A COMPOSITION FORMED FROM A CALCIUM OR MAGNESIUM CARBONATE-COMPRISING MATERIAL AND A SURFACE-TREATMENT COMPOSITION COMPRISING AT LEAST ONE CROSS-LINKABLE COMPOUND

Abstract

A composition formed from a calcium or magnesium carbonate-including material and a surface-treatment composition including at least one cross-linkable compound, a dry process for the preparation of such a composition, a curable elastomer mixture comprising an elastomer resin and the composition, a cured elastomer product formed from the curable elastomer mixture, a process for preparing the cured elastomer product, the use of at least one cross-linkable compound including at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-including material in the compounding of an elastomer formed from an elastomer resin and at least one calcium or magnesium carbonate-comprising material as filler as well as an article formed from the cured elastomer product.

Claims

1. A composition formed from a calcium or magnesium carbonate-comprising material selected from among sedimentary ground calcium carbonate, precipitated calcium carbonate, surface-reacted calcium carbonate, precipitated hydromagnesite and mixtures thereof, and from 0.5 to 20 wt.-%, based on the total weight of the calcium or magnesium carbonate-comprising material, of a surface-treatment composition comprising at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material.

2. The composition according to claim 1, wherein the sedimentary ground calcium carbonate is selected from the group consisting of marble, limestone, dolomite, chalk and mixtures thereof, or the precipitated calcium carbonate is selected from the group consisting of the aragonitic, vateritic and calcitic mineralogical crystal forms, colloidal precipitated calcium carbonate, and mixtures thereof.

3. The composition according to claim 1, wherein the calcium carbonate-comprising material is sedimentary ground calcium carbonate and/or precipitated calcium carbonate and has i) a weight median particle size d.sub.50 value measured by the sedimentation method in the range from 0.1 μm to 10 μm, and/or ii) a top cut (d.sub.98) measured by the sedimentation method of ≤45 μm, and/or iii) a specific surface area (BET) of from 0.5 to 150 m.sup.2/g as measured using nitrogen and the BET method according to ISO 9277:2010, and/or iv) a residual total moisture content of ≤2 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

4. The composition according to claim 1, wherein the calcium carbonate-comprising material is surface-reacted calcium carbonate being a reaction product of (sedimentary) ground calcium carbonate or precipitated calcium carbonate with carbon dioxide and one or more H.sub.3O.sup.+ ion donors, wherein the carbon dioxide is formed in situ by the H.sub.3O.sup.+ ion donors treatment and/or is supplied from an external source or the magnesium carbonate-comprising material is precipitated hydromagnesite and has i) a volume median particle size d.sub.50 from 0.1 to 75 μm, and/or ii) a volume top cut particle size d.sub.98 from 0.2 to μm, and/or iii) a specific surface area of from 15 m.sup.2/g to 200 m.sup.2/g, measured using nitrogen and the BET method.

5. The composition according to claim 1, wherein the at least one functional group that is suitable for reacting with the calcium or magnesium carbonate-comprising material of the cross-linkable compound comprises one or more terminal triethoxysilyl, trimethoxysilyl and/or organic acid anhydride and/or salts thereof and/or carboxylic acid group(s) and/or salts thereof.

6. The composition according to claim 1, wherein the cross-linkable compound is at least one grafted polymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a homo- or copolymer comprising butadiene units and optionally styrene units or a sulfur-containing trialkoxysilane.

7. The composition according to claim 6, wherein the at least one grafted polymer is a) a grafted polybutadiene homopolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene homopolymer and having i) a number average molecular weight Mn measured by gel permeation chromatography from 1,000 to 20,000 g/mol, and/or ii) a number of functional groups per chain in the range from 2 to 12, and/or iii) an anhydride equivalent weight in the range from 400 to 2,200, or b) a grafted polybutadiene-styrene copolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene-styrene copolymer and having a 1,2 vinyl content from 20 to 80 mol.-%, based on the total weight of the grafted polybutadiene-styrene copolymer.

8. The composition according to claim 1, wherein the composition is formed in that the at least one calcium or magnesium carbonate-comprising material and the at least one cross-linkable compound are provided as physical mixture and/or in that the at least one calcium or magnesium carbonate-comprising material is contacted with the at least one cross-linkable compound such that a treatment layer comprising the at least one cross-linkable compound and/or salty reaction products thereof is formed on the surface of the at least one calcium or magnesium carbonate-comprising material.

9. The composition according to claim 1, wherein the surface-treatment composition comprises at least one further surface-treatment agent selected from the group consisting of I) a phosphoric acid ester blend of one or more phosphoric acid mono ester and/or salts thereof and/or one or more phosphoric acid di-ester and/or salts thereof, and/or II) at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof and/or III) at least one mono-substituted succinic anhydride consisting 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 at least C2 to C30 in the substituent and/or salts thereof, and/or IV) at least one polydialkylsiloxane, and V) mixtures of one or more materials according to I) to IV).

10. A dry process for the preparation of a composition according to claim 1, the process comprises at least the steps of: a) providing a calcium or magnesium carbonate-comprising material selected from among sedimentary ground calcium carbonate, precipitated calcium carbonate, surface-reacted calcium carbonate, precipitated hydromagnesite and mixtures thereof; b) providing at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material in an amount from 0.1 to 10 mg/m.sup.2, based on the total weight of the calcium or magnesium carbonate-comprising material, c) optionally providing at least one further surface-treatment agent selected from the group consisting of: I) a phosphoric acid ester blend of one or more phosphoric acid mono ester and/or salts thereof and/or one or more phosphoric acid di-ester and/or salts thereof, and/or II) at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof and/or III) at least one mono-substituted succinic anhydride consisting 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 at least C2 to C30 in the substituent and/or salts thereof, and/or IV) at least one polydialkylsiloxane, and V) mixtures of one or more materials according to I) to IV), d) optionally heating the at least one cross-linkable compound, and e) contacting the calcium or magnesium carbonate-comprising material under mixing, in one or more steps, with the at least one cross-linkable compound, f) if present, heating the at least one further surface-treatment agent to its melting point or above such that a molten surface-treatment agent is obtained and contacting the calcium or magnesium carbonate-comprising material under mixing, in one or more steps, with the molten surface-treatment agent simultaneously or subsequently to the at least one cross-linkable compound.

11. A curable elastomer mixture comprising a) an elastomer resin, and b) from 5 to 300 wt.-%, based on the total weight of the elastomer resin, of the composition according to claim 1, wherein the composition is dispersed in the elastomer resin.

12. The curable elastomer mixture according to claim 11, wherein the elastomer resin is selected from natural or synthetic rubber.

