DE60310093T2 - POLYOLEFIN FIBERS AND THEIR USE IN THE MANUFACTURE OF HIGH VOLUMINOUS NONWOVENS WITH HIGH RESET CAPACITY - Google Patents

Abstract

Non-woven materials from polyolefin-based fibres which have bulk and resilience comparable to polyester fibres are described herein, thus expanding the utility of polyolefin fibres and nonwovens to a plethora of industrial applications which previously excluded products based on polyolefin fibres due to their hitherto inadequate bulk or resilience. Control of polyolefin fibre characteristics such as the fibre/fibre friction, fibre crystallinity, draw ratio, or selection of the spin finish so as to comprise essentially of an aqueous emulsion of polysiloxanes render them suitable for preparing bulky and resilient nonwovens.

Description

Field of invention

bulky Polyolefin nonwovens are made by the regulation of polyolefin fiber characteristics receive. The fiber / fiber friction and crystallinity become in addition to other physical characteristics of the fibers used to manufacture from bulky and resilient Nonwoven fabrics are suitable described. These new fibers allow that polyolefin nonwoven fabrics can be used in technologies that because of their previous insufficient mass or springback earlier were excluded on polyolefin fibers and earlier on polyesters and nylons were limited or dominated by it.

background the invention

ordinary Polypropylene staple fibers do not provide non-woven fabrics with high springback and bulkiness, at least not to the same extent as polyester fibers.

fibers out of ordinary Polyolefins such as polypropylene and polyethylene insufficient, nonwovens with sufficient mass and springback to provide a suitable alternative to nonwovens to provide polyester.

Conventional polyolefin fibers have a bulk of approximately 20-25 ^cm3 / g and a resilience of approximately 85%. The inventors are part of a group that has commercialized a polyolefin fiber product with an improved mass, but in which product springback has been significantly reduced. Fibervisions HY-Comfort fibers have an improved bulkiness ^® of up to 45 cm ³ / g, but a resilience of less than 50%. However, and in particular, HY-Comfort ^® fibers found no non-woven fabrics with a mass corresponding to the mass of polyesters. It would be of great commercial interest to increase the mass of a nonwoven fabric made from polyolefin fibers.

Polyester nonwovens, depending on the oven-solidifying method and the finish type, have a mass of about 100 cm ³ / g and a resilience of approximately 75%.

US 6388013 is directed to polyolefin fibers with improved balance of properties, including increased toughness, increased modulus, and increased elongation. This was achieved by incorporating from 1 to 10% by weight of aromatic hydrocarbon resin in the polypropylene fiber-forming composition based on a propylene homopolymer or copolymer or a mixture of these propylene polymer resins with a non-propylene-containing resin. The present invention provides polyolefin fibers having improved toughness obtained by adding a small amount of aromatic hydrocarbon resin to the polyolefin. Polypropylene fibers extruded and drawn from the blend showed higher toughness and thus have the ability to be processed at higher speeds and finer deniers.

US 5770532 describes a process for hardening a nonwoven fabric composed of staple artificial fibers, including polyester, polyethylene or polypropylene fibers, or spun fibers of man-made fiber-forming materials, including polyester, polyethylene or polypropylene, in a mass of 10 mm or more without binding fibers, including a bicomponent or special melt fibers, and is made without binder, and which can be mixed with natural fibers, characterized in that the fleece is hardened only by a single Wasserbenadlungsvorgang with a water pressure of only 60 bar.

US 5589256 is directed to a process for producing high density, lightly dense fibers having adhered particulates. The high mass fibers have hydrogen bonding functionalities or coordinated covalent bonding functionalities, and a binder is used on the fibers to bind the particles of the fibers. The binder has a functional group that forms a hydrogen bond or a coordinated covalent bond with the particles, and a functional group that forms a hydrogen bond with the fibers. A substantial portion of the particles adhered to the fibers are bound in particulate form to the binder by hydrogen bonds or coordinated covalent bonds, and the binder is in turn bound to the fibers by hydrogen bonding. The fibrous product comprises pressure-compacted individualized fibers having a mass of 0.1 to 0.7 g / cc and hydrogen bonding functionalities; and particles bound by a binder to the fibers interposed between the particles and the fibers by the particles having a hydrogen bond or coordinated kova lenten binding functionality, and the binder having a functional group capable of forming a hydrogen bond between binder and Partiklen or a coordinated covalent bond between binder and particles, and a functional group capable of hydrogen bonding between binder and fibers form. The binder may be selected from the group consisting of (a) a polymeric binder having repeating units, wherein each repeating unit has a functional group capable of forming a hydrogen bond or a coordinated covalent bond with the particles or a hydrogen bond with the fibers; and (b) a non-polymeric organic binder, wherein the product comprises 0.05-80% of the bound particles, wherein the bound particles bound to the fibers are bound primarily by a hydrogen bond or a coordinated covalent bond.

US 5478646 describes a high-strength polypropylene fiber having an average size of 10,000 - 0.1 denier, which is prepared by extruding a raw material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more, and possibly by expanding the resulting extruded one Material is achieved.

US 5,204,174 relates to a nonwoven web composed of raised and disoriented thermoplastic fibers formed from a blend of propylene polymer and butylene polymer wherein the blend has a weight of 90% to 50% polypropylene and 10% to 50% polybutylene. The resulting nonwoven fabrics have increased load capacity, tear resistance, drape and conformability.

US 4563392 relates to a coated polyolefin fiber comprising (a) a monofilament or multifiber of polyethylene or polypropylene having an average molecular weight of at least about 500,000, polyethylene having a toughness of at least about 15 g / denier and a tensile modulus of at least about 300 g / denier and, for polypropylene having a tenacity of at least 8 g / denier and a tensile modulus of at least about 160 g / denier; and (b) a coating on the monofilament or at least a portion of the fibers of the multifibre having a polymer having ethylene or propylene crystallinity, the coating being present in an amount of between about 0.1% and about 200% of the weight of the fibers occurs.

in the The state of the art there is nothing that raises the Mass of polyolefin nonwoven fabric is directed to a significant amount or this increase brings about. The inventors of the present invention have a solution on the problem of missing mass in polyolefin nonwovens found.

