Method for Preparing a Functional Fiber Technical field

The present invention relates to a method for preparing a functional fiber, which comprises a step of forming a polymeric composition comprising at least one functional additive, a polymer and an alkoxylated polyethyleneimine. The polymeric composition is being subjected to a spin ning process for producing the functional fiber. In particular, the present invention relates to an alkoxylated polyethylenimine to be used in the preparation of a functional fiber, wherein said functional fiber comprises a polymer matrix and at least one functional additive.

Background Art

Various sectors of the textile industry have a high need for polymer fiber materials with addi tional functional benefit for the consumer. Application sectors for such fiber materials include for example as interlining material in the apparel industry, industrial textiles, for example hy giene applications, wound dressings, as carrier materials, as building and transportation mate rial, as cosmetic material or as filters, for example for the filtration of wastewater or exit air and binding of air and water ingredients.

Fabric comprising functional additives are obtainable in principle either by fabric production along a textile value-added chain or fibrous nonwoven web formation in each case from func tionality additized fibers, the coating of sheetlike textile structure with additive dispersions or the incorporation of solid or liquid functional additives in already produced fibrous nonwoven web structures.

In the prior art, there are some techniques relating to functional fabrics or fibers. For example, U.S. Patent No. 6,540,807 relates to a technique of antibacterial fiber, wherein the fabric is weaved to form a filter and the fabric includes thermoplastic resin and antibacterial agent. For instance, U.S. Patent No. 5,180,585, disclosed a microbe-inhibiting particle that could be in corporated into a polymer melt to make a fiber or other articles. Another U.S. Patent No. 5,897, 673 teaches fibers containing fine metallic particles that are cross-linked to the poly meric fiber.

Production of a functional fiber having a relative higher fraction of functional additive to render more added benefit of imparting functional properties, gives rise to some technical problems in terms of incompatibility between polymer matrix and functional agents, and stability of the polymer-containing spinning solution with high amount addition of functional agents. Due to this, prior art materials produced in the form of functional textile fabrics can contain only small amount of functional agents. As a result, the prepared functional fiber can only meet compara- tively low-quality requirements in respect of functionality and an additional amount of func tional agents is always required during a production process of functional fibers.

This is the reason one of the major challenges for a process for preparing a functional fiber without encountering the problem of incompatibility and stability. It is thus an object of the present invention to address the ever-increasing demand in the market for functional fibers, which shall be inexpensive to produce and also have satisfactory functionality.

Summary of Invention

In one aspect, the present invention is directed to a method for preparing a functional fiber, which comprises a step of forming a polymeric composition comprising at least one functional additive, a polymer and an alkoxylated polyethyleneimine, wherein the alkoxylated polyeth- yleneimine has alkylene oxide segments attached to the nitrogen atoms of the polyethylene imine; wherein the alkylene oxide segments are selected from the group consisting of ethylene oxide segment and C ₃ -C ₆ -alkylene oxide segments, preferably the alkylene oxide segments are com prised of ethylene oxide segment and C ₃ -C ₆ -alkylene oxide segments, more preferably the al kylene oxide segments are comprised of ethylene oxide segment and C ₃ -C -alkylene oxide segments, most preferably the alkylene oxide segments are comprised of ethylene oxide seg ment and C ₃ -alkylene oxide segments; wherein the amount of alkylene oxide segments is on average in the range of from 1 to 120 alkylene oxide segments per nitrogen atom, for example in the range of from 1 to 100 alkylene oxide segments per nitrogen atom, preferably 1 to 80 alkylene oxide segments per nitrogen atom, more preferably 1 to 70 alkylene oxide segments per nitrogen atom, most preferably 1 to 60 alkylene oxide segments per nitrogen atom, such as 1 to 55 alkylene oxide segments per nitrogen atom and wherein the weight average molecular weight (Mw) of the alkoxylated poly ethyleneimine is from 1,000 to 1,000,000 g/mol, preferably in the range of 5,000 to 500,000, more preferably in the range of 10,000 to 50, 000, most preferably in the range of 30,000 to 50,000 g/mol.

