JP2002526219A - Liquid permeable web that is durably wettable - Google Patents

Abstract

  (57) [Summary] PROBLEM TO BE SOLVED: To provide a liquid permeable web which is improved and durable. Disclosed is a durable, wettable liquid permeable web that is particularly useful as a topsheet material for absorbent articles such as infant diapers, adult diapers, feminine hygiene articles, and the like. . A durable, wettable liquid permeable web is made by applying a relatively durable hydrophilic coating to at least one surface of the web (polymer film or nonwoven) using plasma polymerization. Also disclosed are an absorbent article comprising a durably wettable liquid permeable web as a topsheet and a plasma polymerization process for producing a durable wettable liquid permeable web. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

This application is a continuation-in-part of co-pending application Ser. No. 09 / 157,845, filed Sep. 29, 1998.

The present invention relates to durable, wettable liquid permeable webs that are particularly suitable as topsheets for absorbent articles. More particularly, the invention relates to a polymer film or nonwoven having at least one surface provided with a thin coating of an organic material. The thin organic coating is applied by a plasma induced CVD process. The thin organic coating makes the web more durable and hydrophilic than other methods known in the art. The invention also relates to a method for producing a durable wettable liquid permeable web, and to an article comprising a durable wettable liquid permeable web as a topsheet.

[0003]

[Prior art]

Polymer webs and nonwoven webs are common components such as disposable absorbent articles, dryer sheets, and the like. More specifically, macroexpanded
Three-dimensional polymer films have been used as topsheet materials for disposable absorbent articles. As used herein, the term "macroscopically expanded", when used to describe a three-dimensional web, is made to follow a surface of a three-dimensional shaped structure, with both surfaces being three-dimensional of the shaped structure. Refers to a morphological web or a web having a unique three-dimensional morphology due to the web structure. Regardless of whether the three-dimensional form is unique or made through a molding process, if the vertical distance between the viewer's eye and the plane of the web is about 12 inches, this form Is easily visible to the naked eye. In contrast, the term "flat" as used herein to describe nonwovens and polymer films refers to the condition of the entire web when viewed macroscopically on a macroscopic scale. In this context, a "flat" web includes fine-scale surface aberrations that are not readily visible to the naked eye when the vertical distance between the viewer's eye and the plane of the web is greater than about 12 inches. May be included on one or both sides.

[0004] After transferring liquid deposited on one surface to the opposite surface, a macroscopically expanded opening having openings that is particularly suitable for keeping the transferred liquid away from the skin of the wearer. 3
One of the three-dimensional polymer webs is disclosed in commonly assigned US Pat. No. 3,929,135 (1975).
(Granted to Thompson on December 30, 2012). This disclosure is incorporated herein by reference. Thompson is made of a liquid-impermeable material,
A macroscopically expanded three-dimensional web (e.g., a topsheet) having a tapered capillary configuration is described. The capillary has a bottom opening in the plane of the topsheet and a top opening remote from the topsheet plane, the top opening being in direct contact with the absorbent pad used in the disposable absorbent article. ing. Th
The ompson topsheet allows liquid to move freely from the wearer's body into the absorbent member of the device, but the backflow of this liquid is suppressed. This results in a very dry surface in contact with the user as compared to what was previously available. Another macroscopically expanded three-dimensional plastic web with openings suitable for use as an absorbent article such as a sanitary napkin topsheet is disclosed in commonly assigned US Pat. No. 4,342,314 (August 1982). (Granted to Radal et al. On 3rd). This patent is incorporated herein by reference. This Ra
The macroscopically expanded three-dimensional plastic web disclosed in the dal patent,
It has a fibrous appearance and exhibits a tactile sensation that is favorably accepted by consumers when used as a contact surface with a wearer. The assignee teaches in the same patent to Thompson and Radal et al. That a web of the type described above applies a pressure differential to the web while supporting the web on a three-dimensional molded structure, which web macro By extending to a three-dimensional cross-section of a molded structure that is expanded to support the web. If it is required to provide an opening in the macroscopically expanded three-dimensional web, the pressure (vacuum is described) until the opening is completely formed in the area of the web corresponding to the opening in the molding structure. Is applied continuously.

[0005] Also, liquid-based multi-stage processes such as US Pat. No. 4,609,518 (1
(Guide to Curro et al., September 2, 986) (hereinafter referred to as the "518 patent") to provide a film having very small and very large openings adjacent to each other. Developed in As disclosed in this patent, by forming very small (eg, micron sized) openings in the opposite direction to the openings formed for the large openings, liquids that are not initially absorbed can be reduced. The possibility of running off the web surface is prevented. As a result, liquids that are not immediately transported through the large openings are suppressed from flowing down from the web surface, and are subsequently absorbed through the relatively large openings to allow for absorbent articles that use the web as a topsheet material. Deposits on the core. Also, these small openings formed outwardly reduce the degree of web / skin contact and reduce the stiffness of the film. As a result, the user feels more comfortable. Wearers report that the surface of such topsheets is soft and silky. Separately, the '518 patent discloses a film in which very small and large openings are formed in the same direction.

In the above references, where a wettable film material is required, regardless of the method used to form the openings, the originally hydrophobic polymer web is generally surface treated with a wetting agent, It has a structure like that. The surface treatment is usually performed by spraying a surfactant on the web surface or immersing the web in a bath containing the surfactant. With any of these methods, in addition to the fact that it is not possible to accurately control the place and level of the surface treatment, the surface treatment is performed when the film provided with the opening is used as the top sheet of the absorbent article. The problem is that significant amounts of surfactant migrate into the openings and other components (eg, the absorbent core) with adverse effects. In addition, surface treatments have the disadvantage that the desired wetting agent or surfactant tends to run off after multiple exposures to such liquids. As such, the treated film, when used as an absorbent article topsheet, loses its ability to transport liquid from the skin into the absorbent article core when wetted multiple times.

In US Pat. No. 4,535,020 (issued Aug. 13, 1985 to Thomas et al.), A surface treatment of a vacuum formed film having openings is coated with a hydrophilic surfactant prior to extrusion for film formation. Are mixed with a polymer resin (referred to herein as "surfactant mixed with resin" or "RIS"). (See also, US Patent Application Serial No. 08/7, the same assignee.
No. 13,377 (filed on September 13, 1996 by YPLee et al.), U.S. Pat. No. 4,923,914 (granted to Nohr et al. On May 8, 1990), U.S. Pat. No. 5,057,262 (Non-October 15, 1991)
Ohr et al.), U.S. Patent No. 5,120,888 (granted to Nohr et al. on June 9, 1992). ) Th
According to the teachings of omas, the resin / surfactant mixture is extruded,
After the opening is subsequently formed, the incompatible surfactant eventually blooms to the film surface, resulting in a more durable and wettable web. But R
As with the surface treatment, IS has some problems in that the surfactant will run off during use and / or during manufacture, particularly when forming web openings using liquid pressure differentials. Also, hydrophilic webs formed using RIS technology are not immediately wettable, and may not be wettable for some time, depending on the relationship between resin, surfactant and environmental conditions. There is. Similarly, when such webs are used in absorbent articles, there is some time delay before the surfactant (runs down during wear) is replenished to the web surface.