Summary the invention

The Invention is based on new polyolefin fibers for the improvement the mass of nonwovens made therefrom are.

• ii) einem Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) einem Ziehverhältnis von mindestens 1:1,5; und
• iv) einer Faser-Kristallinität von mindestens 50%

ausgewählt ist.A first aspect of the invention relates to a novel polyolefin-based polymer fiber which is suitable for producing a high mass nonwoven fabric. The fiber of the invention is based on polyolefin polymer and has at least one of the features selected from the group consisting of i) a fiber / fiber friction of at most 600 g;

• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5; and
• iv) a fiber crystallinity of at least 50%

is selected.

One Another aspect of the invention is directed to a method for Preparation of a polyolefin-based fiber, wherein the method through the use of a nucleated polymer, a draw ratio of at least 1: 1.5, typically with a final fiber fineness of 2 to 10 dtex, and a spin finish comprising essentially one Emulsion of modified polysiloxanes, is characterized.

The present invention discloses that high mass fibers do not necessarily correspond to high mass nonwoven fabrics. The present invention discloses important fiber properties that can be used to define the fiber features, which in turn correspond to high mass nonwoven fabric, including the selected spin finish; and / or the selected polymer grade used to make the fibers and / or the selected target ratio in the manufacture of the fibers. An important Purpose of the nonwoven material made from a polyolefin-based staple fiber as defined herein. Another purpose of the invention is directed to a non-woven material based on polyolefin-based staple fiber wherein the nonwoven material has a mass of at least 30 cm ³ / g and a spring back of at least 50%.

An interesting aspect of the present invention relates to the process of making bulky nonwoven webs of polyolefin based fibers where the mass and resilience of the nonwoven webs are comparable to the bulk and resilience of the polyester materials. Using new fibers, the appropriate preparation methods or the appropriate bonding method, the inventors of the present invention have nonwovens with a bulkiness of up to almost 80 cm ³ / g and a resilience of almost 86% was prepared. This compares favorably with conventional nonwovens made from conventional polyolefin fibers, said nonwovens having a weight of about 22 cm ³ / g and a resilience of approximately 86%. An important purpose of the invention relates to a process for making a nonwoven material, which process comprises the use of a fiber of the invention or the use of fibers made by the process of making fibers of the invention.

Further Aspects of the invention relate to a hygiene product that is a nonwoven material of the invention, and a method for producing a hygiene product, which method involves the use of a nonwoven material of the invention includes.

description the invention

The terms "bulk" and "bulkiness" as used herein relate to voluminosity, that is to say a high volume per weight and in cm ³ / g measured.

Of the Term "fiber / fiber friction" as used herein denotes the force required to separate the fibers apart is.

Of the Term "fiber crystallinity" as used herein indicates the presence of a three-dimensional sequence a molecular level in the polymer, wherein the fiber crystallinity through Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD) is measured.

Of the Term "springback" as used herein indicates the restoration of the original shape and size removing the load or strain that caused the deformation for example the ability after compression to the original shape or the original one State to go back.

The Inventors of the present invention have polyolefin-based Fibers produced a nonwoven material, its mass and springback with the mass and springback of polyester fibers is comparable, the usefulness of polyolefin fibers and nonwovens to a plethora of commercial Applications that were formerly based on polyolefin fibers Products excluded because they have insufficient mass or springback possessed.

The Surprisingly, inventors of the present invention have found that high mass fibers do not necessarily include nonwoven fabric correspond to high mass. The inventors of the present invention have found that low fiber-to-fiber friction too a larger mass with respect to the nonwoven compared to higher fiber / fiber friction fibers leads. Without being bound to a particular theory, this is, at least partly, due to the fact that the fibers with low friction during the process used of carding and thermal bonding easier to move freely. Because of their smooth texture, these fibers have low friction a low fiber mass.

The Mass of nonwoven material hangs, at least in part, from the characteristics of the polyolefin fibers. The Inventors of the present invention have found that the Fiber characteristics greatly affect the mass of the nonwoven fabric, and they have produced fibers used to make nonwovens the desired Mass are suitable.

• i) einer Faser-zu-Faserreibung von höchstens 600 g;
• ii) einem Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) einem Ziehverhältnis von mindestens 1:1,5, typisch mit einer endgültigen Faserfeinheit von 2 bis 10 dtex;
• iv) einer Faser-Kristallinität von mindestens 50%

ausgewählt ist.A first purpose of the invention relates to fibers which are suitable for the production of bulky nonwovens. The inventors of the present invention have identified the characteristics of the fibers which require any features to obtain the bulky nonwoven fabrics, namely fiber-to-fiber friction which, at least in part, can be regulated by the selected spin finish, which spin finish in the we significantly comprises an emulsion of polysiloxanes; a suitable draw ratio; and a suitable fiber crystallinity. The inventors of the present invention have found that adequately setting any one of these parameters enables the production of fibers that enable bulky nonwoven fabrics. Thus, the polyolefin polymer-based fiber must have at least one of the features selected from the group consisting of

• i) fiber-to-fiber friction of at most 600 g;
• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5, typically with a final fiber fineness of 2 to 10 dtex;
• iv) a fiber crystallinity of at least 50%

is selected.

As indicated fiber-to-fiber friction is an important parameter, which must be reasonably fixed to the bulky polyolefin nonwovens to obtain. In a preferred embodiment, the fiber-to-fiber friction is at most 500 g, such as at most 400 g. The fiber / fiber friction is typically between 200 and 1000 g, such as between 200 and 800 g, preferably between 200 and 600 g, more preferably between 200 and 500 g, most preferred between 200 and 400 g.

The Inventors of the present invention have found that the Type of spin finish has a remarkable impact on the fiber mass Has. It has been found that the type of spin finish is the Fiber / fiber friction in a sense which regulates the fiber mass to a certain extent. It has thus found that a spin finish that has a low fiber / fiber friction yields a low fiber mass expresses. Without to a specific one Theory has been suggested to have this effect the smooth nature of the fibers is due where the fibers are not are able to separate from each other, which is why one results in relatively low fiber mass.

