WO2016004325A1

WO2016004325A1 - Blends of fatty-acid coated carbonate with untreated carbonate for use in melt processing of carbonate-filled polymers

Info

Publication number: WO2016004325A1
Application number: PCT/US2015/039015
Authority: WO
Inventors: Douglas Wicks; Christopher Paynter; David Taylor; David ANSTINE; Craig Deporter
Original assignee: Imerys Pigments, Inc.
Priority date: 2014-07-02
Filing date: 2015-07-02
Publication date: 2016-01-07
Also published as: WO2016004291A1

Abstract

A blended filler composition may include a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate. A surface treatment of the treated alkali earth metal carbonate may include a monolayer concentration of the surface treatment. A polymer filler composition may include a surface-treated alkali earth metal carbonate, wherein a surface treatment of the alkali earth metal carbonate includes less than a monolayer concentration. A method of forming a filled polymer article may include mixing a polymeric resin with a filler composition and extruding the mixture to form a polymer article. The filler composition may include a blend of a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate. The filler composition may include a treated alkali earth metal carbonate having a surface treatment having less than a monolayer concentration of the surface treatment.

Description

[0001] This PCT International Application claims the benefit of priority of U.S. Provisional Patent Application No. 62/020,145, filed July 2, 2014, and U.S. Provisional Patent Application No. 82/067,288, filed October 22, 2014, the subject matter of both of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to compositions for use in melt-processing of filled polymer products, including polymer fibers, polymer nonwovens, and polymer films.

BACKGROUND OF THE DISCLOSURE

[0003] Commercial products can be formed from components that may include nonwoven fabrics and monofilament fibers of polymeric resins. For instance, monofilament fibers may be used to make staple fibers, yarns, fishing line, woven fabrics, non-woven fabrics, artificial furs, diapers, feminine hygiene products, adult incontinence products, artificial turf, packaging materials, wipes, towels, industrial garments, medical drapes, medical gowns, foot covers, sterilization wraps, table cloths, paint brushes, napkins, trash bags, and various personal care articles. Some filled products, such as artificial turf, may also be made by slitting polymer films instead of using monofilament fibers. [0004] Nonwoven fabrics and monofilament fibers can be made by melt spinning, dry spinning, or wet spinning. In particular, nonwoven fabrics and

monofilament fibers may be produced by spinning a polymeric resin into the shape of a fiber, such as by heating the resin to at least its softening temperature and extruding the resin through a spinneret. Monofilament fibers may also be produced by extruding the resin and attenuating the streams of resin by hot air to form fibers with a fine diameter. Commercial products can also be formed from polymeric films, such as for packaging or protective layers.

[0005] The textile and commercial industries consume a large amount of thermoplastic polymeric resin each year, about 300 million pounds of monofilament fiber. These fibers may incorporate various mineral fillers, such as calcium carbonate and kaolin, during production of non-woven products, polymeric films, and molded parts. In modern processes, increasing polymeric resin prices have created cost-benefits associated with increasing the quantity of mineral fillers and decreasing the quantity of resin in many products. By incorporating at least one mineral filler, the required amount of virgin polymer resin material decreases while the end product may have comparable quality in areas such as fiber strength, texture, and appearance.

[0006] In order to facilitate the manufacture of filled polymer materials, such as fibers, nonwoven fabrics, and films, a surface treatment can be added to the filler material. Calcium carbonate (CaC0₃) is a commonly used filler/extender for the polymer industry. Due to its hydrophilic nature and having a high surface energy, it may be incompatible with the most common hydrophobic polymers, such as, for example, polyethylene (PE) and polypropylene (PP), which may exhibit a tow surface energy. Moreover, moisture pick-up by calcium carbonate may pose additional problems during handling and processing. As a result, surface treatments, such as stearic acid, have been used to render the calcium carbonate surface hydrophobic, making the calcium carbonate more compatible with various polymers.

[0007] The presence of free stearic acid associated with coated calcium carbonate may be undesirable for a number of reasons. For example, residual, unbonded stearic acid in stearic-acid-freated calcium carbonate compositions may interfere with downstream processes. Unreacted stearic acid may lead to, for example, smoke generation, difficulties in printing, undesirable emissions to the environment, and/or extruder die-buildup in polymer processing applications. In other instances, stearic acid may sublime during processing and deposit as a build-up on processing equipment, thereby contaminating processing equipment. In fiber formation, sublimed stearic acid at the spinneret can cause fiber breakage. In film processing, the

sublimated stearic acid may cause pores, voids, or tears in the polymer film, thereby potentially adversely affecting the film's properties. In addition, product performance may be adversely affected due to surface aesthetics and adhesion.

[0008] Although traditional processing methods incorporate a monolayer concentration of a surface treatment, it is found that sublimation of the surface treatment still causes adverse effects on the polymer fibers or films. It is traditionally believed in the art that undercoating a filler particle leads to processing and handling problems, such as insufficient wetting of the filler particle to promote strong contact between the filler and the polymer. This poor contact may weaken the resulting polymer. [0009] Therefore, it may be desirable to provide a filler composition that reduces sublimation of the surface treatment to mitigate or eliminate adverse effects during processing, It may also be desirable to provide a method for processing a polymer fiber or film, such that the effects of sublimation of the surface coating are reduced.

SUGARY OF THE DISCLOSURE

[0010] In the following description, certain aspects and embodiments will become evident. It should be understood that the aspects and embodiments, in their broadest sense, could be practiced without having one or more features of these aspects or embodiments. It should be understood that these aspects and embodiments are merely exemplary.

[001 1] According to a first aspect, a blended functional filler composition may include a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate, wherein a surface treatment of the treated alkali earth metal carbonate may include a monolayer concentration of the surface treatment.

[0012] According to another aspect, a polymer filler composition may include a surface-treated alkali earth metal carbonate, wherein a surface treatment of the alkali earth metal carbonate includes less than a monolayer concentration.

[0013] According to still another aspect, a method of forming a filled polymer article may include mixing a polymeric resin with a filler composition and extruding the mixture to form a polymer article, wherein the filler composition includes a blend of a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate. [0014] According to still a further aspect, a method of forming a filled polymer article may include mixing a polymeric resin with a filler composition and extruding the mixture to form a polymer article, wherein the filler composition may include a treated alkali earth metal carbonate having a surface treatment having less than a monolayer concentration of the surface treatment.

[0015] According to yet another aspect, a method of mitigating effects of mechano-oxidative degradation products during melt processing of filled polymer articles may include mixing a polymeric resin with a filler composition, and

melt-processing the mixture to form a polymer article. The filler composition may include a blend of treated alkali earth metal carbonate and an untreated alkali earth metal carbonate.

[0018] Reference will now be made in detail to exemplary embodiments.

[0017] According to some embodiments, a blended functional fsiler composition may include a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate, wherein a surface treatment of the treated alkali earth metal carbonate may include a monolayer concentration of the surface treatment.

[0018] According to some embodiments, a polymer filler composition may include a surface-treated alkali earth metal carbonate, wherein a surface treatment of the alkali earth metal carbonate includes less than a monolayer concentration.

[0019] According to some embodiments, a method of forming a filled polymer article may include mixing a polymeric resin with a filler composition and extruding the mixture to form a polymer article, wherein the filler composition includes a blend of a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate.

[0020] According to some embodiments, a method of forming filled polymer article may include mixing a polymeric resin with a filler composition and extruding the mixture to form a polymer article, wherein the filler composition may include a treated alkali earth metal carbonate having a surface treatment having less than a monolayer concentration of the surface treatment.

[0021] According to some embodiments, a method of mitigating effects of mechano-oxidative degradation products during melt processing of filled polymer articles may include mixing a polymeric resin with a filler composition, and

melt-processing the mixture to form a polymer article. The filler composition may include a blend of treated alkali earth metal carbonate and an untreated alkali earth metal carbonate. For example, the method may include mitigating detrimental effects of mechano-oxidative degradation products during melt processing by immobilizing the degradation products.

Alkali Earth Me QlCarbonate

[0022] A filler material may include an alkali earth metal carbonate. The alkali earth metal carbonate may include a carbonate of calcium, magnesium, barium, or strontium, or a carbonate of two or more alkaline earth metals, e.g., obtained from dolomite. Hereafter, certain embodiments may tend to be discussed in terms of calcium carbonate, and/or in relation to aspects where the calcium carbonate is processed and/or treated. The invention should not be construed as being limited to such embodiments and may be applicable to any alkali earth metal carbonate. [0023] A calcium carbonate-containing material may be produced in a known way from marble, chalk, limestone, dolomite, ca!cite, aragonite, precipitated calcium carbonate (PCC), or ground calcium carbonate (GCC). A magnesium carbonate may be produced from, for example, magnesite. The alkali earth metal carbonate may also include a synthetic alkali earth metal carbonate, such as, for example, synthetic calcium carbonate produced as a precipitate by a reaction of calcium hydroxide and carbon dioxide in a known way.