In a further aspect, the present invention is directed to a method for preparing a functional fiber, which comprises a step of forming a polymeric composition comprising at least one func tional addtive, a polymer and an alkoxylated polyethyleneimine, wherein the alkoxylated poly ethyleneimine has the alkylene oxide segments in the alkoxylated polyethylenimine of the pre sent invention are comprised of ethylene oxide segment and C ₃ -alkylene oxide segments, wherein the amount of alkylene oxide segments is on average in the range of from 35 to 70 alkylene oxide segments per nitrogen atom, preferably the amount of alkylene oxide segments is on average in the range of from 35 to 60 alkylene oxide segments per nitrogen atom, more preferably the amount of alkylene oxide segments is on average in the range of from 35 to 55 alkylene oxide segments per nitrogen atom, and the molar ratio of ethylene oxide segment to the remaining alkylene oxide segment is in the range of 1 : 10 to 6: 1, for example 1 : 10 to 5: 1, preferably in the range of 1 :2 to 3: 1, more preferably in the range of 1 : 1 to 2: 1, such as 3 :2, and the weight average molecular weight of the alkoxylated polyethylenimine of the present invention is in the range of from 20,000 to 50,000 g/mol, preferably of 25,000 to 45,000 g/mol, more preferably of 35,000 to 40,000 g/mol.

Preferably, the at least one functional additive and the alkoxylated polyethyleneimine are blended prior to being added into the polymer. Preferably, the polymer can be dissolved in a solvent or can be in a melted state.

In a further aspect, the present invention relates to use of the alkoxylated polyethyleneimine in a process for preparing a functional fiber, wherein the functional fiber comprises a polymer matrix and at least one functional additive.

The application has now discovered unexpectedly that the retention of the functional additive on and/or within the fiber has been improved. In other words, the addition of the alkoxylated polyethyleneimine in the spinning solution may improve the compatibility of the polymer fiber and the functional additive.

Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Expressions“a”,“an”, and“the”, when used to define a term, includes both the plural and sin gular forms of the term.

As used herein, the expression“at least one” means one or more and thus includes individual components as well as mixture/combinations.

As used herein, the words“comprising” (and any form comprising, such as“comprise” and “comprises”“having” (and any form of having, such as“have” and“has”), including (and any form of including, such as“include” and“includes”), or“containing” (and any form of contain ing, such as“contain” and“contains”), are inclusive or open-ended. They do not exclude addi tional, unrecited elements or method steps.

The term“polymer”, as used herein, includes both homopolymers, that is, polymers prepared from a single reactive compound, and copolymers, that is, polymers prepared by reaction of at least two polymer forming reactive, monomeric compounds. The term“polymeric composition”, as used herein, refers to a composition that comprises at least one polymer component.

The term“functional additive”, as used herein, refers to additives that may be added to a pol ymeric fiber to perform desired functions.

The term“functional fiber”, as used herein, means a fiber having a desired function.

The first aspect of the present invention is directed to a method for preparing a functional fi ber, which comprises a step of forming a polymeric composition comprising at least one func tional additive, a polymer and an alkoxylated polyethyleneimine, wherein the alkoxylated poly- ethyleneimine has alkylene oxide segments attached to the nitrogen atoms of the polyeth yleneimine; wherein the alkylene oxide segments are selected from the group consisting of ethylene oxide segment and C ₃ -C ₆ -alkylene oxide segments, preferably the alkylene oxide segments are com prised of ethylene oxide segment and C ₃ -C ₆ -alkylene oxide segments, more preferably the al kylene oxide segments are comprised of ethylene oxide segment and C ₃ -C -alkylene oxide segments, most preferably the alkylene oxide segments are comprised of ethylene oxide seg ment and C ₃ -alkylene oxide segments; wherein the amount of alkylene oxide segments is on average in the range of from 1 to 120 alkylene oxide segments per nitrogen atom, for example in the range of from 1 to 100 alkylene oxide segments per nitrogen atom, preferably 1 to 80 alkylene oxide segments per nitrogen atom, more preferably 1 to 70 alkylene oxide segments per nitrogen atom, most preferably 1 to 60 alkylene oxide segments per nitrogen atom, such as 1 to 55 alkylene oxide segments per nitrogen atom and wherein the weight average molecular weight (Mw) of the alkoxylated polyethyleneimine is from 1,000 to 1,000,000 g/mol, preferably in the range of 5,000 to 500,000, more preferably in the range of 10,000 to 50,000, most preferably in the range of 30,000 to 50,000 g/mol.