[0008] Despite the teachings in the prior art, there remains a need for a liquid permeable web or film material having improved durable wettability over time and / or after exposure to liquid attack. Have been. Such materials are particularly suitable for use in disposable absorbent structures. There is still a need for a process that provides such a durable, wettable liquid permeable web.

[0009]

[Problems to be solved by the invention]

Accordingly, it is an object of the present invention to provide a liquid permeable web having improved durable wettability.

[0010]

[Means for Solving the Problems]

This durable wettability is achieved by applying a plasma-induced hydrophilic coating to at least one surface of the starting web to make the resulting web durably hydrophilic.

The present invention relates to a durable, wettable liquid permeable web that is particularly useful as a topsheet material for absorbent articles. In one aspect, the invention relates to a liquid-permeable web that is durably wettable, comprising: (i) a web selected from the group consisting of a polymer film and a nonwoven fabric; and (ii) at least one surface of the web. A substantially continuous hydrophilic coating having a thickness of less than about 2.5 μm applied by plasma polymerization to at least one surface of the liquid-permeable web that is durably wettable after aging. A liquid permeable web wherein the contact angle is about 60 ° or less greater than the contact angle before aging.

In a similar aspect, at least one surface of the treated web has a contact angle after washing that is about 60 ° or less greater than a contact angle before washing. Preferably, both states are on one web.

[0013] The present invention is also an absorbent article comprising a liquid-permeable topsheet that is durably wettable, the topsheet comprising a web and a hydrophilic coating on at least one surface of the web. The hydrophilic coating relates to an absorbent article which is applied to the substrate by plasma polymerization.

Finally, the present invention relates to a plasma polymerization process for producing a durable, wettable liquid permeable web as described herein.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

I. Liquid Permeable Webs that are Durably Wet As described in more detail below, the present invention provides a durable wettable fabric made by applying a hydrophilic coating to a starting polymer film or nonwoven fabric using a plasma polymerization process. Is about the web.

As used herein, the term “web” refers to a starting substrate (ie, a polymer film or nonwoven) to which a hydrophilic coating has been applied. Conversely, the term "durably wettable liquid permeable web" or "treated web" refers to the final product-a polymer film or nonwoven having a durable hydrophilic coating.

As used herein, the term “liquid permeable” refers to a web or treated web that is transferred from one side of the web or treated web to the opposite side of the web or treated web. Refers to the ability to transport liquid in a manner that is efficient enough to allow the treated web to be used as a component of a disposable article. The web may be originally liquid permeable or may be rendered liquid permeable by subjecting it to processing steps, such as providing openings, as used herein. Or means continuous enough to obtain hydrophilic or wettability properties as defined by the claimed contact angle limitation.

As used herein, the terms “hydrophilic” and “wettable” are used interchangeably and are susceptible to wetting by aqueous liquids deposited thereon (eg, aqueous body fluids) Mean surface. Hydrophilicity and wettability are typically dictated by the contact angle and the associated liquid and solid surface tension. This means that Am
erican Chemical Society publication `` Contact Angle, Wettability and Adhesion
(Edited by Robert F. Gould, copyright 1964). The web surface is wetted by the liquid (ie, both conditions usually occur simultaneously) when the contact angle between the liquid and the web surface is below 90 ° or when the liquid tends to spread naturally on the web surface (both conditions usually occur simultaneously). Hydrophilic). Conversely, a contact angle of 90
The surface is considered to be hydrophobic when the temperature exceeds 0 ° and the liquid does not spread naturally on the web surface. Generally, the smaller the contact angle between the surface and the liquid, the more hydrophilic the surface.

The durable, wettable liquid permeable webs according to the present invention are characterized by the hydrophilic properties created by the otherwise more hydrophobic films over a long period of time and after exposure to liquids. To the extent that it is maintained, it is "durably wettable". As discussed above, conventional approaches that have approached making hydrophobic films wettable have improved wettability initially, but have increased wettability over extended periods and / or exposure to liquids. The result was the undesirable properties of being lost. Without being bound by theory, it is believed that typical hydrophilic polymer and surface treated (eg, corona discharge treated) polymer systems undergo a “hydrophobic recovery” process. During the hydrophobicity recovery process, the wettability of the surface tends to decrease over time. This is because it is thermodynamically advantageous that a segment of a molecular chain having a low surface energy is exposed on the polymer surface. During aging, the hydrophilic molecular segments reorient and fill themselves, exposing the hydrophobic segments to the polymer surface. When chemical cross-linking is induced on the polymer surface, the cross-linking limits the mobility of the polymer chains and significantly slows down the "recovery of hydrophobicity" process, thus maintaining the wettability of the polymer surface for extended periods Tend to be Applicants' invention provides a chemically permeable crosslinking of the polymer by a radiation curing process, so that a durable, wettable liquid permeable web can be produced.

As used herein, durable wettability refers to durable wettable liquid permeable webs (as mentioned above, the more hydrophobic starting “web” herein.
After aging (referred to as "after aging") and / or after exposure to liquids (referred to as "after washing"), the wettability properties of Described by the ability to maintain. The method for measuring the contact angle after aging and the contact angle after washing will be described later.

As already mentioned, the durable wettability of the durable wettable liquid permeable web according to the invention is achieved using a plasma process. Plasma is often referred to as the fourth state of matter. When energy is applied to a solid (eg, a polymer film or nonwoven), the solid can undergo a transition to a liquid state. With more energy, the liquid becomes a gas. Upon further application of the appropriate type of energy, the gas dissociates into a plasma. Plasma exists in various forms. Preferred plasmas useful herein are low pressure or vacuum processes, which cause the web to be at ambient temperature (ie, about 20 ° C.).
° C) or near. As a result, thermal degradation of the web during processing and / or thermal distortion of the formed web during processing is prevented. In the plasma processing chamber, active species in the form of electrons, free radicals, ions, and high-energy neutral particles collide with the surface of the web (eg, polymer) to break molecular bonds, and new functional groups form on the surface. Made in Also, the reaction of these active and high energy species in the gas phase results in the deposition of a thin coating on at least one surface of the web.