[0024] According to some embodiments, the treated alkali earth metal carbonate may have a low moisture pick up susceptibility. For example, the treated alkali earth metal carbonate may have a moisture pick up susceptibility such that its total surface moisture level is below about 2.0 mg/g, such as, for example, below about 1.0 mg/g, below about 0.5 mg/g, or below about 0.4 mg/g of the dry treated mineral filler product, after exposure to an atmosphere of 50% of relative humidity for 48 hours at a temperature of about 23 °C.

[0025] According to some embodiments, the alkali earth metal carbonate filler may have a moisture content of in the range from about 0.01 wt% to about 0.15 wt% based on the dry weight of the alkali earth metal carbonate, such as, for example, in the range from about 0.02 wt% to about 0.1 wt%, in the range from about 0.03 wt% to about 0.08 wt%, or in the range from about 0.03 wt% to about 0.06 wt% based on the dry weight of the alkali earth metal carbonate.

[0028] In some embodiments, the alkali earth metal carbonate may be prepared by attrition grinding. "Attrition grinding," as used herein, refers to a process of wearing down particle surfaces resulting from grinding and shearing stress between the moving grinding particles. Attrition can be accomplished by rubbing particles together under pressure, such as by a gas flow. In some embodiments, the attrition grinding may be performed autogenously, where the alkali earth metal carbonate particles are ground only by other alkali earth metal carbonate particles of the same type (e.g., calcium carbonate being ground only by calcium carbonate).

[0027] In another embodiment, the alkali earth metal carbonate may be ground by the addition of a grinding media other than calcium carbonate. Such additional grinding media can include ceramic particles (e.g., silica, alumina, zirconia, and aluminum silicate), plastic particles, or rubber particles.

[0028] In some embodiments, the calcium carbonate is ground in a mill.

Exemplary mills include those described in U.S. Patent Nos. 5,238,193 and 8,634,224, the disclosures of which are incorporated herein by reference. As described in these patents, the mill may comprise a grinding chamber, a conduit for introducing the calcium carbonate into the grinding chamber, and an impeller that rotates in the grinding chamber, thereby agitating the calcium carbonate.

[0029] In some embodiments, the calcium carbonate is dry ground, where the atmosphere in the mill is ambient air. In some embodiments, the calcium carbonate may be wet ground.

[0030] The ground calcium carbonate may be further subjected to an air sifter or hydrocyclone. The air sifter or hydrocyclone can function to classify the ground calcium carbonate and remove a portion of residual particles greater than, for example, 20 microns. According to some embodiments, the classification can be used to remove residual particles greater than 50 microns, greater than 40 microns, greater than 30 microns, greater than 10 microns, or greater than 5 microns. According to some embodiments, the ground calcium carbonate may be classified using a centrifuge, hydraulic classifier, or elutriator.

[0031] According to some embodiments, calcium carbonate may be subjected to size selection using a rotary or centrifugal sifter. Suitable examples of sifters include rotary sifters, such as the "K range" of centrifugal (rotary) sifters commercially available from Kek-Gardner (Kek~Gardner Ltd, Springwood Way, Macclesfield, Cheshire SK10 2^nd; www.kekgardner.com). For example, the K650C is a small pilot machine with a 850 mm length of drum and the K1350 possesses a drum length of 1350 mm. The sifter may be fitted with a screen possessing a suitable mesh size. The screen may be a fine woven screen or a laser ablated screen. The screen may be made from nylon or stainless steel. Other suitable rotary (or centrifugal) sifters may be obtained from

KASON (KASON Corporation, 67-71 East Willow Street, Millburn, New Jersey, USA; www.kason.com) and SWECO (SWECO, PO Box 1509, Florence, KY 41022, USA; www.sweco.com).

[0032] In a typical centrifugal sifter, material is fed into the feed inlet and redirected into the cylindrical sifting chamber by means of a feed screw. Rotating, helical paddles within the chamber continuously propel the material against a mesh screen, while the resultant, centrifugal force on the particles accelerates them through the apertures. These rotating paddles, which do not make contact with the screen, also serve to breakup soft agglomerates. Most over-sized particles and trash are ejected via the oversize discharge spout. Typically, centrifugal sifters are designed for gravity-fed applications, and for sifting in-line with pneumatic conveying systems. Suitable sifters include single and twin models and those available with belt drive or direct drive. The units may be freestanding or adapted for easy mounting on new or existing process equipment. Removable end housings allow for rapid cleaning and screen changes.

[0033] In other embodiments, the amount of coarse material present in the particulate filler may be reduced to very low values or zero by the use of a mill classifier, for example a dynamic mill classifier or a cell mill fitted with a classifier. A mill classifier may comprise block rotors, blade rotors, and/or a blade classifier. Suitable examples of mill classifiers include dynamic mill classifiers and cell mills fitted with a classifier, such as those commercially available from Atritor (Atritor Limited, Coventry, West Midlands, England; www.atritor.com), a suitable example being the multirotor cell mill.

[0034] In some embodiments, the ground calcium carbonate disclosed herein may be free of dispersant, such as a polyacrylate. In another embodiment, a dispersant may be present in a sufficient amount to prevent or effectively restrict floccuiation or agglomeration of the ground calcium carbonate to a desired extent, according to normal processing requirements. The dispersant may be present, for example, in levels up to about 1 % by weight relative to the dry weight of the alkali earth metal carbonate.

Examples of dispersants include polyelectrolytes such as po!yacrylates and copolymers containing polyacrylate species, including polyacrylate salts (e.g., sodium and

aluminium optionally with a Group Π metal salt), sodium hexametaphosphates, non-ionic polyol, po!yphosphoric acid, condensed sodium phosphate, non-ionic surfactants, a!kanolamine, and other reagents commonly used for this function.

[0035] A dispersant may be selected from conventional dispersant materials commonly used in the processing and grinding of alkali earth metal carbonate, such as calcium carbonate. Such dispersants will be recognized by those skilled in this art. Dispersants are generally water-soluble salts capable of supplying anionic species, which in their effective amounts may adsorb on the surface of the alkali earth metal carbonate particles and thereby inhibit aggregation of the particles. The unsolvated salts suitably include alkali metal cations, such as sodium. Solvation may in some cases be assisted by making the aqueous suspension slightly alkaline. Examples of suitable dispersants also include water soluble condensed phosphates, for example, polymetaphosphate salts (general form of the sodium salts: (NaP0₃)_x), such as tetrasodium metaphosphate or so-called "sodium hexametaphosphate" (Graham's salt); water-soluble salts of polysilicic acids; polyelectrolytes; salts of homopolymers or copolymers of acrylic acid or methacrylic acid; or salts of polymers of other derivatives of acrylic acid, suitably having a weight average molecular mass of less than about 20,000. Sodium hexametaphosphate and sodium polyacrylate, the latter suitably having a weight average molecular mass in the range of about 1 ,500 to about 10,000, are preferred.

[0036] In certain embodiments, the production of the ground calcium carbonate includes using a grinding aid, such as propylene glycol, or any grinding aid known to those skilled in the art.

Surface Treatments

[0037] The alkali earth metal carbonate may be treated to include a treatment layer located on the surface of the alkali earth metal carbonate mineral. For example, a surface-treatment may include a fatty-acid coating. A surface treatment may include, for example, a treatment with an organic carboxylic acid. The organic carboxylic acid may have the following general structure:

where R is a carbon-containing compound having from 8 to 40 carbon atoms, such as, for example from 8 to 40 carbon atoms.

[0038] According to some embodiments, and organic carboxylic acid may include an aliphatic carboxylic acid, such as, for example, caproic acid. 2-ethylhexanoic acid, caprylic acid, neodecanoic acid, capric acsd, valeric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, tall oil fatty acid, napthenic acid, montanic acid, coronaric acid, linoleic add, linolenic acid, 4,7,10,13,18,19- docosahexaenoic acid, 5,8,1 1 , 14, 17-eicosapentaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isononanoic acid, or combinations thereof.

According to some embodiments, the aliphatic carboxylic acid may be a saturated or unsaturated aliphatic carboxylic ac d.

[0039] According to some embodiments, the aliphatic carboxylic acid may include a mixture of two or more aliphatic carboxylic acids, such as, for example, a mixture of two or more of caproic acid, 2-ethylhexanoic acid, caprylic acid, neodecanoic acid, capric acid, valeric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, tall oil fatty acid, napthenic acid, montanic acid, coronaric acid, linoleic acid, linolenic acid, 4,7,10,13,16,19-docosahexaenoic acid, 5,8,1 1 ,14,17- eicosapeniaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, and isononanoic acid,

[0040] According to some embodiments, the weight ratio of a mixed aliphatic carboxy!ic acid may range from about 90:10 to about 10:90 by weight, from about 80:20 to about 20:80, from about 70:30 to about 30:70, or from about 60:40 to about 40:60 by weight. According to some embodiments, the weight ratio of aliphatic carboxylic acids in a mixture may be about 50:50 by weight.

