SURFACE-TREATED COMPACTED MATERIAL

Abstract

The present invention relates to a process for producing a compacted material comprising the steps of providing a powder material and a polymer binder, simultaneously or subsequently feeding the powder material and the polymer binder into a high speed mixer unit, mixing the powder material and the polymer binder in the high speed mixer unit until formation of a compacted material, and reducing the temperature of the obtained compacted material below the melting point or glass transition temperature of the polymer binder.

Claims

1. A process for producing a compacted material comprising the following steps: a) providing at least one powder material, b) providing a polymer binder, c) simultaneously or subsequently feeding the at least one powder material of step a) and the polymer binder of step b) into a high speed mixer unit, d) mixing the at least one powder material of step a) and the polymer binder of step b) in the high speed mixer unit until formation of a compacted material, and e) reducing the temperature of the compacted material obtained from step d) below the melting point or glass transition temperature of the polymer binder, wherein the at least one powder material comprises a surface-treated filler material product comprising a calcium carbonate-comprising filler material and a treatment layer on at least a part of the surface of the calcium carbonate-comprising filler material, wherein the treatment layer comprises i) at least one mono-substituted succinic anhydride and/or at least one mono-substituted succinic acid and/or salty reaction products thereof, and/or ii) a phosphoric acid ester or blend of one or more phosphoric acid mono-ester and salty reaction products thereof and/or one or more phosphoric acid di-ester and salty reaction products thereof.

2. The process of claim 1, wherein the calcium carbonate-comprising filler material is natural ground calcium carbonate, precipitated calcium carbonate, surface-modified calcium carbonate, or a mixture thereof, and preferably natural ground calcium carbonate.

3. The process of claim 1, wherein the calcium carbonate-comprising filler material has a weight median particle size d.sub.50 from 0.05 to 10 μm, preferably from 0.1 to 7 μm, more preferably from 0.25 to 5 μm, and most preferably from 0.5 to 4 μm.

4. The process of claim 1, wherein the at least one mono-substituted succinic anhydride consists of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from C2 to C30, preferably from C3 to C25, and most preferably from C4 to C20 in the substituent.

5. The process of claim 1, wherein I) the one or more phosphoric acid mono-ester consists of an o-phosphoric acid molecule mono-esterified with one alcohol molecule selected from unsaturated or saturated, branched or linear, aliphatic or aromatic alcohols having a total amount of carbon atoms from C6 to C30, preferably from C8 to C22, more preferably from C8 to C20, and most preferably from C8 to C18 in the alcohol substituent, and/or II) the one or more phosphoric acid di-ester consists of an o-phosphoric acid molecule di-esterified with two alcohol molecules selected from the same or different, unsaturated or saturated, branched or linear, aliphatic or aromatic fatty alcohols having a total amount of carbon atoms from C6 to C30, preferably from C8 to C22, more preferably from C8 to C20, and most preferably from C8 to C18 in the alcohol substituent.

6. The process of claim 1, wherein the surface-treated filler material product comprises the treatment layer in an amount of at least 0.1 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising filler material, preferably in an amount from 0.1 to 3 wt.-%.

7. The process of claim 1, wherein the at least one powder material is added in an amount from 50 to 99 wt.-%, based on the total weight of the compacted material, preferably from 60 to 98 wt.-%, more preferably from 80 to 92 wt.-%, and most preferably from 87 to 90 wt.-%.

8. The process of claim 1, wherein the polymer binder has a rotational viscosity from 100 to 400 000 mPa.Math.s, preferably from 1 000 to 100 000 mPa.Math.s, and more preferably from 5 000 to 50 000 mPa.Math.s, at 190° C.

9. The process of claim 1, wherein the polymer binder is selected from the group consisting of polyolefins, ethylene copolymers, e.g. ethylene-1-octene copolymers, metallocene based polypropylenes, polypropylene homo- or co-polymers, preferably amorphous polypropylene homopolymers, and combinations thereof.

10. Compacted material obtained by a process according to claim 1.

11. Use of a compacted material according to claim 10 as additive in a polymer composition.

12. Use of a compacted material according to claim 10 in a process for producing a polymer composition, wherein the compacted material is added to at least one polymer, said at least one polymer preferably being selected from at least one thermoplastic polymer.