A plasma system suitable for use with the present invention incorporates a parallel plate electrode design. In this design, the material to be processed is directly exposed to the primary electric field of RF energy, but is not part of the circuit. The resulting main plasma is particularly more uniform and efficient. It is the material (the part)
Is exposed to glow discharge in all three dimensions. With respect to high pressure processes (but within the general definition of low temperature gas plasma), some forms of gas delivery systems are designed to generate a uniform laminar flow of process gas over the entire chamber volume. What is done is useful. In a multi-electrode / shelf design, it is important that each electrode receive the same amount of RF energy. In this way, a uniform glow discharge occurs between each shelf or in each plasma zone. In addition, solid state devices (Solid state componen
ts) and microprocessor control of system parameters (process time, flow rates, power levels, and working pressures) ensure process uniformity, efficiency, and reproducibility.

Since the plasma is an electrically conductive atmosphere, the plasma has a characteristic impedance to the output of the RF generator. Thus, the preferred plasma process always uses a matching network to match the plasma impedance to the output impedance of the RF generator. A state-of-the-art plasma system suitable for use in the present invention is HIMONT Plasma Science (Foster City, CA) (HIMONT U
The system incorporates an automatic matching network and error checking during the process.

A low temperature plasma is generated in a reduced pressure gas atmosphere at a pressure of about 0.001 to about 10 Torr, preferably about 0.01 to about 5 Torr, more preferably about 0.05 to about 1 Torr, most preferably About 0.05 to about 0.4 To
rr. The power supply to the device can be at a radio high frequency of about 40 kHz to about 3 GHz, preferably about 13 to about 27 MHz, and most conveniently about 14 MHz. To achieve the desired plasma conditions in the gaseous atmosphere, the power delivered to the device should be from about 10 to about 10,600 W, preferably from about 50 to about 500
It can vary from 0W, more preferably from about 250 to about 3000W, most preferably from about 500 to about 2500W. The power used depends somewhat on the working volume of the chamber. The most preferred range is from about 500 to about 2500 W
Is suitable for a HIMONT Plasma Science PS0500D gas plasma device with a working volume of about 5.0 cubic feet. The plasma processing time is a few seconds to a few minutes, preferably about 20 seconds to about 30 minutes, and most preferably about 60 seconds to about 20 minutes.

It should be understood that process pressure, time, and power are not independent, but interrelated variables. The level of effect selected for each of these variables determines the degree of web surface modification and / or coating thickness. Also, the chamber volume and chamber shape are related along with the sample size and sample surface shape. Choosing the level of these variables is well within the ordinary skill of those skilled in the art to which this invention belongs.

The hydrophilic coating layer is deposited on the surface of a suitable web (with or without preformed openings) by low temperature plasma induced vapor deposition (ie, polymerization) of the monomer or combination of monomers. Apply a hydrophilic coating to the web. In a preferred embodiment, the monomer is a silicon-containing compound having 1 to 3 silicon atoms, wherein the compound is selected from the group consisting of: (I) A silane of the formula SiR ₄ . Here, when each R is the same,
May be different and selected from: H; linear or branched alkyl or alkoxy of C ₁ -C _8; or unsubstituted or C ₁ C ₆ -C which is substituted by a linear or branched alkyl of -C _{4 10} aryl; vinyl radical . That _{-CH = CH 2; C 3 -C} 5 allyl radical; If where R is H, only 1 or 2 R is H. (Ii) Organosilicones based on a structure consisting of alternating silicon and oxygen atoms and various organic radicals bound to silicon. The chemical formula is R'R "R '" Si-
[-O-Si (R ') (R ")-] _n -R'". Wherein R ', R ", R'" may be different even in the same, it is a linear or branched alkyl or alkoxy of C ₁ -C _8. R 'and R "may be hydrogen (provided that R' and R"
% Or less is hydrogen). n is 1, 2, or 3. (Iii) mixtures thereof.

Representative silicon compounds include, but are not limited to:
Not necessarily. Hexamethyldisiloxane (HMDSO), methyltrimethoate
Xysilane (MTMS), vinyltrimethoxysilane (VTMS), vinyltrimethoxysilane
Ethoxysilane (VTES), ethylmethoxysilane (EMS), ethyltrime
Toxisilane (ETMS), Tetraethoxysilane (TES), Cyclohexyl
Methyl-dimethoxysilane (CMDMS), dicyclopentyl-dimethoxysila
(DCDMS), phenyltriethoxysilane (PES), diphenyldimethoate
Xysilane (DPDMS), tetramethyldisiloxane (TMDSO), hexa
Methyl trisiloxane (HMTSO). Use the silicon compound in gaseous state
Introduce into plasma deposition chamber. Silicon compound is introduced into the chamber
Before heating to a temperature of about 40 ° C to about 100 ° C, usually about 40 ° C to about 60 ° C
Vapor pressure to generate sufficient vapor pressure to deposit the coating at the appropriate rate.
Let it. Simultaneously with gaseous oxygen and argon together with gaseous silicon compound
Feed into the deposition chamber. However, oxygen and argon are separate suppliers.
Feed using a stage and another mass flow controller. Depending on the application, O _Two Is about 25cm^Three/ Min (standard condition) (“sccm”) to about 1200 sc
cm, the flow rate of the gaseous silicon compound is about 10 sccm to about 250 sccm, A
The flow rate of r is between about 1 sccm and about 150 sccm. With argon,
The deposition rate of the gaseous material used increases. Therefore, argon is used in the process
Preferably. Argon and flow rates for monomer (eg, HMDSO) flow rates
The flow rates of oxygen and oxygen are preferably as follows. Mass flow Q1 is 3%
It represents argon and 97% oxygen, and the vapor mass flow rate Q2 is the mass of the monomer.
Expressing the flow rate, a preferred ratio of Q1: Q2 is from about 10: 1 to about 1: 2.
, More preferably from about 5: 1 to about 1: 1, most preferably about 3: 2.

In the plasma deposition process using the silicon compound according to the present invention, oxygen is indispensable. Without oxygen, it is not possible to achieve a plasma-induced hydrophilic coating with the silicon compounds described above. Whatever the effect of oxidation by oxygen, it seems necessary to use oxygen if one intends to achieve the hydrophilic coatings of the present invention.

[0029] The total vapor pressure of the gaseous material introduced into the plasma deposition chamber for depositing the hydrophilic coating layer is from about 0.04 to about 0.5 Torr, preferably about 0.5 torr.
35 to about 0.45 Torr, most preferably about 0.4 Torr. The process pressure must be such that a low bias potential on the RF applied electrode is achieved. The total vapor pressure for the hydrophilic coating layer is from about 0.04 to about 0
. 4 Torr, preferably about 0.06 to about 0.13 Torr, depending on the process used and the substrate being processed.

Alternatively, the monomer vapor deposition may be accomplished using the flash vaporization technique described in US Pat. No. 4,842,893, issued to Yializis on Apr. 29, 1988. The disclosure of this document is incorporated herein by reference.