The term“polyethyleneimine” in the context of the present invention does not only refer to polyethyleneimine homopolymers but also to polyalkyleneimines containing NH-CH2-CH2-NH structural elements together with other alkylene diamine structural elements, for example NH- CH2-CH2-CH2-NH structural elements, NH-CH ₂ -CH(CH ₃ )-NH structural elements, NH-(CH ₂ )4-NH structural elements, NH-(CH ₂ ) ₆ -NH structural elements or (NH-(CH ₂ ) ₈ -NH structural elements but the NH-CH2-CH2-NH structural elements being in the majority with respect to the molar share. Preferred polyethyleneimines contain NH-CH2-CH2-NH structural elements being in the majority with respect to the molar share, for example amounting to 60 mol-% or more, more preferably amounting to at least 70 mol-%, referring to all alkyleneimine structural elements. In a special embodiment, polyethylenimine refers to those polyalkylene imines that bear one or zero alkyleneimine structural element per molecule that is different from NH-CH ₂ -CH ₂ -NH.

The“polyethyleneimine” in the context of the present invention is branched, preferably highly branched. The degree of the branching may be determined by a skilled person according to practical application.

In an embodiment wherein the alkylene oxide segments are comprised of ethylene oxide seg ment and C ₃ -C ₆ -alkylene oxide segments, more preferably the alkylene oxide segments are comprised of ethylene oxide segment and C ₃ -C -alkylene oxide segments, most preferably the alkylene oxide segments are comprised of ethylene oxide segment and C ₃ -alkylene oxide seg ments. The molar ratio of ethylene oxide segment to the remaining alkylene oxide segment may be in the range of 1 : 10 to 6: 1, for example 1 : 10 to 5: 1, preferably in the range of 1 :2 to 3: 1, more preferably in the range of 1 : 1 to 2: 1. In a most preferred embodiment, the molar ratio of ethylene oxide segment to the remaining alkylene oxide segment is 3:2.

In some preferred embodiments of the present invention, the alkylene oxide segments in the alkoxylated polyethyleneimine of the present invention are comprised of ethylene oxide seg ment and C ₃ -alkylene oxide segments, wherein the amount of alkylene oxide segments is on average in the range of from 35 to 70 alkylene oxide segments per nitrogen atom, preferably the amount of alkylene oxide segments is on average in the range of from 35 to 60 alkylene oxide segments per nitrogen atom, more preferably the amount of alkylene oxide segments is on average in the range of from 35 to 55 alkylene oxide segments per nitrogen atom, and the molar ratio of ethylene oxide segment to the remaining alkylene oxide segment is in the range of 1 : 10 to 6: 1, for example 1 : 10 to 5: 1, preferably in the range of 1 :2 to 3: 1, more preferably in the range of 1 : 1 to 2: 1, such as 3:2, and the weight average molecular weight of the alkox ylated polyethyleneimine of the present invention is in the range of from 20,000 to 50,000 g/mol, preferably of 25,000 to 45,000 g/mol, more preferably of 35,000 to 40,000 g/mol.