13. The use of claim 12, wherein the at least one thermoplastic polymer is selected from the group consisting of homopolymers and/or copolymers of polyolefins, polyamides, polystyrenes, polyacrylates, polyvinyls, polyurethanes, halogen-containing polymers, polyesters, polycarbonates, and mixtures thereof.

14. Use of a compacted material according to claim 10 in a process for producing a polymer product, the process preferably being selected from melt processing techniques, and more preferably being selected from profile extrusion, cable extrusion, film extrusion, moulding, fibre spinning, co-kneading, or pultrusion.

15. Use of a compacted material according to claim 10 in a polymer product, wherein the product is a fibre, preferably a carpet fibre, a filament, a thread, a woven material, a nonwoven material, a film, preferably a blown-film or a breathable film, a profile, a cable, or a moulded product.

16. Use of a compacted material according to claim 10 in an article, wherein the article is selected from the group consisting of healthcare products, geotextile products, agriculture products, horticulture products, clothing, footwear products, baggage products, household products, industrial products, packaging products, building products, upholstery products, industrial apparel, medical products, home furnishings, protective products, cosmetic products, hygiene products, filtration materials, carpets and construction products.

17. A polymer composition comprising a compacted material according to claim 10, said polymer composition preferably being a thermoplastic polymer composition.

18. Use of a polymer composition according to claim 17 in a process for producing a polymer product, the process preferably being selected from melt processing techniques, and more preferably being selected from profile extrusion, cable extrusion, film extrusion, moulding, fibre spinning, co-kneading, or pultrusion.

19. A polymer product comprising a compacted material according to claim 10 or a polymer composition comprising said compacted material wherein the product is a fibre, preferably a carpet fibre, a filament, a thread, a woven material, a nonwoven material, a film, preferably a blown-film or a breathable film, a profile, a cable, or a moulded product.

20. An article comprising a polymer product according to claim 19, wherein the article is selected from the group consisting of healthcare products, geotextile products, agriculture products, horticulture products, clothing, footwear products, baggage products, household products, industrial products, packaging products, building products, upholstery products, industrial apparel, medical products, home furnishings, protective products, cosmetic products, hygiene products, filtration materials, carpets and construction products.

Description

EXAMPLES

1. Measurement Methods

[0324] In the following, measurement methods implemented in the examples are described.

[0325] Ash Content

[0326] The ash content in wt.-% of a compacted material sample, based on the total weight of the sample, was determined by incineration of a sample in an incineration crucible which was put into an incineration furnace at 570° C. for 2 hours. The ash content was measured as the total amount of remaining inorganic residues.

[0327] Linear Density (Dtex)

[0328] The titer or linear density expressed in dtex is measured according to EN ISO 2062 and corresponds to the weight in grams of 10 000 m yarn. A sample of 25 or 100 meters was wound up on a standard reel under a pretension of 0.5 cN/tex and weighted on an analytical scale. The grams per 10 000 m yarn length were then calculated.

[0329] Fabric Weight

[0330] Fabric weight or mass per unit area [g/m.sup.2] was measured according to EN ISO 9864.

[0331] Tenacity, Elongation at Break, and Tensile Strength of Fibres and Nonwoven Fabrics

[0332] Tenacity was calculated from the breaking force and the linear density, and expressed in centinewton per tex [cN/tex]. The test was carried out on a dynamometer with a constant stretching speed, applicable standards for this test are EN ISO 5079 and ASTM D 3822.

[0333] The breaking force is the force needed to be applied on a yarn to make it break. It is expressed in Newton [N]. The elongation at break is the increase of the length produced by stretching a yarn to its breaking point. It is expressed as a percentage [%] of its initial length.

[0334] Tensile strength expressed in kN/m and the elongation at maximum load expressed in % were measured in machine direction (MD) and in cross machine direction (CD). The energy value according to EN ISO 10319 was calculated by the tensile strength (MD+CD)/2.

[0335] Static Puncture Resistance (CBR Test) of Nonwoven Fabrics

[0336] Static puncture resistance expressed in kN was measured according to EN ISO 12236. This method specifies the determination of the puncture resistance by measuring the force required to push a flat-ended plunger through geosynthetics.

[0337] Rotational Viscosimetry

[0338] The rotational viscosity was measured by a rheometer from Anton Paar, Austria, model Physica MCR 300 Modular Compact rheometer, with a plate-plate system having a diameter of 25 mm, a gap of 0.2 mm and a shear rate of 5 s.sup.−1.