The web that undergoes plasma polymerization may be flat (two-dimensional) or complex (3
dimension. Films and nonwoven fabrics provided with openings in advance) may be used. That is, the plasma treatment may be performed before or after the opening is formed in the web. In a preferred embodiment, a plasma treatment is performed after the openings are formed to better maintain a uniform hydrophilic coating on the web surface.

The above-mentioned state-of-the-art plasma system sold by HIMONT Plasma Science, such as the PS0500D reactor, is equipped with a throttle valve so that it is possible to change the process pressure while maintaining the same gas flow rate. I have.

The plasma treatment time to obtain the desired hydrophilic coating is typically about 1
Minutes to about 10 minutes, preferably about 1.5 minutes to about 4 minutes, most preferably about 1.
5 minutes to about 2.5 minutes. The RF power used to effect the gas phase reaction is typically from about 200 to about 1500 W, preferably from about 1000 to about 1400 W
, Most preferably from about 1100 to about 1300 W. RF typically used
The power is between about 1200 and about 2500 W, depending on the substrate being processed and the throughput requirements. The resulting hydrophilic coating can be made in various thicknesses, but is typically about 0.1 to about 2.5 μm, preferably about 1 to about 2 μm.

As already mentioned, the plasma-induced hydrophilic coating exhibits a contact angle to water of less than 90 °, so that even a small amount of water dripping on the treated web will cause the coated surface of the treated web to naturally Spread. In a preferred embodiment,
The treated web is exposed to a low temperature plasma gas composition (also referred to herein as a "surface reforming gas stream") or such as, but not limited to, infrared, electron beam, thermionic or ultraviolet. ) May be further processed by exposure to an energy source such as a device that emits). The latter is also referred to herein as "radiation curing". A device suitable as an energy source in the present invention is disclosed in U.S. Pat. No. 4,842,893, issued to Yializis on Apr. 29, 1988. The disclosure of this document is incorporated herein by reference.

In the embodiment of the surface reforming gas flow, it is preferable that the surface reforming gas flow contains N ₂ O and CO _{2 in} order to enhance the wettability of the hydrophilic coating. In one such preferred embodiment, the plasma gas composition comprises from about 80 to about 40 mole% of N ₂ 0 and about 20 to about 60 mole% of CO _2, preferably from about 70 to about 45 mole% Of N ₂ 0 and about 30 to about 55 mol% of CO ₂ , most preferably about 60 to about 45 mol% of N ₂ O and about 40 to about 55 mol% of C 2
O ₂ (where the amount of N ₂ O and CO _{2 in} the mixture equals 100 to 10 mol%) for a period of time sufficient to modify the surface of the hydrophilic coating to increase its wettability. ,contains.

In a radiation curing embodiment, the radiation source is preferably a gas discharge electron beam gun. The electron gun directs a stream of electrons over the monomer through the emitter window to further cure the monomer and increase the wettability of the hydrophilic coating. Curing is achieved by applying an electron beam voltage to the dielectric thickness
hickness). For example, at 10K electron volts,
Proceed through the deposited monomer by about 1 μm.

The plasma process is generally performed as follows. After placing the starting web to be processed in the vacuum chamber, the chamber pressure is reduced, typically to about 0.005 Torr. The process gas or process gas mixture used is introduced into the chamber and the chamber pressure is kept constant between 0.04 and 0.4 Torr. The internal dimensions of the working area are approximately 1.73 × 0.76 × 1.02 m (width × height × depth) and the total working volume is 1.34 m ³ . The plasma is generated using a suitable high frequency form of energy (typically 13.56 MHz radio frequency energy). In the system described above, the operation is performed at a total power input capacity of 2500 W or less. RF
The energy dissociates the gas and produces a plasma characterized by a unique glow. Because the process is performed under reduced pressure, the bulk temperature of the gas is near ambient. Therefore, it is called low-temperature gas plasma, glow discharge, or low-temperature gas glow discharge.
This process is called direct plasma polymerization because the web that is exposed to the plasma state is placed in an electric field. In contrast, co-pending U.S. patent application Ser.
Patent No. 57840 (filed on September 21, 1998 by P. France et al.) "DURABLY WETT
ABLE POLYMERIC WEBS REPARED USING A REMOTE PLASMA POLYMERIZATION PROCESS
Please refer to. In this document, a durable wet web is referred to as an indirect (remo
te) ”describes a method of fabricating using plasma polymerization. Electrons or ions generated in the plasma bombard the web surface, removing or breaking bonds and producing free radicals. Because these free radicals are unstable, they react with the free radicals or radicals in the plasma gas to achieve a more stable state, and new moieties are formed on the web surface. In addition, the high-energy electrons in the glow discharge destroy gas-phase molecules and cause complex chemical reactions, resulting in the deposition of a thin hydrophilic coating on at least one surface of the web.

Typically and preferably, an initial step is performed before plasma depositing the hydrophilic coating on the web. The purpose of this step is to clean the web surface and increase the adhesion of the subsequently deposited thin hydrophilic coating. Cleaning is performed by exposing the web surface to radiation from an energy source, such as, but not limited to, infrared, electron beam, thermionic or ultraviolet, (referred to herein as radiation cleaning), or by plasma cleaning. be able to. A device suitable as an energy source in the present invention is disclosed in U.S. Pat. No. 4,842,893, issued to Yializis on April 29, 1988. In a radiation cleaning embodiment, the radiation source is preferably a gas discharge electron beam gun. An electron gun sends a stream of electrons through the emitter window to the web surface, removing or breaking bonds and producing free radicals. These free radicals are unstable and tend to fulfill a more stable state, so that the free radicals serve as a bonding site for the monomers used to form the hydrophilic coating of the web. Cleaning is controlled by matching the voltage of the electron beam to the dielectric thickness or the desired cleaning depth. For example, at 10 K electron volts, it travels through the web by a depth of about 1 μm.

In the plasma cleaning embodiment, the gas is typically Ar alone or O ₂
Either alone or as a mixture of Ar and O ₂ (eg, in a 1: 1 ratio). Gas flow rates are typically from about 20 to about 100 sccm (cc / min at standard conditions), preferably from about 40 to 80 sccm, and most preferably from about 50 to about 60 sccm. RF power is about 1100 watts and process pressure is about 0.040 Torr
r.

The next step after the optional initial step is plasma deposition of the hydrophilic coating described above. This step is described in more detail in a later example. Often (but not always) additional steps follow the surface treatment step with CO ₂ and N ₂ O to enhance wettability or plasma coating uniformity. Useful process gases are Ar and / or O _2. Process times are usually about 1 to 3 minutes, and typically about 2 minutes are optimal. Gas flow rate is about 40 to about 250 sc
cm, the process pressure is about 0.200 to about 0.400 Trr, and R
F input power is about 150 to about 1500 W.