In still more preferred embodiments of the present invention, the alkylene oxide segments in the alkoxylated polyethyleneimine of the present invention comprise ethylene oxide segments and C ₃ -alkylene oxide segments, the amount of the ethylene oxide segments is in the range of from 20 to 35 ethylene oxide segments per nitrogen atom, and the amount of the C ₃ -alkylene oxide segments is in the range of from 15 to 30 C ₃ -alkylene oxide segments per nitrogen at om; preferably, the amount of ethylene oxide segment is in the range of from 20-30 ethylene oxide segments per nitrogen atom, and the amount of the C ₃ -alkylene oxide segments is in the range of 15 to 25 C ₃ -alkylene oxide segments per nitrogen atom.

There is no specific requirement on the process for obtaining the alkoxylated polyethyleneimine of the present invention. The alkoxylated polyethyleneimine of the present invention can be obtained by alkoxylation of polyethyleneimine via a process commonly known in the art. For example, the alkoxylated polyethyleneimine of the present invention may be obtained by the process described in such as US5445765, the disclosure of which is incorporated by reference.

The alkoxylated polyethyleneimine of the present invention described herein above, and with its preferred embodiments, is used and applied for preparation of a functional fiber. The alkox ylated polyethyleneimine of the present invention described herein above, and with its pre ferred embodiments, can be used and applied in a method for preparing a functional fiber in order to address the needs for improving of compatibility and stability when incorporating func tional additives into a polymer matrix.

The present invention has for its purpose to provide a method for preparing a functional fiber with high functional benefit for various use sectors depending on the nature of the functional additives. The method comprises a step of forming a polymeric composition comprising at least one functional additive, a polymer and the alkoxylated polyethyleneimine. In some embodi ments, the at least one functional additive and the alkoxylated polyethyleneimine are added into the polymer matrix to form the polymeric composition. In some embodiments, the func tional additive and the alkoxylated polyethyleneimine can be added to the polymer matrix sep arately or simultaneously to form the polymeric composition. In some embodiments, the func tional additive and the alkoxylated polyethylenemine are blended prior to being added into the polymer matrix to form the polymeric composition. In still some embodiments, the functional additive and the alkoxylated polyethylenemine are blended and dispersed in a solvent prior to being incorporated into the polymer matrix to form the polymeric composition. Any conven tional stirring technique can be subsequently used to form the polymeric composition homoge neously.

According to any one of the invention embodiments, the alkoxylated polyethyleneimine is used in an amount of 0.01% to 1.5% by weight based on the total amount of polymer; the fraction of functional additive is in an amount of 1% to 50% by weight based on the total amount of polymer and the average diameter of the functional additive ranges from 0.01 to 500 mi crometers. Preferably, the alkoxylated polyethyleneimine is used in an amount of 0.01% to 1%, more preferably of 0.05% to 1% by weight based on the total amount of polymer; the fraction of functional additive is in an amount of 5% to 40% by weight based on the total amount of polymer and the average diameter of the functional additive ranges from 0.01 to 300 mi crometers. In some preferred embodiments, the weight ratio of the alkoxylated polyethylene imine to the functional additive is in the range of 1 : 100 to 1 : 10, in particular, in the range of 1 :70 to 1 : 30, in more particular, in the range of 1 :60 to 1 :40.

Suitable functional additives include, but not limit to, activated carbon, carbon black, super absorbents, ion exchange resins, phase-change materials, metal oxides, flame retardants, abrasives, zeolites, sheet-silicates, such as bentonites, or modified sheet-silicates, cosmetic materials, paraffins, fragrance finishes, paraffins, waxes, oils, nanosilver, dyes, polychromic and/or thermos-chromic agents, active pharmaceutical ingredients or anti-bacterials, insecti cides or else active ingredients.

In some embodiments, to exhibit other functional effects, the functional additives compounded and added in the polymer matrix of the present invention are microcapsule, and the functional material is encapsulated in the microcapsule, wherein the material of the microcapsule can be chitin, polyurethane elastomer or thermoplastic elastomer. The material inside the microcap sule is called as the core material whereas the wall is called a shell. The microcapsules used for producing a functional fiber have diameters between a few micrometers and a few millimeters. Many special and functional properties can be imparted to the fiber by microencapsulating the core material, this core material can be any substance having a special function to perform for the fiber.

