JP7106514B2 - CaCO3 in polyester for nonwovens and fibers - Google Patents

Description

The present invention relates to nonwoven fabrics, processes for preparing nonwoven fabrics, articles comprising such nonwoven fabrics and uses of such nonwoven fabrics and the use of fibers for the manufacture of nonwoven fabrics and the use of calcium carbonate as a filler for nonwoven fabrics.

Nonwovens are sheet or web structures made by bonding together fibers or filaments. These nonwovens can be flat or lofty, depending on the process by which they are manufactured and the materials used, and can be adapted for a variety of uses. In contrast to other textiles such as woven or knitted fabrics, nonwovens do not need to go through a preliminary stage of yarn spinning in order to be turned into a web of a certain pattern. A certain percentage of recycled fabric can be used in the nonwoven depending on the strength of the material required for a particular use. Conversely, some nonwovens can be recycled after use with proper processing and equipment. Therefore, nonwovens may be more environmentally friendly fabrics for certain applications, particularly in areas and industries where disposable or single use products are important, such as hospitals, schools or nursing homes.

Today, nonwovens are mainly produced from thermoplastic polymers such as polypropylene, polyethylene, polyamides or polyesters. The advantages of polyester fibers or filaments are their high crystallinity, high tenacity and strength. Polyethylene terephthalate (PET) is the most widely used class of polyester and is characterized by high modulus, low shrinkage, heat-set stability, lightfastness and chemical resistance, which account for PET's great versatility. be done. One of the major drawbacks of PET is its slow crystallization rate, which does not allow reasonable cycle times in manufacturing processes such as injection molding. Nucleating agents such as talc are therefore often added. However, these extraneous particles can act as stress concentrators, which can affect the mechanical properties of the polymer. Nucleated PET is therefore often reinforced with glass fibers.

Talc-filled PET is described in an article titled "Oxygen barrier properties of crystallized and talc-filled poly(ethylene polymer) et al." published in Journal of Polymer Science: Part B: Polymer Physics, 1999, 37, 847-857. disclosed in US 5,886,088A relates to a PET resin composition containing an inorganic nucleating agent. A method for producing a thermoplastic polymeric material filled with calcium carbonate is described in WO2009/121085A1. WO2012/052778A1 relates to tearable polymeric films comprising polyester and calcium carbonate or mica fillers. Spinning of PET fibers containing modified calcium carbonate has been reviewed by Boonsri Kusktham and described in an article entitled "Spinning of PET fibers mixed with calcium carbonate", which was published in Asian Journal of Textile, 2011, 1(2), 106-113.

Extruded fibers and nonwoven webs containing titanium dioxide and at least one mineral filler are disclosed in US 6,797,377 B1. WO 2008/077156 A2 describes spunlaminated fibers comprising a polymer resin and one filler and nonwoven fabrics comprising such fibers. Nonwovens of synthetic polymers with improved bonding compositions are disclosed in EP2465986A1. WO 97/30199 relates to fibers or filaments suitable for the production of nonwovens, the fibers or filaments consisting essentially of polyolefins and inorganic particles.

In view of the above, improving the properties of polyester-based nonwovens remains important to those skilled in the art.

U.S. Patent Application Publication No. 5,886,088 WO2009/121085 WO2012/052778 U.S. Pat. No. 6,797,377 WO2008/077156 EP-A-2465986 WO 97/30199

Sekelik et al. , Journal of Polymer Science: Part B: Polymer Physics, 1999, 37, 847-857 Boonsri Kusktham, Asian Journal of Textile, 2011, 1(2), 106-113

It is an object of the present invention to provide nonwoven fabrics with improved soft feel and higher stiffness. It would also be desirable to provide nonwovens that can be tailored with respect to hydrophobicity or hydrophilicity. It would also be desirable to provide nonwovens containing reduced amounts of polymer without significantly affecting the quality of the nonwoven.

It is also an object of the present invention to provide a process for making nonwoven fabrics from polyester-based polymer compositions, particularly PET compositions, which can reduce cycle time during melt processing. It would also be desirable to provide a process for making nonwoven fabrics that allows the use of recycled polyester, particularly recycled PET.

The foregoing and other objects are solved by the subject matter defined herein in the independent claims.

According to one aspect of the invention there is provided a nonwoven comprising at least one polymer comprising polyester and at least one filler comprising calcium carbonate.

According to another aspect, the invention comprises:
a) providing a mixture of at least one polymer comprising polyester and at least one filler comprising calcium carbonate;
b) forming the mixture into fibers, filaments and/or film filament structures;
c) forming a nonwoven fabric from fibers, filaments and/or film filament structures.

According to yet another aspect, the present invention provides articles comprising the nonwoven fabrics of the present invention, wherein the articles include construction, consumer apparel, industrial apparel, medical products, home furnishings, protective clothing, etc. Selected from articles, packaging materials, cosmetics, sanitary products or filter media.

According to yet another aspect, the present invention provides the use of calcium carbonate as a filler in nonwoven fabrics comprising at least one polymer comprising polyester.

According to yet another aspect, the present invention provides the use of fibers for the manufacture of nonwoven fabrics, wherein the fibers comprise at least one polymer comprising polyester and at least one filler comprising calcium carbonate. include.

According to yet another aspect, the present invention is used in the construction, waterproofing, thermal insulation, acoustic insulation, roofing, consumer apparel, upholstery and clothing industries, industrial apparel, medical products, home furnishings, Use of the nonwoven fabric of the invention in protective articles, packaging materials, cosmetics, hygiene articles or filter media is provided.

Advantageous embodiments of the invention are defined in the corresponding dependent claims.

According to one embodiment, the polyester is polyglycolic acid, polycaprolactone, polyethylene adipate, polyhydroxyalkanoate, polyhydroxybutyrate, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid or It is selected from the group consisting of this mixture or this copolymer, preferably the polyester is polyethylene terephthalate. According to another embodiment, the polyester has a number average molecular weight of 5000 to 100000 g/mol, preferably 10000 to 50000 g/mol, more preferably 15000 to 20000 g/mol.