[0339] Filter Pressure Value (FPV)

[0340] The filter pressure test was performed on a commercially available Collin Pressure Filter Test Teach-Line FT-E20T-IS. The test method was performed in agreement with European Standard EN 13900-5 with each of the corresponding polymer compositions (16 g effective calcium carbonate per 200 g of final sample, diluent: LLDPE ExxonMobil LL 1001 VX) using a 14 um type 30 filter (GKD Gebr. Kufferath AG, DUren, Germany), wherein no melt pump was used, the extruder speed was kept at 100 rpm, and wherein the melt temperature was 225 to 230° C. (temperature setting: 190° C./210° C./230° C./230° C./230° C.).

[0341] Yield Stress of Blown or Breathable Films

[0342] Yield stress determination was performed according to ISO 527-3. The film specimen width was 15 mm and the testing length 5 cm.

[0343] Yield Elongation of Blown or Breathable Films

[0344] Yield stress determination was performed according to ISO 527-3. The film specimen width was 15 mm and the testing length 5 cm.

[0345] Tensile E-Modulus of Blown or Breathable Films

[0346] Yield stress determination was performed according to ISO 527-3. The film specimen width was 15 mm and the testing length 5 cm. The E-modulus corresponded to the inclination of the tensile test curve between the points at 0.02% and 2% of elongation.

[0347] Visual Evaluation of the Blown Films

[0348] Film samples have been put under a light microscope. Calcium carbonate agglomerates appeared black upon illumination from below and white upon illumination from above.

[0349] Visual Evaluation of the Breathable Films

[0350] The evaluation is done visually during the processing of the breathable film without any auxiliary means for enlargement. The rating “ok” means that no holes, no pinholes, and no stripes were observed.

[0351] Dart Drop Test of Blown Film

[0352] Measurement was performed according to ASTMD 1709A.

[0353] Water Vapour Transmission Rate (WVTR) of Breathable Film

[0354] The WVTR value of the breathable films was measured with a Lyssy L80-5000 (PBI-Dansensor A/S, Denmark) measuring device according to ASTM E398.

[0355] Hydrostatic Pressure Test of Blown or Breathable Films

[0356] The hydrostatic pressure test has been carried out according to a procedure which is equivalent to AATCC Test Method 127-2013, WSP 80.6 and ISO 811. A film sample (test area=10 cm.sup.2) was mounted to form a cover on the test head reservoir. This film sample was subjected to a standardized water pressure, increased at a constant rate until leakage appears on the outer surface of the film, or water burst occurs as a result of film failure (pressure rate gradient=100 mbar/min.). Water pressure was measured as the hydrostatic head height reached at the first sign of leakage in three separate areas of the film sample or when burst occurs. The head height results were recorded in centimetres of water or millibars pressure on the specimen. A higher value indicated greater resistance to water penetration. The TEXTEST FX-3000, Hydrostatic Head Tester (Textest AG, Switzerland), was used for the hydrostatic pressure measurements.

2. Materials

[0357] Powder Material

[0358] CC1 (inventive): Natural ground calcium carbonate, commercially available from Omya International AG, Switzerland (d.sub.50: 1.7 μm; d.sub.98: 6 pm), surface-treated with 0.7 wt.-% alkenyl succinic anhydride (CAS [68784-12-3], concentration >93%), based on the total weight of the ground calcium carbonate. BET: 3.4 g/m.sup.2, residual moisture content: 0.1 wt.-%, moisture pick-up: 0.58 mg/g.

[0359] CC2 (comparative): Natural ground calcium carbonate, commercially available from Omya International AG, Switzerland (d.sub.50: 1.7 μm; d.sub.98: 6 μm), surface-treated with 1 wt.-% stearic acid (commercially available from Sigma-Aldrich, Croda, USA) based on the total weight of the ground calcium carbonate. BET: 3.4 g/m.sup.2, residual moisture content: 0.1 wt.-%, moisture pick-up: 0.38 mg/g.

[0360] CC3 (comparative): Natural ground calcium carbonate, commercially available from Omya International AG, Switzerland (d.sub.50: 1.7 μm; d.sub.98: 6 μm), surface-treated with 0.55 wt.-% octanoic acid (product number 00040, commercially available from TCI Europe N.V, Belgium) based on the total weight of the ground calcium carbonate. BET: 3.4 g/m.sup.2, residual moisture content: 0.1 wt.-%, moisture pick-up: 0.41 mg/g.