As specified depends the fiber / fiber friction, at least in part, of the selected spin finish from. In the present context, "spin finish" refers to an aqueous composition which in the spinning process (first finish) and in the subsequent expansion process (second finish) can be used on the fibers. The spin finish facilitates the spinning process by lubricating the fibers and be made antistatic among other things. Antistatic agents can used to ensure that the fibers by the spinning and Ausdehnverfahren not electrically getting charged; anionic, cationic and nonionic antistatic Means can in spin finish as specified herein. The total amount of the antistatic agent used on the fibers is preferably as low as possible, Meanwhile the desired antistatic effect is still achieved, for example, between 0.01 and 0.5% by weight, preferably between 0.02 and 0.35% by weight and more preferably between 0.05 and 0.2% by weight on the weight of the fibers. The amount of antistatic agent is also preferably kept to a minimum in the second spin finish. The amount of spin finish that during of the spinning process is greater than the amount used during the Expansion method is used. If the second spin finish a cationic antistatic agent, comes the cationic antistatic agents preferably in an amount of at most 20%, more preferably at most 10%, based on the total active content of the second spin finish, in front.

Furthermore the spin finish may contain a lot of cohesive imparting agent, to ensure, that the fibers are in bundles held together. This allows on the other hand that the fibers can be processed, without being involved. Examples of Cohesion Borders that For this Purpose used are neutral vegetable oils, long chain alcohols, ethers and esters, sarcosines and non-ionic ones surfactants Means as specified herein.

The Spin finish can also contain lubricants produced by the manufacturing process regulate both fiber / fiber friction and fiber / metal friction, so that the fibers while the processing will not be worn or frayed. Especially have to Fiber / metal friction during the spinning stage, fiber / metal friction against the pulleys, and fiber / fiber friction as well as fiber / metal friction in the crimping machine are regulated.

Typical contains the spin finish also water and emulsifiers or surface-active Means containing the more or less lipophilic component in the aqueous solution maintained. Water is a preferred solvent in the present Invention: other solvents should be avoided as much as possible in order to exclude potential environmental risks.

The Fibers of the invention typically comprise a spin finish that is substantially an emulsion of polysiloxanes. The fibers of the invention more typically include a spin finish, which is essentially from an aqueous Emulsion composed of polysiloxanes. The aqueous emulsion of polysiloxanes, the for those suitable for use in spin finish typically comprise at least 25% active content, such as at least 30% active content, preferably at least 35% active content, such as about 40%. The spin finish suitably becomes in a concentration from 2-15%, how to Example 5-10%, used.

In a typical embodiment the fibers have a spin finish level of about 0.2 to 1% by weight, as far as the fiber is concerned, such as 0.25 to 0.9%, preferably 0.3 to 0.85%, most preferably 0.35 to 0.85%.

Without being bound to any specific spin finish, a particularly suitable spin finish of the present invention is the Synthesin 7490 FILL ^®. The spin finish comprises a silicone-based elastomer comprising inter alia an emulsion of modified polysiloxanes. A plethora of finishing types, as is the case with Synthesin 7490 FILL ^® comprises an emulsion of modified polysiloxanes are suitable. The spin finish is suitably water-soluble at ambient temperature and may be used by dipping, padding or spraying. The spin finish crosslinks upon drying at a temperature of about 100 ° C, such as 80 ° C.

The Spin finish can be used in two or more stages. The total concentration of suitable active components in spin finish, i.e. antistatic agent, lubricants, emulsifiers and cohesive Average is typically lower in the first spin finish (generally 0.7-2.5% active content) than in the second spin finish (generally 4-12% active) Salary). Normally, the viscosity of the first spin finish is thus lower. It may therefore be advantageous in the dispersion with the lowest viscosity, i.e. in the first spin finish to use any high viscosity component.

One another important feature of the fiber, a high mass in the nonwoven fabric Achieve is the fiber crystallinity. As indicated, the crystallinity of the fiber suitably at least 50%. In embodiments wherein the fiber crystallinity is attainable a high mass in the nonwoven fabric is manipulated, the fiber crystallinity is preferred at least 55%, such as at least 60%, as by DSC or XRD measured.

In According to another aspect of the present invention, the mass can the selected one polymer grade (or matrix polymer) used to make the fiber be regulated. The polymer may be polypropylene homopolymers and arbitrary Copolymers thereof with ethylene, 1-butene, 4-methyl-1-pentene, etc., and linear Polyethylenes with different masses, such as polyethylene high mass, low mass polyethylene and linear polyethylene be selected with low mass and mixtures thereof. The polymeric material may be combined with other non-polyolefin polymers, such as Polyamide or polyester, to be mixed, provided that the Polyolefins still the largest part make up the composition.

In In another aspect of the present invention, the fiber mass through the selected nucleating agent, for example, the nucleating agent used in the crude polyolefin material, be regulated. Nucleating agents are often common in the commercial Senses in combination with crystallizable thermoplastic polymers used to improved features, such as improved mechanical properties, grant. Typical known nucleating agents are metallic salts of aliphatic or aromatic carboxylic acids, branched Polymers containing dendritic branches and minerals, such as for example, chalk, gypsum, clay kaolin, mica, talc and silicates. Recently solve developed nucleating agent in the polymer melt, such as compounds that on D-sorbitol and 1,3-2,4-bis- (3,4-dimethylbenzylidene) -D-sorbitol based on.

The Effect of the nucleating agent is the crystallization process to initiate in the mother polymer. The nucleating agents do one very big Surface area, and they are preferred nucleation sites in the parent polymer. Of the Nucleation process is a thermodynamic process that essentially by reducing the specific surface area of the nucleating agents, for example, by reducing the specific surface area of the Chalk or talc particles in the mother polymer.

The nucleating agent also promotes the polymer crystallization process. Thus, the nuclei make the mother polymer more or less crystalline, for example substantially more amorphous than crystalline, or substantially more crystalline than amorphous. As used herein, "crystalline" refers to crystalline regions in the amorphous polymer matrix, for example, regions in which the polymer chains or portions of the polymer chains are aligned substantially in parallel with each other in ordered patterns. In contrast, "amorphous" refers to regions in the polymer matrix in which there is essentially no tuning or arrangement of the polymer chains.