For the purpose of the present invention, the polymeric composition may be subjected to a spinning process for preparing the functional fiber comprising a polymer matrix and functional additives. The fiber can be produced via any conventional spinning method known to the per son skilled in the art. Suitable spinning processes include such as those spinning methods in volving a spinning solution, such as wet spinning and dry spinning, melt-spinning and electro spinning process.

In a typical wet spinning process, a spinning solution, or dope, is formed from a polymer or polymer precursor composition. The solution contains a dissolved polymer in a solvent which may be prepared by combining a pre-formed polymer with a solvent, or which may be formed by in situ polymerization of the monomers in the solution. The wet spinning solution with dis solved polymer is pumped through spinnerets into a coagulation bath here referred to as a fiber-forming bath in which the fibers are coagulated and wet spinning solution solvent is re moved, filaments or fibers are formed from the dissolved polymer as the solution leaves the spinnerets and enters the bath. At the exit of the bath, the fibers are collected in bundles of the desired tex or denier. The collected fibers are then finished, crimped and dried, drying can comprises collapsing and relaxing the fiber structure. Finally, the fibers are subjected to tow and cue operations. In a dry spinning operation, the same steps are taken as in wet spinning except the fiber is not formed and the solvent is not removed by a coagulation bath, but the fiber is formed and the solvent removed by dry means, such as by evaporation in a stream of air or an inert gas.

According to any one of the invention embodiments, the functional additive and the alkoxylated polyethyleneimine can be admixed with the polymer matrix to form the polymeric composition. In some embodiments, the functional additive and the alkoxylated polyethyleneimine are ad mixed with the polymer matrix prior to dissolution of the polymer in a solvent. In some further embodiments, the functional additive and the alkoxylated polyethyleneimine can be added into polymer-containing spinning solution to form the polymeric composition. In some further em- bodiments, the functional additive and the alkoxylated polyethyleneimine can be added into polymer-containing spinning solution, separately or simultaneously. In some embodiments, the functional additive and the alkoxylated polyethyleneimine are blended prior to being incorpo rated into the polymer-containing spinning solution to form the polymeric composition. In still some embodiments, the functional additive and the alkoxylated polyethyleneimine are blended and dispersed in a solvent prior to being incorporated into the polymer-containing spinning solution to form the polymeric composition.

Any conventional stirring technique can be subsequently used to form the polymeric composi tion homogeneously. With the addition of the alkoxylated polyethyleneimine, the functional additive can be well dispersed throughout polymer-containing spinning solution used to form the fiber. By well dispersed, it is meant that the functional additive is substantially, homogene ously distributed throughout the solution. Preferably, the functional additive does not fall out of, or settle to the bottom of the solution.

With respect to introducing the functional additive and the alkoxylated polyethyleneimine to the polymer-containing spinning solution, any manner of introduction can be used. The functional additive and the alkoxylated polyethyleneimine can be added in dry form directly into the spin ning solution or as a dispersion. Also, they may first be dispersed in a solvent to form a disper sion before being added into the polymer and the solvent of the spinning solution. If they are supplied in the form of a dispersion, the solvent used in the dispersion is preferably capable of forming a dispersion and maintaining the functional additive in a highly dispersed state. The solvent used in the dispersion is preferably compatible and more preferably miscible with the solvent used in the wet spinning solution for dissolving the polymer. The dispersion containing the functional additive and the alkoxylated polyethyleneimine may further comprise a disper sant and/or a surfactant.

