Nonwovens fabrics produced from multicomponent fibers comprising sulfopolyesters

Abstract

A process for making a nonwoven fabric is provided comprising: (A) collecting multicomponent fibers to form a non-woven web; wherein the multicomponent fiber comprises at least one water dispersible sulfopolyester and at least one water non-dispersible polymer; wherein said multicomponent fiber has a plurality of domains comprising the water non-dispersible polymer; wherein the domains are substantially isolated from each other by the water dispersible sulfopolyester intervening between the domains; (B) contacting the non-woven web with water at a sufficient temperature and pressure to remove a portion of the water dispersible sulfopolyester thereby forming a microfiber web; and (C) hydroentangling the microfiber web to produce the nonwoven fabric. A process is also provided wherein steps (B) and (C) are combined. Fibrous articles utilizing the nonwoven fabrics are also provided.

1 . A process for making a nonwoven fabric comprising:
 (A) collecting multicomponent fibers to form a non-woven web; wherein said multicomponent fiber comprises at least one water dispersible sulfopolyester and at least one water non-dispersible polymer; wherein said multicomponent fiber has a plurality of domains comprising said water non-dispersible polymer; wherein said domains are substantially isolated from each other by said water dispersible sulfopolyester intervening between said domains;   (B) contacting said non-woven web with water at a sufficient temperature and pressure to remove a portion of said water dispersible sulfopolyester thereby forming a microfiber web; and   (C) hydroentangling said microfiber web to produce said nonwoven fabric.   
   
   
       2 . A process according to  claim 1  wherein said sulfopolyester comprises dicarboxylic acid monomer residues, sulfomonomer residues, diol monomer residues, and repeating units. 
   
   
       3 . A process according to  claim 2  wherein said dicarboxylic acids are selected from aliphatic diacids, cycloaliphatic dicarboxylic acids, aromatic dicarboxylic acids, and combinations thereof. 
   
   
       4 . A process according to  claim 3  wherein said dicarboxylic acids are selected from succinic, glutaric, adipic, azelaic, sebacic, fumaric, maleic, itaconic, 1,3-cyclohexane dicarboxylic, 1,4-cyclohexanedicarboxylic, diglycolic, 2,5-norbornanedicarboxylic, phthalic, terephthalic, 1,4-naphthalenedicarboxylic, 2,5-naphthalenedicarboxylic, 2,6-naphthalenedicarboxylic, 2,7-naphthalenedicarboxylic, diphenic, 4,4′-oxydibenzoic, 4,4′-sulfonyldibenzoic, isophthalic, and combinations thereof. 
   
   
       5 . A process according to  claim 2  wherein said sulfomonomer is a metal sulfonate salt of a sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid, or combinations thereof. 
   
   
       6 . A process according to  claim 2  wherein said diol residues are selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, poly(ethylene) glycols, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexane-dimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, p-xylylenediol, and combinations thereof. 
   
   
       7 . A process according to  claim 2  wherein said sulfopolyester further comprises at least one branching monomer. 
   
   
       8 . A process according to  claim 7  wherein said branching monomer is at least one selected from the group consisting of 1,1,1-trimethylol propane, 1,1,1-trimethylolethane, glycerin, pentaerythritol, erythritol, threitol, dipentaerythritol, sorbitol, trimellitic anhydride, pyromellitic dianhydride, dimethylol propionic acid, or combinations thereof. 
   
   
       9 . A process according to  claim 1  wherein said water-nondispersible polymers are selected from polyolefins, polyesters, polyamides, polylactides, polycaprolactone, polycarbonate, polyurethane, polyvinyl chloride, and combinations thereof. 
   
   
       10 . A process according to  claim 1  wherein the shaped cross section of said multicomponent fiber is an islands-in-the-sea, segmented pie, or sheath-core configuration. 
   
   
       11 . A process according to  claim 1  wherein said sulfopolyester has a glass transition temperature (Tg) of at least 57° C. and said water dispersible sulfopolyester comprises:
 (i) residues of one or more dicarboxylic acids;   (ii) about 4 to about 40 mole %, based on the total repeating units, of residues of at least one sulfomonomer having 2 functional groups and one or more sulfonate groups attached to an aromatic or cycloaliphatic ring wherein said functional groups are hydroxyl, carboxyl, or a combination thereof;   (iii) one or more diol residues wherein at least 25 mole %, based on the total diol residues, is a poly(ethylene glycol) having a structure
   H—(OCH 2 —CH 2 ) n —OH 
 wherein n is an integer in the range of 2 to about 500; and 
   (iv) 0 to about 25 mole %, based on the total repeating units, of residues of a branching monomer having 3 or more functional groups wherein said functional groups are hydroxyl, carboxyl, or a combination thereof;   wherein said fiber has a plurality of segments comprising said water-nondispersable polymers and said segments are substantially isolated from each other by said sulfopolyester intervening between said segments.   
   