13. The curable elastomer mixture according to claim 11, wherein the mixture further comprises additives.

14. A cured elastomer product formed from the curable elastomer mixture of a claim 11.

15. A process for preparing a cured elastomer product as defined in claim 14, wherein the process comprises the steps of a) providing an elastomer resin, b) providing from 5 to 300 wt.-%, based on the total weight of the elastomer resin, of at least one calcium or magnesium carbonate-comprising material as filler, c) providing from 0.1 to 10 mg/m.sup.2, based on the total weight of the calcium or magnesium carbonate-comprising material, of at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material, d) optionally providing at least one further surface-treatment agent selected from the group consisting of I) a phosphoric acid ester blend of one or more phosphoric acid mono ester and/or salts thereof and/or one or more phosphoric acid di-ester and/or salts thereof, and/or II) at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof and/or III) at least one mono-substituted succinic anhydride consisting 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 at least C2 to C30 in the substituent and/or salts thereof, and/or IV) at least one polydialkylsiloxane, and V) mixtures of one or more materials according to I) to IV), e) optionally providing further additives additives, f) contacting the components of step a), step b), step c) and optionally step d) and step e) in any order, and g) curing the mixture obtained in step f) such that a cured elastomer product is formed.

16. The process according to claim 15, wherein in contacting step f) firstly the at least one calcium or magnesium carbonate-comprising material of step b) is contacted under mixing, in one or more steps, with the at least one cross-linkable compound of step c) and, if present, subsequently or simultaneously, with the at least one further surface-treatment agent of step d) such that a surface treatment layer comprising the at least one cross-linkable compound and/or salty reaction product(s) thereof and optionally the at least one further surface-treatment agent and/or salty reaction product(s) thereof is/are formed on the surface of said at least one calcium or magnesium carbonate-comprising material of step b), and secondly this surface-treated calcium or magnesium carbonate-comprising material is contacted under mixing, in one or more steps, with the elastomer resin of step a).

17. The process according to claim 16, wherein the further additives of step e) are contacted under mixing, in one or more steps, with the surface-treated calcium or magnesium carbonate-comprising material before or after, the surface-treated calcium or magnesium carbonate-comprising material is contacted under mixing, in one or more steps, with the elastomer resin of step a).

18. The process according to claim 15, wherein contacting step f) is carried out during curing step g) in that the at least one cross-linkable compound is contacted under mixing with the elastomer resin of step a) before or after adding the at least one calcium or magnesium carbonate-comprising material.

19. A method comprising compounding an elastomer formed from an elastomer resin and at least one calcium or magnesium carbonate-comprising material as filler with at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material, to increase the mechanical properties of such a compounded elastomer in comparison to the same elastomer formed from the same elastomer resin and at least one calcium or magnesium carbonate-comprising material but without the at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material.

20. An article formed from a cured elastomer product according to claim 14, wherein the article is selected from the group comprising tubeless articles, membranes, sealings, gloves, pipes, cable, electrical connectors, oil hoses, shoe soles, O-ring seals, shaft seals, gaskets, tubing, valve stem seals, fuel hose, tank seals, diaphragms, flexi liners for pumps, mechanical seals, pipe coupling, valve lines, military flare blinders, electrical connectors, fuel joints, roll covers, firewall seals, clips for jet engines, and the like.

Description

EXAMPLES

1. Measurement Methods

[0406] In the following, measurement methods implemented in the examples are described.

Particle Size Distribution

[0407] Volume median particle size d.sub.50 (vol) and volume top cut particle size d.sub.98 (vol) are evaluated using a Malvern Mastersizer 3000 Laser Diffraction System. The d.sub.50 or d.sub.98 value, measured using a Malvern Mastersizer 3000 Laser Diffraction System, indicates a diameter value such that 50% or 98% by volume, respectively, of the particles have a diameter of less than this value. The raw data obtained by the measurement are analysed using the Mie theory, with a particle refractive index of 1.57 and an absorption index of 0.005.

[0408] The weight median particle size d.sub.50 (wt) and weight top cut particle size d.sub.98 (wt) is determined by the sedimentation method, which is an analysis of sedimentation behaviour in a gravimetric field. The measurement is made with a Sedigraph™ 5120, Micromeritics Instrument Corporation. 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 were dispersed using a high speed stirrer and sonicated.

[0409] The processes and instruments are known to the skilled person and are commonly used to determine the particle size of fillers and pigments.

Specific Surface Area (SSA)

[0410] The specific surface area was measured via the BET method according to ISO 9277:2010 using nitrogen as adsorbing gas on a Micromeritics ASAP 2460 instrument from Micromeritics. The samples were pretreated in vacuum (10-5 bar) by heating at 150° C. for a period of 60 min prior to measurement.

Porosimetry

[0411] The specific pore volume was measured using a mercury intrusion porosimetry measurement using a Micromeritics Autopore V 9620 mercury porosimeter having a maximum applied pressure of mercury 414 MPa (60000 psi), equivalent to a Laplace throat diameter of 0.004 μm (˜nm). The equilibration time used at each pressure step is 20 seconds. The sample material is sealed in a 3 cm.sup.3 chamber powder penetrometer for analysis. The data are corrected for mercury compression, penetrometer expansion and sample material compression using the software Pore-Comp (Gane, P. A. C., Kettle, J. P., Matthews, G. P. and Ridgway, C. J., “Void Space Structure of Compressible Polymer Spheres and Consolidated Calcium Carbonate Paper-Coating Formulations”, Industrial and Engineering Chemistry Research, 35(5), 1996, p 1753-1764.).

[0412] The total pore volume seen in the cumulative intrusion data can be separated into two regions with the intrusion data from 214 μm down to about 1-4 μm showing the coarse packing of the sample between any agglomerate structures contributing strongly. Below these diameters lies the fine interparticle packing of the particles themselves. If they also have intraparticle pores, then this region appears bi modal, and by taking the specific pore volume intruded by mercury into pores finer than the modal turning point, i.e. finer than the bi-modal point of inflection, the specific intraparticle pore volume is defined. The sum of these three regions gives the total overall pore volume of the powder, but depends strongly on the original sample compaction/settling of the powder at the coarse pore end of the distribution.

[0413] By taking the first derivative of the cumulative intrusion curve the pore size distributions based on equivalent Laplace diameter, inevitably including pore-shielding, are revealed. The differential curves clearly show the coarse agglomerate pore structure region, the interparticle pore region and the intraparticle pore region, if present. Knowing the intraparticle pore diameter range it is possible to subtract the remainder interparticle and interagglomerate pore volume from the total pore volume to deliver the desired pore volume of the internal pores alone in terms of the pore volume per unit mass (specific pore volume). The same principle of subtraction, of course, applies for isolating any of the other pore size regions of interest.

Amount of Surface-Treatment Layer

[0414] The amount of the treatment layer on the magnesium and/or calcium ion-containing material is calculated theoretically from the values of the BET of the untreated magnesium and/or calcium ion-containing material and the amount of the one or more compound(s) that is/are used for the surface-treatment. It is assumed that 100% of the one or more compound(s) are present as surface treatment layer on the surface of the magnesium and/or calcium ion-containing material.

Molecular Weight

[0415] The number-average molecular weight M.sub.n is measured by gel permeation chromatography, according to ISO 16014-1:2019 and ISO 16014-2/2019.

Acid Number

[0416] The acid number is measured according to ASTM D974-14.

Iodine Number

[0417] The iodine number is measured according to DIN 53241/1.