According to one embodiment, the calcium carbonate is ground calcium carbonate, precipitated calcium carbonate, modified calcium carbonate, surface treated calcium carbonate or mixtures thereof, preferably surface treated calcium carbonate. According to another embodiment, the calcium carbonate has a thickness of 0.1 to 3 μm, preferably 0.4 to 2.5 μm, more preferably 1.0 to 2.3 μm, most preferably 1.2 to 1.8 μm. It has an average particle size d ₅₀ . According to yet another embodiment, the calcium carbonate has a topcut particle size d ₉₈ of 1 to 10 μm, preferably 5 to 8 μm, more preferably 4 to 7 μm, most preferably 6 to 7 μm. According to yet another embodiment, calcium carbonate is present in the nonwoven from 0.1 to 50% by weight, preferably from 0.2 to 40% by weight, more preferably from 1 to 35% by weight, based on the total weight of the nonwoven. %.

According to one embodiment of the process of the present invention, in step b) the mixture is formed into fibers, preferably by an extrusion process, more preferably by a meltblowing process, a spunbonding process or a combination thereof. According to another embodiment of the process of the present invention, the nonwoven is formed by collecting fibers on a surface or carrier. According to yet another embodiment of the process of the present invention, steps b) and c) are a multi-layer nonwoven, preferably spunbond-meltblown-spunbond (SMS), meltblown-spunbond-meltblown (MSM), spunbond. - meltblown-spunbond-meltblown (SMSM), meltblown-spunbond-meltblown-spunbond (MSMS), spunbond-meltblown-meltblown-spunbond (SMMS) or meltblown-spunbond-spunbond-meltblown (MSSM) Repeated two or more times to produce a nonwoven fabric.

In the present invention, the following terms should be understood to have the following meanings.

The term "crystallinity" as used in the context of the present invention refers to the portion of the molecules that are ordered within the polymer. The remaining portion is called "amorphous". Polymers may crystallize upon cooling due to melting, mechanical stretching or solvent evaporation. Crystalline regions are generally more densely packed than amorphous regions and crystallization can affect the optical, mechanical, thermal and chemical properties of a polymer. Crystallinity is described in percent and can be measured by differential scanning calorimetry (DSC).

"Grounded calcium carbonate" (GCC) in the sense of the present invention is obtained from natural products such as limestone, marble, calcite, chalk, etc., and is subjected to grinding, sieving and/or wet treatment, e.g. and/or calcium carbonate processed through dry processing.

The term "intrinsic viscosity" as used in the context of the present invention is a measure of the ability of a polymer in solution to increase the viscosity of the solution and is stated in dl/g.

"Modified Calcium Carbonate" (MCC) in the sense of the present invention means natural ground or precipitated calcium carbonate with internal structural modifications or surface reactants, i.e. "surface-reacted calcium carbonate" may be characterized. A "surface-reacted calcium carbonate" is a material comprising calcium carbonate and an insoluble, preferably at least partially crystalline, calcium salt of an anion of an acid on its surface. Preferably, the insoluble calcium salt extends from the surface of at least a portion of the calcium carbonate. The calcium ions forming the at least partially crystalline calcium salt of the anion are predominantly derived from the starting calcium carbonate material. MCC is described, for example, in US2012/0031576A1, WO2009/074492A1, EP2264109A1, EP2070991A1 or 2264108A1.

In the present invention, the term "nonwoven" refers to a flat, flexible, porous sheet structure made by interlacing layers or networks of fibers, filaments or film-like filament structures.

Throughout this document, the "particle size" of the calcium carbonate filler is expressed as the distribution of particle sizes of the calcium carbonate filler. The value dx represents the diameter for which _x % _by weight of particles have a diameter less than dx. This means that the value of d20 is the size below which 20% by weight of all particles are smaller, and the value of _d98 is the size below which ₉₈ % by weight of all particles are. That is. The value of _d98 is also called "top cut". The value of d50 is therefore the weight median particle size, ie ₅₀ % by weight of all particles are larger or smaller than this particle size. Unless stated otherwise in the present invention, particle size is described as weight median particle size _d50 . To determine the weight median particle size d50 value or the _topcut particle size _d98 value, a Micromeritics (USA) Sedigraph 5100 or 5120 apparatus can be used.

The term "polymer" as used herein generally includes homopolymers and copolymers, such as block, graft, random and alternating copolymers, as well as blends and variations thereof.

A "precipitated calcium carbonate" (PCC) in the sense of the present invention is a synthetic material, generally by reaction of carbon dioxide with calcium hydroxide (slaked lime) in an aqueous environment followed by precipitation, or by precipitation of calcium in water. and obtained by precipitating a carbonate source. Additionally, precipitated calcium carbonate can be the product of introducing calcium salts and carbonates, such as calcium chloride and sodium carbonate, into an aqueous environment. PCC may be vaterite, calcite or aragonite. PCCs are described, for example, in EP2447213A1, EP2,524,898A1, EP2371766A1 or unpublished European Patent Application No. 12164041.1.

In the sense of the present invention, "surface-treated calcium carbonate" is ground, precipitated or modified calcium carbonate comprising a treatment or coating layer, eg a layer of fatty acids, surfactants, siloxanes or polymers.

Where the term "comprising" is used in the specification and claims, other elements are not excluded by the term. In the present invention the term "consisting of" is considered a preferred embodiment of the term "comprising of". In the following, where a group is defined to include at least a certain number of embodiments, this should also be understood to disclose the group preferably consisting only of those embodiments. be.

When an indefinite or definite article is used when referring to a singular noun, e.g., "a", "an" or "the", the noun is used unless specifically stated otherwise. Includes plural.