When forming the spinning solution, the various components can be added in any order. The solution should maintain the polymer in a dissolved state and may include conventional spin ning solution solvents. Suitable solvents include aqueous solvents, water-containing ionic liq uids and organic solvents, such as dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide (DMSO), ethylene carbonate, aqueous solution of sodium thiocyanate (NaSCN) having NaSCN concentrations of from about 45% by weight to about 55% by weight, aqueous solution of ni tric acid (HN0 ₃ ) having preferred HN0 ₃ concentrations of from about 65% to about 75% by weight , aqueous solutions of zinc chloride (ZnCI ₂ ) having ZnCI ₂ concentrations of from about 55% by weight to about 65% by weight, N-methylmorpholine N-oxide or N-methylmorpholine N-oxide monohydrate; ionic liquids, such as l-ethyl-3-methylimidazolium acetate, 3-ethyl-l- methylimidazolium chloride or 3-butyl-l-methylimidazolium chloride, dimethylformamide, di- methylacetamide or dimethyl sulfoxide mixed with lithium chloride or NaOH-thiourea-water or optionally mixtures thereof. When an organic solvent is used to dissolve the polymer, the same solvent is preferably used to form the dispersion containing the functional additive and the alkoxylated polyethyleneimine. When an aqueous solution is used to dissolve the polymer, a dilute solution or water is preferably used to form the dispersion containing the functional addi tive and the alkoxylated polyethyleneimine.

Examples of suitable polymer for preparing the spinning solution include, natural polymers, for example polysaccharide and polysaccharide derivatives, in particular cellulose, cellulose ace tate, protein and protein derivatives, solvent-formable synthetic polymers, such as polylactic acid, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride, polyethylene oxide, polyamide, pol- yethersulfone, polysulfone metha-aramid or their copolymers. The solvent(s) present in the spinning solution for each of the polymers are conventional and known to those skilled in the art.

In a preferred embodiment of the present invention, the method for preparing the functional fiber includes the following steps: using cellulose pulp as raw material; the producing steps include impregnating, squeezing, crushing, ageing, sulfidizing, filtering, ripening, spinning, sourcing and drying; the method also includes an adding step of the functional additive and the alkoxylated polyethyleneimine, the said adding step is to add the functional additive and the alkoxylated polyethyleneimine into the cellulose xanthate obtained in the sulfidizing step, after stirring, the mixture fully dissolved to form the polymeric composition to produce the viscose spinning solution.

According to any one of the invention embodiments, the concentration of polymer in the spin ning solution is in the range of from about 5% by weight to about 40% by weight based on the weight of the solution, preferably, in the range of from about 5% by weight to about 20% by weight based on the weight of the solution.

The fiber-forming bath when the spinning process used is wet spinning, which can also be re ferred to as a coagulation bath, can comprise any conventional coagulation bath medium. Pref erably, the fiber-forming bath comprises a water-solvent mixture or solution that promotes the formation of fiber filaments from the spinning solution as the solution is pumped through the spinnerets. Persons skilled in the art would be aware of the suitable techniques and conditions such as operation temperature, viscosity of the spinning solution, to be adopted, depending upon a number of factors including the polymeric component(s) and solvent(s) of the spinning solution.

According to some embodiments of the present invention, the functional fiber can be produced via the melt-spinning process, which is conducted by heating and melting the polymer, and extruding the melted polymer from spinning holes into air, while cooling in the air, winding at a constant speed, and solidifying while the melted material is thinning, a fiber is thus formed, and then executing thermal stretching to enhance mechanical properties of the fiber. In the melting-spinning process, the spannable polymers obtained from a polymeric process at a temperature higher than the melting point thereof are extruded from the holes in the spinning plate.

Suitable polymers for the melt-spinning process are known to those skilled persons. The poly mer can be selected from any of the types of polymers known in the art that are capable of being formed into fibers, including polyolefins, polyvinyl, polyvinyl alcohol, polyesters, polyam ides, co-polymers containing any of the aforementioned polymers as blocks of a copolymer, and combinations thereof. Specific polyolefins operative herein include polypropylene; polyeth ylene; polybutene; and polyisobutylene; polyamides such as NYLON 6 and NYLON 6.6; poly acrylates, polystyrenes, polyurethanes; acetal resin; polyethylene vinyl alcohol; polyesters in cludes polyethylene terephthalate, polyethylene naphathalate, polytrimethylene terephthalate, poly(l, 4-cyclohexylene dimethylene terephthalate, polycarbonates and aliphatic polyesters include polylactic acid, polyphenylene sulfide, thermoplastic elastomers, polyacrylonitrile, cellu lose and cellulose derivatives, polyaramides, acetals, fluoropolymers, copolymers and terpoly- mers thereof, and mixtures or blends thereof.

