SURFACE-TREATED ULTRAFINE CALCIUM CARBONATE FOR IMPROVING THE MECHANICAL PROPERTIES OF POLYETHYLENE/POLYPROPYLENE COMPOSITIONS

Abstract

The present invention relates to a filled polymer composition comprising polyethylene, polypropylene and an ultrafine calcium carbonate-containing filler material surface-treated with a surface-treatment agent, which has a total amount of carbon atoms from C4 to C34 and comprises at least one carboxyl group and/or a derivative thereof. The present invention further relates to a process for producing said filled polymer composition, the use of the surface-treated calcium carbonate-containing filler material for improving the mechanical properties of a polymer composition comprising polyethylene and polypropylene, as well as an article comprising the inventive filled polymer composition.

Claims

1.-17. (canceled)

18. A filled polymer composition comprising a) at least one polyethylene polymer, b) at least one polypropylene polymer, and c) a surface-treated calcium carbonate-containing filler material in an amount from 5 wt.-% to 70 wt.-%, based on the total weight of the composition, wherein the surface-treated calcium carbonate-containing filler material comprises an ultrafine calcium carbonate-containing filler material having i) a weight median particle size (d.sub.50) value in the range from 0.03 μm to 1.0 μm and ii) a top cut (d.sub.98) value of 10 μm or less, and a surface-treatment layer on at least a part of the surface of said ultrafine calcium carbonate-containing filler material, wherein the surface-treatment layer comprises at least one surface-treatment agent and/or salty reaction products thereof, wherein the at least one surface-treatment agent i) has a total amount of carbon atoms from C.sub.4 to C.sub.34, and ii) comprises at least one carboxyl group and/or a derivative thereof.

19. The filled polymer composition of claim 1, wherein the ultrafine calcium carbonate-containing filler material has i) a weight median particle size (d.sub.50) value in the range from 0.06 μm to 1.0 μm, and/or ii) a top cut (d.sub.98) value of 8 μm or less, and/or iii) a specific surface area (BET) from 0.5 to 120 m.sup.2/g, as measured by the BET method, and/or iv) a residual total moisture content of at most 0.5 wt.-%, based on the total dry weight of the ultrafine calcium carbonate-containing filler material.

20. The filled polymer composition of claim 1, wherein the ultrafine calcium carbonate-containing filler material has i) a weight median particle size (d.sub.50) value in the range from 0.15 to 0.5 μm, and/or ii) a top cut (d.sub.98) value of 2.5 μm or less, and/or iii) a specific surface area (BET) from 8 to 20 m.sup.2/g, as measured by the BET method, and/or iv) a residual total moisture content of at most 0.3 wt.-%, based on the total dry weight of the ultrafine calcium carbonate-containing filler material.

21. The filled polymer composition of claim 1, wherein the surface-treatment layer is present on the ultrafine calcium carbonate-containing filler material in an amount of from 0.1 to 10 wt.-%, based on the total amount of the surface-treated calcium carbonate-containing filler material.

22. The filled polymer composition of claim 1, wherein the surface-treatment layer is present on the ultrafine calcium carbonate-containing filler material in an amount of from 2 to 4 wt.-%, based on the total amount of the surface-treated calcium carbonate-containing filler material.

23. The filled polymer composition of claim 1, wherein the surface-treatment layer does not comprise an unsaturated compound.

24. The filled polymer composition of claim 1, wherein the surface-treated calcium carbonate-containing filler material has i) a hydrophilicity in the range from 0.01 to 4, indicated as the volumetric ratio of water:ethanol, measured at +23° C. (±2° C.) with the sedimentation method, and/or ii) a moisture pick up susceptibility from 0.01 to 5 mg/g.

25. The filled polymer composition of claim 1, wherein the surface-treated calcium carbonate-containing filler material has i) a hydrophilicity in the range from 0.04 to 1, indicated as the volumetric ratio of water:ethanol, measured at +23° C. (±2° C.) with the sedimentation method, and/or ii) a moisture pick up susceptibility from 0.03 to 1.2 mg/g.

26. The filled polymer composition of claim 1, wherein the at least one surface-treatment agent is a saturated surface-treatment agent.

27. The filled polymer composition of claim 1, wherein the at least one surface-treatment agent is a saturated surface-treatment agent selected from the group consisting of I) at least one saturated aliphatic linear or branched carboxylic acid and/or a salt thereof, II) at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, and cyclic aliphatic group having a total amount of carbon atoms from C.sub.2 to C.sub.30 in the substituent and/or a salt or an acid thereof, III) salty reaction products of the materials according to I) and II), and IV) mixtures of the materials according to I) to III).