[0361] Polymer Binder and Surface Treatment Agent

[0362] Binder A: Homo-polypropylene (Borflow HL 520FB), MFR=2,000 g/10 min (230° C., 2.16 kg, ISO 1133) according to technical data sheet, rotational viscosity=20 000 mPa.Math.s at 190° C., commercially available from Borealis, Austria.

[0363] Binder B: Ethylene-1-octene-copolymer (Affinity GA 1900), density (ASTM D792)=0.87 g/cm.sup.3, according to technical data sheet, rotational viscosity=8 500 mPa.Math.s at 190° C., commercially available from The Dow Chemical Company, USA.

[0364] Surface treatment agent 1 (=SA4): Metallocene based polypropylene wax (Licocene PP-1302), density (23° C.; ISO 1183)=0.87 g/cm.sup.3, according to technical data sheet, rotational viscosity=130 mPa.Math.s at 190° C., commercially available from Clariant International Ltd., Switzerland.

[0365] Thermoplastic Polymer

[0366] Polymer D: Homo-polypropylene (Moplen HP 561R), MFR=25 g/10 min (230° C., 2.16 kg, ISO 1133) according to technical data sheet, commercially available from LyondellBasell, Netherlands.

[0367] Polymer E: Homo-polypropylene (PP HF420FB), MFR=19 g/10 min (230° C., 2.16 kg, ISO 1133) according to technical data sheet, commercially available from Borealis, Austria.

[0368] Polymer F: Linear low density polyethylene (Dowlex NG 5056G), MFR=1.1 g/10 min (190° C., 2.16 kg, ISO 1133), density (23° C.; ISO 1183)=0.919 g/cm.sup.3, according to technical data sheet, available from Dow, Switzerland.

[0369] Polymer G: Linear low density polyethylene (Dowlex 2035), MFR=6 g/10 min (190° C., 2.16 kg, ISO 1133), density (23° C.; ISO 1183)=0.919 g/cm.sup.3, according to technical data sheet, available from The Dow Chemical Company, USA.

[0370] Polymer H: Low density polyethylene (Dow SC 7641), MFR=2 g/10 min (190° C., 2.16 kg, ISO 1133), density (23° C.; ISO 1183)=0.923 g/cm.sup.3, according to technical data sheet available from The Dow Chemical Company, USA.

3. Examples

Example 1

Preparation of Compacted Material for Multifilaments

[0371] A horizontal “Ring-Layer-Mixer/Pelletizer”, namely “Amixon RMG 30” with process length of 1,200 mm, and diameter of 230 mm, equipped with 3 feeding ports in sequence, and 1 outlet port, was used. The cylinder was fitted with a heating/cooling double wall. Mixing and compacting was obtained by a rotating, cylindrical, pin-fitted screw.

[0372] The powder material CC1 was fed gravimetrically into the first feed port at a rate of 22.6 kg/h. The polymer binder or polymer binder blend was injected in liquid state at a temperature of 230° C. through feeding port 2 at a rate of 2.4 kg/h.

[0373] The employed amounts of powder material CC1 and the type and amounts of the polymer binders and surface treatment agent are indicated in Table 1 below.

[0374] Mixing and compacting of the powder material and the polymer binder or polymer binder blend was carried out in the “Ring-Layer-Mixer/Pelletizer” at 180° C. and a screw speed of 800 rpm.

[0375] The mixture left the mixer/pelletizer through the outlet port, was transferred by gravity into a second Ring-Layer-Mixer/Pelletizer for compacting and cooling, operated at a temperature of 140° C. and a screw speed of 400 rpm. In this example, both units were of identical size and dimensions. The resulting compacted material left the unit through the outlet port, and was free of dust and free flowing.

TABLE-US-00001 TABLE 1 Compositions and properties of prepared compacted materials CM1 to CM3 (wt.-% is based on total weight of the compacted material). CM1 CM2 CM3 CC1 [wt.-%] 88.0 88.0 88.0 Binder A [wt.-%] —  9.6 12.0 Binder B [wt.-%] 12.0 — — SA4 [wt.-%] —  2.4 — Ash content [wt.-%] 87.2 87.5 87.7

Example 2

Preparation of Multifilament Fibres

[0376] Different amounts of the compacted materials CM1 to CM3 produced according to Example 1 were mixed with polymer D. Multifilaments were produced from the obtained mixtures using a Collin Multifilament Lab Line CMF 100 (Dr. Collin GmbH, Germany), equipped with a single screw extruder with melt pump and spinneret diameter 50 mm with 34 filaments having a diameter of 0.3 mm. The spinning system was also equipped with a cooling chamber for quenching the multifilament fibre and stretching godets and a winder. Limanol B29 (commercially available from Schill+Seilacher GmbH, Germany) was used as spinning oil. The draw ratio was 2 for samples 1 to 8. The following godet roll temperatures were used, godet 1:80° C., godet 2: 85° C., godet 3: 90° C., and godet 4: 90° C.