[0041] According to some embodiments, the aliphatic carboxylic acid may include one or more of a linear, branched, substituted, or non-substituted carboxylic acid. The aliphatic carboxylic acid may be chosen from aliphatic monocarboxylic acids. Alternatively or additionally, the aliphatic carboxylic acid may be chosen from branched aliphatic monocarboxylic acids.

[0042] According to some embodiments, the surface treatment may include an aromatic carboxylic acid, such as, for example, alkylbenzoic acid, hydroxybenzoic acid, aminobenzoic acid, protocatechuic acid, or combinations thereof.

[0043] According to some embodiments, the surface treatment may include a Rosin acid, such as, for example, palustrinic acid, neoabietic acid, abietic acid, or levopimaric acid.

[0044] According to some embodiments, R may include one or more of a straight chain or branched alkyi, phenyl, substituted phenyi, C6-40 alkyl substituted with up to four OH groups, C6-40 alkyl, amido, maleimido, amino or acetyl substituted hydrocarbon radicals. [0045] According to some embodiments, the surface treatment may include a combination of one or more of an aliphatic carboxylic acid, an aromatic carboxylic acid, or a Rosin acid.

[0046] According to some embodiments, the organic carboxylic acid may be a liquid at room temperature, such as, for example, an organic carboxylic acid having a viscosity of less than 500 mPa-s at 23 °C when measured in a DV III Ultra model Brookfield viscometer equipped with the disc spindle 3 at a rotation speed of 100 rpm and room temperature (23±1 °C).

[0047] According to some embodiments, the alkali earth metal carbonate may be treated by forming a treatment layer including at least one organic carboxylic acid and/or one or more reaction products of at least one organic carboxylic acid on the surface of the alkali earth metal carbonate filler resulting in a treated alkali earth metal carbonate filler.

[0048] According to some embodiments, the treated alkali earth metal carbonate may include a stearate treatment, such as, for example ammonium stearate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, zinc stearate, aluminum stearate, zirconium stearate, or cobalt stearate. According to some embodiments, the treated alkali earth metal carbonate may include a salt of at least one of a valerate, stearate, iaurate, palmitate, caprylate, neodecanoate, caproate, myristate, behenate, lignocerate, napthenate, montanate, coronarate, iinoleate,

docosahexaenoate, eicosapentaenoate, hexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof, such as, for example, ammonium, calcium, barium, magnesium, strontium, zinc, aluminum, zirconium, or cobalt forms of the

aforementioned salts.

[0049] According to some embodiments, the surface treatment may include a blend of a carboxylic acid and a salt of a carboxySic acid. According to some

embodiments, the weight ratio of a mixed carboxylic acid and salt thereof may range from about 90:10 to about 10:90 by weight (acid:salt), from about 80:20 to about 20:80, from about 70:30 to about 30:70, or from about 80:40 to about 40:60 by weight

(acid:salt). According to some embodiments, the weight ratio of carboxylic acid and salt in a mixture may be about 50:50 by weight (acid:sait).

[0050] According to some embodiments, the treated alkali earth metal carbonate filler may have a volatile onset temperature of greater than or equal to about 100 °C. According to some embodiments, the treated alkali earth metal carbonate filler may have a volatile onset temperature of greater than or equal to about 130 °C, greater than or equal to about 150 °C, greater than or equal to about 160 °C, greater than or equal to about 170 °C, greater than or equal to about 200 °C, greater than or equal to about 220 °C, greater than or equal to about 250 °C, greater than or equal to about 260 °C, such as, for example, greater than or equal to 270 °C, greater than or equal to 280 °C, greater than or equal to 290 °C, greater than or equal to 300 °C, greater than or equal to 310 °C, or greater than or equal to 320 °C.

[0051] As used in this disclosure, the terms "polymer," "resin," "polymeric resin," and derivations of these terms may be used interchangeably. [0052] According to some embodiments, the polymeric resin is chosen from conventional polymeric resins that provide the properties desired for any particular yarn, woven product, non-woven product, film, moid, or other applications.

[0053] According to some embodiments, the polymeric resin may be a thermoplastic polymer, including but not limited to, a polyolefin, such as, for example, polypropylene and polyethylene homopolymers and copolymers, including copolymers with 1-butene, 4-methyl~1-pentene, and 1-hexane; po!yamides, such as nylon;

polyesters; and copolymers of any of the above-mentioned polymers. Examples of thermoplastic polymers may also include polyolefin homopolymers or copolymers (e.g., low density or high density polyethy!enes, linear poiyethylenes, polypropy!enes, ethylene-propylene copolymers, ethylene(vinyl acetate) copolymers, and ethylene- (acrylic acid) copolymers, halogenated poiyethylenes (such as chlorinated

polyethylene), polybutene, polymethylbutene, polyisobutylene, polystyrenes and polystyrene derivatives (e.g., SB, ABS, SA, and SBS rubbers), PVCs, polycarbonates, polysulphones, polyether sulphones, PEEK, saturated polyesters (e.g., polyethylene terephthalates and/or polybutylene terephthalates), and polyphenylene oxides and blends, mixtures or copolymers containing these species.

[0054] According to some embodiments, the polymeric resin may include an isotropic semi-crystalline polymer. An isotropic semi-crystalline polymer may be melt- processable, melting in a temperature range that makes it possible to spin the polymer into fibers in the melt phase without significant decomposition. Exemplary isotropic semi-crystalline polymers may include, but are not limited to, poly(alkylene

terephthalates), poly(aikylene naphthalates), poly(arylene sulfides), aliphatic and aliphatic-aromatic poiyamicles, polyesters comprising monomer units derived from cyclohexanedimethanol and terephtha!ic acid, poly{ethy!ene terephthalate),

poly(butylene terephthalate), poly(ethylene naphthalate), poly(phenylene sulfide), and poly(1 ,4-cyclohexanedimethanol terephthalate), wherein the 1 ,4-cyclohexanedimethanol may be a mixture of c s- and trans- isomers, nylon-6, and nylon-66.

[0055] According to some embodiments, the polymeric resin may include a semi-crystalline polymer polyolefin, including but not limited to, semi-crysta!line polyethylene and polypropylene. According to some embodiments, the polymeric resin may include an extended chain polyethylene having a high tensile modulus, made by the gel spinning or the melt spinning of very or ultrahigh molecular weight polyethylene.

[0058] According to some embodiments, isotropic polymers that cannot be processed in the melt may also be used as the polymeric resin. For example, the isotropic polymer may include RAYON® , cellulose acetate, poiybenzimidazole, poly[2,2^,-(m~phenyiene)-5,5'~bibenzimidazole]. According to some embodiments, isotropic polymers may be dry spun using acetone; N.N'-dimethylacetamide; or polar aprotic solvents, including but not limited to N-methylpyrrolidinone as a solvent.

[0057] According to some embodiments, the polymeric resin may include a liquid crystalline polymer (LCP). LCPs may generally produce fibers with high tensile strength and/or modulus. According to some embodiments, the LCP may be

processable in the melt (i.e., fhermotropic). According to some embodiments, LCPs that exhibit liquid crystalline behavior in solution may be blended with a hard filler, and then wet or dry spun to yield monofilament fibers. According to some embodiments, the liquid crystalline polymer may include any aromatic polyamide that is soluble in polar aprotic solvents, including, but not limited to, N-methy!pyrrolidinone, and that can be spun into monofilament fibers. According to some embodiments, an aromatic polyamide made from p-phenylenediamine and terephthalic acid (including, but not limited to, polymers sold under the KEVLAR® trademark) can be filled and wet spun to yield monofilament fibers. According to some embodiments, the liquid crystalline polymer may not be liquid crystalline under some or all of a given condition or set of conditions, but may still yield high modulus fibers. According to some embodiments, the liquid crystalline polymer may exhibit lyotropic liquid crystalline phases at some concentrations and in some solvents, but isotropic solutions at other concentrations and/or in other solvents.

[0058] According to some embodiments, the liquid crystalline polymers (LCPs) may include thermotropic LCPs. Exemplary thermotropic LCPs include, but are not limited to, aromatic polyesters, aliphatic-aromatic polyesters, aromatic

poly(esferamides). aliphatic-aromatic poly(esteramides), aromatic poly{esterimides), aromatic poly(estercarbonates), aromatic polyamides, aliphatic-aromatic polyamides and poly(azomethines). According to some embodiments, the thermotropic LCPs are aromatic polyesters and poly(esteramides) that form liquid crystalline melt phases at temperatures less than about 360 °C and include one or more monomer units derived from the group consisting of terephthalic acid, isophthaiic acid, 1 ,4-hydroquinone, resorcinol, 4,4 -dihydroxybiphenyl, 4,4'-biphenyldicarboxylic acid, 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 2,6-naphthalenedicarboxylic acid, 2,6- dihydroxynaphthalene, 4-aminophenol, and 4~aminobenzoic acid. According to some embodiments, the aromatic groups may include substituents that do not react under the conditions of the polymerization, such as lower alkyl groups having 1-4 carbons, aromatic groups, F, CI, Br, and I.