In a preferred embodiment the polyolefin is selected from the group consisting of isotactic or syndiotactic polypropylene homopolymers, homo- and copolymers of monoolefins, such as ethylene, propylene, alpha olefins, 4-methyl-1-pentene and mixtures thereof, linear polyethylenes, High mass polyethylene, low mass polyethylene and Linear low mass polyethylene and mixtures thereof selected. More preferably, the polyolefin is selected from the group consisting of homopolymeric polypropylene and homopolymeric polyethylene. Yet more preferably, the polyolefin is homopolymeric polypropylene.

Of the Degree of crystallinity is regulated, at least in part, by the nucleating agent. This in turn, also influences the mechanical properties of the polymer. For example, the polymer chains or parts of the polymer chains, which are densely packed in the crystalline regions, more polymer chains per unit area, to a certain load to support. Since in the crystallites, the polymer chains over relatively long distances in dense and permanent Are contact, are the secondary ones forces which hold them together, cumulatively larger than in the amorphous regions. A substantially more crystalline polymer thus becomes the starch and Increase the strength of the polymer.

In a typical embodiment In the invention, the polyolefin polymer is a nucleated polymer. The Nucleating agent is suitably composed of the group talc, chalk, gypsum, clay kaolin, silicates, aromatic carboxylic acid salts, Phosphate ester salts and sorbitol-based compounds selected. The Nucleating agent is most suitable talcum. In the embodiment, wherein the polyolefin polymer is a nucleated polymer with talc When nucleated, nucleation becomes typical to a level of 5000 to 10,000 ppm of talc carried out.

Without can be bound to any specific polymer grade, a preferred polypropylene polymer grade raw material when used in the present invention, Adstif HA840R. The Adstif HA840R is a highly engineered homopolymer with an extremely high strength and shine. The polymer quality becomes an increase of crystallinity nucleated with 8500 ppm talc. In a further aspect of the present invention Invention provide fibers homopolymerizing the Adstif HA840R Raw material are made, compared to fibers with a higher flexural modulus with fibers made of standard polypropylene material are made. Without being tied to any specific theory to be, it is suggested that the higher flexural modulus, by the Adstif HA840R is obtained due to the fact that the homopolymer is nucleated with talc. The nucleated homopolymer is therefore more crystalline and therefore stiffer. For example, has the Adstif HA840R as used in the present invention a flexural modulus of about 2250 MPa. Compared with this value the polypropylene homopolymer quality, as for example the PPH7059, a common one Raw materials have a flexural modulus of about 1450 MPa.

The Fiber mass, at least in part, is due to the selected draw ratio Production of fibers regulated. As used herein, "draw ratio" or "draw ratio" refers to the relationship between the speed of the last and first set of roles.

The Fibers of the present invention are normally used a draw ratio from about 1: 1.5 to about 1: 8, such as 1: 1.5 to 1: 6, such as for example 1: 1.5 to 1: 4, about 1: 2 to 1: 8, about 1: 2 to 1: 6, or about 1: 2 to 1: 4 for Polypropylene fibers, and from 1: 2 to 1: 4.5 for polyethylene fibers and polypropylene / polyethylene bicomponent fibers extended, which in a reasonable fineness, typical like for example about 2 to 20 dtex, such as 2 to 10 dtex, for example typically 3 to 9 dtex, most typically 5 to 8 dtex. The draw ratio affects the crystallinity, that is, at higher draw ratios the polymer chains increasingly coordinated and thus more crystalline become. Bigger drawing conditions also tend to be essentially the crystalline regions the fiber length along which these fibers are substantially anisotropic power. Increasingly crystalline fibers are increasingly resulting stiffer fibers, for example, the higher the crystallinity and the Alignment of the crystals are the higher the stiffness of the fibers.

The draw ratio of a polypropylene fiber capable of producing a high mass nonwoven fabric is preferably in the interval from 1: 2 to 1: 4. The polypropylene fiber of the present invention typically has a draw ratio of about 1: 1.5 to 1: 6, such as about 1: 2 to 1: 5, preferably 1: 2.5 to 1: 4.

To The present invention provides high crystallinity of the individual Fibers a bulky nonwoven material, for example, give more crystalline and thus stiffer fibers give a more voluminous appearance to the nonwoven material. Without being bound by any specific theory, it is suggested when the nonwoven material is subjected to an external force, the high crystallinity fibers have the ability to distract, as it were and because of the inborn stiffness in the original ones Restore condition. This feature is, at least in part, due to the springback quantified. rebound denotes the ability after removing a strain or strain, which is a Deformation causes to restore the original shape and size. The springback the fiber suitable for making a bulky nonwoven material is typically at least about 30%, such as at least about 40%, such as about 42%.

The mass of a fiber suitable for making a bulky nonwoven material as indicated does not necessarily correspond to the mass of the nonwoven fabric. Typically, the fibers of the invention which are suitable for preparing a bulky non-woven fabric, however, have a mass of at least about 20 cm ³ / g, preferably at least about 30 cm ³ / g and 35 cm ³ / g, such as at least about 40 cm ³ / g.

The Flexural modulus of a polyolefin used to make a fiber which is used to produce a bulky nonwoven fabric of the invention is typically at least 1200 MPa, such as at least 1500 MPa.

• i) einer Faser/Faserreibung von höchstens 600 g;
• ii) einem Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) einem Ziehverhältnis von mindestens 1:1,5;
• iv) einer Faser-Kristallinität von mindestens 50%;
• iv) das Polyolefin-Polymer ist ein nukleiertes Polymer;
• vi) das Polyolefin hat einen Biegemodul von mindestens 1500 MPa;
• vii) einem ST dtex-Wert von 2 bis 20 dtex; und
• viii) einer Faser-Masse von 20 cm³/g, vorzugsweise mindestens etwa 30 cm³/g,

ausgewählt sind.As indicated, the proper regulation results in any of the characteristics of a fiber selected from the group comprising fiber-to-fiber friction; the spin finish; the draw ratio; and the fiber crystallinity is selected in a fiber suitable for producing a bulky nonwoven fabric. The fiber based on the polyolefin polymer of the invention preferably has at least two of the characteristics selected from the group consisting of

• i) a fiber / fiber friction of at most 600 g;
• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5;
• iv) a fiber crystallinity of at least 50%;
• iv) the polyolefin polymer is a nucleated polymer;
• vi) the polyolefin has a flexural modulus of at least 1500 MPa;
• vii) an ST dtex value of 2 to 20 dtex; and
• viii) a fiber mass of 20 cm ³ / g, preferably at least about 30 cm ³ / g,

are selected.