[0377] For comparison, a standard type masterbatch (MB1) containing 70 wt.-% CC1 was produced on industrial scale. The precise filler content of the masterbatch was determined by the ash content which was 72.2 wt.-%. The melt flow rate (MFR, 230° C., 2.16 kg, ISO 1133) of the masterbatch was 9.13 g/10 min.

[0378] The compositions of the produced multifilaments are compiled in Table 2 below.

[0379] The mechanical properties (elongation at break and tenacity) of the testing samples were determined as described above. The results of the mechanical tests are also shown in Table 2 below.

TABLE-US-00002 TABLE 2 Composition and mechanical properties of the produced multifilaments (wt.-% is based on total weight of the compacted material). Content Melt Compacted of CC1 pressure Elongation material/ in fibres extrusion Tenacity at break Sample masterbatch [wt.-%] [bar] [cN/dtex] [%] 1 MB1 21.2 40.5 0.72 183 (comp.) 2 CM1 18.5 22.8 0.80 206 3 CM2 16.3 23.8 0.82 198 4 CM3 17.6 21.9 0.84 201 5 MB1 38.9 40.7 0.50 201 (comp.) 6 CM1 34.6 24.3 0.40 170 7 CM2 37.7 28.3 0.40 114 8 CM3 45.4 35.6 0.30 155

[0380] The results shown in Table 2 above, reveal that multifilaments comprising a compacted material according to the present invention can be produced in good quality and mechanical properties with different powder material amounts. Furthermore, it can be gathered from Table 2 that the samples comprising the inventive compacted material show a reduced melt pressure during extrusion compared to the samples containing the comparative masterbatch. A reduced melt pressure is advantageous with respect to the processability of the material and indicates an improved dispersion of the powder material within the polymer matrix. In addition the mechanical properties of the multifilaments improve when a compacted material is applied as starting material for the spinning process.

Example 3

Preparation of Compacted Material for Nonwoven Fabrics

[0381] A horizontal “Ring-Layer-Mixer/Pelletizer”, namely “Amixon RMG 30” with process length of 1,200 mm, and diameter of 230 mm, equipped with 3 feeding ports in sequence, and 1 outlet port, was used. The cylinder was fitted with a heating/cooling double wall. Mixing and compacting was obtained by a rotating, cylindrical, pin-fitted screw.

[0382] The powder material CC1 or CC2, respectively, was fed gravimetrically into the first feed port at a rate of 22.6 kg/h. The polymer binder or polymer binder blend was injected in liquid state at a temperature of 230° C. through feeding port 2 at a rate of 2.4 kg/h.

[0383] The employed types and amounts of the powder materials, polymer binders, and surface treatment agent are indicated in Table 3 below.

[0384] Mixing and compacting of the powder material and the polymer binder or polymer binder blend was carried out in the “Ring-Layer-Mixer/Pelletizer” at 180° C. and a screw speed of 800 rpm.

[0385] The mixture left the mixer/pelletizer through the outlet port, was transferred by gravity into a second Ring-Layer-Mixer/Pelletizer for compacting and cooling, operated at a temperature of 140° C. and a screw speed of 400 rpm. In this example, both units were of identical size and dimensions. The resulting compacted material left the unit through the outlet port, and was free of dust and free flowing.