[0059] According to some embodiments, the LCPs may have monomer repeat units derived from 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid in a ratio in the range from about 15:85 to about 85:15 on a mole basis, such as, for example, in the range from about 27:73 to about 73:27 on a mole basis, or from about 40:80 to about 80:40 on a mold basis.

[0060] Additional polymeric resins, such as those described in International Publication No, WO 2009/094321 may also be used.

Treated Alkali Earth Metal Carbonate Fillers

[0061] Without wishing to be bound by a particular theory, it is believed that alkali earth metal carbonate fillers, such as, for example, calcium carbonate-containing mineral fillers, may be associated with the presence of volatiles evolving at

temperatures reached during the application of such mineral fillers and/or in the processing of polymer products comprising the carbonate mineral fillers. Exemplary volatiles include:

volatiles inherently associated with the mineral filler ("inherent volatiles"), and may be especially associated with the presence of water;

volatiles introduced during the treatment of the mineral filler ("added volatiles'), for example, to render the mineral filler more dispersible within a polymeric resin;

volatiles generated by the reaction of inherent and/or added organic materials with the mineral filler, which may be induced or enhanced by temperatures reached during the introduction and/or processing of the polymeric resin that includes a mineral filler, such as during the extrusion or compounding process; and/or

volatiles generated by the degradation of inherent organic materials and/or added organic materials to form C0₂, water, and/or possibly low molecular mass fractions of these organic materials, which may be induced or enhanced by temperatures reached during the introduction and/or processing of the polymeric resin that includes a mineral filler, such as during the extrusion or compounding process.

[0062] Examples of such volatiles may be described in this disclosure in relation to stearic acid surface treatment to facilitate explanation, although it is understood that the disclosure is not limited to stearic acid, which is discussed merely to facilitate understanding. A first category of surface treatment molecules includes "free" surface treatment molecules (such as "free" stearic acid). Free surface treatment molecules result from having surface treatments amounts in excess of a monolayer concentration. The excess surface treatment (e.g., stearic acid) may not be bound, either chemically or physically, to the alkali earth metal carbonate. As a result, during melt processing, the free surface treatment molecules may sublime, which may adversely affect the properties of the filled polymer product by creating voids, tears, fiber breakage, dripping, "dog-legging" of fibers, clumps, or knots. Sublimated surface treatments may also contaminate processing equipment.

[0083] A second category of surface treatment molecules includes "reacted" surface treatment molecules (such as "reacted" stearic acid). The reacted stearic acid reacts with the surface of the alkali earth metal carbonate to chemisorb or physisorb to the surface. Without wishing to be bound by a particular theory, it is believed that the reacted stearic acid (or other surface treatment) does not readily sublimate during processing.

[0084] A third category of surface treatment molecules includes "loosely bound" surface treatment molecules (such as loosely bound" stearic acid). Loosely bound stearic acid (or other surface treatment) is bound to the surface of the alkali earth metal carbonate to a lesser degree than "reacted" stearic acid, such as, for example, through physisorption to the surface of the alkali earth metal carbonate. As a result, loosely bound stearic acid is not "free" stearic acid, but the loose binding may result in the stearic acid sublimating during processing, which may result in adverse effects on the resulting polymer product and processing equipment, such as the adverse effects described above. Without wishing to be bound by a particular theory, it is believed that loosely bound stearic acid may contribute to sublimated stearic acid even in monolayer concentrations of surface treatments.

[0085] "Monolayer concentration." as used herein, refers to an amount sufficient to form a monolayer on the surface of the calcium carbonate particles. Such values will be readily calculable to one skilled in the art based on, for example, the surface area of the calcium carbonate particles.

[0086] According to some embodiments, the adverse effects resulting from sublimation of the surface treatment may be mitigated or reduced by providing less than a monolayer concentration of the surface treatment. Providing less than a monolayer concentration can be achieved through severai methods, either alone or in combination. [0087] According to some embodiments, adverse effects sometimes associated with processing polymers (e.g., polyolefins) in the presence of heat and/or mechanical input, for example, during melt-processing such as, for example, extrusion (e.g., of a polymer film), spinning a spunlaid fiber, and melt spinning a spunlaid fiber, may result in mechano-oxidative degradation products. Such mechano-oxidative degradation products, sometimes complex mixtures, may have a significant fraction of organic acid end groups, and may have undesirable effects on the polymer article, for example, as mentioned above (e.g., defects, recondensation onto processing equipment). Without wishing to be bound by theory, it is believed that such undesirable effects resulting from the mechano-oxidative degradation products may be mitigated or reduced by providing less than a monolayer concentration of the surface treatment of alkali earth metal carbonate fillers, which may retain reactive surfaces that may react with and/or immobilize the mechano-oxidative degradation products. Alternatively, undesirable effects resulting from the mechano-oxidative degradation products may be mitigated or reduced by providing a blended functional filler composition that may include a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate, wherein a surface treatment of the treated alkali earth metal carbonate may include a monolayer concentration of the surface treatment.

[0088] Without wishing to be bound by theory, it is believed that the alkali earth metal carbonate fillers having less than a monolayer concentration of the surface treatment and the blended functional filler composition including a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate includes reactive surfaces that can react with and immobilize mechano-oxidatsve degradation products (e.g., organic acids). As such, polymer products can be processed at higher temperatures to result in lower viscosities of the higher temperature polymer melt, and thus increase throughputs, without increasing defects or decreasing quality.

[0089] According to some embodiments, an alkali earth metal carbonate filler composition may include a blend of a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate. The blend of treated and untreated alkali earth metal carbonates may be referred to herein as a "blended" composition or "blended filler" composition. According to some embodiments, the treated alkali earth metal carbonate may be treated as described above, such as, for example with stearic acid and/or stearate.

[0070] According to some embodiments, the ratio of treated to untreated alkali earth metal carbonate in the blended filler composition may range from about 99:1 to about 60:40 (treated:untreated) by weight. For example, the ratio of treated to untreated alkali earth metal carbonate may range from about 98:2 to about 80:20 (treated: untreated) by weight, from about 98:2 to about 90:10 (treated: untreated) by weight, from about 98:2 to about 94:6 (treated:untreated) by weight, or from about 98:4 to about 94:6 (treated:untreated) by weight.

[0071] Without wishing to be bound by a particular theory, it is believed that by blending treated and untreated alkali earth metal carbonates to create a blended filler composition, the sublimated loosely bound or free surface treatment may react with the untreated alkali earth metal carbonate material rather than forming voids, blemishes, or other defects in the polymer product. It is also believed that the reaction of the sublimated surface treatment with the untreated alkali earth metal carbonate may prevent the treatment from building up and contaminating the processing equipment,

[0072] According to some embodiments, the treated alkali earth metal carbonate may be treated with a monolayer concentration of the surface treatment. For example, the alkali earth metal carbonate may be surface treated in a treatment vessel containing a water-dry atmosphere in which the surface treatment is in a liquid (e.g., droplet) and/or vapor form. For example, calcium carbonate may be treated by exposing the calcium carbonate to a carboxylic acid, such as stearic acid, vapor or liquid. The amount of vapor or liquid in the reaction vessel should be controlled so as not to exceed a monolayer concentration of the surface treatment.

[0073] The mixture may be blended at a temperature sufficient for at least a portion of the carboxylic acid to react (e.g., sufficient for a majority of the carboxylic acid to react) with at least a portion of the calcium carbonate. For instance, the mixture may be blended at a temperature sufficient such that at least a portion of the carboxylic acid may coat at least a portion of the calcium carbonate (e.g., the surface of the calcium carbonate).

[0074] According to some embodiments, the alkali earth metal carbonate may be treated by exposing the surface of the alkali earth metal carbonate to the surface treatment agent in the reaction vessel at a temperature at which surface treatment is in a fluid or vaporized state. For example, the temperature may be in the range from about 20 °C to about 300 °C, such as, for example, from about 25 °C to 100 °C, from about 50 °C to 150 °C, from about 100 °C to 200 °C, or from about 100 °C to 150 °C. The temperature selected in the atmosphere of the treatment vesse! should provide sufficient heat to ensure melting and good mobility of the molecules of the surface treatment agent, and therefore, good contacting of and reaction with the surface of the alkali earth metal carbonate particles.

[0075] In some embodiments, a mixture of the alkali earth metal carbonate and carboxy!ic acid, such as stearic acid, may be blended at a temperature high enough to melt the carboxylic acid. For example, the alkali earth metal carbonate may be blended at a temperature in the range from about 65 °C to about 200 °C. In other embodiments, the mixture may be blended at a temperature in the range from about 65 °C to about 150 °C, for example, at about 120 °C. In further embodiments, the mixture may be blended at a temperature in the range from about 65 °C to about 100 °C. In still other embodiments, the mixture may be blended at a temperature in the range from about 65 °C to about 90 °C. In further embodiments, the mixture may be blended at a temperature in the range from about 70 °C to about 90 °C.