Materials useful as polymer films for plasma treatment to obtain hydrophilic coatings are obtained from thermoplastic polymers. As used herein, the term “thermoplastic polymer” generally refers to any thermoplastic polymer that can be used to make a film. Examples of thermoplastic polymers (only as examples) include: End-capped polyacetals such as poly (oxymethylene) or polyformaldehyde, poly (trichloroacetaldehyde), poly (n-valeraldehyde), poly (acetaldehyde), poly (propionaldehyde), etc .; acrylic polymers, For example, polyacrylamide, poly (acrylic acid), poly (methacrylic acid), poly (ethyl acrylate), poly (methyl methacrylate), etc .; fluorocarbon polymers such as poly (tetrafluoroethylene), perfluorinated
) Ethylene-propylene copolymer, ethylene-tetrafluoroethylene copolymer, poly (chlorotrifluoroethylene), ethylene-chlorotrifluoroethylene copolymer, poly (vinylidene fluoride), poly (vinyl fluoride)
Polyamides such as poly (6-aminocaproic acid) or poly (ε-caprolactam), poly (hexamethylene adipamide), poly (hexamethylene sebacamide), poly (11-aminoundecanoic acid) and the like; polyaramid, For example, poly (imino-1,3-phenyleneiminoisophthaloyl) or poly (m-phenyleneisophthalamide); polyarylene such as poly-p-xylylene, poly (chloro-p-xylylene); polyaryl ether; For example, poly (oxy-2,6-dimethyl-1,4-phenylene) or poly (p-phenylene oxide); polyarylsulfone such as poly (oxy-1,4-phenylene)
Phenylenesulfonyl-1,4-phenyleneoxy-1,4-phenylene-isopropylidene-1,4-phenylene), poly (sulfonyl-1,4-phenyleneoxy-phenylene-sulfonyl-4,4′-biphenylene) and the like; Polycarbonates such as poly (bisphenol A) or poly (carbonyldioxy-1,4
-Phenylene-isopropylidene-1,4-phenylene) and the like; polyesters,
For example, poly (ethylene terephthalate), poly (tetramethylene terephthalate), poly (cyclohexylene-1,4-dimethylene terephthalate) or poly (oxymethylene-1,4-cyclohexyl-enemethyleneoxyterephthaloyl); polyaryl Sulfides, such as poly (p-phenylene sulfide) or poly (thio-1,4-phenylene); polyimides, such as poly (pyromellitimide-1,4-phenylene); polyolefins, such as polyethylene, polypropylene, poly (1- Butene), poly (2-butene), poly (1-pentene), poly (2-pentene), poly (3-methyl-1-pentene)
, Poly (4-methyl-1-pentene), 1,2-poly-1,3-butadiene, 1,
4-poly-1,3-butadiene, polyisoprene, polychloroprene, polyacrylonitrile, poly (vinyl acetate), poly (vinylidene chloride), polystyrene and the like; copolymers of the above, such as acrylonitrile-butadiene-styrene (ABS) Copolymers and the like.

Preferred polymers are polyolefins and polyesters, with polyolefins being more preferred. Even more preferred are those containing only hydrogen and carbon atoms and having 1
Alternatively, it is a polyolefin produced by addition polymerization of plural kinds of unsaturated monomers. Examples of such polyolefins are, in particular, polyethylene, polypropylene, poly (1-butene), poly (2-butene), poly (1-pentene), poly (2-pentene), poly (3-methyl-1-). Pentene), poly (4-methyl-1)
-Pentene), 1,2-poly-1,3-butadiene, 1,4-poly-1,3-butadiene, polyisoprene and the like. Also, such terms are meant to include blends of two or more polyolefins, random copolymers and block copolymers made from two or more different unsaturated monomers. Due to their commercial importance, the most preferred polyolefins are polyethylene and polypropylene.

In addition to polymer films, webs that can be used to make the durable, wettable liquid permeable webs of the present invention include spunbonded nonwovens, hydroentangled nonwovens, needled nonwovens, and Polymericl (polymericl
y bound) non-woven fabric and the like, but are not limited thereto. Preferred nonwoven webs are typically formed from, but are not limited to, organic textile fibers such as: Cotton, wool, wood, jute, viscose rayon, nylon, polyester, polyolefin, carbon, or mixtures thereof. Inorganic fibers such as glass and metal may be used alone or in combination, or may be combined with organic fibers. For staple fibers,
The fiber length is from about 1/4 inch to about 2 inches or more. For spunbonded webs, the fiber length is not fixed. Staple fibers used in hydroentangled, needled, and polymerized nonwovens are processed by conventional textile machines.

For example, when making a polymer bonded nonwoven web, a carding machine may be used to form a continuous length of two-dimensional loosely bound fibers known as a carded web. These webs may be collected to form a multi-layer or three-dimensional fiber web of significant weight (eg, on the order of several grams to thousands of grams per yard). In a continuous nonwoven fibrous web, the woven fibers are arranged at various angles with respect to the longitudinal axis of the web. When the carding machine is operated to form a web, the majority of the fibers are usually oriented in the machine direction, while an isotropic web can be formed, for example, by air laying. The fibrous webs described above are typically impregnated (polymerically bonded) with a polymeric binder. In a preferred form, the polymeric binder is added as an emulsion of acrylic, polyvinyl acetate, or similar polymer nature, and mixtures thereof. Preferably, the fibers are non-woven, substantially dart-oriented and cohesively bonded with the polymeric binder.

[0045] Hydroentangled and needled webs are distinguished from polymerized bonded webs primarily in that they rely on the physical entanglement of the fibers to obtain the integrity of the web. In contrast to polymer bonded and physically entangled webs, spunbonded webs typically consist of very long fibers bonded together by a solvent or melting process.

As already mentioned, the web may be in the form of a flat film or may be a three-dimensional film provided with openings in advance. The coating is durable and increases the surface energy of the web, making the treated web more wettable. The coating is durable in that it is retained for a long time, even after exposure to water or other aqueous liquids. In this regard, the webs of the present invention are described in one respect in terms of their ability to remain wet for extended periods of time and / or after exposure to liquids. The ability to maintain wettability over an extended period is assessed by measuring the contact angle after aging of the web. This measurement involves storing the treated web at 60 ° C. for 16 hours and aged artificially before measuring the contact angle. The ability to maintain wettability after exposure to liquids is assessed by measuring the contact angle after washing the web. This measurement involves immersing a 2 inch × 2 inch treated web in a 250 mL water bath at 65 ° C. for 90 seconds with forced agitation before measuring the contact angle. Procedures and equipment for measuring the contact angle between a liquid and a web surface are well known in the art. However, the web wettability of the present invention is evaluated using the contact angle with water (measured using a goniometer (Model # 100-00, Rame-Hart, Mountain Lakes, NJ)). All contact angle measurements are reported as average measurements for three samples.