• i) einer Faser/Faserreibung von höchstens 600 g;
• ii) einem Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) einem Ziehverhältnis von mindestens 1:1,5;
• iv) einer Faser-Kristallinität von mindestens 50%;
• iv) das Polyolefin-Polymer ist ein nukleiertes Polymer;
• vi) das Polyolefin hat einen Biegemodul von mindestens 1500 MPa;
• vii) einem ST dtex-Wert von 2 bis 20 dtex; und
• viii) einer Faser-Masse von 20 cm³/g, vorzugsweise mindestens etwa 30 cm³/g,

ausgewählt sind.The fiber of the invention suitably has at least three of the features, such as at least four of the features, such as at least five, six, seven or eight of the features selected from the group consisting of

• i) a fiber / fiber friction of at most 600 g;
• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5;
• iv) a fiber crystallinity of at least 50%;
• iv) the polyolefin polymer is a nucleated polymer;
• vi) the polyolefin has a flexural modulus of at least 1500 MPa;
• vii) an ST dtex value of 2 to 20 dtex; and
• viii) a fiber mass of 20 cm ³ / g, preferably at least about 30 cm ³ / g,

are selected.

• i) einer Faser/Faserreibung von höchstens 600 g;
• ii) einem Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) einem Ziehverhältnis von mindestens 1:1,5;
• iv) einer Faser-Kristallinität von mindestens 50%, und
• iv) das Polyolefin-Polymer ist ein nukleiertes Polymer,

ausgewählt sind.More preferably, the fiber of the present invention has at least two of the features consisting of the group consisting of

• i) a fiber / fiber friction of at most 600 g;
• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5;
• iv) a fiber crystallinity of at least 50%, and
• iv) the polyolefin polymer is a nucleated polymer,

are selected.

• i) einer Faser/Faserreibung von höchstens 600 g;
• ii) einem Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) einem Ziehverhältnis von mindestens 1:1,5;
• iv) einer Faser-Kristallinität von mindestens 50%,
• iv) das Polyolefin-Polymer ist ein nukleiertes Polymer; und mindestens eins der Merkmale, wie zum Beispiel mindestens zwei der Merkmale, die aus der Gruppe bestehend aus
• vi) das Polyolefin hat einen Biegemodul von mindestens 1500 MPa;
• vii) einem ST dtex-Wert von 2 bis 20 dtex; und
• viii) einer Faser-Masse von 20 cm³/g, vorzugsweise mindestens etwa 30 cm³,

ausgewählt sind.The fiber of the present invention suitably has at least two of the features selected from the group consisting of

• i) a fiber / fiber friction of at most 600 g;
• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5;
• iv) a fiber crystallinity of at least 50%,
• iv) the polyolefin polymer is a nucleated polymer; and at least one of the features, such as at least two of the features consisting of the group
• vi) the polyolefin has a flexural modulus of at least 1500 MPa;
• vii) an ST dtex value of 2 to 20 dtex; and
• viii) a fiber mass of 20 cm ³ / g, preferably at least about 30 cm ³ ,

are selected.

• i) eine Faser/Faserreibung von höchstens 600 g;
• ii) ein Spinnfinish, umfassend im wesentlichen eine Emulsion von Polysiloxanen;
• iii) ein Ziehverhältnis von mindestens 1:1,5; und
• iv) eine Faser-Kristallinität von mindestens 50%.

In a most preferred embodiment, the fiber based on polyolefin polymer of the present invention is such that the polyolefin polymer is a nucleated polymer and has the fiber

• i) a fiber / fiber friction of at most 600 g;
• ii) a spin finish comprising substantially an emulsion of polysiloxanes;
• iii) a draw ratio of at least 1: 1.5; and
• iv) a fiber crystallinity of at least 50%.

One Another purpose of the invention relates to a nonwoven material, the a polyolefin-based staple fiber as defined above is.

The The present invention also relates to a process for the preparation a nonwoven fabric made of staple fibers, which process the stages the (a) forming a nonwoven fabric comprising staple fibers according to fiber specifications given herein, and (b) bonding the nonwoven fabric includes. Press the staple fibers in particular a low fiber / fiber friction, such as at most 600 g, such as at most 400 g, suitably at most 300 g, off.

Alternatively, the nonwoven material is defined based on the invention, polyolefin-based staple fibers, and wherein the nonwoven material has a mass of at least 30 cm ³ / g and a resilience of at least 50%. The nonwoven material typically has a spring back of at least 55%, such as at least 60%.

The Nonwoven material typically has a mass of at least 35%, such as for example, at least 40%, preferably at least 45%, more preferably at least 50%, more preferably at least 55%, most preferably at least 60%.

One Another purpose of the invention relates to a process for the preparation a polyolefin-based fiber, the process being characterized by use a nucleated polymer, a draw ratio of at least 1: 1.5 and a spin finish comprising substantially an emulsion of modified polysiloxanes, is characterized.

In a preferred embodiment In the present invention, the fibers described herein are polyolefin-based Staple fibers or copolymers thereof. Polyolefins used for the production of such fibers include polyolefins derived from the Group consisting of isotactic or syndiotactic homopolymers as well as arbitrary Copolymers thereof with ethylene, 1-butene, 4-methyl-1-pentene, etc. and linear Polyethylenes with different masses, such as polyethylene high mass, low mass polyethylene and linear polyethylene are selected with low mass and mixtures thereof. The polymeric material may be combined with other non-polyolefin polymers, such as Polyamide or polyester, to be mixed, provided that the Polyolefins still the largest part make up the composition. The polymer becomes suitable selected from polyethylene and polypropylene.