28. The filled polymer composition of claim 1, wherein the at least one surface-treatment agent is an unsaturated surface-treatment agent selected from the group consisting of I) at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched and cyclic unsaturated group having a total amount of carbon atoms from C.sub.2 to C.sub.30 in the substituent and/or a salt or an acid thereof, and II) salty reaction products of the materials according to I).

29. The filled polymer composition of claim 1, wherein a) the at least one polypropylene polymer is present in an amount from 0.5 to 99 wt.-%, based on the total weight of the polymer in the filled polymer composition, and/or b) the surface-treated calcium carbonate-containing filler material is present in an amount from 5 wt.-% to 70 wt.-%, based on the total weight of the filled polymer composition.

30. The filled polymer composition of claim 1, wherein a) the at least one polypropylene polymer is present in an amount from 1 to 30 wt.-%, based on the total weight of the polymer in the filled polymer composition, and/or b) the surface-treated calcium carbonate-containing filler material is present in an amount from 7 wt.-% to 40 wt.-%, based on the total weight of the filled polymer composition.

31. The filled polymer composition of claim 1, which does not comprise a peroxide reagent and/or a reaction product thereof.

32. The filled polymer composition of claim 1, further comprising at least one additive selected from the group consisting of a further filler, talc, mica, kaolin, bentonite, UV-absorbers, light stabilizers, processing stabilizers, antioxidants, heat stabilizers, nucleating agents, metal deactivators, impact modifiers, plasticizers, lubricants, rheology modifiers, processing aids, pigments, dyes, optical brighteners, antimicrobials, antistatic agents, slip agents, anti-block agents, coupling agents, dispersants, compatibilizers, oxygen scavengers, acid scavengers, markers, antifogging agents, surface modifiers, flame retardants, blowing agents, smoke suppressors, and mixtures thereof, and/or further comprising at least one of a further polymer, polystyrene, polyesters, polyethylene terephthalate, polylactic acid, polyhydroxybutyrate, polyethylene-2,5-furandicarboxylate, polyvinyl chloride, polybutadiene, polyacrylonitrile, polymethylmethacrylate, polyamides, polyurethanes, and mixtures thereof.

33. The filled polymer composition of claim 1, wherein the impact strength of the filled polymer composition is increased by at least 5%, determined by ISO 179-1eA:2010-11, compared to the same polymer composition not comprising the surface-treated calcium carbonate-containing filler material or compared to the same polymer composition comprising the same ultrafine calcium carbonate-containing filler material lacking a surface-treatment layer.

34. The filled polymer composition of claim 1, wherein the tensile modulus of the filled polymer composition is increased by at least 5%, determined by ISO 527-1:2019, compared to the same polymer composition not comprising the surface-treated calcium carbonate-containing filler material or compared to the same polymer composition comprising the same ultrafine calcium carbonate-containing filler material lacking a surface-treatment layer.

35. An article comprising the filled polymer composition of claim 1.

36. A process for the production of a filled polymer composition, comprising the steps of a) providing at least one polyethylene polymer and at least one polypropylene polymer and/or a polymer mixture comprising polyethylene and polypropylene, b) providing a surface-treated calcium carbonate-containing filler material, wherein the surface-treated calcium carbonate-containing filler material comprises an ultrafine calcium carbonate-containing filler material having i) a weight median particle size (d.sub.50) value in the range from 0.03 μm to 1.0 μm and ii) a top cut (d.sub.98) value of 10 μm or less, and a surface-treatment layer on at least a part of the surface of said ultrafine calcium carbonate-containing filler material, wherein the surface-treatment layer comprises at least one surface-treatment agent and/or salty reaction products thereof, wherein the at least one surface-treatment agent i) has a total amount of carbon atoms from C.sub.4 to C.sub.34, and ii) comprises at least one carboxyl group and/or a derivative thereof, c) mixing, in any order, the polyethylene polymer and the polypropylene polymer and/or the polymer mixture of step a), and the surface-treated calcium carbonate-containing filler material of step b) to obtain a mixture, and d) compounding the mixture of step c) to obtain a filled polymer composition, wherein the filled polymer composition comprises the surface-treated calcium carbonate-containing filler material in an amount from 5 wt.-% to 70 wt.-%, based on the total weight of the filled polymer composition.