Total Residual Moisture Content

[0418] The total residual moisture content was determined by thermogravimetric analysis (TGA). The equipment used to measure the TGA was the Mettler-Toledo TGA/DSC1 (TGA 1 STARe System) and the crucibles used were aluminium oxide 900 μl. The method consists of several heating steps under air (80 mL/min). The first step was a heating from 25 to 105° C. at a heating rate of 20° C./minute (step 1), then the temperature was maintained for 10 minutes at 105° C. (step 2), then heating was continued at a heating rate of 20° C./minute from 105 to 400° C. (step 3). The temperature was then maintained at 400° C. for 10 minutes (step 4), and finally, heating is continued at a heating rate of 20° C./minute from 400 to 600° C. (step 5). The total residual moisture content is the cumulated weight loss after steps 1 and 2.

Analysis on Cross-Linked Elastomer Product Samples

[0419] For all tests on the cured elastomer product samples, a minimum period of 16 h was kept between molding and testing of the product samples. The samples were kept in a controlled environment (temperature: 23±2° C., relative humidity: 50±5%).

Tensile Strength, Elongation at Break, Modulus M300, and Modulus M100:

[0420] Tensile strength, elongation at break, modulus M300, and modulus M100 were measured according to NF ISO 37 on a Zwick T2000, Zwick Z005, or Zwick Z100 device using the parameters outlined in Table 1 below.

TABLE-US-00001 TABLE 1 Tensile strength, elongation at break, modulus M300, and Modulus M100 measurement parameters. Standard NF ISO 37 Type of test piece Type H2 Preparation of test piece Samples were cut from sheets of 2 ± 0.2 mm thickness Cutting direction Parallel of calendering direction State Initial Temperature 23 ± 2° C. Relative humidity 50 ± 5% Number of test pieces used 3 Units MPa for strength Test specimen conditioning Minimum 16 h at 23° C. before test and 50% relative humidity Conditioning after ageing in air None Conditioning after immersion None Rate of grip separation 500 mm/min Relative uncertainty ±10%

Tear Resistance

[0421] Tear resistance (DELFT) was measured according to NF ISO 34-2 on a Zwick T2000, Zwick Z005, Zwick Z100 device using the parameters outlined in Table 2.

TABLE-US-00002 TABLE 2 Tear resistance (DELFT) measurement parameters. Standard NF ISO 34-2 Type of test piece Delft Preparation of test piece Samples were cut from sheets of 2 ± 0.2 mm thickness Cutting direction perpendicular to calendering direction State Initial Temperature 23 ± 2° C. Relative humidity 50 ± 5% Number of test pieces used 3 Test specimen conditioning Minimum 16 h at 23° C. before test and 50% relative humidity Rate of grip separation 500 mm/min Relative uncertainty ±10%

Hardness Shore A

[0422] Hardness (Shore A) was measured according to NE ISO 7619-1 on a Bareiss Digitest II apparatus using the parameters outlined in Table 3.

TABLE-US-00003 TABLE 3 Hardness (Shore A) measurement parameters. Standard NF ISO 7619-1 Type of device A Type of test piece 50 × 25 × (2.0 ± 0.2) mm Number of test pieces used 3 Test carry out 3 s Preparation of test piece Samples were cut from sheets of 2 ± 0.2 mm thickness State Initial Temperature 23 ± 2° C. Relative humidity 50 ± 5% Number of measurements 5 Unit points Test specimen conditioning Minimum 16 h at 23° C. before test and 50% relative humidity Absolute uncertainty ±2 points %

Hardness IRHD

[0423] Hardness (IRHD) was measured according to NE ISO 48-1 on a Wallace IRHD H14/1+Gibitre-PC type N automatic apparatus using the parameters outlined in Table 4.

TABLE-US-00004 TABLE 4 Hardness (IRHD) measurement parameters. Standard NF ISO 48-1 Method N Type of test piece 50 × 20 × (2.0 ± 0.2) mm Number of test pieces used 4 Preparation of test piece Samples were cut from sheets of 2 ± 0.2 mm thickness State Initial Temperature 23 ± 2° C. Relative humidity 50 ± 5% Number of measurements 5 Unit 0 Test specimen conditioning before test Minimum 16 h at 23° C. and 50% relative humidity Conditioning after ageing in air 16 h to 6 days at 23° C. and 50% relative humidity Conditioning after immersion none Absolute uncertainty ±2°

Compression Set

[0424] These tests were provided on compression set plots type B, which are cylindrical molded rubber samples. The diameter of the sample was 13.0±0.5 mm and the thickness was 6.3±0.3 mm. Tests were carried out for 72 h at 10000 using the parameters outlined in Table 5.

TABLE-US-00005 TABLE 5 Compression set. Standard NF ISO 815-1 Method After 30 ± 3 min Type of test piece B Number of test pieces used 3 or 4 nit % Compression 25% Conditioning after immersion none Lubricant Silicone Preparation of test piece molded Temperature 23 ± 2° C. Relative humidity 50 ± 5% Relative uncertainty ±10%

Electric Resistivity

[0425] Electrical resistivity was measured according to ISO 14309 with a Keithley electrometer, type 6517B using the parameters outlined in Table 6.

TABLE-US-00006 TABLE 6 Electrical resistivity Standard ISO 14309 Type of test piece 100 × 100 × 2 mm Number of test pieces used: 1 Preparation of test piece Samples were cut from sheets of 2 ± 0.2 mm thickness State: Initial, 23° C.

2. Materials Used

[0426] The materials used for the present invention had the characteristics set out in the following.

Treatment A

[0427] Treatment A was a grafted polybutadiene homopolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene homopolymer (Mn=3100 Da, Brookfield viscosity (25° C.)=6500 cPs+/−3500, functional groups/chain=2, anhydride equivalent weight 1238; acid number: 40.1-51.5 meq KOH/g, total acid: 7-9 wt.-%, microstructure (molar % of butadiene): 20-35% 1-2 vinyl functional groups) commercially available from Cray Valley under the trade name RICON®130MA8.

Treatment B

[0428] Treatment B was a grafted polybutadiene homopolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene homopolymer (Mn=5000 Da, Brookfield viscosity (25° C.)=48000 cPs, functional groups/chain=5, anhydride equivalent weight 981) commercially available from Cray Valley under the trade name RICON®131MA10.

Treatment C

[0429] Treatment C was a grafted polybutadiene homopolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene homopolymer (Mn=2500 Da, Brookfield viscosity (55° C.)=140000 cPs, functional groups/chain=3, anhydride equivalent weight 583) commercially available from Cray Valley under the trade name RICON®156MA17.

Treatment D

[0430] Treatment D was a low molecular weight grafted polybutadiene-styrene copolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene-styrene copolymer (Mn=9900 Da, Brookfield viscosity (45° C.)=170000 cPs, functional groups/chain=6, anhydride equivalent weight 1651, acid number=28.5-40 meqKOH/g, Styrene amount: 17-27 wt %) commercially available from Cray Valley under the trade name RICON® 184MA6.

Treatment E

[0431] Treatment E was (Bis[3-(triethoxysilyl)propyl] tetrasulfide) from Sigma-Aldrich (CAS: 40372-72-3).