TABLE-US-00003 TABLE 3 Compositions and properties of prepared compacted materials CM4 to CM9 (wt.-% is based on total weight of the compacted material, nm = not measured). CM4 CM5 CM6 CM7 CM8 CM9 CC1 [wt.-%] 88.0 88.0 88.0 — 88.5 88.5  CC2 [wt.-%] — — — 87.0 — — Binder A — 12.0 10.8 13.0 11.5 — [wt.-%] Binder B 12.0 —  1.2 — — 9.2 [wt.-%] SA4 [wt.-%] — — — — — 2.3 Ash content 87.1 87.5 87.3 86.0 nm nm [wt.-%]

Example 4

Preparation of Nonwoven Fabrics

[0386] Different amounts of the compacted materials according to the present invention were mixed with polymer E and were directly dosed together into a single screw extruder equipped with a melt pump. Nonwoven fabrics were produced from these mixtures on a pilot nonwoven Lurgi line. Extruder temperatures were between 230° C. and 250° C. The four spin beams were equipped with melt pumps and spinnerets which contained 600 orifices each with a diameter of 0.8 mm. The extruded filaments were formed into a nonwoven web. The conveyor belt speed was adjusted to 20 meters/minute and hydroentangling was used for bonding the nonwoven web.

[0387] The final bonded nonwoven web with a width of 100 cm had a target fabric weight of 385 g/m.sup.2.

[0388] The compositions of the produced nonwoven materials are compiled in Table 4 below.

TABLE-US-00004 TABLE 4 Compositions of the prepared nonwoven fabrics (wt.-% is based on total weight of the sample). Compacted Content of CC1 or CC2 Sample material (ash content) [wt.-%]  9 — 0 (comparative) 10 CM5 0.9 11 CM5 2.7 12 CM8 2.5 13 CM8 3.1 14 CM7 5.7 (comparative) 15 CM6 3.0 16 CM9 2.3

[0389] The mechanical properties of the testing samples were determined using the corresponding tests described above. The results of the mechanical tests are also shown in Table 5 below.

TABLE-US-00005 TABLE 5 Properties of the produced nonwoven fabrics. Linear Coef- Tensile density Tenacity Fabric ficient strength fibres fibres weight CBR CBR (MD + CD)/2 Sample [dtex] [cN/dtex] [g/m.sup.2] [N/g] [N] [N/g]  9 10.1 2.22 378 6.8 2 570 10.2 (comp.) 10 9.2 2.29 366 7.6 2 788 10.2 11 8.7 2.17 379 7.2 2 743 8.9 12 9.2 2.14 393 7.0 2 732 9.0 13 9.4 2.13 390 7.0 2 743 7.9 14 9.5 2.03 393 6.3 2 493 7.9 (comp.) 15 8.9 2.14 377 6.9 2 597 8.7 16 9.0 2.09 385 6.8 2 636 8.5

[0390] As can be seen from the results compiled in Table 5, nonwoven fabrics comprising the inventive compacted material can be produced in good quality with improved mechanical properties compared to the unfilled nonwoven fabric (sample 9). Moreover, the nonwoven fabric comprising the compacted material using a powder with a treatment layer according to the invention have better mechanical properties than nonwoven fabrics comprising a compacted material using a powder with a different treatment layer (see sample 14).

Example 5

Preparation of Compacted Material for Blown Films

[0391] A horizontal “Ring-Layer-Mixer/Pelletizer”, namely “Amixon RMG 30” with process length of 1,200 mm, and diameter of 230 mm, equipped with 3 feeding ports in sequence, and 1 outlet port, was used. The cylinder was fitted with a heating/cooling double wall. Mixing and compacting was obtained by a rotating, cylindrical, pin-fitted screw.

[0392] The powder material CC1 or CC3, respectively, was fed gravimetrically into the first feed port at a rate of 22.6 kg/h. The polymer binder or polymer binder blend was injected in liquid state at a temperature of 230° C. through feeding port 2 at a rate of 2.4 kg/h.

[0393] The employed types and amounts of the powder materials, polymer binders, and surface treatment agent are indicated in Table 6 below.

[0394] Mixing and compacting of the powder material and the polymer binder or polymer binder blend was carried out in the “Ring-Layer-Mixer/Pelletizer” at 180° C. and a screw speed of 800 rpm.

[0395] The mixture left the mixer/pelletizer through the outlet port, was transferred by gravity into a second Ring-Layer-Mixer/Pelletizer for compacting and cooling, operated at a temperature of 140° C. and a screw speed of 400 rpm. In this example, both units were of identical size and dimensions. The resulting compacted material left the unit through the outlet port, and was free of dust and free flowing.