In some embodiments of the present invention, the functional additive and the alkoxylated polyethyleneimine can be added directly to the melt polymer. A conventional stirring can be subsequently used to make the functional additive homogeneously dispersed throughout the polymer melt. In some embodiments, the functional additive and the alkoxylated polyethylene imine can be blended prior to being introduced into the melt polymer. In still some embodi ments, the functional additive and the alkoxylated polyethyleneimine can be blended and dis persed in a solvent prior to being introduced into the melt polymer to form the polymeric com position.

The amount of the alkoxylated polyethyleneimine ranges from 0.01% to 1% by weight based on the total weight of the melt polymer, preferably from 0.01% to 0.8% by weight based on the total weight of the melt polymer, the functional additive is used in the amount ranging from 1% to 50% by weight based on the total weight of the melt polymer, preferably from 5% to 40% by weight based on the total amount of the melt polymer; and the average diameter of the functional additive ranges from 0.01 to 500 micrometers, preferably 0.01 to 300 microme ters

In some embodiments, the functional additive and the alkoxylated polyethyleneimine can be blended in absence of solvent, in particular, can be blended in a desired temperature to obtain homogeneous blend, prior to the step of being incorporated into the polymer melt, before spinning or during other processing steps. The functional additive is mixed into the polymer melt and homogeneously dispersed throughout the polymer melt. In some embodiments, the functional additive and the alkoxylated polyethyleneimine are mixed or blended with the poly mer melt prior to extrusion using known techniques into extrudable pellets, where the func tional additive is homogeneneously dispersed throughout the polymer matrix. In one embodi- merit, the method of producing functional fiber comprises: preparing the polymer chips as a substrate, (in the amount of 10% to 50% by weight based on the total weight of the fiber) and the polymeric composition of functional additive (in the amount of 1% to 50% by weight based on the total weight of the fiber) and the alkoxylated polyethyleneimine (in the amount of 0.01% to 1% by weight based on the total weight of the fiber), and compounding by a twin- screw extruder to form functional masterbatches, then combining the functional masterbatches with additional polymer matrix, and melting and mixing the functional masterbatches and the additional polymer to form a composite material, and then subjecting the composite material to spinning, cooling, thermal stretching and heat setting to form the functional fiber. The spin ning temperature, the heat stretching temperature and the heat setting temperature are known or can be adjusted by those skilled in the art depending on the polymer type and pro ducing process.

Without being bound to any particular theory, it is believed that the alkoxylated polyethylene imine, which has good affinity to different surfaces, can be used as an excellent surface modifi er to improve the interfacial compatibility between polymer matrix and functional materials being mixed during the preparation of a functional fiber.

The functional fibers of the present invention are useful in variety of goods including, but not limited to apparel textile and industrial textiles with high functional benefit for various applica tion sectors depending on the type of functional additives, for example for hygiene applica tions, as wound dressings, as carrier materials for active ingredients or as carrier materials in composites, as building and transportation materials, as cosmetic materials or as filters, for example for the filtration and binding of air and water ingredients such as phosphates, nitrates and ammonium-nitrogen compounds.

The present invention further relates to use of the alkoxylated polyethyleneimine as described in the abovementioned aspects, in a process for preparing a functional fiber, wherein the func tional fiber comprises a polymer matrix and at least one funtional fiber.

The disclosure is further described in the following examples. The examples are merely illustra tive and do not in any way limit the scope of the disclosure as described and claimed.