Terms such as "obtainable" or "definable" and "obtained" or "defined" are used synonymously. By this is meant, e.g., unless the context clearly dictates otherwise, the term "obtained" may be used, e.g., by an order of steps following the term "obtained," for example. It does not mean that it must be obtained. However, such limited understandings are always included as preferred embodiments by the terms "obtained" or "defined".

The nonwoven fabric of the present invention comprises at least one polymer comprising polyester and at least one filler comprising calcium carbonate. Details and preferred embodiments of the product of the invention are described in more detail below. It is to be understood that these technical details and embodiments also apply to the inventive process for making such nonwovens and the inventive use of nonwovens, fibers, compositions and calcium carbonate.

At Least One Polymer The nonwoven fabrics of the present invention comprise at least one polymer, including polyester.

Polyesters are a class of polymers that contain ester functional groups in the main chain and are generally obtained by polycondensation reactions. Polyesters may include naturally occurring polymers such as cutin, as well as synthetic polymers such as polycarbonate or polybutyrate. Depending on their structure, polyesters may be biodegradable.

According to one embodiment, the polyester is polyglycolic acid, polycaprolactone, polyethylene adipate, polyhydroxyalkanoate, polyhydroxybutyrate, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid or It is selected from the group consisting of this mixture or this copolymer. Any of these polymers may be in pure form, i.e. homopolymeric form, or by copolymerization and/or addition of one or more substituents to the backbone or side chains of the backbone. may be modified.

According to one embodiment of the invention, at least one polymer consists of polyester. The polyester may consist of only one particular type of polyester or a mixture of one or more types of polyester.

The at least one polymer is present in the nonwoven in an amount of at least 40 wt%, preferably at least 60 wt%, more preferably at least 80 wt%, most preferably at least 90 wt%, based on the total weight of the nonwoven. can be done. According to one embodiment, the at least one polymer is present in the nonwoven in an amount of 50 to 99% by weight, preferably 60 to 98% by weight, more preferably 65 to 95% by weight, based on the total weight of the nonwoven. exists in

According to a preferred embodiment of the invention the polyester is polyethylene terephthalate.

Polyethylene terephthalate (PET) is a condensation polymer and may be industrially produced by condensing either terephthalic acid or dimethyl terephthalate with ethylene glycol.

PET may be polymerized by transesterification with the monomers diethyl terephthalate and ethylene glycol or by direct esterification with the monomers terephthalic acid and ethylene glycol. Both transesterification and direct esterification processes are combined batchwise or continuously with a polycondensation step. A batch system requires two reaction vessels, one for the esterification or transesterification and one for the polymerization. A continuous system requires at least three vessels, one for esterification or transesterification, one for reducing excess glycol, and one for polymerization.

PET may also be produced by solid state polycondensation. For example, in such processes, melt polycondensation is continued to the point where the prepolymer has an intrinsic viscosity of 1.0 to 1.4 dl/g at which the polymer is cast into a solid film. Pre-crystallization is performed, for example, by heating above 200° C. until the desired molecular weight of the polymer is obtained.

According to one embodiment, PET is obtained from a continuous, batch or solid state polymerization process.

According to the invention, the term "polyethylene terephthalate" includes unmodified and modified polyethylene terephthalate. Polyethylene terephthalate may be a linear, branched or crosslinked polymer. For example, when glycerol is reacted with a diacid or its anhydride, each glycerol generates a branch point. When internal coupling occurs, for example, the polymer is crosslinked by reaction of hydroxyl groups and acid groups of branches of the same or different molecules. Optionally, the polyethylene terephthalate can be substituted, preferably with C1 to _{C10 alkyl} groups, hydroxyl groups and/or amine groups. According to one embodiment, polyethylene terephthalate is substituted with methyl, ethyl, propyl, butyl, tert-butyl, hydroxyl and/or amine groups. Polyethylene terephthalate can also be modified by copolymerization, for example with cyclohexanedimethanol or isophthalic acid.

Depending on processing and thermal history, PET may exist as both amorphous and semi-crystalline polymers, ie, polymers containing crystalline and amorphous portions. Semicrystalline materials can appear transparent or opaque and white, depending on the crystal structure and grain size.

According to one embodiment, polyethylene terephthalate is amorphous. According to another embodiment, the polyethylene terephthalate is semi-crystalline, preferably the polyethylene terephthalate has a crystallinity of at least 20%, more preferably at least 40%, most preferably at least 50%. According to yet another embodiment, the polyethylene terephthalate has a crystallinity of 10 to 80%, more preferably 20 to 70%, most preferably 30 to 60%. Crystallinity may be measured by differential scanning calorimetry (DSC).

According to one embodiment of the invention, the polyethylene terephthalate has a It has an intrinsic viscosity (IV).

According to another embodiment of the invention, polyethylene terephthalate has a glass transition temperature (T _g ) of 50 to 200°C, preferably 60 to 180°C, more preferably 70 to 170°C.

According to one embodiment of the invention, the polyethylene terephthalate has a number average molecular weight of 5000 to 100000 g/mol, preferably 10000 to 50000 g/mol, more preferably 15000 to 20000 g/mol.

Polyethylene terephthalate may be virgin polymer, recycled polymer or mixtures thereof. Recycled polyethylene terephthalate may be obtained from post-consumer PET bottles, preformed PET scrap, regranulated PET or recycled PET.

According to one embodiment, the polyethylene terephthalate comprises 10 wt%, preferably 25 wt%, more preferably 50 wt%, most preferably 75 wt% recycled PET, based on the total amount of polyethylene terephthalate.

According to one embodiment, at least one polymer consists of polyethylene terephthalate. The PET may consist of a single particular type of PET or a mixture of two or more types of PET.

According to one embodiment, the at least one polymer comprises another polymer, preferably a polyolefin, polyamide, cellulose, polybenzimidazole or mixtures thereof or copolymers thereof. Examples of such polymers are polyhexamethylene diadipamide, polycaprolactam, aromatic or partially aromatic polyamides (“aramids”), nylon, polyphenylene sulfide (PPS), polyethylene, polypropylene, polybenzimidazoles. Or rayon.