[0076] Surface treating the alkali earth metal carbonate may be carried out in a heated vessel in which a rapid agitation or stirring motion is applied to the atmosphere during the reaction of the surface treatment and with the alkali earth metal carbonate, such that the surface treatment agent is well dispersed in the treatment atmosphere. The agitation should not be sufficient to alter the surface area of the alkali earth metal carbonate because such an alteration may change the required surface treatment agent concentration to create, for example, a monolayer concentration. The treatment vessel may include, for example, one or more rotating paddles, including a rotating shaft having laterally extending blades including one or more propellers to promote agitation

2 _*3 and deagglomeration of the carbonate and contacting of the carbonate with the surface treatment agent.

[0077] According to some embodiments, a treated calcium carbonate may be prepared by combining (e.g., blending) the carbonate with stearic acid and water at room temperature in an amount greater than about 0.1 % by weight relative to the total weight of the mixture (e.g., in the form of a cake-mix). The mixture may be blended at a temperature sufficient for at least a portion of the stearic acid to react (e.g., sufficient for a majority of the stearic acid to react) with at least a portion of the surface of the calcium carbonate. For instance, the mixture may be blended at a temperature sufficient such that at least a portion of the stearic acid may coat the surface of the calcium carbonate in a monolayer concentration.

[0078] According to some embodiments, an alkali earth metal carbonate, such as calcium carbonate, may be combined (e.g., blended) at room temperature with stearic acid, or other carboxy!ic acid, and water in an amount greater than about 1 % by weight relative to the total weight of the mixture (e.g., in the form of a cake-mix) to inhibit the formation of free stearic acid. For example, according to some embodiments, the mixture may be blended at a temperature sufficient for at least a portion of the stearic acid to react (e.g., sufficient for a majority of the acid to react, for example, with at least a portion of the calcium carbonate). For example, the mixture may be blended at a temperature sufficient such that at least a portion of the stearic acid may coat at least a portion of the calcium carbonate (e.g., the surface of the calcium carbonate). Treatment of an alkali earth metal carbonate with stearic acid and water is described U.S. Patent No. 8,580,141 to Khanna et al. [0079] After treatment of the alkali earth metal carbonate, the treated alkali earth metal carbonate may be blended with an untreated alkali earth metal carbonate to form a blended composition. The treated and untreated alkals earth metal carbonates may be mixed (e.g., blended) together to promote dispersion of the untreated alkali earth metal carbonate throughout the treated alkali earth metal carbonate. According to some embodiments, the mixing of the treated and untreated alkali earth metal carbonates may occur at room temperature or at an elevated temperature.

[0080] Particle sizes, and other particle size properties, of the treated and untreated alkali earth metal carbonate, may be measured using a SED GRAPH 5100 instrument, as supplied by Micromeritics Corporation. The size of a given particle is expressed in terms of the diameter of a sphere of equivalent diameter, which sediments through the suspension, i.e., an equivalent spherica! diameter or esd. The particle size of the treated alkali earth metal carbonate is expressed in terms of the particle size prior to the surface treatment.

[0081] According to some embodiments, the treated alkali earth metal carbonate may be characterized by a mean particle size (d₅₀) value, defined as the size at which 50 percent of the calcium carbonate particles have a diameter less than or equal to the stated value, in some embodiments, the treated alkali earth metal carbonate may have a d₅o in the range from about 0.1 micron to about 50 microns, such as, for example, in the range from about 0.1 micron to about 30 microns, from about 0.1 micron to about 20 microns, from about 0.1 micron to about 10 microns, from about 0.1 micron to about 5 microns, from about 0.1 micron to about 3 microns, from about 0.1 micron to about 2 microns, from about 0.1 micron to about 1 micron, from about 0.5 microns to about 2 microns, from about 1 micron to about 5 microns, from about 5 microns to about 20 microns, or from about 5 microns to about 10 microns.

[0082] According to some embodiments, the untreated alkali earth metal carbonate may be characterized by a mean particle size (d₅₀) value in the range from about 0.1 micron to about 50 microns, such as, for example, in the range from about 0.1 micron to about 30 microns, from about 0.1 micron to about 20 microns, from about 0.1 micron to about 10 microns, from about 0.1 micron to about 5 microns, from about 0.1 micron to about 3 microns, from about 0.1 micron to about 2 microns, from about 0.1 micron to about 1 micron, from about 0.5 microns to about 2 microns, from about 1 micron to about 5 microns, from about 5 microns to about 20 microns, or from about 5 microns to about 10 microns.

[0083] According to some embodiments, the treated alkali earth metal carbonate may be characterized by a top cut size (d₉₈) value, defined as the size at which 98 percent of the calcium carbonate particles have a diameter less than or equal to the stated value. In some embodiments, the treated alkali earth metal carbonate may have a da₈ in the range from about 2 microns to about 100 microns, such as, for example, in the range from about 5 microns to about 50 microns, from about 2 micron to about 20 microns, or from about 5 microns to about 20 microns.

[0084] According to some embodiments, the untreated alkali earth metal carbonate may be characterized by a top cut size (dg₈) value in the range from about 2 microns to about 100 microns, such as, for example, in the range from about 2 microns to about 100 microns, such as, for example, from about 5 microns to about 50 microns, from about 2 micron to about 20 microns, or from about 5 microns to about 20 microns. [0085] In certain embodiments, the treated alkali earth metal carbonate and the untreated alkali earth metal carbonate may have the same, substantially the same, or similar particle size distributions. According to some embodiments, the treated alkali earth metal carbonate and the untreated alkali earth metal carbonate may have different particle size distributions. For example, the treated alkali earth metal carbonate may have a larger particle size distribution that the untreated alkali earth metal carbonate, such as, for example, a larger median or mean particle size and/or a broader overall size distribution. In other embodiments, the treated alkali earth metal carbonate may have a smaller particle size distribution that the untreated alkali earth metal carbonate, such as, for example, a smaller median or mean particle size and/or a narrower overall size distribution. When the treated and untreated alkali earth metal carbonates have different distributions, the blended filler material may have, for example, a bimodal or multimodal distribution of particle sizes.

[0088] According to some embodiments, when the blended filler composition consists of different particle size distributions, the ratio of the coarse component of the blend to the fine component of the blend may range from about 10:1 to about 1 : 10 by weight (coarseiine), such as, for example, from about 8:1 to about 1 :1 by weight, from about 8:1 to about 4:1 by weight, from about 8:1 to about 8:1 by weight, from about 5:1 to about 1 : 1 by weight, from about 4: 1 to about 2: 1 by weight, from about 2: 1 to about 1 :2 by weight, from about 1 :2 to about 1 :4 by weight, from about 1 :1 to about 1 :5 by weight, from about 1 :4 to about 1 :8 by weight, from about 1 :6 to about 1 :8 by weight, or from about 1 :1 to about 1 :8 by weight (coarse:fine). [0087] According to some embodiments, a treated alkali earth metal carbonate may be undercoated with a surface treatment. As used herein, the term "undercoated" or "undercoating" refers to a surface treatment that includes less than a monolayer concentration of the surface treatment of a treated alkali earth metal carbonate. For example, the undercoated alkali earth metal carbonate may include a surface treatment that includes from about 50% to about 95% of a monolayer concentration, such that from about 5% to about 50% of the surface of the alkali earth metal carbonate is not reacted with the surface treatment. According to some embodiments, the undercoating may range from about 50% to about 95% of a monolayer concentration, such as, for example, from about 70% to about 95%, from about 80% to about 95%, from about 85% to about 95%, from about 90 to about 95%, from about 80% to about 90%, or from about 85% to about 90% of a monolayer concentration. The undercoated alkali earth metal carbonate may be prepared by the same methods as a treated alkali earth metal carbonate, except that the concentration of surface treatment is reduced to create the desired level of undercoating.

[0088] Without wishing to be bound by a particular theory, it is believed that an undercoated alkali earth metal carbonate may reduce or mitigate the effects of sublimated surface treatments during processing of a polymer containing the

undercoated alkali earth metal carbonate, because the sublimated treatment, whether loosely bound or released from the alkali earth metal carbonate, reacts with the untreated portions of the carbonate surface. As a result, the sublimated treatment agents may be prevented from creating voids, blemishes, tears, or clumps in fibers or films, causing dog-legging of fibers, or causing contaminant buildup in the processing equipment.

[0089] According to some embodiments, an undercoated alkali earth metal carbonate may be used as a filler for a polymeric resin. According to some

embodiments, an undercoated alkali earth metal carbonate may be blended with an uncoated alkali earth metal carbonate, as described above. According to some embodiments, a monolayer concentration-treated alkali earth metal carbonate may be blended with an undercoated alkali earth metal carbonate. According to some embodiments, two different undercoated alkali earth metal carbonates may be blended together. Blended alkali earth metal carbonates may include the properties, treatments ratios, and mixtures described above, except that they vary in the amount of surface treatment.

