Fine fibers made from polymer crosslinked with resinous aldehyde composition

Abstract

A fine fiber can be made having a structure with an axial core and a coating layer. The fiber can have a polymer core and one or two layers surrounding the core. The fine fiber can be made from a polymer material and a resinous aldehyde (e.g., melamine-aldehyde) composition such that the general structure of the fiber has a polymer core surrounded by at least a layer of the resinous aldehyde composition.

1 .- 30 . (canceled) 
     
     
         31 . A filter media comprising a filtration substrate and a layer comprising a plurality of fine fibers, the fine fibers comprising a core phase and a coating phase; wherein the core phase comprises a polymer and the coating phase comprises a resinous aldehyde composition; wherein at least a portion of the polymer is crosslinked by the resinous aldehyde composition; and further wherein the fine fiber does not include polyvinyl alcohol crosslinked with melamine-formaldehyde. 
     
     
         32 . The filter media of  claim 31  wherein the fine fibers are prepared from a resinous aldehyde composition comprising reactive alkoxy groups and a polymer comprising active hydrogen groups, wherein the molar ratio of resinous aldehyde composition to polymer is such that the molar ratio of reactive alkoxy groups to active hydrogen groups is greater than 10:100. 
     
     
         33 . The filter media of  claim 32  wherein the active hydrogen groups comprise amido or amino groups. 
     
     
         34 . The filter media of  claim 31  wherein the fine fibers are prepared from the resinous aldehyde composition and the polymer in amounts such that the resinous aldehyde composition is present in an amount of greater than 20 parts by weight per 100 parts by weight of the polymer. 
     
     
         35 . The filter media of  claim 31  wherein the core phase comprises a mixture of the polymer and the resinous aldehyde composition. 
     
     
         36 . The filter media of  claim 31  wherein the fine fibers comprise three phases, wherein the core phase comprises the polymer, the coating phase comprises the resinous aldehyde composition, and a transition phase comprises a mixture of the polymer and the resinous aldehyde composition. 
     
     
         37 . The filter media of  claim 31  wherein the polymer comprises a nylon. 
     
     
         38 . The filter media of  claim 31  wherein the nylon comprises nylon-6, nylon-6,6, nylon-6,10, mixtures or copolymers thereof. 
     
     
         39 . The filter media of  claim 31  wherein the nylon comprises nylon-6-6,6-6,10. 
     
     
         40 . The filter media of  claim 31  wherein the polymer comprises a polyvinyl butyral, an ethylene co-vinyl alcohol co-polymer, or a mixture thereof. 
     
     
         41 . The filter media of  claim 31  wherein the polymer comprises a cellulose derivative selected from the group consisting of ethyl cellulose, hydroxyl ethyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate phthalate, and mixtures thereof. 
     
     
         42 . The filter media of  claim 31  wherein the polymer comprises a poly(meth)acrylic acid homopolymer or copolymer. 
     
     
         43 . The filter media of  claim 42  wherein the polymer comprises a styrene-(meth)acrylic acid copolymer. 
     
     
         44 . The filter media of  claim 31  wherein the polymer comprises a poly(maleic anhydride) homopolymer or copolymer. 
     
     
         45 . The filter media of  claim 44  wherein the polymer comprises a styrene-maleic anhydride copolymer. 
     
     
         46 . The filter media of  claim 31  wherein the resinous aldehyde composition comprises a resinous formaldehyde composition. 
     
     
         47 . The filter media of  claim 46  wherein the resinous formaldehyde composition comprises a resinous melamine-formaldehyde composition. 
     
     
         48 . The filter media of  claim 31  wherein the resinous aldehyde composition comprises a melamine-aldehyde composition; and wherein the aldehyde comprises formaldehyde, acetaldehyde, butyraldehyde, isobutyraldehyde, or mixtures thereof. 
     
     
         49 . The filter media of  claim 31  wherein the resinous aldehyde composition comprises a condensation product of urea and an aldehyde, a condensation product of phenol and an aldehyde, a condensation product of melamine and an aldehyde, or a mixture thereof. 
     
     
         50 . The filter media of  claim 31  wherein the resinous aldehyde composition comprises a condensation product of benzoguanamine and an aldehyde, a condensation product of glycoluril and an aldehyde, or a mixture thereof. 
     
     
         51 . The filter media of  claim 31  wherein the resinous aldehyde composition is present in an amount of greater than or equal to 40 parts per weight per 100 parts per weight of the polymer. 
     
     
         52 . The filter media of  claim 31  wherein the resinous aldehyde composition is present in an amount less than or equal to 100 parts by weight per 100 parts by weight of the polymer. 
     
     
         53 . The filter media of  claim 31  wherein the fine fiber layer has a thickness of 0.05 to 30μ. 
     
     
         54 . The filter media of  claim 31  wherein the filtration substrate is a non-woven substrate. 
     
     
         55 . The filter media of  claim 31  wherein the fine fiber layer is an electrospun layer and the filtration substrate comprises a cellulosic or synthetic nonwoven. 
     
     
         56 . The filter media of  claim 55  wherein the filtration substrate comprises a polyester nonwoven, a polyolefin nonwoven, or a blended nonwoven thereof. 
     
     
         57 . The filter media of  claim 56  wherein the filtration substrate comprises polypropylene nonwoven. 
     
     
         58 . The filter media of  claim 31  wherein the filtration substrate comprises a spunbonded or melt-blown support. 
     
     
         59 . A filter element comprising the filter media of  claim 31 .