TABLE-US-00006 TABLE 6 Compositions and properties of prepared compacted materials CM10 and CM11 (wt.-% is based on total weight of the compacted material). CM10 CM11 (comparative) CC1 [wt.-%] 88.5 — CC3 [wt.-%] — 87.5 Binder A [wt.-%] — — Binder B [wt.-%]  8.6  9.4 SA4 [wt.-%]  2.9  3.1 Ash content [wt.-%] 87.7 86.6

Example 6

Manufacture of Blown Film Samples

[0396] A blown film was produced using 77.1 wt.-% of Polymer F and 22.9 wt.-% of CM11 (BF1=comparative example). Furthermore, a blown film was produced using 77.4 wt.-% of polymer F and 22.6 wt.-% of CM10 (BF2=inventive example). Films were produced on a Dr. Collin blown film extrusion line (60 mm circular die, 1.2 mm die gap, 30 mm screw diameter, L/D ratio=30, screw with mixing element). The films were processed with a BUR (blow up ratio) of 2.2 and the frost line high was kept at 16 cm high (distance from die).

[0397] The extruder had the following configuration:

TABLE-US-00007 TABLE 7 Extrusion parameters. BF1 (comparative) BF2 (inventive) Temperature Zone 1 [° C.] 170 170 Temperature Zone 2 [° C.] 195 195 Temperature Zone 3 [° C.] 215 215 Temperature Zone 4 [° C.] 215 215 Temperature Zone 5 [° C.] 215 215 Output [kg/h] 4.5 4.5 Screw Speed [rpm] 50 50 Die pressure [bar] 204 81 Torque [A] 5.5 4.9

[0398] Extruder speed was kept constantly at 50 rpm and the average film grammage was set to 35 g/m.sup.2 by appropriate adjustment of the line speed. Also the cooling air flow was adjusted accordingly to keep the frost line at the same position.

[0399] Material and Mechanical Properties of Blown Film Samples:

TABLE-US-00008 TABLE 8 Material and mechanical properties of blown film samples BF1 and BF2. BF1 BF2 Blown film sample Direction (comparative) (inventive) Yield stress MD 10.4 9.8 [N .Math. mm.sup.−2] CD 9.6 10.8 Yield elongation MD 11.1 11.0 [%] CD 7.4 7.5 Tensile modulus MD 295 248 [N .Math. mm.sup.−2] CD 301 321 Dart drop fall weight [g] — 858 816 Visual evaluation of film — (−) (+) Ash content [wt.-%] — 21.0 19.5 Film thickness [μm] — 36 36 (−): many agglomerates, (+): no agglomerates, MD = machine direction, CD = cross direction (direction for the manufacturing of the blown film).

[0400] As can be gathered from Table 8 the mechanical properties of the blown films manufactured with a compacted material according to the invention and the comparative blown films are approximately equal. However, the blown films according to the invention are superior in view of their optical properties (no agglomerates have been observed), and their processing properties (see Table 7, lower die pressure and torque). The improvement of the processing properties allows to conduct the manufacturing process in a more energy and cost efficient manner.

Example 7

Preparation of Compacted Material for Breathable Films

[0401] A horizontal “Ring-Layer-Mixer/Pelletizer”, namely “Amixon RMG 30” with process length of 1 200 mm, and diameter of 230 mm, equipped with 3 feeding ports in sequence, and 1 outlet port, was used. The cylinder was fitted with a heating/cooling double wall. Mixing and compacting was obtained by a rotating, cylindrical, pin-fitted screw.

[0402] The powder material CC1 or CC3, respectively, was fed gravimetrically into the first feed port at a rate of 22.6 kg/h. The polymer binder or polymer binder blend was injected in liquid state at a temperature of 230° C. through feeding port 2 at a rate of 2.4 kg/h.

[0403] The employed types and amounts of the powder materials, polymer binders, and surface treatment agent are indicated in Table 9 below.

[0404] Mixing and compacting of the powder material and the polymer binder or polymer binder blend was carried out in the “Ring-Layer-Mixer/Pelletizer” at 180° C. and a screw speed of 800 rpm.

[0405] The mixture left the mixer/pelletizer through the outlet port, was transferred by gravity into a second Ring-Layer-Mixer/Pelletizer for compacting and cooling, operated at a temperature of 140° C. and a screw speed of 400 rpm. In this example, both units were of identical size and dimensions. The resulting compacted material left the unit through the outlet port, and was free of dust and free flowing.