The melts used to make the polyolefin containing fibers may also contain various common fiber additives such as calcium stearate, antioxidants, process stabilizers, compatibilizers and pigments, including bleaching agents such as TiO ₂ and / or other colorants.

The Fibers can either monocomponent or bicomponent fibers, wherein the latter, for example, two-component fibers of the "sheath-and-core" type are where the core is either eccentric (off-center) or concentric (essentially in the middle). Two-component fibers typically have one Core and a shell, the polypropylene / polyethylene, high mass polyethylene / polyethylene with a linear one low mass, polypropylene-random copolymer / polyethylene or polypropylene / polypropylene random copolymer. The cross-sectional shape of the fibers may also be circular, three-lobal, four-lobal his or next to the form cave Own cores.

The Spinning the fibers is preferably done using ordinary Melt spinning, also known as long spinning, achieved, the Spinning and stretching are carried out in two separate stages. Alternatively, others can Means for the production of staple fibers, in particular "compact spinning", the one step by step execution is to execution of the invention.

To the Spinning the polyolefinhaltige material is extruded, and the Polymer melt is passing through the holes a spinneret directed. The extrudates are subsequently cooled and with a stream of air hardens and simultaneously drawn to fibers. After hardening, the fibers are mixed with treated the first spin finish. This is typical with the help of infeed carried out. Alternative systems, such as spraying the fiber bundles or Dipping the fiber bundles in the spin finish, are also suitable.

The Amount of fiber degradation also affects thermobonding properties. Too low fiber degradation thus tends to result in low thermal bond properties fibers and low processability of the spider line. The degradation of the polymer hangs on the amount of stabilizers in the polyolefin-containing material, the temperature of the extruder and the speed and temperature of the extruder cooling air from.

One Means for determining the degradation level of the spun fibers is to measure the melt flow rate (MFR) of the fibers and him with the MFR of the original one To compare polymer material. In a preferred embodiment In the present invention, the MFR of the spun fibers is between 1.5 and 7 times the MFR's of the raw material, typically between 2 and 5 times the MFR's of the raw material. However, it should be pointed out that this is to some extent from the MFR of the raw material depends. Thus, in relation to a raw material with a relatively high MFR the preferred ratio often be slightly lower between fiber MFR and raw material MFR, for example, 3-5 times with respect to a raw material with an MFR from 10-15 and 2-4 times with respect to a raw material MFR of 15-25.

The Drawing process typically includes a series of warm rolls and a hot air oven. The fibers only pass through a set of Rolling, followed by passage through a hot air oven, and after from the passage through a second set of roles. Both the warm rolls as well as the hot air oven are typically at a temperature from about 50-140 ° C, such as about 70-130 ° C, where the temperature is selected according to the fiber type; typically 115-135 ° C in relation on polypropylene fibers, 95-105 ° C in terms of Polyethylene fibers and 110-120 ° C in terms of Polypropylene / polyethylene bicomponent fibers. The speed the second set of roles is faster than the speed of the first set, and thus the heated fibers become accordingly moved out. A second oven and a third set can also be used (two-stage extent), where the third sentence of roles a higher Speed as the second set has. Similarly, more can be done Sets of Rolls and ovens be used. The train ratio is the relationship between the last and first set of roles. The fibers of the Present invention will be typical using a draw ratio from about 1: 1 to about 1:10.

To The draw will be the fiber bundles treated with the second spin finish, for example, using of insertion rollers or by spraying or immersion.

The drawn-out fibers are usually textured (curled), around the fibers for make the carding suitable, for example by awarding a "wavy" shape / for example in that a "wavy" shape of the fibers is awarded. Effective texturing, i. a relative size Number of ripples in the fibers high processing speeds in the card, for example at least 80 m / min, typically at least 150 m / min or even 200 m / min or more, and thus high productivity.

Crimping is suitably performed using a so-called stuffer box, or the fibers may alternatively be air-textured. In certain cases, ie with respect to asymmetric biocomponent fibers, crimping machines can be eliminated because the heat treatment of such fibers results in three-dimensional self-cockling.

The Fibers of the present invention become typical to a level from about 5-15 crimps / cm, typically about 7-12 ripples / cm, textured, where the number of crimps is the number of bends in corresponds to the fibers.

A third spin finish treatment may possibly occur after cooling the fibers are used, for example by a spray process.

To the curling the fibers become typical with regard to fixation and drying passed through a hot air oven. The temperature of the oven depends on the composition of the fibers, but the temperature is in particular below the melting point of the lowest melt component. The oven temperature is typically in the interval of 90-130 ° C, for example 95-125 ° C. In the heat treatment Also, a certain amount of water is removed from the spin finish. The drying process, which is an important factor, for example in view of this, in case of cross-linking, the finish is insoluble too make, granted thus permanent properties. The residual moisture content is preferably less than 2.0% by weight, more preferably less than 1.0% by weight, based on the weight of the fibers.

The dried fibers are then passed to a knife where the Fibers are cut into staple fibers of the desired length. The Fibers of the present invention become typical staple fibers with a length from about 18-180 mm, more preferably about 25-100 mm, especially about 30-75 mm, cut.

At any of the three points on the fiber line, i. after spinning, after drawing or after cooling, can be an antistatic Means are used. The antistatic agent is preferred non-ionic, such as phosphate esters, or anionic, such as for example, phosphate salt, while cationic antistatic agents are less preferred. In a preferred embodiment however, the antistatic agent of the present invention after cooling used.

The Method for producing a nonwoven material of the invention typically the stage of production of fibers having a draw ratio of Fibers of 1: 2 to 1: 8, such as 1: 2 to 1: 6.

The Method of producing a nonwoven material of the invention typically the stage of applying a spin finish, which is essentially from an aqueous Emulsion of polysiloxanes having at least 25% active content, for example at least 30% active content, preferably at least 35% active Salary, for example, about 40% exists. The spin finish becomes suitable in a concentration of 2-15%, such as 5-10%. The spin finish level of the fiber is suitably 0.2 to 1% by weight, such as 0.25 to 0.9%, preferably 0.3 to 0.85%, most preferably 0.35 to 0.85%: The invention also depends a method for producing a nonwoven material, which method the application of a fiber as defined herein, or the Use of a fiber made as defined herein.

to Preparation of the nonwoven material of the invention contributes to the fibers a temperature of 130 to 150 ° C, such as 132 to 148 ° C, preferably at 134 to 144 ° C, suitably using an appropriate biocomponent bound Fiber, such as ES-FiberVisions ES-C Cure fiber, oven solidified.