Examples

Materials:

Alkoxylated Polyethyleneimine (PEI): Alkoxylated PEI comprising the alkylene oxide segments which are comprised of ethylene oxide segment and C ₃ -alkylene oxide segments, wherein the amount of alkylene oxide segments is on average in the range of from 35 to 55 alkylene oxide segments per nitrogen atom, and the molar ratio of ethylene oxide segment to the remaining alkylene oxide segment is 3:2, and the weight average molecular weight of alkoxylated PEI is in the range of from 35,000 to 40,000 g/mol.

Si0 ₂ : Sold by Sigma-Aldrich with an average diameter of lOOnm.

PU microcapsule: polyurethane fragrant microcapsule with an average diameter of 50 mGh. Surfactant : Sodium dodecyl sulfate sold by Sigma-Aldrich

Example 1

Cellulose pulp (made from cotton linter) was used as raw material. The cellulose xanthate was obtained by using any conventional production process. Si0 ₂ particles (1 kg) and the alkoxylat ed PEI (20 g) were added to the rotatory drum mixer and stirred for 1 hour at a temperature of 80°C to obtain the blend. The blend of Si0 ₂ particles and the alkoxylated polyethyleneimine, the cellulose xanthate, sodium hydroxide and water were mixed homogeneously to obtain a blended viscose liquid, which was subsequently to be dissolved in water, filtered and de aerated to obtain the blended spinning dope. The obtained spinning dope contains 5 wt% of a- cellulose, 2 wt% of Si0 ₂ particles, 10 wt% of sodium hydroxide and water.

The functional fiber was produced by spinning in coagulation acid bath with sulfuric acid con tent of 120 g/L, zinc sulfate content of 11 g/L, sodium sulfate content of 330 g/L, the tempera ture of 58°C, and stretching appropriately. The resulting functional fiber was obtained after desulfurization refining and drying.

Comparative Example A

The functional fiber was prepared by the same procedure as Example 1, except for the absence of the alkoxylated polyethyleneimine.

Comparative Example B

The functional fiber was prepared by the same procedure as Example 1, except that the sur factant was used to make the blend with Si0 ₂ particle instead of the inventive alkoxylated pol yethyleneimine.

Example 2

Cellulose pulp (made from cotton linter) was used as raw material. The cellulose xanthate was obtained by using any conventional production process. PU microcapsule (10 kg, 10 wt%) and the alkoxylated PET (25 g) were mixed by mechanical stirring for 1 hour at room temperature to obtain a slurry. The slurry comprising PU microcapsule and the alkoxylated polyethylene imine, the cellulose xanthate, sodium hydroxide and water were mixed homogeneously to ob tain a blended viscose liquid, which was subsequently to be dissolved in water, filtered and de aerated to obtain the blended spinning dope. The obtained spinning dope contains 6 wt% of a- cellulose, 1 wt% of PU microcapsule, 10 wt% of sodium hydroxide and water. The functional fiber was produced by spinning in coagulation acid bath with sulfuric acid con tent of 120 g/L, zinc sulfate content of 11 g/L, sodium sulfate content of 330 g/L, the tempera ture of 58°C, and stretching appropriately. The resulting functional fiber was obtained after desulfurization refining and drying.

Comparative Example C

The functional fiber was prepared by the same procedure as Example 2, except for the absence of the alkoxylated polyethyleneimine.

Comparative Example D

The functional fiber was prepared by the same procedure as Example 2, except that the sur factant was used to make the blend with PU microcapsule instead of the inventive alkoxylated polyethyleneimine.

Measurement of the content of the functional additive in fiber

The obtained functional fiber was dissolved in an aqueous solution containing 50 wt% of N- methylmorpholine-N-oxide (NMMO) at 100°C (the weight ratio of the aqueous solution to the fiber is 100: 1). The insoluble functional material was filtered, washed with deionized water and dried at 150°C . The amount of the insoluble functional additive in the fiber was weighed. The average value was calculated with repeated measurements. The results of the content of func tional additive in fiber are shown in Table 1.

Table 1

It has been found unexpectedly that, the concentrations of the functional additives in the final functional fibers increase with the presence of the alkoxylated polyethyleneimine which im prove the functional material - polymer matrix interfacial compatibility.