According to one embodiment, the at least one polymer comprises at least 50% by weight, preferably at least 75% by weight, more preferably at least 90% by weight, most preferably at least 95% by weight, based on the total amount of at least one polymer. % polyethylene terephthalate.

At least one filler material According to the present invention, the nonwoven comprises at least one filler material comprising calcium carbonate. At least one filler is dispersed within the at least one polymer.

The use of at least one filler containing calcium carbonate in polyester-based nonwovens has certain advantages over conventional nonwovens. For example, the hydrophobicity or hydrophilicity of the nonwoven web can be tailored to the intended use by using a suitable calcium carbonate filler. Additionally, the use of calcium carbonate fillers allows the reduction of polyester in the production of nonwovens without significantly affecting the quality of the nonwovens. Furthermore, the inventors have surprisingly found that the polymer exhibits higher thermal conductivity when calcium carbonate is added as a filler to PET, which results in a faster cooling rate of the polymer. Become. Additionally, without being bound by any theory, it is believed that calcium carbonate acts as a nucleating agent for PET, thus increasing the crystallization temperature of PET. This results in higher crystallization rates, which, for example, further shortens cycle times during melt processing. The inventors have also found that nonwoven webs made from PET containing calcium carbonate fillers have improved soft feel and higher stiffness compared to nonwoven webs made from PET alone. Found it.

According to one embodiment, the calcium carbonate is ground calcium carbonate, precipitated calcium carbonate, modified calcium carbonate, surface treated calcium carbonate or mixtures thereof. Preferably, the calcium carbonate is surface-treated calcium carbonate.

Ground (or natural) calcium carbonate (GCC) is understood to be the naturally occurring form of calcium carbonate mined from sedimentary rocks such as limestone or chalk or from metamorphic marble rock. . Calcium carbonate is known to exist as three types of crystalline polymorphs: calcite, aragonite and vaterite. Calcite, the most common crystalline polymorph, is believed to be the most stable crystalline form of calcium carbonate. Less common is aragonite, which has a discrete or clustered orthorhombic needle crystal structure. Vaterite is the rarest polymorph of calcium carbonate and is generally unstable. Ground calcium carbonate is almost exclusively a polymorph of calcite, which is said to be trigonal rhombohedral and is the most stable of the polymorphs of calcium carbonate. In the sense of this application, the term "source" of calcium carbonate refers to the naturally occurring mineral material from which calcium carbonate is obtained. Sources of calcium carbonate may include other naturally occurring components such as magnesium carbonate, aluminosilicates, and the like.

According to one embodiment of the invention, the source of ground calcium carbonate (GCC) is selected from marble, chalk, calcite, dolomite, limestone or mixtures thereof. Preferably, the source of ground calcium carbonate is selected from marble. According to one embodiment of the invention, the GCC is obtained by dry grinding. According to another embodiment of the invention, the GCC is obtained by wet grinding followed by drying.

A "precipitated calcium carbonate" (PCC) in the sense of the present invention is a synthetic material, generally by precipitation following the reaction of carbon dioxide with lime in an aqueous environment or by precipitation of a source of calcium and carbonate ions in water. , or by precipitation of calcium and carbonate ions such as CaCl ₂ and Na ₂ CO ₃ from solution. Another possible method of producing PCC is the lime-soda process, or the Solvay process, in which PCC is a by-product of ammonia production. Precipitated calcium carbonate exists in three major crystalline forms: calcite, aragonite and vaterite, and each of these crystalline forms has many different polymorphs (crystal habits). Calcite has a trigonal structure and typical crystal habits include scalenohedral (S-PCC), rhombohedral (R-PCC), hexagonal prismatic, tabular, colloidal (C-PCC), cubic and prismatic (P-PCC). Aragonite has an orthorhombic structure, with typical habits including hexagonal prismatic twinning and thin elongated prismatic, curved edge, steep cone, chiselled crystals, dendritic, coral or Varies with worm-like shape. Vaterite belongs to the hexagonal crystal system. The resulting slurry of PCC can be mechanically dewatered and dried.

According to one embodiment of the invention, the calcium carbonate comprises one precipitated calcium carbonate. According to another embodiment of the invention, the calcium carbonate comprises a mixture of two or more precipitated calcium carbonates selected from different crystalline forms and different polymorphs of precipitated calcium carbonate. For example, the at least one precipitated calcium carbonate may comprise one PCC selected from S-PCC and one PCC selected from R-PCC.

Modified calcium carbonate may be characterized by GCC or PCC with internal structural modification, or surface reacted GCC or PCC. Surface-reacted calcium carbonate may be prepared by providing GCC or PCC in the form of an aqueous suspension and adding acid to the suspension. Suitable acids are, for example, sulfuric acid, hydrochloric acid, phosphoric acid, citric acid, oxalic acid or mixtures thereof. In the next step the calcium carbonate is treated with gaseous carbon dioxide. If strong acids such as sulfuric acid or hydrochloric acid are used in the acid treatment step, carbon dioxide is inevitably produced in situ. Alternatively or additionally, carbon dioxide can be supplied from an external source. Surface-reacted calcium carbonate is described, for example, in US2012/0031576A1, WO2009/074492A1, EP2264109A1, EP2070991A1 or EP2264108A1.

The surface treated calcium carbonate may be characterized by GCC, PCC or MCC including a treatment or coating layer on the surface. For example, calcium carbonate may be treated or coated with a hydrophobizing surface treatment such as, for example, an aliphatic carboxylic acid, its salt or ester, or siloxane. Suitable fatty acids are, for example, C5 to _{C28 fatty} acids such as stearic acid, palmitic acid, myristic acid, lauric acid or mixtures thereof. Calcium carbonate may also be treated or coated with, for example, polyacrylates or polydiallyldimethylammonium chloride (polyDADMAC) to make it cationic or anionic. Surface-treated calcium carbonate is described, for example, in EP2159258A1.