37. The process of claim 36, wherein i) mixing step c) and compounding step d) are performed simultaneously and/or ii) compounding step d) is performed at a temperature in the range from 150 to 260° C., and/or iii) compounding step d) is an extrusion step.

38. The process of claim 36, wherein i) mixing step c) and compounding step d) are performed simultaneously, wherein the surface-treated calcium carbonate-containing filler material of step b) is admixed after mixing the polyethylene polymer and the polypropylene polymer and/or the polymer mixture of step a), and wherein the mixture of the polyethylene polymer and the polypropylene polymer and/or the polymer mixture of step a) is at least partially in the molten state and/or ii) compounding step d) is performed at a temperature in the range from 180 to 230° C., and/or iii) compounding step d) is an extrusion step.

39. The process of claim 36, wherein mixing step c) comprises the sub-steps of c1) forming a masterbatch of the surface-treated calcium carbonate-containing filler material provided in step b) and at least one polyethylene polymer or at least one polypropylene polymer provided in step a), wherein the masterbatch comprises the surface-treated calcium carbonate-containing filler material in an amount from 40 to 80 wt.-%, based on the total amount of the masterbatch, and c2) mixing the masterbatch obtained in step c1) with the same or different at least one polyethylene polymer and/or at least one polypropylene polymer and/or polymer mixture comprising polyethylene and polypropylene of step a) to obtain a mixture comprising polyethylene and polypropylene.

40. The process of claim 36, wherein mixing step c) comprises the sub-steps of c1) forming a masterbatch of the surface-treated calcium carbonate-containing filler material provided in step b) and at least one polyethylene polymer or at least one polypropylene polymer provided in step a), wherein the masterbatch comprises the surface-treated calcium carbonate-containing filler material in an amount from 50 to 70 wt.-%, based on the total amount of the masterbatch, and c2) mixing the masterbatch obtained in step c1) with the same or different at least one polyethylene polymer and/or at least one polypropylene polymer and/or polymer mixture comprising polyethylene and polypropylene of step a) to obtain a mixture comprising polyethylene and polypropylene, wherein mixing step c2) and compounding step d) are performed simultaneously.

41. The process of claim 36, further comprising the step of e) forming the filled polymer composition obtained in step d) into an article.

42. The process of claim 36, further comprising the step of e) forming the filled polymer composition obtained in step d) into an article, by injection moulding or film or sheet formation.

Description

EXAMPLES

I. Analytical Methods

BET Specific Surface Area of a Material

[0434] Throughout the present document, the specific surface area (in m.sup.2/g) of the mineral filler is determined using the BET method (using nitrogen as adsorbing gas), which is well known to the skilled man (ISO 9277:2010). The total surface area (in m.sup.2) of the mineral filler is then obtained by multiplication of the specific surface area and the mass (in g) of the mineral filler prior to treatment.

Amount of Surface-Treatment Layer

[0435] The amount of the treatment layer on the calcium carbonate-containing filler material is calculated theoretically from the values of the BET of the untreated calcium carbonate-containing filler material and the amount of at least one hydrophobizing agent that are used for the surface-treatment.

Particle Size Distribution (Mass % Particles with a Diameter <X) and Weight Median Diameter (d.sub.50) of a Particulate Material

[0436] As used herein and as generally defined in the art, the “d.sub.50” value is determined based on measurements made by using a Sedigraph™ 5100 of Micromeritics Instrument Corporation and is defined as the size at which 50% (the median point) of the particle mass is accounted for by particles having a diameter equal to the specified value.

[0437] The method and the instrument are known to the skilled person and are commonly used to determine grain size of fillers and pigments. The measurement is carried out in an aqueous solution of 0.1 wt.-% Na.sub.4P.sub.2O.sub.7. The samples are dispersed using a high speed stirrer and supersonics.

Impact Properties

[0438] The impact properties are measured according to ISO 179-1eA:2010-11 on a HIT5.5P device from Zwick Roell. Measurements are performed on notched samples with a hammer of 2 J. All measurements are performed on samples that have been stored under similar conditions after preparation.

II. Experimental Part

Part 1: Surface-Treated Calcium Carbonate Preparation

Materials Used in the Examples:

1. Polymer Resin

[0439] Example 1: The polymer resins used are a virgin linear low density polyethylene (CAS No. 9002-88-4) LLDPE 6101XR (MFR 20 g/10 min) commercially available from ExxonMobil and a virgin polypropylene (CAS No. 9003-07) PP HF136MO (MFR 20 g/10 min) from Borealis.