[0090] According to some embodiments, the treated or undercoated alkali earth metal carbonate may be treated with an organic carboxylic acid or salt thereof, or a mixture of an organic carboxylic acid and salt of an organic carboxylic acid. For example, according to some embodiments, some or all of the stearic acid may be replaced by ammonium stearate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, zinc stearate, aluminum stearate, zirconium stearate, or cobalt stearate. Other salts may include, for example, calcium valerate, barium valerate, magnesium valerate, strontium valerate, zinc valerate, aluminum valerate, zirconium valerate, or cobalt valerate, which may replace some or all of valeric acid. In some embodiments, some or all of the organic carboxylic acid may be replaced with a salt of the organic carboxylic acid. For example, some or all of the carbolxylic acid may be replaced by a salt of at least one of a valerate, stearate, laurate, palmitate, caprylate, neodecanoate, caproate, myristate, behenate, lignocerate, napthenate, montanate, coronarate, linoleate, docosahexaenoate, eicosapentaenoate, bexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof, such as, for example, ammonium, calcium, barium, magnesium, strontium, zinc, aluminum, zirconium, or cobalt forms of the aforementioned salts. For example, the ratio of acid to salt may range from about 5:95 to about 95:5 (acid:salt) by weight, from about 10:90 to about 90:10 by weight, from about 80:20 to about 20:80 by weight, from about 70:30 to about 30:70 by weight, from about 80:40 to about 40:60 by weight, or from about 45:55 to about 55:45 by weight. According to some embodiments, all of the stearic acid (or other surface treatment) may be replaced by a salt, such as stearate, which may be used to create a monolayer concentration or an undercoated alkali earth metal carbonate.

[0091] The alkali earth metal carbonate, whether treated, untreated,

undertreated, blended, unblended, or any combination thereof, may be further subjected to an air sifter or hydrocyclone. The air sifter or hydrocyclone can function to classify the ground calcium carbonate and remove a portion of residual particles greater than 20 microns. According to some embodiments, the classification can be used to remove residual particles greater than 40 microns, greater than 30 microns, greater than 15 microns, greater than 10 microns, or greater than 5 microns. According to some embodiments, the ground calcium carbonate may be classified using a centrifuge, hydraulic classifier, or elutriator.

[0092] According to some embodiments, the various techniques for mitigating the adverse effects of sublimated stearic acid or other surface treatments described herein may be used in any combination. For example, an undercoated alkali earth metal carbonate may be used as a filler for a polymeric resin. The undercoated alkali earth metal carbonate may be blended with an untreated alkali earth metal carbonate in some embodiments. A treated or undercoated alkali earth metal carbonate may have some or ail of an organic carboxylic acid replaced with a salt of the carboxylic acid, and may, in some embodiments, be optionally blended with an untreated alkali earth metal carbonate.

[0093] According to some embodiments, the treated, undercoated, and/or blended alkali earth metal carbonates may be used as a filler for a polymer product, such as, for example, a filler for a polymer fiber or film.

[0094] According to some embodiments, monofiliment fibers, may be produced according to any appropriate process or processes now known to the skilled artisan or hereafter discovered. A monofilament fiber may include the production of a continuous monofilament fiber of at least one polymeric resin and at least one filler. Exemplary techniques include, but are not limited to, melt spinning, dry spinning, wet spinning, spinbonding, or meltblowing processes. Melt spinning may include an extrusion process to provide molten polymer mixtures to spinneret dies. According to some embodiments, monofilament fibers may be produced by heating the polymeric resin to at least about its melting point as it passes through the spinneret dies.

[0095] The treated, undercoated, or blended alkali earth metal carbonate filler may be incorporated into the polymeric resin using any method conventionally known in the art or hereafter discovered. For example, alkali earth metal carbonate may be added to the polymeric resin during any step prior to extrusion, for example, during or prior to the heating step or as a "masterbatch" in which the polymeric resin and the filler are premixed and optionally formed into granulates or pellets, and melted or mixed with additional virgin polymeric resin before extrusion of the fibers. According to some embodiments, the virgin polymeric resin may be the same or different from the polymeric resin containing the filler.

[0096] The molten polymer may then be continuously extruded through at least one spinneret to produce long filaments. The extrusion rate may vary according to the desired application, and appropriate extrusion rates will be known to the skilled artisan. Extrusion of the filled polymer from the spinnerets may be used to create, for example, a non-woven fabric.

[0097] According to some embodiments, the a polymeric film may be created from the molten filled polymer according to methods known in the art or hereinafter discovered. For example, melt compounding may also be used to extrude films, tubes, shapes, strips, and coatings onto other materials, injection moulding, blow moulding, or casting, and thermoforming and formation of tubes or pipes(such as where the polymer is a PVC polymer). The melt compounding may for example be carried out in a suitable compounder or screw extruder. A thermoplastic material to be compounded may suitably be in a granular or pelletized form. The temperature of the compounding and moulding, shaping or extrusion processes will depend upon the thermoplastic material being processed and materials incorporated therein. The temperature will be above the softening point of the thermoplastic material.

EXAMPLES [0098] Calcium carbonate filler samples A~E were prepared as calcium- carbonate-filled polymeric resins. Sample A was prepared by adding 1.0% by weight stearic acid to a ground caScium carbonate having a median particle diameter (d₅o) of 1.8 microns to provide a monolayer concentration of stearic acid. Sample B was prepared by mixing one part untreated ground calcium carbonate having a d₅₀ of 1.1 micron with nine parts of monolayer-treated calcium carbonate prepared in sample A. The mixture was blended for 10 minutes in a Henschel mixer at 1000 rpm at room temperature. Sample C was prepared by mixing 0.8% by weight (45 g) stearic acid with 4.5 kg of ground calcium carbonate having a d₅₀ of 1 .1 micron in a Henschel mixer for at 1000 rpm for 10 minutes at 93.3 °C. Without wishing to be bound by a particular theory, it is believed that sample C is an undercoated treatment of stearic acid (e.g., less than a monolayer concentration). Sample D was prepared as described for sample C, except that 1.0% by weight of stearic acid was added to the filler, representing a monolayer concentration of stearic acid. Sample E was prepared in the same way as sample C, except that 1.2% by weight of stearic acid was added to the carbonate, representing stearic acid in excess of the monolayer concentration.

[0099] Filled polymer samples A-E were prepared by loading a 35 melt polypropylene homopolymer with 50% by weight of each of filler samples A-E, respectively. The filled polymer samples were each prepared using a Werner and Pfleiderer ZSK-30 twin screw extruder having the temperature profile shown in Table 1 with the screws rotating at 230 rpm. The polymeric resin was fed into the mouth of the extruder at a rate of 1 1.3 kg/hr using a Hardy C2 feeder. Filler samples A-E separately fed into the extruder at zone 5 at 11.3 kg/hr using a Ktron feeder for each of polymer samples A-e, respectively.

TABLE 1

[0100] After filled polymer samples A-E were prepared, each compound was pelletized using a Gala industries LPU underwater pelletizer.

[0101] Once the filled polymer pellets were prepared, each filled polymer sample was passed through the extruder at the temperature profile shown in Table 1 to determine the amount of subiimable stearic acid in the sample. To determine the amount of subiimable stearic acid in the polymer samples, the screw speeds were reduced to 150 rpm to form a vacuum seal in the barrel of the extruder. Each resin sample was fed into the mouth of the extruder at a rate of 13.6 kg/hr for 20 minutes using a Hardy C2 feeder. To collect the sublimed stearic acid, a Greenburg-Smith high- velocity impinge was connected to zone 7 of the extruder. The vacuum pressure at the extruder was maintained between 254 and 381 mm-Hg using a vacuum pump at 835 mm-Hg. The lower half of the impinge was submerged in an insulated ice bath at 10 °C, Between samples, virgin (i.e.. unfilled) 35 melt polypropylene was used to flush the extruder by passing the virgin polymer resin through the extruder until the exudate was clear.

[0102] For each filled polymer sample A-E, the sublimated stearic acid was collected from the impinger. The amount of collected stearic acid for each sample is shown in Table 2 below.

T \E L,EE 2

[0103] As shown in Table 2, the polymer resins containing the blended filler of treated and untreated calcium carbonate (sample B) and undercoated calcium

carbonate (sample C) resulted in significantly less sublimated stearic acid than the polymer resins containing a monolayer concentration of stearic acid (samples A and D) and containing greater than a monolayer concentration (sample E).

[0104] Without wishing to be bound by a particular theory, it is believed that the polymer containing the undercoated filler (sample C) contains less loosely bound and/or free stearic acid than samples A, B, D, and E. When portions of the stearic acid sublimate, it is believed that the sublimated acid reacts with the unreacted surface of the calcium carbonate, thereby resulting in less overall sublimated (e.g.. liberated" or volatile) stearic acid in the sample.