In some embodiments, the treated web of the present invention has a post-aged contact angle prior to aging of the treated web (ie, a contact angle measured before storage at 60 ° C. for 16 hours). About 60 ° or less. Preferably, the treated web has a contact angle after aging of about 40 ° greater than the contact angle before aging.
Not more than, more preferably not more than about 20 °, and even more preferably not more than about 10 °. In another embodiment, the treated web of the present invention has a post-washing contact angle prior to washing of the treated web (i.e., immersing the treated web in a 250 mL water bath at 65 ° C. for 90 seconds to force the treated web. (Contact angle measured before agitating the sample) by about 60 ° or less. In this regard, the treated web preferably has a contact angle after washing of less than about 40 °, more preferably less than about 20 °, and even more preferably about 1 ° less than the contact angle before washing.
Greater than 0 °. In a preferred embodiment, the treated web of the present invention comprises
Both the requirements after aging and after washing described above are shown.

The treated web of the present invention has a contact angle after aging or a contact angle after washing (preferably both) of less than about 90 °, preferably about 70 ° or less, more preferably about 70 ° or less. 50 ° or less, even more preferably about 30 ° or less, most preferably about 20 ° or less.

II. Absorbent Article As used herein, the term "absorbent article" generally refers to a device used to absorb and contain bodily exudates, and more specifically, to or near the body of a wearer. Refers to a device that is deployed to absorb and contain various exudates released from the body. The term "absorbent article" is intended to include diapers, menstrual pads, tampons, sanitary napkins, incontinence pads, training pants, etc., as well as wipes, bandages, wound care articles. The term "disposable" as used herein refers to absorbent articles that are not intended to be laundered or otherwise repaired or reused as absorbent articles (i.e., they are discarded after some use, preferably recycled). And is otherwise composted in a way that is compatible with the environment). A "single" absorbent article may be formed as a single structure or as separate parts that are united to form a coordinated entity, such as separate holders and pads. Operation parts (manipulative par
ts).

The overall size, shape, and / or configuration of an absorbent article incorporating or using the treated web of the present invention, whatever it is, is of no importance to the principles of the present invention. It should be understood that it has no functional relevance. However, such parameters must be considered along with the intended liquid and intended functionality when determining the proper shape of the web.

The absorbent article also comprises, besides the treated web of the present invention, an absorbent core for holding any absorbed body fluid. Typical absorbent structures used as the absorbent core in the present invention are described in the following documents. US Patent 4,950,
No. 264 (issued to Osborn on August 21, 1990); U.S. Pat. No. 4,610,678 (to Weisman et al.)
U.S. Pat. No. 4,834,735 (granted to Alemany et al. On May 30, 1989), European Patent Application No. 0198683 (Procter & Gamble, Duenk on Oct. 22, 1986)
U.S. Patent No. 4,673,402 (issued to Weisman et al. On June 16, 1987) and U.S. Patent No. 4,888,231 (issued to Angstadt on December 19, 1989). The absorbent core may further comprise a dual core system including an acquisition core / distribution core of chemically stiffened fibers disposed over the absorbent storage core. This is described in U.S. Pat.No. 5,234,423, `` Absorbent Article With Elastic Waist Feature and Enhanc
ed Absorbency "(granted to Alemany et al. on August 10, 1993), and U.S. Pat. No. 5,147.
No. 345, `` High Efficiency Absorbent Articles For Incontinence Management ''
(Granted to Young, LaVon and Taylor on September 15, 1992). The disclosures of all these patents are incorporated herein by reference.

A preferred embodiment of a single disposable absorbent article according to the present invention is a menstrual pad,
It is a sanitary napkin. As used herein, the term "sanitary napkin" is used by women to wear near the vulvar area (usually outside the genitourinary tract) and provide fluids from menstruation and other vaginal discharges from the wearer's body (e.g., Refers to absorbent articles for absorbing and containing blood, menses, and urine). Interlabial devices that are partially located inside and outside the wearer's vaginal vestibule, respectively, are also within the scope of the invention. Suitable feminine hygiene products are disclosed in the following documents: U.S. Patent No. 4,556,146 (Swanson et al.
US Pat. No. 4,589,876 (granted to Van Tilberg et al. On Apr. 27, 1993); US Pat. No. 4,687,478 (Granted to Van Tilburg on Aug. 18, 1987); US Pat. No. 4,950,264 U.S. Pat. No. 5,009,653 (granted to Osborn, III on Apr. 23, 1991), U.S. Pat. No. 5,267,992 (granted to Van Tilburg).
U.S. Patent No. 5,389,094 (granted to Lavash et al. On February 14, 1995); U.S. Patent No. 5,413,568 (granted to Roach et al. On May 9, 1995); U.S. Pat. number 5,
No. 460,623 (issued to Emenaker et al. On Oct. 24, 1995); U.S. Pat. No. 5,489,283 (Va
n Tilburg on February 6, 1996), US Patent No. 5,569,231 (Emenaker et al., 1996)
No. 5,620,430 (granted to Bamber on April 15, 1997)
. The disclosure of each document is incorporated herein by reference.

In a preferred embodiment of the present invention, the sanitary napkin has two flaps, each adjacent to and laterally extending from a side end of the absorbent core. The flap is located between the end of the wearer's panty and the thigh because the flap covers the end of the wearer's panty in the crotch region. The flaps serve at least two purposes. First, the flaps serve to prevent the wearer's body and panties from being soiled by menstrual fluid, preferably by forming a double wall barrier along the edges of the panties. Second, attachment means are preferably provided on the garment-facing surface of the flap so that the flap can be folded under the panty and attached to the garment-facing side of the panty.
Thus, the flap serves to hold the sanitary napkin in place on the panty. The flaps can be made from a variety of materials, such as materials similar to topsheets, backsheets, tissues or combinations of these materials. The flap may also be a separate member that attaches to the body of the napkin, or may constitute an extension of the topsheet and backsheet (ie, be unitary). Many sanitary napkins with flaps suitable or compatible with the sanitary napkins of the present invention are described in U.S. Pat. No. 4,687,478, "Shaped Sanitary Napkin With Fap".
laps "(granted to Van Tilburg on August 18, 1987); U.S. Pat. No. 4,589,876," Sani
tary Napkin "(granted May 20, 1986 to Van Tilburg). The disclosure of each patent is incorporated herein by reference.