Treatment F

[0432] Treatment F was a mono-substituted alkenyl succinic anhydride (2,5-Furandione, dihydro-, mono-C.sub.15-20-alkenyl derivs., CAS No. 68784-12-3), which was a blend of mainly branched octadecenyl succinic anhydrides (CAS #28777-98-2) and mainly branched hexadecenyl succinic anhydrides (CAS #32072-96-1). More than 80% of the blend was branched octadecenyl succinic anhydrides. The purity of the blend was >95 wt %. The residual olefin content was below 3 wt %.

Treatment G

[0433] Treatment G was a fatty acid mixture which was a 1:1 mixture of stearic acid and palmitic acid.

Treatment H

[0434] Treatment H was a low molecular weight vinyl butadiene functionalized with maleic anhydride (M.sub.n=5000 g/mol, Brookfield viscosity: 48000 cps at 25° C., 28 wt.-% 1-2 vinyl functional groups; functional groups/chain=5), commercially available under the trade name RICOBOND®1031 (Cray Valley).

Calcium Carbonate-Comprising Filler Material 1 (Powder 1)

[0435] Powder 1 was a dry sedimentary ground calcium carbonate from Italy (d.sub.50 (wt)=3.4 μm, d.sub.98 (wt)=14 μm, BET specific surface area=2.6 m.sup.2/g).

Calcium Carbonate-Comprising Filler Material 2 (Powder 2)

[0436] Powder 2 was a stearic acid-surface treated dry sedimentary ground calcium carbonate from Italy (d.sub.50 (wt)=3.4 μm, d.sub.98 (wt)=14 μm, BET specific surface area=2.6 m.sup.2/g).

Surface-Treated Calcium Carbonate-Comprising Filler Material 3 (Powder 3)

[0437] 900 g of powder 1 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2000 rpm, 120° C.). After that time, 0.8 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment A (7.2 g) was added to the mixture. Stirring and heating was then continued for another 20 minutes (120° C., 2000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 3).

Surface-Treated Calcium Carbonate-Comprising Filler Material 4 (Powder 4)

[0438] 900 g of powder 1 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2000 rpm, 120° C.). After that time, 0.8 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment B (7.2 g) was added to the mixture. Stirring and heating was then continued for another 20 minutes (120° C., 2000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 4).

Surface-Treated Calcium Carbonate-Comprising Filler Material 5 (Powder 5)

[0439] 900 g of powder 1 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2000 rpm, 120° C.). After that time, 0.8 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment C (7.2 g) was added to the mixture. Stirring and heating was then continued for another 20 minutes (120° C., 2000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 5).

Surface-Treated Calcium Carbonate-Comprising Filler Material 6 (Powder 6)

[0440] 900 g of powder 1 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2000 rpm, 120° C.). After that time, 0.8 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment D (7.2 g) was added to the mixture. Stirring and heating was then continued for another 20 minutes (120° C., 2000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 6).

Surface-Treated Calcium Carbonate-Comprising Filler Material 7 (Powder 7)

[0441] 900 g of powder 1 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2000 rpm, 120° C.). After that time, 0.4 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment A (3.6 g) and 0.4 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment G (3.6 g) were added directly one after another in the given order to the mixture. Stirring and heating is then continued for another 20 minutes (120° C., 2000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 7).

Surface-Treated Calcium Carbonate-Comprising Filler Material 8 (Powder 8)

[0442] 900 g of powder 1 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2000 rpm, 120° C.). After that time, 0.4 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment A (3.6 g) and 0.4 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment F (3.6 g) were added directly one after another in the given order to the mixture. Stirring and heating was then continued for another 20 minutes (120° C., 2000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 8).

Surface-Treated Calcium Carbonate-Comprising Filler Material 9 (Powder 9)

[0443] Powder 9 was a wet ground and dried sedimentary ground calcium carbonate from Norway partially treated (0.6 wt %) with treatment G (d.sub.50 (wt)=0.3 μm, d.sub.98 (wt)=1.4 μm (measured with sedigraph), BET specific surface area=14.4 m.sup.2/g).

Surface-Treated Calcium Carbonate-Comprising Filler Material 10 (Powder 10)

[0444] 400 g of powder 9 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 5 minutes (800 rpm, 120° C.). After that time, 2.5 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment A (10 g) were added to the mixture. Stirring and heating was then continued for another 10 minutes (120° C., 800 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 10). The material obtained had a residual total moisture content of 0.08 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Calcium Carbonate-Comprising Filler Material 11 (Powder 11)

[0445] 400 g of powder 9 was placed in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 5 minutes (1000 rpm, 90° C.). After that time, 2.5 parts by weight relative to 100 parts by weight CaCO.sub.3 of Treatment E (10 g) were added to the mixture. Stirring and heating was then continued for another 15 minutes (90° C., 1000 rpm). After that time, the mixture was allowed to cool and the free-flowing powder was collected (powder 10).

Precipitated Calcium Carbonate-Comprising Filler Material 12 (Powder 12)

[0446] Powder 12 was a precipitated calcium carbonate from Austria (d.sub.50 (wt)=1.5 μm, d.sub.98 (wt)=8 μm (measured with sedigraph), BET specific surface area=34.4 m.sup.2/g).

Surface-Treated Precipitated Calcium Carbonate-Comprising Filler Material 13 (Powder 13)

[0447] Powder 13 was prepared by surface-treating powder 12 with 2.5 wt % of treatment A. To carry out the treatment, the treatment A (25 g) was first dispersed in 200 mL of deionized water, heated to 60° C. and neutralized to pH 10 with sodium hydroxide solution.

[0448] A suspension of powder 12 (1.00 kg in 7 L deionized water) was prepared in a 10 L ESCO batch reactor and heated to 85° C. The pH was adjusted to 10 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes, and the suspension was then transferred to a metallic tray and dried in an oven (110° C.). The dried cake was then deagglomerated using a Retsch SR300 rotor beater mill.

Precipitated Calcium Carbonate-Comprising Filler Material 14 (Powder 14)

[0449] Powder 14 was a precipitated calcium carbonate from Austria (d.sub.50 (wt)=2.7 μm, d.sub.98 (wt)=3.9 μm (measured with sedigraph), BET specific surface area=70.8 m.sup.2/g).

Surface-Treated Precipitated Calcium Carbonate-Comprising Filler Material 15 (Powder 15)

[0450] Powder 15 was prepared by surface-treating powder 14 with 2.5 wt % of treatment A. To carry out the treatment, the treatment A (25 g) was first dispersed in 200 mL of deionized water, heated to 60° C. and neutralized to pH 10 with sodium hydroxide solution.

[0451] A suspension of powder 14 (1.00 kg in 7 L deionized water) was prepared in a 10 L ESCO batch reactor and heated to 85° C. The pH was adjusted to 10 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes, and the suspension was then transferred to a metallic tray and dried in an oven (110° C.). The dried cake was then deagglomerated using a Retsch SR300 rotor beater mill.

Calcined Kaolin-Comprising Filler Material 16 (Powder 16)

[0452] Powder 16 was a high purity fully calcined kaolin from Imerys (Polestar 200P) with a d.sub.50 (wt) of 2 μm (measured with sedigraph).