[0440] Example 2: The polymer resins used are a virgin linear low density polyethylene (CAS No. 9002-88-4) Dowlex® 2631.10UE (MFR 7 g/10 min) commercially available from Resinex® and a virgin polypropylene PP (CAS No. 9003-07) Moplen™ HP525J (MFR 3 g/10 min) from LyondellBasell@.

[0441] Example 3: The polymer resins used are a virgin high density polyethylene HDPE (CAS No. 9002-88-4) and a virgin polypropylene PP (CAS No. 9003-07) Moplen HP525J (MFR 3 g/10 min) from LyondellBasell.

[0442] Example 4: The polymer resin used is KWR105M2 (MFR 4 g/10 min), a mixture of high density polyethylene HDPE and 15% polypropylene derived from post-consumer waste polymer from KW Plastics.

2. Calcium Carbonate-Containing Filler Material CC1

[0443] The calcium carbonate CC1 is an untreated dry ground marble from Italy (d.sub.50=1.7 μm, d.sub.98=8 μm (measured with Sedigraph), BET SSA=4.1 m.sup.2/g).

3. Calcium Carbonate-Containing Filler Material CC2

[0444] The calcium carbonate CC2 is a dry ground marble from Italy (d.sub.50=1.7 μm, d.sub.98=8 μm (measured with Sedigraph), BET SSA=4.1 m.sup.2/g) treated with a fatty acid mixture (about 40 wt.-% stearic acid and about 60 wt.-% palmitic acid).

4. Calcium Carbonate-Containing Filler Material CC3

[0445] The calcium carbonate CC3 is an untreated wet ground spray dried limestone from France (d.sub.50=0.7 μm, d.sub.98=2.9 μm (measured with Sedigraph), BET SSA=7.9 m.sup.2/g)

5. Calcium Carbonate-Containing Filler Material CC4

[0446] The calcium carbonate CC4 is a wet ground spray dried limestone from France (d.sub.50=0.7 μm, d.sub.98=2.9 μm (measured with Sedigraph), BET SSA=7.9 m.sup.2/g) treated with a fatty acid mixture (about 40 wt.-% stearic acid and about 60 wt.-% palmitic acid).

6. Calcium Carbonate-Containing Filler Material CC5

[0447] The calcium carbonate CC5 is a fine marble powder from Norway (d.sub.50=0.3 μm, d.sub.98=1 μm (measured with Sedigraph), BET SSA=14.4 m.sup.2/g) treated with a fatty acid mixture (about 40 wt.-% stearic acid and about 60 wt.-% palmitic acid).

Part 2: Processing Parameters

Example 1: Samples Containing 30 wt.-% Filler in a Polymer Matrix of 70 wt.-% LLDPE/30 wt.-% PP

[0448] Filled polymer compositions CP-1 to CP-7 were produced on a twin-screw extruder from MARIS (Extruder Type™ 20HT (D=20 mm, L/D=48, D/d=1.55, 11 Nm/cc, 15 kW, die: 2 holes of 3 mm diameter) with the following line settings: [0449] Extruder temperatures: 100° C./230° C./230° C./210° C./170° C./170° C./170° C./170° C./170° C./170° C./180° C./200° C./220° C. [0450] Screw speed: 450 rpm (max speed possible: 1500 rpm)

[0451] The polymer matrix used is a mixture of a linear low-density polyethylene (LLDPE) that can be obtained from ExxonMobil under the tradename LLDPE 6101XR and a virgin polypropylene from Borealis under the tradename PP HF136MO. The composition of the polymer matrix is a ratio of 70 wt.-% LLDPE-30 wt.-% PP.

TABLE-US-00001 TABLE 1 Preparation and composition of filled polymer compositions CP-1 to CP-7 Sample Filler material (comparative/inventive) Polymer 1 (wt.-%) Polymer 2 (wt.-%) (wt.-%) CP-1 (comparative) LLDPE 6101XR (70%) PP HF136MO (30%) / CP-2 (comparative) / PP HF136MO (100%) / CP-3 (comparative) LLDPE 6101XR (49%) PP HF136MO (21%) CC 1 (30%) CP-4 (comparative) LLDPE 6101XR (49%) PP HF136MO (21%) CC 2 (30%) CP-5 (comparative) LLDPE 6101XR (49%) PP HF136MO (21%) CC 3 (30%) CP-6 (inventive) LLDPE 6101XR (49%) PP HF136MO (21%) CC 4 (30%) CP-7 (inventive) LLDPE 6101XR (49%) PP HF136MO (21%) CC 5 (30%)