   
       12 . A process according to  claim 1  wherein said sulfopolyester has a melt viscosity of less than 12,000 poise measured at 240° C. and 1 rad/sec shear rate. 
   
   
       13 . A process according to  claim 12  wherein said sulfopolyester has a melt viscosity less than 6,000 poise measured at 240° C. and 1 rad/sec shear rate. 
   
   
       14 . A process according to  claim 13  wherein said sulfopolyester has a melt viscosity less than 4,000 poise measured at 240° C. and 1 rad/sec shear rate. 
   
   
       15 . A process according to  claim 1  wherein said collecting is accomplished by at least one method selected from the group consisting of mechanical needling, chemical binding, thermally calendaring, ultrasonic fusing, and hydroentangling. 
   
   
       16 . A process according to  claim 15  wherein said collecting is accomplished by hydroentangling and the hydroentangling energy in said hydrotangling step involves about 20% to about 50% of the amount of hydroentangling energy expended in Step (C). 
   
   
       17 . A process according to  claim 1  wherein said multicomponent fibers are produced by a spunbond process or meltblown process. 
   
   
       18 . A process according to  claim 1  wherein the weight of said nonwoven web ranges from about 10 grams/m 2  to about 800 grams/m 2 . 
   
   
       19 . A process according to  claim 18  wherein the weight of said nonwoven web ranges from about 10 grams/m 2  to about 400 grams/m 2 . 
   
   
       20 . A process according to  claim 19  wherein the weight of said nonwoven web ranges from about 50 grams/m 2  to about 150 grams/m 2 . 
   
   
       21 . A process according to  claim 1  wherein the extraction temperature of said water dispersible sulfopolyester ranges from about 20° C. to about 100° C. 
   
   
       22 . A process according to  claim 1  wherein the pressure of the water during Step (B) ranges from about 30 bar to about 600 bar. 
   
   
       23 . A process according to  claim 22  wherein the pressure of the water during Step (B) ranges from about 50 barr to about 300 barr. 
   
   
       24 . A process according to  claim 1  wherein said nonwoven web is contacted with the water in Step (B) for a time sufficient to remove about 30% by weight to about 100% by weight of the total water dispersible sulfopolyester contained in said nonwoven web. 
   
   
       25 . A process according to  claim 24  wherein said nonwoven web is contacted with the water in Step (B) for a time sufficient to remove greater than 90% by weight of the total water dispersible sulfopolyester from said nonwoven web. 
   
   
       26 . A process according to  claim 25  wherein said nonwoven web is contacted with the water in Step (B) for a time sufficient to remove greater than 95% by weight of the total water dispersible sulfopolyester from said nonwoven web. 
   
   
       27 . A process according to  claim 1  wherein said nonwoven web is contacted with water for a time period of from about 10 to about 600 seconds whereby said water dispersible sulfopolyester is dissipated or dissolved. 
   
   
       28 . A process according to  claim 1  wherein the microfibers in the microfiber web have an average fineness of less than 30% of the denier of said multicomponent fiber. 
   
   
       29 . A process according to  claim 28  wherein said microfibers in said microfiber web have an average fineness of 1 dpf or less. 
   
   
       30 . A process according to  claim 29  wherein said microfibers in said microfiber web have an average fineness of 0.5 dpf or less. 
   
   
       31 . A process according to  claim 1  wherein said nonwoven web is contacted with water in Step (B) using water jets. 
   
   
       32 . A process according to  claim 31  wherein one to eight water jet heads are utilized. 
   
   
       33 . A process according to  claim 31  wherein the amount of water used in Step (B) ranges from about 500 times to about 1000 times the weight of said nonwoven web. 
   
   
       34 . A process according to  claim 1  wherein the wash water from Step (B) and Step (C) can be reclaimed. 
   
   
       35 . A process according to  claim 34  wherein 80% or more of the wash water is reclaimed. 
   
   
       36 . A process according to  claim 1  wherein the temperature of the water in Step (C) is less than 40° C. 
   
   
       37 . A process according to  claim 1  wherein the pressure of the water in Step (C) ranges from about 150 bar to about 250 bar. 
   
   
       38 . A process according to  claim 1  wherein less than 1% by weight of the water dispersible sulfopolyester in Step (C) is removed from said microfiber web. 
   
   
       39 . A process according to  claim 38  wherein in Step (C) less than 0.5% by weight of the water dispersible sulfopolyester is removed from the microfiber web. 
   
   
       40 . A process according to  claim 38  wherein in Step (C) less than 0.1% by weight of the water dispersible sulfopolyester is removed from the microfiber web. 
   