In a preferred embodiment of the present invention, an acquisition layer may be arranged between the topsheet and the absorbent core. The trapping layer provides for exudate discharge onto or into the absorbent core (
It can perform several functions, such as improving wicking. There are several reasons why it is important to improve exudate emissions. For example,
The exudate is more evenly distributed throughout the absorbent core, allowing the sanitary napkin to be made relatively thin. Discharge as described herein may include transporting liquid in one, two, or all directions (i.e., in the xy plane and / or z-direction). The acquisition layer may be comprised of a variety of different materials, including nonwoven or woven webs of the following materials. Synthetic fibers such as polyester, polypropylene, polyethylene; natural fibers such as cotton, cellulose; blends of such fibers; any equivalent material or any combination of materials. Examples of sanitary napkins having an acquisition layer and a topsheet are described in U.S. Pat. No. 4,950,264 (granted to Osborn) and U.S. Pat. No. 07 / 810,774 "Absorbent
Article Having Fused Layers ”(filed on December 17, 1991 under the name of Cree et al.)
It is more fully described. The disclosure of each reference is incorporated herein by reference. In a preferred embodiment, the acquisition layer and the topsheet are joined together, most preferably by fusing (as more fully described in the referenced Cree application), using any of the conventional means for joining webs together. May be joined.

The menstrual pad may be manufactured as follows. Spiral pattern H2031 Findlay hot melt adhesive on silicone coated release paper 0.04g /
Apply in ² . This adhesive layer is transferred to the upper surface (surface facing the wearer) of the auxiliary top sheet by winding the auxiliary top sheet and the coated release paper together with a hand roller. Deputy top seat is Fort James Airlaid Tissue, Grade 817
It is made of a nonwoven material known as (commercially available from Fort James, Inc., Green Bay, WI). After attaching the topsheet of the present invention to the adhesive surface of the subtopsheet, the two are gently pressed with a hand roller and joined. Two strips of 1/4 inch double-sided tape are applied along the long ends of the polyethylene backsheet. The addition of the absorbent core creates a complete absorbent structure.

As used herein, the term “diaper” refers to clothing usually worn by infants and incontinent people and worn around the lower part of the wearer's torso. However, it should be understood that the present invention is applicable to other absorbent articles such as incontinence briefs, incontinence pads, training pants, diaper inserts, tissue paper, paper towels, and the like. The diaper of the present invention generally includes the liquid-permeable topsheet of the present invention, a liquid-impermeable backsheet bonded to the topsheet, and an absorbent core disposed between the topsheet and the backsheet. Prepare. It may also include additional structural members, such as elastic members for securing the diaper in place on the wearer, and fastening means (eg, tape tab fasteners).

Although the topsheet, backsheet, and absorbent core can be combined in various well-known configurations, the preferred configuration of the diaper is disclosed in US Pat. No. 3,860,003 (B
uell was granted on January 14, 1975). The disclosure of this document is incorporated herein by reference. Alternatively, preferred configurations of the disposable diaper herein are also disclosed in the following documents. U.S. Patent 4,
No. 808,178 (Aziz et al. Issued Feb. 28, 1989); U.S. Pat. No. 4,695,278 (Lawson
No. 4.816,025 (granted to Foreman on Mar. 28, 1989). The disclosure of each patent is incorporated herein by reference. Incontinence products suitable for adult wearers are described in the following documents. U.S. Patent 4,
Nos. 253,461 (granted to Strickland et al. On Mar. 3, 1981); U.S. Pat. Nos. 4,597,760 and 4,597,761 (granted to Buell); U.S. Pat. No. 4,704,115; U.S. Pat.
No. 02 (granted to Ahr et al.), U.S. Patent No. 4.964,860 (granted Gipson et al. On Oct. 23, 1990), U.S. Patent Application No. 07 / 637,090 (filed by Noel et al. On Jan. 3, 1991) ) (International Publication WO92 / 11830 (published July 23, 1992)). The disclosure of each reference is incorporated herein by reference.

[0058] The absorbent core of the diaper is disposed between the topsheet and the backsheet. The absorbent core can be made in various sizes and shapes (eg, rectangular, hourglass, asymmetric, etc.). However, the total absorbent capacity of the absorbent core must be compatible with the design liquid loading for the intended use of the absorbent article or diaper. Also, the size and absorbent capacity of the absorbent core can be varied to suit wearers from infants to adults.

As already mentioned, the absorbent core may comprise a liquid distribution member. In a preferred configuration, the absorbent core preferably further comprises a capture layer or member that communicates the liquid with the liquid distribution member and is disposed between the liquid distribution member and the topsheet. The acquisition layer or member may be composed of a variety of different materials, including nonwoven or woven webs of the following materials. Synthetic fibers such as polyester, polypropylene, polyethylene; natural fibers such as cotton, cellulose; blends of such fibers; any equivalent material or any combination of materials.

[0060] In a preferred embodiment, the diaper comprises an elastic leg cuff. Stretch leg cuffs can be made in many different configurations, including those described in the following references. U.S. Patent No. 3,860,003; U.S. Patent No. 4,909,803 (Aziz et al. Issued March 20, 1990); U.S. Patent No. 4,695,278 (Lawson, September 1987).
No. 4,795,454 (granted to Dragoo on January 3, 1989). Each document is incorporated herein by reference. In use, to attach the diaper to the wearer, position the back wasteband portion below the wearer's back and then wear the rest of the diaper. Pull between the legs of the wearer to position the front wasteband portion at the front of the wearer. next,
A tape tab or other fastener is secured to the area, preferably facing the outside of the diaper.

[0061]

【Example】

The following examples are illustrative and are not meant to limit the invention disclosed and claimed herein in any way. For Example 2, the mass flow controller used to send the silicon-containing monomer for the deposition process was:
Calibrated for HMDSO flow rate. The flow rates of other gases were calculated based on the specific heat of each gas. The accuracy of the mass flow controller in these cases is ±
5% or better.

Example 1 This example illustrates the plasma treatment process and the advantages of the present invention of applying a durable hydrophilic coating to a flat polyethylene film. A flat polyethylene (PE) film having an average thickness of 1 mil was obtained from Tredegar Film Products (Terre Haute, Ind.) With material composition designation code X-8318-1.
Get it at The three plasma processes are performed by a plasma reactor (Advanced Plasma Sy
Stem, Model D, radio frequency (RF): 40 KHz) under the gas input and process conditions shown in Table 1 below.

[0063]

[Table 1]

The resulting plasma treated web sample is then tested for surface wettability before and after rapid aging conditions. By rapid aging, it is meant that the web sample is conditioned at 60 ° C. for 16 hours before measuring wettability. Contact angle with water (goniometer (model # 100-
00, measured at Rame-Hart, Mountain Lakes, NJ)
Evaluate web wettability. The high wet durability of the plasma coating obtained with HMDSO was confirmed, as indicated by the equivalent contact angles seen between the pre-aged and post-aged samples (see Table 2).

[Table 2]

Example 2 This example illustrates another plasma treatment process and the advantages of the present invention of applying a durable hydrophilic coating to a flat PE film. A flat polyethylene (PE) film having an average thickness of 1 mil was obtained from Tredegar Film Products (Te
rre Haute, Indiana) with material composition designation code X-8318-1.
The three steps of plasma treatment are performed in a plasma reactor (Plasma Science PS0500D).
It is performed under the gas input and process conditions shown in Table 3 below.