Example 2: Samples Containing 30% Filler Varying the Polymer Matrix Composition

[0452] Filled polymer compositions CP-8 to CP-15 were produced on a twin-screw extruder 25:1 from Three Tec (Extruder Type ZE12, die: 0.5 mm) with the following line settings: [0453] Extruder temperatures: 20° C. (feeding)—190° C./210° C./210° C./190° C. [0454] Feeding speed: 12% [0455] Screw speed: 30 rpm [0456] Conveyor speed: 1 rpm [0457] Cut speed: 14 rpm

[0458] The polymer matrix used is a mixture of a linear low-density polyethylene (LLDPE) that can be obtained from Resinex under the tradename Dowlex2631.10UE and a virgin polypropylene from LyondellBasell under the tradename Moplen HP525J. The composition of the polymer matrix ratio is varying from 90 wt.-% LLDPE-10 wt.-% PP, to 70 wt.-% LLDPE-30 wt.-% PP, then 30 wt.-% LLDPE-70 wt.-% PP and finally 10 wt.-% LLDPE-90 wt.-% PP.

All polymeric components (granules) were grinded on a Retsch SR300 rotor beater mill prior to use.

TABLE-US-00002 TABLE 2 Preparation and composition of filled polymer compositions CP-8 to CP-15 Sample Filler material (comparative/inventive) Polymer 1 (wt.-%) Polymer 2 (wt.-%) (wt.-%) CP-8 (comparative) Dowlex 2631.10UE Polypropylene Moplen HP / (90%) 525J (10%) CP-9 (inventive) Dowlex 2631.10UE Polypropylene Moplen HP CC 5 (30%) (63%) 525J (7%) CP-10 (comparative) Dowlex 2631.10UE Polypropylene Moplen HP / (70%) 525J (30%) CP-11 (inventive) Dowlex 2631.10UE Polypropylene Moplen HP CC 5 (30%) (49%) 525J (21%) CP-12 (comparative) Dowlex 2631.10UE Polypropylene Moplen HP / (30%) 525J (70%) CP-13 (inventive) Dowlex 2631.10UE Polypropylene Moplen HP CC 5 (30%) (21%) 525J (49%) CP-14 (comparative) Dowlex 2631.10UE Polypropylene Moplen HP / (10%) 525J (90%) CP-15 (inventive) Dowlex 2631.10UE Polypropylene Moplen HP CC 5 (30%) (7%) 525J (63%)

Example 3: Samples Containing 30 wt.-% Filler in a Polymer Matrix of 70 wt.-% HDPE/30 wt.-% PP

[0459] Filled polymer compositions CP-16 to CP-22 were produced on a twin-screw extruder 25:1 from Three Tec (Extruder Type ZE12, die: 0.5 mm) with the following line settings: [0460] Extruder temperatures: 20° C. (feeding)—210° C./230° C./230° C./210° C. [0461] Feeding speed: 15% [0462] Screw speed: 50 rpm [0463] Conveyor speed: 1.5 rpm [0464] Cut speed: 25 rpm

[0465] Besides the conveyor belt a water bath is used to cool down the strand before cutting it.

[0466] The polymer matrix used is a mixture of a high-density polyethylene (HDPE) and a virgin polypropylene from LyondellBasell under the tradename Moplen HP525J. The composition of the polymer matrix ratio is 70 wt.-% HDPE-30 wt.-% PP.

All polymeric components (granules) were grinded on a Retsch SR300 rotor beater mill prior to use.

TABLE-US-00003 TABLE 3 Preparation and composition of filled polymer compositions CP-16 to CP-22 Sample Polymer 1 Filler material (comparative/inventive) (wt.-%) Polymer 2 (wt.-%) (wt.-%) CP-16 (comparative) HDPE (100%) CP-17 (comparative) HDPE (70%) PP HF136MO (30%) / CP-18 (comparative) / PP HF136MO (100%) / CP-19 (comparative) HDPE (49%) PP HF136MO (21%) CC 1 (30%) CP-20 (comparative) HDPE (49%) PP HF136MO (21%) CC 2 (30%) CP-21 (inventive) HDPE (49%) PP HF136MO (21%) CC 4 (30%) CP-22 (inventive) HDPE (49%) PP HF136MO (21%) CC 5 (30%)

Example 4: Samples Containing 20 wt.-% Filler in a Polymer Derived from Post-Consumer Waste Polymer