[0105] With respect to the polymer resin containing the blended polymer (sample B), it is believed that the sublimated stearic acid from the treated calcium carbonate reacts with the untreated calcium carbonate, thereby reducing the overall sublimated or liberated stearic acid during processing. Without wishing to be bound by a particular theory, it is believed that this interaction between the volatile stearic acid and the untreated surface of the calcium carbonate may be seen by the reduction of sublimed stearic acid being reduced by 70% in sample B as compared to sample A, even though only 10% of the calcium carbonate in sample B was untreated.

[0108] Without wishing to be bound by a particular theory, it is believed that the higher amounts of sublimated stearic acid in samples A and D may result from an increasing amount of loosely bound and/or free stearic acid at a monolayer

concentration. The further increase in liberated stearic acid in sample E may result from the further increase in free stearic acid at a concentration greater than the monolayer concentration.

[0107] As shown in Table 2, the use of a blended functional filler composition having treated and untreated carbonate materials, or the use of an undercoated filler carbonate material, may result in decreased amounts of sublimed or liberated stearic acid. This reduction in sublimed stearic acid may reduce the formation of voids, blemishes, holes, or fears in the film or fibers, may mitigate dog-legging of fibers, or may prevent the buildup of contaminants in the processing equipment when processing filled polymer resins. Although sample B is discussed with respect to a monolayer concentration of stearic acid on the treated carbonate, it is understood that the treated carbonate may contain less than a monolayer concentration (e.g., an undercoated carbonate). It is also understood that the untreated carbonate in sample B may be replaced by an undercoated carbonate. According to some embodiments, the blended filler may contain two undercoated carbonates having different levels of undercoating.

[0108] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

WHATJS.CLA!MED.jS:

1. A blended functional filler composition comprising:

a treated alkali earth metal carbonate; and

an untreated alkali earth metal carbonate,

wherein a surface treatment of the treated alkali earth metal carbonate comprises at least a monolayer concentration of the surface treatment.

2. The blended functional filler composition of claim 1 , wherein the treated alkali earth metal carbonate comprises an alkali earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate, barium carbonate, or strontium carbonate.

3. The blended functional filler composition of claim 1 , wherein the treated alkali earth metal carbonate has a median particle size in the range from about 0.1 micron to about 10 microns.

4. The blended functional filler composition of claim 1 , wherein the untreated alkali earth metal carbonate has a median particle size in the range from about 0.1 micron to about 10 microns.

5. The blended functional filler composition of claim 1 , wherein the treated alkali earth metal carbonate and the untreated alkali earth metal carbonate have different particle size distributions.

6. The blended functional filler composition of claim 1 , wherein the treated alkali earth metal carbonate and the untreated alkali earth metal carbonate have substantially the same particle size distribution.

7. The blended functional filler composition of claim 1 , wherein the surface treatment comprises an organic carboxylic acid or salt thereof.

8. The blended functional filler composition of claim 7, wherein the organic carboxylic acid or salt thereof comprises an aliphatic carboxylic acid or salt thereof having a chain length in the range from C8 to C40.

9. The blended functional filler composition of claim 7, wherein the organic carboxylic acid is chosen from the group consisting of caproic acid; 2-ethylhexanoic acid: caprylic acid; neodecanoic acid; capric acid; valeric acid; lauric acid; myristic acid; palmitic acid; stearic acid; behenic acid; lignoceric acid; tall oil fatty acid; napthenic acid; montanic acid; coronaric acid; linoieic acid; linolenic acid; 4,7,10,13,16,19- docosahexaenoic acid; 5,8,1 1 ,14,17-eicosapentaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isononanoic acid, and mixtures thereof.

10. The blended functional filler composition of claim 7, wherein the organic carboxylic acid or salt thereof comprises an aromatic carboxylic acid or salt thereof.

1 1 . The blended functional filler composition of claim 1 , wherein the surface treatment comprises at least one of a valerate, stearate, laurate, palmstate, caprylate, neodecanoate, caproate, myristate, bebenate, lignocerate, napthenate, montanate, coronarate, lino!eate, docosahexaenoate, eicosapentaenoate, hexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof.

12. The blended functional filler composition of claim 1 , wherein the ratio of treated alkali earth metal carbonate to untreated alkali earth metal carbonate ranges from about 99:1 to about 80:40 (treated: untreated) by weight.

13. The blended functional filler composition of claim 1 , wherein the ratio of treated alkali earth metal carbonate to untreated alkali earth metal carbonate ranges from about 99:1 to about 80:20 (treated:untreated) by weight.

14. A polymer filler composition comprising:

a surface-treated alkali earth metal carbonate,

wherein a surface treatment of the alkali earth metal carbonate comprises less than a monolayer concentration,

15. The polymer filler composition of claim 14, wherein the surface-treated alkali earth metal carbonate comprises an alkali earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate, barium carbonate, or strontium carbonate.

16. The polymer filter composition of claim 14, wherein the surface-treated alkali earth metal carbonate has a median particle size in the range from about 1 micron to about 10 microns.

17. The polymer filler composition of claim 14, wherein the surface treatment comprises an organic carboxy!ic acid or salt thereof.

18. The polymer filler composition of claim 17, wherein the organic carboxy!ic acid or salt thereof comprises an aliphatic carboxylic acid or salt thereof having a chain length in the range from C8 to C40.

19. The polymer filler composition of claim 17, wherein the organic carboxylic acid is chosen from the group consisting of caproic acid; 2-efhylhexanoic acid; caprylic acid; neodecanoic acid; capric acid; valeric acid; lauric acid; myristic acid; palmitic acid; stearic acid; behenic acid; lignoceric acid; tall oil fatty acid; napthenic acid; montanic acid; coronaric acid; linoleic acid; linolenic acid; 4,7,10,13,16,19-docosahexaenoic acid; 5,8,1 1 ,14,17-eicosapentaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isononanoic acid, and mixtures thereof.

20. The polymer filler composition of claim 17, wherein the organic carboxylic acid or salt thereof comprises an aromatic carboxylic acid or salt thereof.

21. The polymer filler composition of claim 17, wherein the surface treatment comprises at least one of a valerate, stearate, laurate, palmitate, caprylate,

neodecanoate, caproate, myristate, behenate, lignocerate, napthenate, montanate, coronarate, linoleate, docosahexaenoate, eicosapentaenoate, hexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof,

22. The polymer filler composition of claim 14, further comprising an untreated alkali earth metal carbonate,

wherein the surface-treated alkali earth metal carbonate and the untreated alkali earth metal carbonate form a blended filler composition.

23. The polymer filler composition of claim 22, wherein the untreated alkali earth metal carbonate has a median particle size in the range from about 1 micron to about 10 microns.

24. The polymer filler composition of claim 22, wherein the surface-treated alkali earth metal carbonate and the untreated alkali earth metal carbonate have different particle size distributions.

25. The polymer filler composition of claim 22, wherein the ratio of surface-treated alkali earth metal carbonate to untreated alkali earth metal carbonate ranges from about 99:1 to about 60:40 (surface-treated:untreated) by weight.

28. The polymer filler composition of claim 22, wherein the ratio of surface-treated alkali earth metal carbonate to untreated alkali earth metal carbonate ranges from about 99:1 to about 80:20 (surface-treated:untreated) by weight,

27. The polymer filler composition of claim 14, further comprising a second treated alkali earth metal carbonate,

wherein the surface-treated alkali earth metal carbonate and the second treated alkali earth metal carbonate form a blended filler composition.

28. The polymer filler composition of claim 27, wherein a surface treatment of the second treated alkali earth metal carbonate comprises less than a monolayer concentration, and

wherein the amount of surface treatment of the surface-treated alkali earth metal carbonate is different from the amount of surface treatment of the second treated alkali earth metal carbonate.

29. The polymer filler composition of claim 27, wherein a surface treatment of the second treated alkali earth metal carbonate comprises at least a monolayer

concentration of the surface treatment.

30. A method of forming a filled polymer article, the method comprising:

mixing a polymeric resin with a filler composition; and

extruding the mixture to form a polymer article, wherein the filler composition comprises a blend of a treated alkali earth metal carbonate and an untreated alkali earth metal carbonate,

31. The method of claim 30, wherein extruding the mixture comprises spinning a spunlaid fiber.

32. The method of claim 31 , wherein spinning the spunlaid fiber comprises melt spinning the spunlaid fiber.

33. The method of claim 30, wherein extruding the mixture comprises extruding the mixture to form a polymer film.

34. The method of claim 30, wherein the treated alkali earth metal carbonate has a surface treatment comprising a monolayer concentration of the surface treatment.

35. The method of claim 30, wherein the treated alkali earth metal carbonate has a surface treatment comprising less than a monolayer concentration of the surface treatment.

36. The method of claim 30, wherein the polymeric resin comprises at least one of a thermoplastic polymer, an isotropic semi-crystalline polymer, a semi-crystalline polymer olefin, or a liquid crystal polymer.