Carbon Black-Comprising Filler Material 17 (Powder 17)

[0453] Powder 17 was a N550 carbon black filler obtained from Orion engineered Carbons GmbH (Purex® HS 45, iodine number: 43±5 mg/g; STSA surface area (according to ASTM D 6556): 39±5 m.sup.2/g).

Precipitated Silica-Comprising Filler Material 18 (Powder 18)

[0454] Powder 18 was a precipitated silica from Evonik (Ultrasil VN3) with a BET specific surface area of 180 m.sup.2/g.

Calcined Kaolin-Comprising Filler Material 19 (Powder 19)

[0455] Powder 19 was high purity fully calcined kaolin from Imerys (Polestar 200R) with a d.sub.50 of 2 μm.

Calcium Carbonate Comprising Filler Material 20 (Powder 20)

[0456] Powder 20 was a calcium carbonate from Imerys (Micronic O) with a d.sub.50 of 2.4 μm, a d.sub.98 of 9 μm and a BET specific surface area of 2.0 m.sup.2/g.

Surface-Reacted Calcium Carbonate Comprising Filler 21 (Powder 21)

[0457] Powder 21 was a surface-reacted calcium carbonate composed of 80% hydroxyapatite and 20% calcite (BET=85 m.sup.2/g, d.sub.50 (vol)=6.1 μm, d.sub.98 (vol)=13.8 μm; measured with laser diffraction), prepared with the following method:

[0458] In a mixing vessel, 350 liters of an aqueous suspension of (sedimentary) ground calcium carbonate was prepared by adjusting the solids content of a ground marble calcium carbonate from Hustadmarmor, Norway, with a particle size distribution of 90 wt.-% less than 2 μm as determined by sedimentation, such that a solids content of 10 wt.-%, based on the total weight of the aqueous suspension, was obtained.

[0459] Whilst mixing the suspension, 62 kg of a 30% concentrated phosphoric acid was added to said suspension over a period of 10 minutes at a temperature of 70° C. Finally, after the addition of the phosphoric acid, the slurry was stirred for additional 5 minutes, before removing it from the vessel and drying.

Surface-Treated Surface-Reacted Calcium Carbonate Comprising Filler 22 (Powder 22)

[0460] Powder 22 was prepared by surface treatment of powder 21 with 7.5% of treatment E. Surface treatment was carried out in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany). Powder 21 (300 g) was put in the mixer and stirred at 500 rpm and room temperature. Treatment E (7.5 wt.-%, 24 g) was then added dropwise to the mixture and stirring was continued for another 10 minutes. After that time, the mixture was allowed to cool and the powder was collected.

Precipitated Hydromagnesite Filler 23 (Powder 23)

[0461] Powder 23 was a precipitated Hydromagnesite (BET specific surface area: 84.2 m.sup.2/g, d.sub.50 (vol)=7.6 μm; d.sub.95 (vol)=20.6 μm).

Surface-Treated Precipitated Hydromagnesite Filler 24 (Powder 24)

[0462] Powder 24 was prepared by surface-treating powder 23 with 2.5 wt.-% of treatment A. To carry out the treatment, the treatment A (25 g) was first dispersed in 100 mL of deionized water, heated to 60° C. and neutralized to pH 9-10 with sodium hydroxide solution.

[0463] A suspension of powder 23 (1 kg in 7.5 L deionized water) was prepared in a 10 L ESCO batch reactor (ESCO-Labor AG, Switzerland) and heated to 85° C. The pH was adjusted to 10-11 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes, and the suspension was then transferred to metallic tray and dried in an oven (110° C.). The dried cake was then deagglomerated using a SR300 rotor beater mill (Retsch GmbH, Germany).

Calcined Kaolin-Comprising Filler Material 25 (Powder 25)

[0464] Powder 25 was a fine calcined kaolin from Imerys (Polestar 400) with a d.sub.50 of 0.6 μm

Surface-Treated Calcium Carbonate-Comprising Filler Material 26 (Powder 26)

[0465] Powder 26 was a wet ground and dried sedimentary ground calcium carbonate from Norway treated (3.6 wt %) with treatment G (d.sub.50 (wt)=0.3 μm, d.sub.98 (wt)=1.4 μm, BET specific surface area=14.4 m.sup.2/g). The material had a residual total moisture content of 0.08 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Precipitated Hydromagnesite Filler 27 (Powder 27)

[0466] Powder 27 was a precipitated hydromagnesite (BET specific surface area=46.7 m.sup.2/g, d.sub.50 (vol)=8.75 μm; d.sub.98 (vol)=29 μm). The material had a residual total moisture content of 3.76 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Precipitated Hydromagnesite Filler 28 (Powder 28)

[0467] Powder 28 was prepared by surface-treating powder 27 with 3 wt.-% of treatment G and 3 wt % of treatment A. To carry out the treatment, the treatment G (24 g) was first dispersed in 500 mL of deionized water, heated to 80° C. 5.4 g of sodium hydroxide dissolved in 100 mL water was added to it. The corresponding sodium salt dissolved in water. In parallel, treatment A (24 g) was first dispersed in 400 mL of deionized water, heated to 60° C. and neutralized to pH 9-10 with sodium hydroxide.

[0468] After that, a suspension of powder 27 (800 g in 5 L deionized water) was prepared in a 10 L ESCO batch reactor (ESCO-Labor AG, Switzerland) and heated to 85° C. The neutralized treatment agents prepared above were then added under vigorous stirring. Mixing was continued at 80° C. for 45 minutes. The suspension was then filtered on a filter press, and the filter cake was then transferred to metallic tray and dried in an oven (110° C.). The dried cake was then deagglomerated using a SR300 rotor beater mill equipped with a 200 m sieve (Retsch GmbH, Germany). The material had a residual total moisture content of 1.48 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Carbon Black Filler Material 29 (Powder 29)

[0469] Powder 29 was a N220 carbon black filler, commercially available from Cabot under the Vulcan® 6, iodine number: 121 mg/kg, STSA surface area (according to ASTM D 6556): 104 m.sup.2/g).

Calcium Carbonate-Comprising Filler Material 30 (Powder 30)

[0470] Powder 30 was ground calcium carbonate powder from France (Micromya-OM), d.sub.50 (wt)=2.4 μm, d.sub.98 (wt)=20 μm. The material had a residual total moisture content of 0.01 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Surface-Reacted Calcium Carbonate Comprising Filler 31 (Powder 31)

[0471] Powder 31 was prepared by surface treatment of powder 21 with 7 wt.-% of treatment F. Surface treatment was carried out in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany). Powder 21 (500 g) was put in the mixer and stirred at 500 rpm and 120° C. Treatment F (7 wt.-%, 35 g) was then added dropwise to the mixture and stirring was continued for another 15 minutes. After that time, the mixture was allowed to cool and the powder was collected. The material obtained had a residual total moisture content of 1.09 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material and a moisture pick-up of 17 mg/g.

Surface-Treated Surface-Reacted Calcium Carbonate Comprising Filler 32 (Powder 32)

[0472] Powder 32 was prepared by surface treatment of powder 21 with 8 wt.-% of treatment E. Surface treatment was carried out in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany). Powder 21 (500 g) was put in the mixer and stirred at 500 rpm and 70° C. Treatment E (8 wt.-%, 40 g) was then added dropwise to the mixture and stirring was continued for another 15 minutes. After that time, the mixture was allowed to cool and the powder was collected.