[0467] Filled polymer compositions CP-23 to CP-27 were produced on a twin-screw extruder from MARIS (Extruder Type™ 20HT (D=20 mm, L/D=48, D/d=1.55, 11 Nm/cc, 15 kW, die: 2 holes of 3 mm diameter) with the following line settings [0468] Extruder temperatures: 70° C./190° C./190° C./180° C./170° C./170° C./170° C./170° C./170° C./170° C./180° C./190° C./210° C. [0469] Screw speed: 400 rpm (max speed possible: 1500 rpm)
The polymer matrix used is a mixture of high-density polyethylene (HDPE) and 15% polypropylene (PP) that can be obtained from KW Plastics under the tradename KWR105M2

TABLE-US-00004 TABLE 4 Preparation and composition of filled polymer compositions CP-23 to CP-27 Sample Filler material (comparative/inventive) Polymer (wt.-%) (wt.-%) CP-23 (comparative) KWR105M2 (100%) / CP-24 (comparative) KWR105M2 (80%) CC 1 (20%) CP-25 (comparative) KWR105M2 (80%) CC 2 (20%) CP-26 (inventive) KWR105M2 (80%) CC 4 (20%) CP-27 (inventive) KWR105M2 (80%) CC 5 (20%)

Part 3: Effect on Impact Properties

[0470] Charpy samples were made by using a Xplore IM12 injection moulder from Xplore Instruments B.V with pellets produced as described in Tables 1, 2, 3 and 4 with the settings indicated in Table 5:

TABLE-US-00005 TABLE 5 Xplore IM12 conditions Melt temperature 210° C. Mould temperature 45° C. Melting time 3 min Pressure 1 + time 7 bars 2 s Pressure 2 + time 7 to 8 bars 3 s Pressure 3 + time 8 bars 12 s 

[0471] The dimension of the produced samples are the following ones: 80 mm×10 mm×4 mm. These samples have been notched by using an Automatic NotchVis Plus from CEAST. The radius of the notch is 0.25 mm with a depth of 2 mm. Impact tests are made according to ISO179-1eA (notched).

TABLE-US-00006 TABLE 6.1 Effect of the particle size of the ultrafine calcium carbonate-containing filler material on impact properties of the filled polymer compositions according to ISO179-1eA. CP-1 CP-2 CP-3 CP-4 CP-5 CP-6 CP-7 (comp) (comp) (comp) (comp) (comp) (inv) (inv) Resilience (kJ/m.sup.2) 7.0 2.6 2.5 4.9 2.1 7.6 11.9

[0472] As can be seen from table 6.1, with untreated filler a reduction of the particle size does not allow for an improvement of the impact strength. But, it can be observed that once the filler is treated, decreasing the particle size of the filler improves the impact strength of the filled polymer composition significantly.

TABLE-US-00007 TABLE 6.2 Impact properties according to ISO179-1eA of different filled polymer compositions containing 30 wt.-% filler. CP-8 CP-9 CP-10 CP-11 (comp) (inv) (comp) (inv) Resilience (kJ/m.sup.2) 14.2 20.2 6.8 19.7 CP-12 CP-13 CP-14 CP-15 (comp) (inv) (comp) (inv) Resilience (kJ/m.sup.2) 3.9 6.5 3.3 6

[0473] As can be seen from table 6.2, this example confirms that the impact strength/resilience can be improved by using a surface-treated ultrafine calcium carbonate-comprising filler material, when compared to a similar unfilled composition regardless of the composition of the polymer mixture.

TABLE-US-00008 TABLE 6.3 Effect of the particle size of the ultrafine calcium carbonate-containing filler material on impact properties of polymer compositions according to ISO179-1eA. CP-16 CP-17 CP-18 CP-19 CP-20 CP21 CP-22 (comp) (comp) (comp) (comp) (comp) (inv) (inv) Resilience (kJ/m.sup.2) 22.8 10.6 4.9 5.9 9.0 27.3 23.4

[0474] As can be seen from table 6.3, when the filler is surface-treated, decreasing the particle size of the filler improves the impact strength of the polymer composition.

TABLE-US-00009 TABLE 6.4 Effect of the particle size of the ultrafine calcium carbonate-containing filler material on impact properties of polymer compositions according to ISO179-1eA. CP-23 CP-24 CP-25 CP-26 CP-27 (comp) (comp) (comp) (inv) (inv) Resilience (kJ/m.sup.2) 8.4 3.4 8.1 15.8 11.3

[0475] As can be seen from table 6.4, when the filler is surface-treated, using a surface-treated ultrafine calcium carbonate improves the impact strength of the polymer composition derived from waste polymers.