According to one embodiment, the modified calcium carbonate is a surface-reacted calcium carbonate, preferably obtained from reaction with sulfuric acid, hydrochloric acid, phosphoric acid, citric acid, oxalic acid or mixtures thereof and carbon dioxide. .

According to another embodiment, the surface _- treated calcium carbonate is from treatment with fatty acids, salts thereof, esters thereof or combinations thereof, preferably aliphatic C5 to _C28 fatty acids, salts thereof, including treated layers or surface coatings resulting from treatment with these esters or combinations thereof, more preferably from treatment with ammonium stearate, calcium stearate, stearic acid, palmitic acid, myristic acid, lauric acid or mixtures thereof.

According to one embodiment, the calcium carbonate has a thickness of 0.1 to 3 μm, preferably 0.4 to 2.5 μm, more preferably 1.0 to 2.3 μm, most preferably 1.2 to 1.8 μm. It has an average particle size d ₅₀ . Additionally or alternatively, the calcium carbonate has a topcut particle size d ₉₈ of 1 to 10 μm, preferably 5 to 8 μm, more preferably 4 to 7 μm, most preferably 6 to 7 μm.

Calcium carbonate is present in the nonwoven in an amount of 0.1 to 50% by weight, preferably 0.2 to 40% by weight, more preferably 1.0 to 35% by weight, based on the total weight of the nonwoven. can be done. According to another embodiment, the calcium carbonate is present in the nonwoven in an amount of 0.5 to 20% by weight, 1.0 to 10% by weight, 5.0 to 40% by weight,7. It is present in an amount of 5 to 30% by weight or 10 to 25% by weight.

According to one embodiment, the calcium carbonate is dispersed within the at least one polymer and is 0.1 to 50% by weight, preferably 0.2 to 40% by weight, based on the total weight of the at least one polymer. %, more preferably in an amount of 1 to 35% by weight. According to another embodiment, the calcium carbonate is dispersed within the at least one polymer and is, based on the total weight of the at least one polymer, 0.5 to 20% by weight, 1.0 to 10% by weight, It is present in an amount of 5.0 to 40%, 7.5 to 30% or 10 to 25% by weight.

According to one embodiment, at least one filler consists of calcium carbonate. The calcium carbonate may consist of only one particular type of calcium carbonate or a mixture of two or more types of calcium carbonate.

According to another embodiment, at least one filler comprises another mineral pigment. Examples of further pigment particles include silica, alumina, titanium dioxide, clay, calcined clay, talc, kaolin, calcium sulfate, wollastonite, mica, bentonite, barium sulfate, gypsum or zinc oxide.

According to one embodiment, the at least one filler comprises at least 50% by weight, preferably at least 75% by weight, more preferably at least 90% by weight, most preferably at least Contains 95% by weight of calcium carbonate.

According to one embodiment, the at least one filler is present in the nonwoven in an amount of 0.1 to 50% by weight, preferably 0.2 to 40% by weight, more preferably 1 to 50% by weight, based on the total weight of the nonwoven. It is present in an amount of 35% by weight.

According to another embodiment, the at least one filler is dispersed within the at least one polymer and is from 1 to 50% by weight, preferably from 2 to 40% by weight, based on the total weight of the at least one polymer. , more preferably in an amount of 5 to 35% by weight.

According to one aspect of the invention there is provided the use of calcium carbonate as a filler within a nonwoven comprising at least one polymer comprising polyester. According to another aspect of the invention there is provided the use of calcium carbonate as a filler within a nonwoven fabric, wherein the filler is dispersed within at least one polymer comprising polyester.

According to one preferred embodiment of the present invention there is provided the use of calcium carbonate as a filler in nonwovens comprising polyethylene terephthalate. According to another preferred embodiment of the present invention there is provided the use of calcium carbonate as a filler within a nonwoven fabric, wherein the filler is dispersed within at least one polymer comprising polyethylene terephthalate. Preferably, the calcium carbonate is surface-treated calcium carbonate.

According to another aspect of the invention there is provided the use of calcium carbonate as a filler in non-woven fibers, filaments and/or film-like filament structures comprising at least one polymer comprising polyester, preferably polyethylene terephthalate. be done. According to another aspect of the invention there is provided the use of calcium carbonate as a filler in non-woven fibers, filaments and/or film-like filament structures comprising at least one polymer comprising polyester, preferably polyethylene terephthalate. and wherein the filler is dispersed within the at least one polymer.

Nonwovens Nonwovens are flat, flexible, porous sheet structures made by interlacing layers or networks of fibers, filaments and/or film-like filament structures.

According to one aspect of the present invention, nonwoven fibrous, filament and/or film filament structures are provided comprising at least one polymer comprising polyester and at least one filler comprising calcium carbonate.

According to one embodiment, the nonwoven comprises at least one polymer comprising polyester and at least one filler comprising calcium carbonate, wherein the at least one filler is dispersed within the at least one polymer. According to another embodiment, the nonwoven comprises at least one polymer and at least one filler in the form of fibers, filaments and/or film-like filament structures, wherein the at least one filler is , dispersed within at least one polymer.

The fibers and/or filaments may have a diameter of 0.5 to 40 μm, preferably 5 to 35 μm. Additionally, the fibers and/or filaments can have any cross-sectional shape, such as circular, oval, rectangular, dumbbell-shaped, kidney-shaped, triangular or irregular. The fibers and/or filaments can also be hollow fibers and/or bicomponent and/or ternary fibers.