TABLE-US-00009 TABLE 9 Compositions and properties of prepared compacted materials CM12 and CM13 (wt.-% is based on total weight of the compacted material). CM12 CM13 (comparative) CC1 [wt.-%] 88 — CC3 [wt.-%] — 87 Binder B [wt.-%] 9.6 10.4 SA4 [wt.-%] 2.4 2.6

Example 8

Preparation of Breathable Films

[0406] Breathable films were produced by a pilot-extrusion cast-film line with integrated MDO-II unit (Dr. Collin GmbH, Germany) the extruder temperature settings were 195° C.-210° C.-230° C.-230° C., and the rotation speed of the extruder was approximately 35 rpm using CM12 and CM13. The roller speed of the stretching unit was 125/125%.

[0407] CM12 and CM13 were pre-dried for 4 hours at 80° C. CM 12 (=inventive example) was dosed together with Polymer G and Polymer H (weight ratio 9:1, 9 weight parts polymer G) in the extrusion funnel using a gravimetric weigh feeder to obtain a calcium carbonate content of 50 wt.-% (=57.5 wt.-% CM12). CM 13 (=comparative example) was dosed together with Polymer G and H (weight ratio 9:1, 9 weight parts polymer G) in the extrusion funnel using a gravimetric weigh feeder to obtain a calcium carbonate content of 50 wt.-% (=56.8 wt.-% CM13).

[0408] The extrusion pressure increased when using CM12 (comprising CC1) within 1 hour from 38 to 42 bar, whereas when using CM13 (comprising CC3) the extrusion pressure increased from 48 to 161 bar.

[0409] The film quality of the obtained breathable films was inspected visually and the films were tested regarding their water vapour transmission rate (WVTR) and their hydrostatic pressure. The results are shown in Table 10 below.

TABLE-US-00010 TABLE 10 Compositions and properties of prepared breathable films. Compacted Film WVTR Hydrostatic pressure Sample material quality (g/cm.sup.2 day) (mbar) 17 CM12 Ok 4220 277 18 CM13 Ok 3750 235 (comparative)

[0410] The results shown in Table 10 confirm that the inventive breathable film has a good quality and breathability, which is superior to the comparative breathable film. Moreover, with the coating according to present invention a higher filler load was possible. In the comparative example (=CM13) a lower filler load was necessary to obtain good dispersion.

Example 9

Preparation of Compacted Material for Evaluation of the Degree of Dispersability

[0411] For the powder treatment a high speed batch mixer from MTI-Mischtechnik Industrieanlagen GmbH Type LM 1.5/2.5/5 with a 2.5 L vessel and with a three part standard mixing tool was used. The mixer was heated to 175° C., and 364 g of a calcium carbonate (CC1 or CC3) were filled in the vessel. The vessel was closed and the mixer was run for 2 minutes at 700 rpm. Then the mixer was opened and 32 g of a polypropylene homopolymer with a solid density of 0.86 g/ml and a melting point (DSC) of 152° C. was added to the preheated powder. The mixer was closed again and run for 12 minutes at 700 rpm.

[0412] To test the dispersion of the obtained treated powder a Dr. Collin lab extruder FT-E2OT-IS with a standard screw and with a standard tape die was used. The heating zones were heated to 190°/210° C./230° C./230° C. and the extruder was run at 100 rpm. 75 wt.-% of polymer G and 25 wt.-% of the obtained powder were continuously fed in the extruder by a gravimetric dosage system. 10 g of extruded tape were then compression moulded between two chromed steel plates at 190° C. The obtained film was optically inspected under a binocular magnifier with magnification of 50. A very good dispersion was rated with mark 6 and a very low dispersion is rated with mark 1 (see Table 11).

TABLE-US-00011 TABLE 11 Compositions and properties of prepared compacted materials CM14 to CM16 (wt.-% is based on total weight of the compacted material). CM14 CM15 CM16 (comparative) CC1 [wt.-%] 90 89 — CC3 [wt.-%] — — 89 Binder B [wt.-%] 8 8.8 8.8 SA4 [wt.-%] 2 2.2 2.2 Ash content [wt.-%] 89.7 87.5 87.9 Mark.sup.a) 2 6 2 .sup.a)Mark regarding degree of dispersability.

[0413] As can be seen by comparison of CM14 and CM15 at an approximately equal ash content, the dispersability of the material according to the invention is much better. Moreover, CM14 shows that a higher filler load is possible for the compacted material according to the invention. If CC3 was used as filler, it was not possible to obtain a higher filler load than for CM16.