One Another aspect of the invention relates to a hygiene product, the Nonwoven material as defined herein. Another purpose of Invention relates to a method for producing a hygiene product, which method involves the use of a nonwoven material as herein includes defined.

The Fibers described below in the Examples are diminished various parameters that are used to determine the Fiber mass or the nonwoven fabric mass are important. The most significant these parameters are the crystallinity and the fiber / fiber friction. Both the mass and the springback fibers and nonwoven fabric are made according to any of the standard methods, those skilled in the art are determined.

All Measurements have been measured according to ISO 554 Standard Atmosphere 23/50.

The Measure of Fiber crystallinity can, as by differential scanning calorimetry (DSC) or by X-ray Diffraction (XRD) can be determined, using both methods Experts are known.

Dimensions and springback can according to the Inda Standard test "Measuring Compression and Recovery of Highloft Nonwoven "IS to be measured 120.3 - 92. This Method is also adapted for measuring the mass and springback of the fibers Service.

Examples

example 1

The Mass and springback the different fibers and their corresponding nonwovens go out Table 1 below.

As It can be seen from the data in Table 1, has a number of Parameters affect the mass and springback of both fibers and on the nonwoven: inter alia, the type of matrix polymer used, the type of spin finish used during the drawing process and the Drawing ratio. Two other parameters are measured, namely the fiber / fiber friction and the fiber crystallinity, which parameters also to a certain extent the type of used Matrix polymer, of the type of spin finish used during the Pulling process and drawing relationship depend. The mass and springback the fibers and the nonwoven fabric thus depend directly on the type of Matrix polymer, spin finish type, draw ratio, and indirectly from fiber / fiber friction and crystallinity, to For example, these features only reflect the type of used Matrix polymer, the type of spin finish used and the draw ratio, the used in the manufacturing process. The fiber / fiber friction and crystallinity values are used to contribute to the relationship between the many parameters of the present invention. The crystallinity will be both by differential scanning calorimetry (DSC) as well as by X-ray Diffraction (XRD) is measured, and the fiber / fiber friction decreases measured by the method described herein.

table Figure 1 shows that the inventors of the present invention surprisingly found that both the type of matrix polymer and the type of spin finish in terms of mass and springback the fibers and the nonwoven fabric are important.

Trends reflected in Table 1 show that fibers with Synthesin 7490 FILL, which are in the Traction process used has a lower fiber / fiber friction than fibers in which only Silastol GF602-c is used. This effect becomes clear when samples number 2 and 4 are compared with samples 3 and 5.

Furthermore have fibers with used Silastol GF602-c an improved mass (Fiber mass as opposed to nonwoven mass), compared to Synthesin 7490 FILL used in the pulling process. This effect will clearly when samples number 2 and 4 are compared with samples 3 and 5, Table 1.

fibers, made from Adstif HA840R (nucleated polypropylene homopolymer) are, have a higher crystallinity compared to fibers made from PPH7059 (non-nucleated polypropylene homopolymer) are. This effect becomes clear when samples number 2 and 4 with Samples 3 and 5 are compared, Table 1.

fibers, made from Adstif HA840R (nucleated polypropylene homopolymer) are, have an improved mass compared with fibers that are made PPH7059 (non-nucleated polypropylene homopolymer) are and for the same finish was used. This effect becomes clear if the sample number 4 with the sample number 2, and the sample number 5 with the sample number 3, Table 1.

fibers with a high draw ratio result in a high fiber mass and a high nonwoven mass compared to fibers with a lower draw ratio. Around to draw that conclusion, it is necessary that the same Type of polymer and spin finish used, for example, have the conditions be the same to make a comparison. The trend is clear For example, if samples 5, 8 and 10 are compared, see Table 1.

Nonwovens, which are based on fibers with Synthesin 7490 FILL used an improved mass compared to nonwovens in which only Silastol GF602-c is used. This effect becomes apparent when Samples number 3 and 5 are compared with samples 2 and 4, Table 1.

Nonwovens, based on fibers made from Adstif HA840R (nucleated polypropylene homopolymer) are, have an improved mass compared to nonwovens, based on fibers made from PPH7059 (non-nucleated polypropylene homopolymer) are made. This effect becomes apparent when the sample number 4 with the sample number 2, and the sample number 5 with the sample number 3, Table 1.

Example 2

The achieved mass and springback, As far as the fiber and the nonwoven are concerned, see Table 2 out. The nonwovens were made using 30% ES-C bico fibers, at a bond interval of 134-140 ° C, oven solidified. Test number 1 is used as a benchmark, for example an ordinary homopolymer (PPH 7059 matrix polymer), used in which no nucleating agent has been added.

table 2 Maximum mass related to selected fibers and nonwovens was obtained.

From Table 2 in particular the sample 1 and 4 must be highlighted. Sample No. 1 includes the standard PPH 7059 matrix polymer (no nucleation) and an ordinary spin finish GF602-c, while Sample 4 comprises a nucleated Adstif HA840R matrix polymer and a Synthesin 7490 FILL spin finish. When comparing the two samples, it can be concluded that the sample number 4 expresses a mass value with respect to the nonwoven which corresponds to an increase of about 164% (from 28 cm ³ / g to 74 cm ³ / g). According to the present invention, and without being bound by any specific theory, this surprising jump in bulkiness is expected to result from the combined use of a nucleated homopolymer (Adstif HA840R) with the Synthesin 7490 FILL spin finish, which gives high crystallinity and stiff fibers. caused. This combination also gives fibers with a surprisingly low fiber / fiber friction, which in turn provides a reasonably high mass of the nonwoven (for example, the fiber / fiber movement is relatively "free").