37. The method of claim 36, wherein the polymeric resin comprises a thermoplastic polymer selected from the group consisting of a polyolefin, a

polypropylene homopolymer, a polypropylene copolymer, a polyethylene homopolymer, a polyethylene copolymer, a polyamide, a polyester, an ethylene-propylene copolymer, an ethylene(vinyl acetate) copolymer, ethylene~(acrylic acid) copolymer, a halogenated polyethylenes, a polybutene, a polymethyibutene, a polyisobutylene, a polystyrene, a polystyrene derivative, PVC, a polycarbonate, a polysulphone, a polyether sulphone, PEEK, a saturated polyester, and a polyphenylene oxide.

38. The method of claim 30, wherein the treated alkali earth metal carbonate comprises an alkali earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate, barium carbonate, or strontium carbonate.

39. The method of claim 30, wherein the treated alkali earth metal carbonate and the untreated alkali earth metal carbonate have different particle size distributions.

40. The method of claim 30, wherein the surface treatment comprises an organic carboxylic acid or salt thereof.

41. The method of claim 40, wherein the organic carboxylic acid is chosen from the group consisting of caproic acid; 2-ethylhexanoic acid; capryiic acid; neodecanoic acid; capric acid; valeric acid; lauric acid; myrisfic acid; palmitic acid; stearic acid;

behensc acid; lignoceric acid; tail oil fatty acid; napthenic acid; montanic acid; coronaric acid; linoieic acid; linolenic acid; 4,7, 10,13, 16,19-docosahexaenoic acid; 5,8,1 1 ,14,17- eicosapentaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isononanoic acid, and mixtures thereof.

42. The method of claim 30, wherein the surface treatment comprises at least one of a valerate, stearate, laurate, palmitate, caprylate, neodecanoate, caproate, myristate, behenate, lignocerate, napthenate, montanate, coronarate, iinoleate, docosahexaenoate, eicosapenfaenoate, hexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof.

43. The method of claim 30, wherein the ratio of treated alkali earth metal carbonate to untreated alkali earth metal carbonate ranges from about 99:1 to about 80:20 (treated: untreated) by weight.

44. A method of forming a filled polymer article, the method comprising:

mixing a polymeric resin with a filler composition; and

extruding the mixture to form a polymer article,

wherein the filler composition comprises a treated alkali earth metal carbonate having a surface treatment comprising less than a monolayer concentration of the surface treatment.

45. The method of claim 44, wherein extruding the mixture comprises spinning a spunlaid fiber.

48. The method of claim 45, wherein spinning the spun!aid fiber comprises melt spinning the spunlaid fiber.

47. The method of claim 44, wherein extruding the mixture comprises extruding the mixture to form a polymer film.

48. The method of claim 44, wherein the polymeric resin comprises at least one of a thermoplastic polymer, an isotropic semi-crystalline polymer, a semi-crystalline polymer olefin, or a liquid crystal polymer.

49. The method of claim 48, wherein the polymeric resin comprises a

thermoplastic polymer selected from the group consisting of a polyolefin, a

polypropylene homopolymer, a polypropylene copolymer, a polyethylene homopo!ymer, a polyethylene copolymer, a polyamsde, a polyester, an ethylene-propylene copolymer, an ethylene(vinyl acetate) copolymer, ethylene-(acrylic acid) copolymer, a haiogenated polyethylenes, a polybutene, a polymethylbutene, a polyisobutylene, a polystyrene, a polystyrene derivative, PVC. a polycarbonate, a polysulphone, a polyether sulphone, PEEK, a saturated polyester, and a polyphenylene oxide.

50. The method of claim 44, wherein the treated alkali earth metal carbonate comprises an alkali earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate, barium carbonate, or strontium carbonate.

51. The method of claim 44, wherein the treated alkali earth metal carbonate has a median particle size in the range from about 1 micron to about 10 microns,

52. The method of claim 44, wherein the surface treatment comprises an organic carboxylic acid or salt thereof.

53. The method of claim 52, wherein the organic carboxylic acid or salt thereof comprises an aliphatic carboxylic acid or salt thereof having a chain length in the range from C8 to C40.

54. The method of claim 52, wherein the organic carboxylic acid is chosen from the group consisting of caproic acid, 2-ethylhexanoic acid; caprylic acid, neodecanoic acid, capric acid, valeric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, tall oil fatty acid, napthenic acid, montanic acid, coronaric acid, linoleic acid, linolenic acid, 4,7, 10, 13,16,19-docosahexaenoic acid, 5,8,1 1 ,14,17- eicosapentaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isononanoic acid, and mixtures thereof.

55. The method of claim 52, wherein the organic carboxylic acid or salt thereof comprises an aromatic carboxylic acid or salt thereof.

56. The method of claim 52, wherein the surface treatment comprises at least one of a valerate, stearate, Curate, palmitate, caprylate, neodecanoate, caproate, myristate, behenate. lignocerafe, napthenate, montanate. coronarate, linoleate, docosahexaenoate, eicosapentaenoate, hexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof.

57. The method of claim 44. wherein the filler composition further comprises a second treated alkali earth metal carbonate.

58. The method of claim 57, wherein a surface treatment of the second treated alkali earth metal carbonate comprises less than a monolayer concentration, and

wherein the amount of surface treatment of the treated alkali earth metal carbonate is different from the amount of surface treatment of the second treated alkali earth metal carbonate.

59. The method of claim 57, wherein a surface treatment of the second treated alkali earth metal carbonate comprises at least a monolayer concentration of the surface treatment.

60. A method of mitigating effects of mechano-oxidative degradation products during melt-processing of filled polymer articles, the method comprising:

mixing a polymeric resin with a filler composition; and

melt-processing the mixture to form a polymer article, wherein the filler composition comprises a blend of treated alkali earth metal carbonate and an untreated alkali earth metal carbonate.

61. The method of claim 60, wherein the melt-processing comprises extrusion.

62. The method of claim 60, wherein the melt-processing comprises spinning a spunlaid fiber.

63. The method of claim 62, wherein spinning the spunlaid fiber comprises melt spinning the spunlaid fiber.

64. The method of claim 60, wherein melt-processing the mixture comprises extruding the mixture to form a polymer film.

65. The method of claim 60, wherein the treated alkali earth metal carbonate has a surface treatment comprising a monolayer concentration of the surface treatment.

66. The method of claim 60, wherein the treated alkali earth metal carbonate has a surface treatment comprising less than a monolayer concentration of the surface treatment.

67. The method of claim 60, wherein the polymeric resin comprises at least one of a thermoplastic polymer, an isotropic semi-crystalline polymer, a semi-crystalline polymer olefin, or a liquid crystal polymer,

68. The method of claim 67, wherein the polymeric resin comprises a

thermoplastic polymer selected from the group consisting of a polyolefin, a

polypropylene homopolymer, a polypropylene copolymer, a polyethylene homopolymer, a polyethylene copolymer, a polyamide, a polyester, an ethylene-propylene copolymer, an ethylene(vinyl acetate) copolymer, ethySene-(acrylic acid) copolymer, a haiogenated polyethylenes, a polybutene, a polymet ylbutene, a polyisobutylene, a polystyrene, a polystyrene derivative, PVC, a polycarbonate, a polysulphone, a polyether sulphone, PEEK, a saturated polyester, and a polyphenylene oxide.

69. The method of claim 60, wherein the treated alkali earth metal carbonate comprises an alkali earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate, barium carbonate, or strontium carbonate.

70. The method of claim 60, wherein the treated alkali earth metal carbonate and the untreated alkali earth metal carbonate have different particle size distributions.

71 . The method of claim 60, wherein the surface treatment comprises an organic carboxyiic acid or salt thereof.

72. The method of claim 71 , wherein the organic carboxy!ic acid is chosen from the group consisting of caproic acid; 2-ethylhexanoic acid; capryiic acid; neodecanoic acid; capric acid; valeric acid; iauric acid; myristic acid: palmitic acid; stearic acid;

behenic acid; lignoceric acid; tall oil fatty acid; napthenic acid; montanic acid; coronaric acid; linoleic acid; lino!enic acid; 4,7,10,13.16,19-docosahexaenoic acid; 5,8,1 1 ,14,17- eicosapenfaenoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isononanoic acid, and mixtures thereof.

73. The method of claim 60, wherein the surface treatment comprises at least one of a valerate, stearate, laurate, palmitate, capryiate. neodecanoate, caproafe, myristate, behenate, lignocerate, napthenate, montanate, coronarate, linoleate, docosahexaenoate, eicosapentaenoate, hexanoate, heptanoate, octanoate, nonanoate, isononanoate, or mixtures thereof.

74. The method of claim 80, wherein the ratio of treated alkali earth metal carbonate to untreated alkali earth metal carbonate ranges from about 99: 1 to about 80:20 (treated:untreated) by weight.