In addition to at least one polymer and at least one filler, the nonwoven fabric may contain other additives such as waxes, optical brighteners, heat stabilizers, antioxidants, antistatic agents, antiblocking agents, dyes, pigments. , polishes, surfactants, natural or synthetic oils. The nonwoven may also contain other inorganic fibers, preferably glass fibres, carbon fibres, or metal fibres. Alternatively or additionally, natural fibers such as cotton, flax, silk or wool may be added. Nonwovens may also be reinforced by reinforcing yarns in the form of textile surface structures, preferably in the form of fabrics, laminates, knitted fabrics, knitwear or nonwovens.

According to one embodiment, the nonwoven consists of at least one polymer comprising polyester and at least one filler comprising calcium carbonate. According to another embodiment, the nonwoven comprises at least one polymer comprising polyethylene terephthalate and at least one filler comprising calcium carbonate. According to yet another embodiment, the nonwoven consists of polyethylene terephthalate and calcium carbonate.

According to an exemplary embodiment, the nonwoven comprises at least one polymer in an amount of 50 to 99% by weight and at least one filler in an amount of 1 to 50% by weight, preferably 60% by weight, based on the total weight of the nonwoven. to 98% by weight of at least one polymer and 2 to 40% by weight of at least one filler, more preferably 65 to 95% by weight of at least one polymer and 5 to 35% by weight of At least one filler material is included. According to another exemplary embodiment, the nonwoven consists of 90% by weight polyester, preferably polyethylene terephthalate, and 10% by weight calcium carbonate, preferably ground calcium carbonate, based on the total weight of the nonwoven. . According to yet another exemplary embodiment, the nonwoven is made from 80% by weight polyester, preferably polyethylene terephthalate, and 20% by weight calcium carbonate, preferably ground calcium carbonate, based on the total weight of the nonwoven. Become.

According to one aspect of the present invention, a process for producing a nonwoven comprises the steps of a) providing a mixture of at least one polymer comprising polyester and at least one filler comprising calcium carbonate; b) the mixture into fibers, filaments and/or film-like filament structures; and c) forming a nonwoven fabric from the fibers, filaments and/or film-like filament structures.

According to a preferred embodiment, the polyester is polyethylene terephthalate and/or the calcium carbonate is surface-treated calcium carbonate.

The mixture of at least one polymer comprising polyethylene terephthalate and at least one filler comprising calcium carbonate provided in process step a) can be prepared by any method known in the art. For example, at least one polymer and at least one filler may be dry blended, melt blended, optionally formed into granules or pellets, or at least one polymer and at least one filler may be premixed, optionally formed into granules or pellets, and mixed with another polymer or filler.

According to one embodiment, in step b) the mixture is formed into fibers, preferably by an extrusion process, more preferably by a meltblowing process, a spunbonding process or a combination thereof. However, any other suitable process known in the art for forming polymers into fibers may be used.

Any meltblown process, spunbond process, or combination thereof known in the art to form a mixture of at least one polymer and at least one filler into fibers may be used. For example, meltblown fibers may be produced by melting a mixture, extruding the mixture through a die or small orifice to form a fiber, and attenuating the molten polymer fibers with hot air. Ambient cold air can then be directed into the hot air stream to cool and solidify the fibers. In the spunbond process, the mixture can be melt spun into fibers by pumping the molten mixture through multiple capillaries arranged in a uniform matrix. After extrusion, the fibers can be attenuated by high velocity air. Air creates a drawing force on the fiber that draws it to the desired denier. The spunbond process may have the advantage of imparting greater tenacity to the nonwoven. The second component may be coextruded in a spunbond process, which may add properties or bondability.

Two typical spunbond processes are well known in the art as the Lurgi process and the Reifenhauser process. The Lurgi process is based on extrusion of molten polymer through a spinneret orifice, followed by air quenching of the newly extruded formed filaments and drawing by suction through a venturi tube. After forming, the filaments are scattered on a conveyor belt to form a nonwoven web.

The Reifenhauser process differs from the Lurgi process in that the filament quench zone is sealed and the quench air flow is accelerated, thus inducing more effective entrapment of the filaments into the air stream.

The fibers formed in process step b) may be drawn or elongated to induce molecular orientation and affect crystallinity. This may result in smaller diameters and improved physical properties.

According to one embodiment of the invention, in step b) the mixture is formed into fibers by combining a meltblowing process with a spunbonding process.

By combining the meltblown process with the spunbond process, a multi-layer nonwoven fabric can be produced, for example, the nonwoven fabric comprises two outer layers of spunbond fabric and an inner layer of meltblown fabric, which is spunbond-meltblown-spun Known in the art as bonded (SMS) nonwovens. Additionally, one or both of these processes may be combined in any arrangement with the bonded fabric resulting from the staple fiber carding process or the nonwoven staple fiber carding process. In such laminated fabrics as described, the layers are generally at least partially consolidated by one of the optional joining methods described further below.

Nonwovens produced by the process of the present invention are multi-layered nonwovens, preferably spunbond-meltblown-spunbond (SMS), meltblown-spunbond-meltblown (MSM), spunbond-meltblown-spunbond-meltblown (SMSM), It can be a meltblown-spunbond-meltblown-spunbond (MSMS), spunbond-meltblown-meltblown-spunbond (SMMS) or meltblown-spunbond-spunbond-meltblown (MSSM) nonwoven. The nonwoven may be compressed, for example by lamination, to bring the layers together.

According to one embodiment, steps b) and c) of the process of the present invention comprise a multi-layer nonwoven, preferably spunbond-meltblown-spunbond (SMS), meltblown-spunbond-meltblown (MSM), spunbond- Meltblown-spunbond-meltblown (SMSM), meltblown-spunbond-meltblown-spunbond (MSMS), spunbond-meltblown-meltblown-spunbond (SMMS) or meltblown-spunbond-spunbond-meltblown (MSSM) nonwovens is repeated two or more times to produce

According to one embodiment, in step c) the nonwoven is formed by collecting fibers on a surface or carrier. For example, the fibers can be collected on a perforated surface such as a moving screen or forming wire. The fibers may be randomly deposited on the perforated surface to form a sheet, and the sheet may be held to the surface by vacuum forces.

