diameter of 3-5 microns was formed. The A component comprises 1% by weight of an alcohol repellent (a fluorochemical available from 3M under the trade name FX1801), 2.1% pigment, 8.3% polybutylene (DP available from Montell) -8911), and 88.6% of polypropylene (3746G available from Exxon Chemical Company). Component B comprises 0.25% by weight of a fluorochemical (FX-1801 available from 3M), 2.1% pigment, 8.3% polybutylene (DP-8911 available from Montell) and 89% 0.3% polypropylene (3746G available from Exxon Chemical Company).
[0038]
Example 4: 17 g / m²A multicomponent fiber meltblown non-woven web having a basis weight of 3-5 microns and an average fiber diameter of 3-5 microns was formed. The A component comprises 1% by weight of an alcohol repellent (a fluorochemical available from 3M under the trade name FX1801), 2.1% pigment, 8.3% polybutylene (DP available from Montell) -8911), and 88.6% of polypropylene (3746G available from Exxon Chemical Company). Component B contained 2.1% pigment, 8.3% polybutylene (DP-8911 available from Montell) and 89.6% polypropylene (3746G available from Exxon Chemical Company).
[0039]
Comparative Example 1: 17 g / m²A monocomponent fiber meltblown nonwoven web having a basis weight of 3-5 microns and an average fiber diameter of 3-5 microns was formed. The fibers contained 2.1% pigment, 7.9% polybutylene (DP-8911 available from Montell) and 90% polypropylene (3746G available from Exxon Chemical Company).
[0040]
Comparative Example 2: 17 g / m²A monocomponent fiber meltblown nonwoven web having a basis weight of 3-5 microns and an average fiber diameter of 3-5 microns was formed. The fibers consist of 1% by weight of an alcohol repellent (a fluorochemical available from 3M under the trade name FX1801), 2.1% pigment, 7.9% polybutylene (DP available from Montell). -8911) and 89% polypropylene (3746G available from Exxon Chemical Company).
[0041]
The nonwoven web described in the previous example was evaluated and the results are shown in Table 1.
[Table 1]

[0042]
The examples shown above have low levels of activators that provide excellent liquid repellency, despite having little or no activator in all components exposed on the outer surface of the fiber. It shows that a cloth can be obtained. Furthermore, the alcohol repellency is comparable to fabrics containing fibers with the active agent distributed among all components forming the outer surface of the fibers.
[0043]
Various patents and other cited materials have been incorporated herein by reference, but if any inconsistency exists between the cited material and the written specification, it is to what extent within the scope thereof. If so, the written specification shall control. Further, while the invention has been described in detail with respect to specific embodiments thereof, it is understood that various changes, modifications, and other alterations may be made without departing from the spirit and scope of the invention. It will be clear to the trader. Accordingly, all such changes, modifications, and other variations are intended to be covered by the appended claims.
[Brief description of the drawings]
FIG.
FIG. 1 shows a cross section of a multicomponent fiber having a striped arrangement of polymer components A and B suitable for use with the present invention.
FIG. 2
1 shows a cross-section of a multicomponent fiber having a wedge-shaped arrangement of polymer components A and B suitable for use with the present invention.
FIG. 3
FIG. 2 shows a cross-section of a multicomponent fiber having an array of polymer components A and B separated by a central component having a plurality of wedge-like components radially extending arms suitable for use with the present invention.
FIG. 4
FIG. 2 is an illustration of a partially stripped multi-layer nonwoven laminate incorporating a meltblown fibrous web containing multicomponent fibers.

Claims (20)

A web of multi-component thermoplastic polymer fibers having a cross-section, a length, and a peripheral surface, wherein the multi-component fibers are disposed in substantially discrete areas within the cross-section of the fibers, and are substantially longitudinal in the longitudinal direction of the fibers. Has at least one component A and at least one component B extending continuously from
Wherein said components A and B each have an exposed portion forming the outer surface of said multicomponent fiber, wherein said component A comprises at least about 25% of the outer surface of said multicomponent fiber. ,
Wherein the component A comprises a thermoplastic polymer and an activator, and further comprises an activator on the exposed portion forming a part of the outer surface of the multicomponent fiber;
Wherein the component B comprises a thermoplastic polymer and comprises 100% to 50% less activator by weight than the component A;
A multi-component fibrous nonwoven web having modified surface properties. The multicomponent fibrous nonwoven web of claim 1, wherein the multicomponent fibers have an average denier less than 4. The multi-component fibrous nonwoven web according to claim 2, wherein component A comprises less than 5% by weight of an activator. The multicomponent fibrous nonwoven web according to claim 2, wherein component B comprises at least 95% less activator than component A. The multi-component of claim 2, wherein the activator is selected from the group consisting of a wetting agent and a liquid repellent, and wherein component A comprises at least about 50% of the outer surface of the multi-component fiber. Fiber non-woven web. 6. The composition of claim 5, wherein component A comprises less than 5% by weight of activator, and wherein component B comprises 75% to 100% less activator than in component A. A multicomponent fiber nonwoven web according to claim 1. The multicomponent fiber nonwoven web according to claim 5, wherein the multicomponent fibers have an average fiber diameter of less than about 10 microns and an average denier of less than 1. The multicomponent fibrous nonwoven web according to claim 5, wherein the activator comprises a wetting agent. The multi-component fibrous non-woven web according to claim 8, wherein the non-woven web comprises an olefin polymer component and has a basis weight between about 17 g / m ² and about 340 g / m ² . The multicomponent fiber has an average denier less than about 1 and further wherein each of the discrete exposed portions of the component B comprises less than 35% of the peripheral surface of the multicomponent fiber. The multicomponent fibrous nonwoven web of claim 1, wherein The multicomponent fibrous nonwoven web according to claim 10, wherein the activator comprises a liquid repellent. The multicomponent fibrous nonwoven web according to claim 11, wherein said component A comprises at least two separate components and is separated by said component B. The multicomponent fibrous nonwoven web according to claim 11, wherein the activator comprises a fluorochemical. The multi-component fibrous nonwoven web according to claim 12, wherein the nonwoven web comprises a meltblown fibrous web. The multi-component fibrous nonwoven web of claim 12, wherein said fibers have an average fiber diameter of less than about 5 microns. 16. The multicomponent fibrous nonwoven web of claim 15, wherein component B comprises at least about 45% by weight of the fiber cross-section. The multi-component fiber nonwoven web of claim 15, wherein the activator comprises an alcohol repellent, and wherein the multi-component fiber non-woven web has an alcohol repellency of at least about 50. . The activator comprises a liquid repellent, further wherein the multicomponent fibers have an average fiber diameter of less than about 5 microns, and further wherein each exposed portion of the component B collectively has an outer surface of the multicomponent fibers. 4. The multicomponent fibrous nonwoven web of claim 3, comprising less than about 50% of the surface. The activator comprises less than 0.75% by weight of the multicomponent fiber, and the nonwoven web has a basis weight of less than 50 g / m ² and an alcohol repellency of at least 65. 19. The multicomponent fibrous nonwoven web according to claim 18, characterized in that: 20. The multicomponent fibrous nonwoven web according to claim 19, wherein the activator comprises a fluorochemical.