Surface-Treated Surface-Reacted Calcium Carbonate Comprising Filler 33 (Powder 33)

[0473] Powder 33 was prepared by surface-treating powder 21 with 7.5 wt.-% of treatment H. To carry the treatment, the treatment agent (60 g) was first dispersed in 400 mL of deionized water, heated to 60° C. and neutralized to pH 9-10 with sodium hydroxide.

[0474] A suspension of powder 21 (0.8 kg in 6 L deionized water) was prepared in a 10 L ESCO batch reactor (ESCO-Labor AG, Switzerland) and heated to 85° C. The pH was adjusted to 10-11 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes. The suspension was then filtered using a filter press (ca 6 bar). The filter cake was then transferred to metallic tray and dried in an oven (110° C.). The dried cake was then deagglomerated using a SR300 rotor beater mill (Retsch GmbH, Germany). The material obtained had a residual total moisture content of 1.43 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Precipitated Hydromagnesite Filler 34 (Powder 34) Powder 34 was a precipitated hydromagnesite (BET specific surface area=46.7 m.sup.2/g, d.sub.50 (vol)=8.8 μm; d.sub.98 (vol)=29 μm, moisture pick-up=27.2 mg/g). The material had a residual total moisture content of 3.74 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Precipitated Hydromagnesite Filler 35 (Powder 35)

[0475] Powder 35 was prepared by surface-treating powder 34 with 7.5 wt.-% of treatment A. To carry out the treatment, the treatment agent (64 g) was first dispersed in 400 mL of deionized water, heated to 60° C. and neutralized to pH 10 with sodium hydroxide solution.

[0476] A suspension of powder 34 (850 g in 6 L deionized water) was prepared in a 10 L ESCO batch reactor and heated to 85° C. The pH was adjusted to 10 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes, and the suspension was then filtered on a filter press and dried overnight in an oven (110° C.). The dried filter cake was then deagglomerated using a Retsch SR300 rotor beater mill. The material obtained had a residual total moisture content of 1.78 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Precipitated Hydromagnesite Filler 36 (Powder 36)

[0477] Powder 36 was prepared by treating a precipitated hydromagnesite powder with treatment agent E. Surface treatment was carried out in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany). The untreated precipitated hydromagnesite powder (400 g) was put in the mixer and stirred at 500 rpm and 70° C. Treatment E (7.5 wt.-%, 30 g) was then added dropwise to the mixture and stirring was continued for another 15 minutes. After that time, the mixture was allowed to cool and the powder was collected (BET specific surface area=32.8 m.sup.2/g, d.sub.50 (vol)=8.6 μm; d.sub.98 (vol)=45 μm).

Surface-Treated Precipitated Calcium Carbonate Filler 37 (Powder 37)

[0478] Powder 37 was prepared by treating a precipitated calcium carbonate from Austria (BET specific surface area=70 m.sup.2/g, d.sub.50 (vol)=2 μm) with 7.5% treatment agent E. Surface treatment was carried out in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany). The untreated PCC (400 g) was put in the mixer and stirred at 500 rpm and 70° C. Treatment E (7.5 wt.-%, 75 g) was then added dropwise to the mixture and stirring was continued for another 15 minutes. After that time, the mixture was allowed to cool and the powder was collected (BET specific surface area=50 m.sup.2/g). The material obtained had a residual total moisture content of 1.3 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Calcium Carbonate-Comprising Filler Material 38 (Powder 38)

[0479] Powder 38 was prepared by treating a ultrafine ground calcium carbonate produced from eggshells (BET specific surface area=16 m.sup.2/g, d.sub.50 (wt)=0.7 μm, d.sub.98 (wt)=4.1 m) with 0.6% treatment agent F, 1.2% treatment agent A and 1% treatment agent E. Surface treatment was carried out in a high speed mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany). The untreated calcium carbonate powder (1 kg) was put in the mixer and stirred at 500 rpm and 120° C. The treatment agents were then added successively to the mixture and stirring was continued for another 15 minutes. After that time, the mixture was allowed to cool and the powder was collected (BET specific surface area=12 m.sup.2/g). The material obtained had a residual total moisture content of 0.30 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Reacted Calcium Carbonate Comprising Filler 39 (Powder 39)

[0480] Powder 39 was a surface-reacted calcium carbonate (BET specific surface area=139 m.sup.2/g, d.sub.50 (vol)=6.1 μm, d.sub.98 (vol)=14.2 μm) prepared with the following method:

[0481] In a mixing vessel, 350 liters of an aqueous suspension of natural ground calcium carbonate was prepared by adjusting the solids content of a ground marble calcium carbonate from Hustadmarmor, Norway with a particle size distribution of 90 wt.-% less than 2 μm as determined by sedimentation, such that a solids content of 10 wt.-%, based on the total weight of the aqueous suspension, is obtained.

[0482] Whilst mixing the suspension, 62 kg of a 30% concentrated phosphoric acid was added to said suspension over a period of 10 minutes at a temperature of 70° C. Additionally, during the phosphoric acid addition, 1.9 kg of citric acid was added rapidly (about 30 s) to the slurry. Finally, after the addition of the phosphoric acid, the slurry was stirred for additional 5 minutes, before removing it from the vessel and drying.

Surface-Treated Surface-Reacted Calcium Carbonate Comprising Filler 40 (Powder 40)

[0483] Powder 40 was prepared by surface-treating powder 39 with 5 wt.-% of treatment A. To carry out the treatment, the treatment agent (35 g) was first dispersed in 300 mL of deionized water, heated to 60° C. and neutralized to pH 10 with sodium hydroxide.

[0484] A suspension of powder 39 (700 g in 7 L deionized water) was prepared in a 10 L ESCO batch reactor and heated to 85° C. The pH was adjusted to 10 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes, and the suspension was then filtered on a Buchner funnel and dried overnight in an oven (110° C.). The dried filter cake was then deagglomerated using a Retsch SR300 rotor beater mill.

Precipitated Hydromagnesite Filler 41 (Powder 41)

[0485] Powder 41 was a precipitated hydromagnesite (BET specific surface area=46.7 m.sup.2/g, d.sub.50 (vol)=8.75 μm; d.sub.98 (vol)=29 μm)

Surface-Treated Precipitated Hydromagnesite Filler 42 (Powder 42)

[0486] Powder 42 was prepared by surface-treating powder 41 with 5 wt.-% of treatment A. To carry out the treatment, the treatment agent (35 g) was first dispersed in 400 mL of deionized water, heated to 60° C. and neutralized to pH 10 with sodium hydroxide. A suspension of powder 41 (700 g in 6 L deionized water) was prepared in a 10 L ESCO batch reactor and heated to 85° C. The pH was adjusted to 10 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes, and the suspension was then filtered on a filter press and dried overnight in an oven (110° C.). The dried filter cake was then deagglomerated using a Retsch SR300 rotor beater mill.