Example 3

Of the Influence of the bonding temperature on the bulkiness and springback is shown in Table 3. The cheapest bulkiness in terms of on the nucleated Adstif HA840R matrix polymer containing the Synthesin 7490 FILL spinning finish is used at a bonding temperature of 140 ° C reached.

table 3 Influence of bonding temperature on mass and springback.

Claims (31)

A fiber comprising polyolefin polymer, wherein the Fiber one i) fiber / fiber friction of at most 600 g; ii) a Spin finish consisting essentially of an aqueous emulsion of polysiloxanes with at least 25% active content; iii) a fiber crystallinity of at least 50% owns. A fiber comprising polyolefin polymer, wherein the fiber i) a fiber / fiber friction of at most Has 600 g; ii) has a spin finish that is substantially from an aqueous Emulsion of polysiloxanes having at least 25% active content; and at least one of iii) a draw ratio of at least 1: 1.5; or iv) the polyolefin polymer, which is a nucleated polymer is. A fiber according to claim 1 or claim 2, wherein the Fiber / fiber friction at most 500 g, preferably at most 400 g, is. A fiber according to claim 1 or claim 2, wherein the Fiber / fiber friction 200 to 600 g, preferably 200 to 500 g, in particular 200 to 400 g. A fiber according to any one of claims 1 to 4, wherein the spin finish essentially from an aqueous one Emulsion of polysiloxanes, for example at least 30% active Content, preferably at least 35% active content, such as about 40% exists. A fiber according to claim 5, wherein the spin finish is in a Concentration of 2-15%, such as 5-10%. A fiber according to any one of claims 5 to 6, wherein the spin finish level the fiber 0.2 to 1% by weight, such as 0.25 to 0.9%, preferably 0.3 to 0.85%, in particular 0.35 to 0.85%. A fiber according to any one of the preceding claims, wherein the fiber crystallinity at least 55%, such as at least 60% as measured by DSC or XRD, is. A fiber according to any one of the preceding claims, wherein the polyolefin polymer a nucleated polymer, wherein the nucleating agent is selected from the Group consisting of talc, metallic salts of aliphatic or aromatic carboxylic acids, branched polymers containing dendritic branches and minerals, such as chalk, gypsum, clay kaolin, mica and silicates and compounds based on D-sorbitol and 1,3-2,4-bis- (3,4-dimethylbenzylidene) -D-sorbitol. selected are. The fiber of claim 9, wherein the nucleating agent Talc is. A fiber according to claim 9, wherein the polyolefin polymer a nucleated polymer germinated with 5,000 to 10,000 ppm talc, is. A fiber according to any one of the preceding claims, wherein the polyolefin from the group consisting of isotactic or syndiotactic Polypropylene homopolymers, Homopolymers and copolymers of monoolefins, such as ethylene, Propylene, alpha olefins, 4-methyl-1-pentene and mixtures thereof, linear Polyethylenes, high-mass polyethylene, low-density polyethylene Bulk and linear low mass polyethylene and blends selected from it is. The fiber of claim 9 wherein the polyolefin is the group consisting of homopolymer polypropylene and homopolymer polyethylene selected is. A fiber according to claim 9, wherein the polyolefin is a Homopolymer polypropylene is. The fiber of claim 1 having a mass of at least about 30 cm ³ / g of at least about 35 cm ³ / g, such as at least about 40 cm ³ / g. A fiber according to any one of the preceding claims, wherein the draw ratio about 1: 2 to 1: 8, such as about 1: 2 to 1: 6, preferably 1: 2 to 1: 5, is. A fiber according to any one of the preceding claims a ST dtex value from 2 to 20 dtex, such as 2 to 10 dtex, typically 3 to 9 dtex, most typically 5 to 8 dtex. A fiber according to any one of the preceding claims a springback of at least 40%. A fiber according to any one of the preceding claims, wherein the polyolefin has a flexural modulus of at least 1500 MPa. A fiber comprising polyolefin polymer according to any one of of the preceding claims, wherein the polyolefin polymer is a nucleated polymer, and the fiber i) a fiber / fiber friction of at most 600 g; ii) a Spin finish comprising substantially an emulsion of polysiloxanes; iii) a draw ratio of at least 1: 1.5 with a final fiber fineness of 2 to 10 dtex; iv) has a fiber crystallinity of at least 50%. A nonwoven material comprising polyolefin-based staple fiber according to any one of claims 1 to 20, wherein the nonwoven material has a mass of at least 30 cm ³ / g and a spring back of at least 50%. The nonwoven material of claim 21, wherein the nonwoven material a springback of at least 55%, for example at least 60%. A sheet material of any of claims 21 to 22, wherein the nonwoven material has a mass of at least 35 cm ³ / g, for example at least 40 cm ³ / g, preferably at least 45 cm ³ / g, in particular min at least 50 cm ³ / g, more preferably at least 55 cm ³ / g, most preferably at least 60 cm ³ / g. Process for the preparation of a polyolefin-based Fiber, the process being characterized by the use of a nucleated Polymers, a draw ratio of at least 1: 1.5 with a final fiber dtex of 2 to 10 dtex, and a spin finish comprising essentially an emulsion of polysiloxanes. The method of claim 24, wherein the polymer is from Polyethylene and polypropylene is selected. A method according to any one of claims 24 to 25, wherein the draw ratio 1: 2 to 1: 8, for example 1: 2 to 1: 6. A method according to any one of claims 24 to 26, wherein the spin finish consists essentially of an aqueous Emulsion of polysiloxanes having at least 25% active content, for Example at least 30% active content, preferably at least 35% active salary, for example about 40%. The method of claim 27, wherein the spin finish in a concentration of 2-15%, for example 5-10% becomes. A method according to any one of claims 27 to 28, wherein the spin finish level the fiber is 0.2 to 1% by weight, for example 0.25 to 0.9%, preferably 0.3 to 0.85%, especially 0.35 to 0.85%. Method for producing a nonwoven material, comprising the use of a fiber as in any one of claims 1 to 20 defines, or the use of a fiber following the procedure according to any of the claims 24 to 39 is made. The method of claim 30, wherein the fiber is at a temperature of 130 to 150 ° C, for example 132 to 148 ° C, preferably at 134 to 144 ° C, oven strengthened.