   
       41 . A process according to  claim 1  wherein said hydroentangling in Step (C) is conducted by water jet heads. 
   
   
       42 . A process according to  claim 41  wherein number of water jet heads range from 1 to about 20. 
   
   
       43 . A process for making a nonwoven fabric comprising:
 (A) collecting multicomponent fibers to form a non-woven web; wherein said multicomponent fiber comprises at least one water dispersible sulfopolyester and at least one water non-dispersible polymer; wherein said multicomponent fiber has a plurality of domains comprising said water non-dispersible polymer; wherein said domains are substantially isolated from each other by said water dispersible sulfopolyester intervening between said domains; and   (B) contacting said non-woven web with water at a sufficient temperature and pressure to remove a portion of said sulfopolyester thereby forming a microfibers and simultaneously hydroentangling said microfibers to produce said nonwoven fabric.   
   
   
       44 . A process according to  claim 43  wherein said sulfopolyester comprises dicarboxylic acid monomer residues, sulfomonomer residues, diol monomer residues, and repeating units. 
   
   
       45 . A process according to  claim 44  wherein said dicarboxylic acids are selected from aliphatic diacids, cycloaliphatic dicarboxylic acids, aromatic dicarboxylic acids, and combinations thereof. 
   
   
       46 . A process according to  claim 45  wherein said dicarboxylic acids are selected from succinic, glutaric, adipic, azelaic, sebacic, fumaric, maleic, itaconic, 1,3-cyclohexane dicarboxylic, 1,4-cyclohexanedicarboxylic, diglycolic, 2,5-norbornanedicarboxylic, phthalic, terephthalic, 1,4-naphthalenedicarboxylic, 2,5-naphthalenedicarboxylic, 2,6-naphthalenedicarboxylic, 2,7-naphthalenedicarboxylic, diphenic, 4,4′-oxydibenzoic, 4,4′-sulfonyldibenzoic, isophthalic, and combinations thereof. 
   
   
       47 . A process according to  claim 44  wherein said sulfomonomer is a metal sulfonate salt of a sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid, or combinations thereof. 
   
   
       48 . A process according to  claim 44  wherein said diol residues are selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, poly(ethylene) glycols, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexane-dimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, p-xylylenediol, and combinations thereof. 
   
   
       49 . A process according to  claim 44  wherein said sulfopolyester further comprises at least one branching monomer. 
   
   
       50 . A process according to  claim 49  wherein said branching monomer is at least one selected from the group consisting of 1,1,1-trimethylol propane, 1,1,1-trimethylolethane, glycerin, pentaerythritol, erythritol, threitol, dipentaerythritol, sorbitol, trimellitic anhydride, pyromellitic dianhydride, dimethylol propionic acid, or combinations thereof. 
   
   
       51 . A process according to  claim 43  wherein said water-nondispersible polymers are selected from polyolefins, polyesters, polyamides, polylactides, polycaprolactone, polycarbonate, polyurethane, polyvinyl chloride, and combinations thereof. 
   
   
       52 . A process according to  claim 43  wherein the shaped cross section of said multicomponent fiber is an islands-in-the-sea, segmented pie, or sheath-core configuration. 
   
   
       53 . A process according to  claim 43  wherein said sulfopolyester has a glass transition temperature (Tg) of at least 57° C. and said water dispersible sulfopolyester comprises:
 (i) residues of one or more dicarboxylic acids;   (ii) about 4 to about 40 mole %, based on the total repeating units, of residues of at least one sulfomonomer having 2 functional groups and one or more sulfonate groups attached to an aromatic or cycloaliphatic ring wherein said functional groups are hydroxyl, carboxyl, or a combination thereof;   (iii) one or more diol residues wherein at least 25 mole %, based on the total diol residues, is a poly(ethylene glycol) having a structure
   H—(OCH 2 —CH 2 ) n —OH 
 wherein n is an integer in the range of 2 to about 500; and 
   (iv) 0 to about 25 mole %, based on the total repeating units, of residues of a branching monomer having 3 or more functional groups wherein said functional groups are hydroxyl, carboxyl, or a combination thereof;   wherein said fiber has a plurality of segments comprising said water-nondispersable polymers and said segments are substantially isolated from each other by said sulfopolyester intervening between said segments.   
   
   
       54 . A process according to  claim 43  wherein said sulfopolyester has a melt viscosity of less than 12,000 poise measured at 240° C. and 1 rad/sec shear rate. 
   
   
       55 . A process according to  claim 54  wherein said sulfopolyester has a melt viscosity less than 6,000 poise measured at 240° C. and 1 rad/sec shear rate. 
   
   
       56 . A process according to  claim 56  wherein said sulfopolyester has a melt viscosity less than 4,000 poise measured at 240° C. and 1 rad/sec shear rate. 
   