[Table 3]

The resulting plasma treated web sample is then evaluated for surface wettability before and after the water washing test. The water-washing test means that a 2-inch × 2-inch web sample is immersed in a 250-mL water bath at 65 ° C. for 90 seconds, and is forcibly stirred (using a Teflon-coated stir bar). Contact angle with water (goniometer (model # 100-00, Rame-Hart, Mount
ain Lakes, NJ) is used to assess web wettability. The high wet durability of the plasma coating obtained with HMDSO was confirmed, as indicated by the equivalent contact angles seen between the pre-washing and post-washing samples (see Table 4).

[Table 4]

While certain embodiments of the invention have been described in considerable detail, variations and modifications of these embodiments may be made without departing from the spirit and scope of the invention as described and claimed. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B05D 3/04 D06M 10/02 C 4L033 7/00 15/643 B32B 5/00 A61F 13/18 310Z 7 / 02 360 D06M 10/02 A41B 13/02 E 15/643 (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE) , LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, A , AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX , NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZA, ZW (71) Applicant ONE PROCTER & GANBLE PLAZA, CINCINNATI, OHIO, UNITED STATES OF AMERICA (72) Inventor Paul Amart, France 45069 West Chester, Ohio, United States of America Rd Miselski, Arseny 45208 Cincinnati, Ohio, United States, Portsmouth Avenue 2940, Apartment 3F Term (reference) 3B029 BB06 4C003 BA01 BA02 BA08 GA03 HA05 HA06 4D075 BB37X BB46X BB47X BB49Z BB70Z CA47 DA04 DB20 DB31 DC30 DC38 4F100 AK01A AK03A AK04A AK07A AK08A AK09A AK29A AK41A AL03A AL05A AT00A BA02 CC00B DG15A EA021 EJ252 EJ52 EJ522 EJ53 EJ54 EJ55 EJ58 EJ61 EJ612 EJ853 GB66 GB72 JB05 JB05B JD15 4L031 AB34 CB05 CB07 CB09 DA08 4L033 AB07 AC07 CA59

Claims (13)

[Claims] 1. A direct plasma polymerization method for making a durable, wettable liquid permeable web for use as a topsheet of an absorbent article, comprising: (i) introducing the web into a plasma reaction zone. (Ii) applying a polymerized monomer coating to at least one surface of the web, wherein the coating is less than 2.5 μm thick and is obtained from a stream of monomer gas that upon plasma polymerization provides a hydrophilic coating. Wherein the web is selected from the group consisting of a polymer film, a polymer film having openings, a nonwoven fabric, and a nonwoven fabric having openings, wherein the polymerized monomer durably wets at least one surface of the web. The method characterized by making it sex. 2. The at least one surface of the durably wettable liquid permeable web has a contact angle after aging that is not more than 60 ° greater than the contact angle before aging, and preferably less than the contact angle before aging. 2. A method according to claim 1, wherein the contact angle is also not more than 40 [deg.], Most preferably not more than 20 [deg.] Than the contact angle before aging. 3. The at least one surface of the liquid-permeable web, which is durably wettable, has a contact angle after washing of not more than 60 ° greater than a contact angle before washing, preferably a contact angle before washing. 3. The method according to claim 1, wherein the contact angle is also not more than 40 [deg.], Most preferably not more than 20 [deg.] Than the contact angle before washing. 4. Prior to introducing the monomer gas stream of step (ii), the web surface is selected to be in a plasma state or from the group consisting of infrared, electron beam, thermionic, or ultraviolet and mixtures thereof. 4. The method of claim 1 further comprising the step of cleaning the web surface by exposing it to an energy source.
A method according to any one of the preceding claims. 5. The step of cleaning the web surface by exposing the web to a plasma state includes introducing a gas flow comprising a material selected from the group consisting of Ar, O ₂ and mixtures thereof. The method of claim 4, wherein 6. The web produced in step (ii) is converted to a stream of surface modifying gas comprising N ₂ O and CO ₂ or from infrared, electron beam, thermionic or ultraviolet light and mixtures thereof. 6. The method according to claim 1, further comprising a step of further modifying the hydrophilic surface by introducing the energy into an energy source selected from the group consisting of:
The method described in the section. 7. The method according to claim 1, further comprising a final step comprising providing openings in the coated web. 8. The method according to claim 1, wherein the polymer film is obtained from a material selected from the group consisting of polyolefins, polyesters, and mixtures thereof. 9. The polymer film comprises polyethylene, polypropylene, poly (1-butene), poly (2-butene), poly (1-pentene), poly (2-pentene), poly (3-methyl-1-). Pentene), poly (4-methyl-1-pentene), 1,2-poly-1,3-butadiene, 1,4-poly-1,3-butadiene, polyisoprene, blends thereof, random copolymers thereof, 9. The method of claim 8, wherein the method is obtained from a material selected from the group consisting of: 10. The flow of the monomer gas is (i) a silane of the formula SiR ₄ .
Here, each R may be the same or different, and is selected from the following. H
C ₁ -C ₈ linear or branched alkyl or alkoxy; C ₆ unsubstituted or substituted by C ₁ -C ₄ linear or branched alkyl;
-C ₁₀ aryl; vinyl radicals; C ₃ -C ₅ allyl radical; provided, 2 following R groups are H; (ii) formula R'R "R '" Si - [ - O-Si (R') (R ")
-] _n -R '". Organosilicone herein R', R", R '" it may be different even in the same, linear or branched alkyl or alkoxy of C ₁ -C ₈ R ′, R ″ may be hydrogen, provided that up to 50% of the R ′ and R ″ groups are hydrogen. N is 1, 2, or 3; (iii) mixtures thereof; 10. The method according to claim 1, wherein the monomer gas stream further contains oxygen when the monomer gas stream comprises a monomer selected from the group consisting of the silane only. The method of claim 1. 11. The flow of the monomer gas may be hexamethyldisiloxane, methyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and oxygen, ethylmethoxysilane, ethyltrimethoxysilane, tetraethoxysilane, cyclohexylmethyl-dimethoxy. A monomer selected from the group consisting of silane, dicyclopentyl-dimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, tetramethyldisiloxane, hexamethyltrisiloxane, and mixtures thereof, wherein said monomer in said monomer gas stream 11. The method of claim 10, wherein when comprises only the silane, the monomer gas stream further comprises oxygen. 12. The method according to claim 1, wherein the gas in the monomer gas stream is ionized by high frequency microwaves or radio wave vibrations. 13. An absorbent article comprising a durable, wettable liquid permeable topsheet made by the method of any of the preceding claims.