According to an optional embodiment of the process of the invention, the resulting nonwoven is subjected to a bonding step. Examples of bonding methods include thermal point bonding or calendering, ultrasonic bonding, hydroentanglement, needling and through-air bonding. Thermal point bonding or calendering is a commonly used method in which the nonwoven fabrics to be bonded are passed through heated calender rolls and anvil rolls. Calender rolls are usually patterned in some way so that the entire fabric is not bonded across the surface. Various patterns can be used in the process of the present invention without affecting the mechanical properties of the web. For example, webs can be bonded according to rib knit patterns, wire weave patterns, diamond patterns, and the like. However, any other joining method known in the art may be used. Optionally, binders, adhesives or other chemicals may be added during the bonding step.

According to another optional embodiment of the process of the present invention, the nonwoven obtained is subjected to a post-treatment step. Examples of post-processing steps are orientation, creping, hydroentanglement or embossing steps.

According to one aspect of the invention there is provided the use of fibers for the manufacture of nonwoven fabrics, wherein the fibers comprise at least one polymer comprising polyester and at least one filler comprising calcium carbonate. According to one preferred embodiment of the present invention there is provided the use of fibers for the manufacture of nonwoven fabrics, wherein the fibers comprise at least one polymer comprising polyethylene terephthalate and at least one filler comprising calcium carbonate. including.

According to another aspect of the invention there is provided the use of a polymer composition for the manufacture of nonwovens, wherein the polymer composition comprises at least one polymer comprising polyester and at least one filler comprising calcium carbonate. Including wood. According to another preferred embodiment of the present invention there is provided the use of a polymer composition for the manufacture of nonwoven fabrics, wherein the polymer composition comprises at least one polymer comprising polyethylene terephthalate and at least one polymer comprising calcium carbonate. Contains one filler.

The nonwoven fabrics of the present invention can be used in many different applications. According to one aspect of the invention, the nonwoven fabrics of the invention are used in construction, waterproofing, thermal insulation, acoustic insulation, roofing, consumer apparel, upholstery and clothing industries, industrial apparel, medical products, Used in household furnishings, personal protective equipment, packaging materials, cosmetics, hygiene products or filter media. According to another aspect of the invention, there is provided an article comprising the nonwoven fabric of the invention, wherein the article is used in construction, consumer apparel, industrial apparel, medical products, household equipment, personal protective equipment, Selected from packaging materials, cosmetics, sanitary products or filter media.

Building examples are house wraps, asphalt overlays, road and railroad subgrades, golf and tennis courts, wall covering linings, acoustic wall coverings, roofing and tile underlinings, soil stabilizers and road linings. Underlayment, foundation stabilizers, erosion control products, canal construction, drainage systems, geomembrane protection and frost control products, agricultural mulch, pond and canal barriers or sand barriers for culvert drainage. Other examples of construction are anchorages or reinforcements for land reclamation.

Examples of consumer apparel are interlinings, clothing and glove insulation, brassiere and shoulder pads, handbag parts or shoe parts. Examples of industrial apparel are tarpaulins, tents or coverings for transport (timber, steel).

Examples of medical supplies are protective clothing, face masks, isolation gowns, surgical gowns, surgical drapes and covers, surgical gowns, caps, sponges, bandages, wipes, orthopedic padding, bandages, tapes, A dental breastplate, oxygenator, dialyzer, intravenous solution or blood filter or transdermal drug delivery device. Examples of household furnishings are pillows, cushions, quilt or comforter fillings, dust covers, insulation, window treatments, blankets, curtain fabrics, carpet backings or carpets.

Examples of protective articles are coated fabrics, reinforced plastics, protective clothing, lab coats, absorbents or fire walls. Examples of packaging materials are desiccant wraps, absorbent wraps, gift boxes, file boxes, various non-woven bags, book covers, mailing envelopes, express mail envelopes or messenger bags. Examples of filter media are gasoline, oil and air filters, including filtrate cartridges and bag filters, vacuum bags, or laminates with nonwoven layers.

The scope and benefits of the present invention will be better understood based on the following examples, which are intended to illustrate specific embodiments of the invention, but are not limited thereto.

1. Measurement Methods and Materials Measurement methods and materials used in the examples are described below.

Particle Size The particle distribution of the calcium carbonate filler was measured using a Micromeritics (USA) Sedigraph 5120. Methods and instruments are well known to those skilled in the art and are commonly used to determine particle size of fillers and pigments. Measurements were carried out in an aqueous solution containing 0.1% by weight of Na ₄ P ₂ O ₇ . The samples were dispersed using a high speed stirrer and ultrasound.

Intrinsic Viscosity Intrinsic Viscosity or IV is a measure of the molecular mass of a polymer and is measured by dilute solution viscometry. All IVs were measured at 25° C. in a 60/40 weight ratio phenol/tetrachloroethane solution according to ASTM D4603 in a Ubbelohde-type capillary viscometer. Usually about 8 to 10 chips were dissolved to make a solution with a concentration of about 0.5%.

Tensile Testing Tensile testing was performed according to ISO 527-3 using 1 BA (1:2) test samples at a speed of 50 mm/min. Properties measured through tensile testing are yield stress, break-strain, break-stress and e-modulus of the polymer or polymer composition.

Charpy Impact Test Charpy impact tests were performed according to ISO 179-2:1997(E) using notched and unnotched test samples of size 50 x 6 x 6 mm.