Precipitated Hydromagnesite Filler 43 (Powder 43)

[0487] Powder 43 was produced through wet grinding of powder 41 (BET specific surface area=46.5 m.sup.2/g, d.sub.50 (vol)=7.9 μm; d.sub.98 (vol)=27 μm). The material had a residual total moisture content of 1.2 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

Surface-Treated Surface-Reacted Calcium Carbonate Comprising Filler 44 (Powder 44)

[0488] Powder 44 was prepared by surface-treating powder 21 with 5 wt.-% of treatment A. To carry the treatment, the treatment agent (35 g) was first dispersed in 400 mL of deionized water, heated to 60° C. and neutralized to pH 9-10 with sodium hydroxide.

[0489] A suspension of powder 21 (0.7 kg in 6 L deionized water) was prepared in a 10 L ESCO batch reactor (ESCO-Labor AG, Switzerland) and heated to 85° C. The pH was adjusted to 10-11 with Ca(OH).sub.2 and the neutralized treatment agent was then added under vigorous stirring. Mixing was continued at 85° C. for 45 minutes. The suspension was then filtered using a filter press (ca 6 bar). The filter cake was then transferred to metallic tray and dried in an oven (110° C.). The dried cake was then deagglomerated using a SR300 rotor beater mill (Retsch GmbH, Germany).

Surface-Treated Calcium Carbonate-Comprising Filler Material 45 (Powder 45)

[0490] Powder 45 was a ultrafine ground calcium carbonate (BET specific surface area=44.1 m.sup.2/g), which was surface treated with 2% treatment A and 15% treatment G. The material obtained had a residual total moisture content of 0.5 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.

3. Examples

Example Series A: Elastomer Formulations

Compounding:

Step 1: Internal Mixing

[0491] As a first step, each batch were mixed in a HAAKE internal mixer with 300 cm.sup.3 capacity equipped with Banbury rotors. The temperature was set at 40° C. at the beginning of each mixing, during the process the temperature raised up to 90° C. depending on the filler being incorporated. The mixing procedure set out in the following table 7 has been used for each batch

TABLE-US-00007 TABLE 7 Internal mixing procedure: Time Speed (min) Operation (rpm) t = 0 Introduction of elastomer and mineral filler (40° C.) 40 t = 1 Insertion of carbon black and oil 40 t = 5 Dumping of the mixture 40

Step 2: External Mixing

[0492] For the second step, mixing with the peroxide curing agent was performed on an instrumented cylinder mixer (150 x350). All the rubbers were mixed with the same times, cylinder speeds, and cylinder spacing as to not influence in their rheological properties comparison. The cooling system was set to 25° C. and the metal guides were set as to allow the rubber to occupy 70% of the cylinder surface. In between two accelerations the cylinders are cleaned and are let cool. The detailed proceedings for this process are described in table 8 below.

TABLE-US-00008 TABLE 8 External mixing procedure Time Cylinder (min) Operation Spacing (mm) t = 0 Introduction of the mix from Step 1 1 t = 2 Insertion of the curing 1 system (peroxide and coagent) t = 6 5 thin passings 0.6 Calendering sheet, thickness 2 mm 2

Step 3: Molding

[0493] The pieces were then molded at 160° C. or 180° C. and 100 kg/cm.sup.2 pressure by compression molding. This way, small 150×150×2 mm sheets were prepared. The curing time, which determines the molding time, was determined through a rheological MDR test. The examples for the series A are set out in table 9 below.

TABLE-US-00009 TABLE 9 Examples for series A: A-E10 A-CE16 Example (inventive) (comparative) EPDM Vistalon 2504 (phr) 100 100 Powder 10 (phr) 100 Powder 16 (phr) 100 Torilis 6200 (phr).sup.# 30 30 Peroxide DC40 (phr) 7 7 NB: all amounts in phr by weight; .sup.#commercially available lubricant from TOTAL

[0494] The effect on the mechanical properties—tensile tests—and on various other mechanical properties of the elastomer compound of the series A are set out in the following tables 10 and 11.

TABLE-US-00010 TABLE 10 Effect on Mechanical properties-tensile tests M100 modulus at M200 modulus at M300 modulus at Strength 100% elongation 200% elongation 300% elongation at break Example (MPa) (MPa) (MPa) (MPa) A-E10 (inventive) 1.1 2 3 11 A-CE16 (comparative) 0.8 1 1.2 3.8

TABLE-US-00011 TABLE 11 Effect on various properties of the elastomer compound Hardness Hardness Tear Electrical Compression IRHD Shore resistance/ resistivity set 72 h- Example (°) A DELFT (MPa) (Ohm/cm.sup.2) 100° C. (%) A-E10 (inventive) 52 48 19.3 6.70E+16 23.1 A-CE16 (comparative) 42 38 14.4 6.40E+15 56.7

Examples Series B: EPDM, Sulfur-Cured Formulation

Compounding:

Step 1: Internal Mixing

[0495] As a first step, each batch was mixed in a HAAKE internal mixer with 300 cm.sup.3 capacity equipped with Banbury rotors. The temperature was set at 40° C. at the beginning of each mixing, during the process the temperature raised up to 90° C. depending on the filler being incorporated. The mixing procedure set out in the following table 12 had been used for each batch

TABLE-US-00012 TABLE 12 Internal mixing procedure: Time (min) Operation Speed (rpm) t = 0 Introduction of elastomer and mineral filler (40° C.) 40 t = 1 Insertion of carbon black and oil 40 t = 5 Dumping of the mixture 40

Step 2: External Mixing

[0496] For the second step, mixing with the peroxide curing agent was performed on an instrumented cylinder mixer (150×350). All the rubbers were mixed with the same times, cylinder speeds, and cylinder spacing as to not influence in their rheological properties comparison. The cooling system was set to 2500 and the metal guides were set as to allow the rubber to occupy 70% of the cylinder surface. In between two accelerations the cylinders are cleaned and are let cool. The detailed proceedings for this process are described in table 13 below.

TABLE-US-00013 TABLE 13 External mixing procedure Time (min) Operation Cylinder Spacing (mm) t = 0 Introduction of the mix from Step 1 1 t = 2 Insertion of the curing system (peroxide and coagent) 1 t = 6 5 thin passings 0.6 Calendering sheet, thickness 2 mm 2

Step 3: Molding

[0497] The pieces were then molded at 16000 or 18000 and 100 kg/cm.sup.2 pressure by compression molding. This way, small 150×150×2 mm sheets were prepared. The curing time, which determines the molding time, was determined through a rheological MDR test. The examples for the series B are set out in table 14 below.

TABLE-US-00014 TABLE 14 Examples for series B B-E11 B-CE9 B-E22 B-CE21 Example (inventive) (comparative) (inventive) (comparative) EPDM KELTAN ® 100 100 100 100 6950C (phr) Powder 11 (phr) 57 Powder 9 (phr) 59 Powder 17 (phr) 40 40 40 40 Powder 22 (phr) 58 Powder 21 (phr) 61.5 Torilis 6200 (phr).sup.# 20 20 20 20 ZnO neige (phr) 5 5 5 5 Stearic acid (phr) 1 1 1 1 Protector octamine 1 1 1 1 (phr) CBS 80 (phr) 2.5 2.5 2.5 2.5 TBzTD 70 (phr) 1 1 1 1 Sulfur (phr) 1.5 1.5 1.5 1.5 NB: all amounts in phr by weight. Amounts of experimental fillers have been adjusted according to the measured density of each filler to correspond to the same volume as 40 phr of Powder 17 (Carbon black); .sup.#commercially available lubricant from TOTAL.