   
       57 . A process according to  claim 43  wherein said collecting is accomplished by at least one method selected from the group consisting of mechanical needling, chemical binding, thermally calendaring, ultrasonic fusing, and hydroentangling. 
   
   
       58 . A process according to  claim 57  wherein said collecting is accomplished by hydroentangling and the hydroentangling energy in said hydrotangling step involves about 20% to about 50% of the amount of hydroentangling energy expended in Step (C). 
   
   
       59 . A process according to  claim 43  wherein said multicomponent fibers are produced by a spunbond process or meltblown process. 
   
   
       60 . A process according to  claim 43  wherein the weight of said nonwoven web ranges from about 10 grams/m 2  to about 800 grams/m 2 . 
   
   
       61 . A process according to  claim 60  wherein the weight of said nonwoven web ranges from about 10 grams/m 2  to about 400 grams/m 2 . 
   
   
       62 . A process according to  claim 61  wherein the weight of said nonwoven web ranges from about 50 grams/m 2  to about 150 grams/m 2 . 
   
   
       63 . A process according to  claim 43  wherein the extraction temperature of said water dispersible sulfopolyester ranges from about 20° C. to about 100° C. 
   
   
       64 . A process according to  claim 43  wherein the pressure of the water during Step (B) ranges from about 30 bar to about 600 bar. 
   
   
       65 . A process according to  claim 64  wherein the pressure of the water during Step (B) ranges from about 50 barr to about 300 barr. 
   
   
       66 . A process according to  claim 43  wherein said nonwoven web is contacted with the water in Step (B) for a time sufficient to remove about 30% by weight to about 100% by weight of the total water dispersible sulfopolyester contained in said nonwoven web. 
   
   
       67 . A process according to  claim 66  wherein said nonwoven web is contacted with the water in Step (B) for a time sufficient to remove greater than 90% by weight of the total water dispersible sulfopolyester from said nonwoven web. 
   
   
       68 . A process according to  claim 67  wherein said nonwoven web is contacted with the water in Step (B) for a time sufficient to remove greater than 95% by weight of the total water dispersible sulfopolyester from said nonwoven web. 
   
   
       69 . A process according to  claim 43  wherein said nonwoven web is contacted with water for a time period of from about 10 to about 600 seconds whereby said water dispersible sulfopolyester is dissipated or dissolved. 
   
   
       70 . A process according to  claim 43  wherein the microfibers in the microfiber web have an average fineness of less than 30% of the denier of said multicomponent fiber. 
   
   
       71 . A process according to  claim 70  wherein said microfibers in said microfiber web have an average fineness of 1 dpf or less. 
   
   
       72 . A process according to  claim 71  wherein said microfibers in said microfiber web have an average fineness of 0.5 dpf or less. 
   
   
       73 . A process according to  claim 43  wherein said nonwoven web is contacted with water in Step (B) using water jets. 
   
   
       74 . A process according to  claim 73  wherein one to eight water jet heads are utilized. 
   
   
       75 . A process according to  claim 73  wherein the amount of water used in Step (B) ranges from about 500 times to about 1000 times the weight of said nonwoven web. 
   
   
       76 . A process according to  claim 43  wherein the wash water from Step (B) and Step (C) can be reclaimed. 
   
   
       77 . A process according to  claim 76  wherein 80% or more of the wash water is reclaimed. 
   
   
       78 . A process according to  claim 43  wherein the temperature of the water in Step (C) is less than 40° C. 
   
   
       79 . A process according to  claim 43  wherein the pressure of the water in Step (C) ranges from about 150 bar to about 250 bar. 
   
   
       80 . A process according to  claim 43  wherein less than 1% by weight of the water dispersible sulfopolyester in Step (C) is removed from said microfiber web. 
   
   
       81 . A process according to  claim 80  wherein in Step (C) less than 0.5% by weight of the water dispersible sulfopolyester is removed from the microfiber web. 
   
   
       82 . A process according to  claim 81  wherein in Step (C) less than 0.1% by weight of the water dispersible sulfopolyester is removed from the microfiber web. 
   
   
       83 . A process according to  claim 43  wherein said hydroentangling in Step (C) is conducted by water jet heads. 
   
   
       84 . A process according to  claim 83  wherein number of water jet heads range from 1 to about 20. 
   
   
       85 . A process according to  claim 1  or  43  wherein said nonwoven fabric is heat set. 
   
   
       86 . A nonwoven fabric produced by the process of  claim 1  or  claim 43  wherein said nonwoven fabric is utilized in at least one of the following end uses: clothing, curtains, upholstery, uniforms, personal care products, hospital/surgical and other medical disposables, multilayer nonwovens, laminates and composites, protective fabrics and layers, geotextiles, industrial wipes, and filter media.