Materials Polymer 1: Lighter S98 PET (commercially available from Equipolymers GmbH, Germany).
Intrinsic Viscosity: 0.85±0.02; T _g : 78° C.; T _m : 247° C.;
Polymer 2: Lighter C93 PET (commercially available from Equipolymers GmbH, Germany).
Intrinsic Viscosity: 0.80±0.02; T _g : 78° C.; T _m : 247° C.;
Filler: Omyafilm 707-OG (ground calcium carbonate) (commercially available from Omya AG, Switzerland).
Particle size _d50 : 1.6 μm; top cut _d98 : 6 μm

2. Example

[Example 1]
A test sample containing only Polymer 1 was prepared, as well as a composition of 90% by weight Polymer 1 and 10% by weight filler, based on the total weight of the composition.

The mechanical properties of the test samples were measured using a 500N tester and applying the tensile test described above at a tension of 5N. The results of the tensile test are shown in Table 1 below.

Inventive Sample B showed higher yield stress and e-modulus compared to Comparative Sample A, but the break-strain and break-stress of Inventive Sample B were reduced. Thus, the polymer composition of the invention (Sample B) had higher elasticity and softness compared to the pure PET polymer (Sample A). This has a positive effect on the tactile properties of nonwoven fabrics produced from such polymer compositions, in particular with respect to the softness of the material. For example, such materials are more favorable against wear.

[Example 2]
A test sample containing only Polymer 2, and a composition of 90% by weight Polymer 2 and 10% by weight filler, and 80% by weight Polymer 2 and 20% by weight filler, based on the total weight of the composition. A composition was prepared.

The mechanical properties of the test samples were measured using a 20 kN tester, applying the tensile test described above at a tension of 4 N, and applying the Charpy impact test. The results of the tensile test are shown in Table 2 below.

Inventive Samples D and E exhibited higher yield stress and e-modulus compared to Comparative Sample C, but the break-strain, break-stress and impact resistance of Inventive Samples C and D sexuality declined. Thus, the polymer compositions of the invention (Samples D and E) had higher elasticity and softness compared to the pure PET polymer (Sample C). This has a positive effect on the tactile properties of nonwoven fabrics produced from such polymer compositions, in particular with respect to the softness of the material. For example, such materials are more favorable against wear.

Claims (14)

A nonwoven fabric comprising at least one polymer comprising polyester and at least one filler comprising calcium carbonate,
The calcium carbonate is present in the _nonwoven in an amount of 10 to 20 wt. having a top cut particle size d of ₉₈ ,
said nonwoven comprising at least one polymer and at least one filler comprising fibers and/or filaments having a diameter of 0.5 to 40 μm,
The polyester is polyethylene terephthalate,
the amount of polyethylene terephthalate is at least 75% by weight relative to the total amount of 100% by weight of the at least one polymer;
non-woven fabric. 2. Nonwoven fabric according to claim 1, wherein the polyester has a number average molecular weight of 5000 to 100000 g/mol. 3. Nonwoven fabric according to claim 2, wherein the polyester has a number average molecular weight of 10000 to 50000 g/mol. 3. Nonwoven fabric according to claim 2, wherein the polyester has a number average molecular weight of 15000 to 20000 g/mol. 5. Nonwoven fabric according to any one of the preceding claims, wherein the calcium carbonate is ground calcium carbonate, precipitated calcium carbonate, modified calcium carbonate, surface treated calcium carbonate or mixtures thereof. 6. Nonwoven fabric according to any one of the preceding claims, wherein the calcium carbonate has a top cut particle size _d98 of 6 to 7 [mu]m. a) providing a mixture of at least one polymer comprising polyester and at least one filler comprising calcium carbonate;
b) forming said mixture into fibers and/or filaments having a diameter of 0.5 to 40 μm;
c) forming a nonwoven fabric from said fibers and/or filaments, wherein said calcium carbonate is present in said nonwoven fabric in an amount of from 10 to 20 % by weight, based on the total weight of said nonwoven fabric;
A method for producing a nonwoven fabric comprising:
The polyester is polyethylene terephthalate, the calcium carbonate has an average particle size _d50 of 1.2 to 1.8 μm and a top cut particle size _d98 of 4 to 7 μm, the amount of polyethylene terephthalate is is at least 75% by weight relative to 100% by weight of the total amount of at least one polymer;
Method. 8. The method of claim 7 , wherein in step b) the mixture is formed into fibers by an extrusion process. 9. The method of claim 8 , wherein said nonwoven fabric is formed by collecting said fibers on a surface or carrier. 10. A method according to any one of claims 7 to 9 , wherein steps b) and c) are repeated two or more times to produce the nonwoven of the multi-layer nonwoven. Use of calcium carbonate as a filler in a nonwoven fabric comprising at least one polymer comprising polyester and at least one filler comprising calcium carbonate,
The calcium carbonate is present in the _nonwoven in an amount of 10 to 20 wt. having a top cut particle size d of ₉₈ ,
said nonwoven comprising at least one polymer and at least one filler comprising fibers and/or filaments having a diameter of 0.5 to 40 μm,
The polyester is polyethylene terephthalate,
the amount of polyethylene terephthalate is at least 75% by weight relative to the total amount of 100% by weight of the at least one polymer;
use. Use of a fiber for the manufacture of a nonwoven fabric comprising at least one polymer comprising polyester and at least one filler comprising calcium carbonate,
said fibers having a diameter of 0.5 to 40 μm,
The calcium carbonate is present in the nonwoven in an amount of 10 to 20% by weight, based on the total weight of the nonwoven, and has an average particle size _d50 of 1.2 to 1.8 μm and having a top cut particle size d of ₉₈ , said polyester being polyethylene terephthalate.
use. Buildings, waterproofing, insulation, acoustic insulation, roofing, consumer apparel, upholstery and clothing industries, industrial apparel, medical products, home furnishings, protective products, packaging materials, cosmetics, sanitary products or filter media 7. Use of the nonwoven fabric according to any one of claims 1 to 6 in 7. A nonwoven fabric according to any one of claims 1 to 6 selected from construction, consumer apparel, industrial apparel, medical products, household equipment, protective products, packaging materials, cosmetics, hygiene products or filter media. Containing goods.