[0498] The effect on the mechanical properties—tensile tests—and on various other mechanical properties of the elastomer compound of the series B are set out in the following tables 15 and 16.

TABLE-US-00015 TABLE 15 Effect on Mechanical properties-tensile tests (series B) M100 (Modulus at 100% Strength at break Elongation at break Example elongation, MPa) (MPa) (%) B-E11 (inventive) 3.4 11.4 307 B-CE9 (comparative) 2.1 8.9 318 B-E22 (inventive) 4.8 15 388 B-CE21 (comparative) 3.9 12.6 345

TABLE-US-00016 TABLE 16 Effect on various properties (series B) Tear Compression Hardness Hardness resistance/ set 72 h- IRHD Shore DELFT 100° C. Example (°) A (MPa) (%) B-E11 (inventive) 70 67 21 41 B-CE9 (comparative) 66 63 19 60 B-E22 (inventive) 76 72 37 42 B-CE21 75 71 Not Not (comparative) measured measured

Examples Series C: Simple EPDM Formulation

Compounding:

Step 1: Internal Mixing

[0499] As a first step, each batch was mixed in a HAAKE internal mixer with 300 cm.sup.3 capacity equipped with Banbury rotors. The temperature was set at 40° C. at the beginning of each mixing, during the process the temperature raised up to 90° C. depending on the filler being incorporated. The mixing procedure set out in the following table 17 had been used for each batch

TABLE-US-00017 TABLE 17 Internal mixing procedure Time Speed (min) Operation (rpm) t = 0 Introduction of elastomer and mineral filler (40° C.) 40 t = 1 Insertion of carbon black and oil 40 t = 5 Dumping of the mixture 40

Step 2: External Mixing

[0500] For the second step, mixing with the peroxide curing agent was performed on an instrumented cylinder mixer (300×700 or 150×350). All the rubbers were mixed with the same times, cylinder speeds, and cylinder spacing as to not influence in their rheological properties comparison. The cooling system was set to 25° C. and the metal guides were set as to allow the rubber to occupy 70% of the cylinder surface. In between two accelerations the cylinders are cleaned and are let cool. The detailed proceedings for this process are described in table 18 below.

TABLE-US-00018 TABLE 18 External mixing procedure Time Cylinder (min) Operation Spacing (mm) t = 0 Introduction of the mix from Step 1 1 t = 2 Insertion of the curing system (peroxide and coagent) 1 t = 6 5 thin passings 0.6 Calendering sheet, thickness 2 mm 2

Step 3: Molding

[0501] The pieces were then molded at 160° C. and 200 bar pressure by compression molding. This way, small 150×150×2 mm sheets were prepared. The curing time, which determines the molding time, was determined through a rheological MDR test. The examples for the series C are set out in table 19 below.

TABLE-US-00019 TABLE 19 Examples for series C C-CE12 C-E13 C-E15 C-CE17 C-CE19 C-CE20 C-E24 Example (comparative) (inventive) (inventive) (comparative) (comparative) (comparative) (inventive) EPDM Vistalon 2504 (phr) 100  100  100  100  Powder 12 (phr) 75* Powder 13 (phr) 75* Powder 15 (phr) 75* Powder 17 (phr) 50  50  50  100 50  50  50  Powder 19 (phr) 73* Powder 20 (phr) 75* Powder 24 (phr) 60* Torilis 6200 (phr).sup.# 10  10  10  10 10  10  10  Peroxide DC40 (phr) 7 7 7 7 7 7 7 Rhenogran TAC 50% 2 2 2 2 2 2 2 (phr) *NB: All formulations were done with an isovolumic amount of fillers. All fillers were coupled 50/50% with carbon black in volume. Therefore, the carbon black reference batch contains 100 phr of N550. The amount of white fillers was calculated using the measured density of the raw material (untreated) to match the volume of 50 phr powder 17 (N550 Carbon Black); .sup.#commercially available lubricant from TOTAL.

[0502] The effect on various mechanical properties of the elastomer compound of the series C are set out in the following tables 20, 21 and 22.

TABLE-US-00020 TABLE 20 Effect on hardness (series C) Hardness IRDH Sample (°) C-E13 (inventive) 79.6 C-E15 (inventive) 84.9 C-CE19 (comparative) 75.7 C-E24 (inventive) 82.8

TABLE-US-00021 TABLE 21 Effect on modulus M100 and strength (series C) Modulus M100 Strength at break Sample (MPa) (MPa) C-E13 (inventive) 6.39 13.37 C-E15 (inventive) 5.001 11.45 C-CE20 (comparative) 3.78 7.34 C-E24 (inventive) 11.63 6.09

TABLE-US-00022 TABLE 22 Effect on elongation and tear resistance (series C) Elongation Tear resistance/ Sample (%) DELFT (MPa) C-E13 (inventive) 183.75 27.74 C-E15 (inventive) 229.25 31.38 C-CE17 (comparative) 144.75 20 C-E24 (inventive) 200 31.6

Example Series D: Elastomer Formulations

Compounding:

[0503] Compounding was performed with a method similar to the one described in Example series A.

TABLE-US-00023 TABLE 23 Examples for series D: D-E9 D-CE25 D-CE26 D-E28 Example (inventive) (comparative) (comparative) (inventive) EPDM Keltan 100 100 100 100 2470s (phr) Powder 9 (phr) 100 Powder 25 (phr) 100 Powder 26 (phr) 100 Powder 28 (phr) 100 Torilis 6200 (phr)- 20 20 20 20 paraffinic oil Active ZnO (phr) 5 5 5 5 Tinuvin P (UV 2.5 2.5 2.5 2.5 protector) (phr) Riowax 54/56 3 3 3 3 (paraffinic wax) (phr) Dicup 40 (peroxide) 7 7 7 7 (phr) Rhenogram 2 2 2 2 TAC-50 (phr) NB: all amounts in phr by weight;

[0504] The effect on the mechanical properties—tensile tests—and on various other mechanical properties of the elastomer compound of the series A are set out in the following tables 24 and 25.

TABLE-US-00024 TABLE 24 Effect on Mechanical properties-tensile tests M100 modulus M300 modulus Strength at 100% at 300% at elongation elongation break Example (MPa) (MPa) (MPa) D-E9 (inventive) 2.5 8.4 8.6 D-CE25 (comparative) 2.6 5 10.2 D-CE26 (comparative) 1 1.6 7 D-E28 (inventive) 3.7 7.3 7.3

TABLE-US-00025 TABLE 25 Effect on various properties of the elastomer compound Hardness Tear resistance/ Compression set 72 h- Example Shore A DELFT (MPa) 100° C. (%) D-E9 (inventive) 66.8 24 8 D-CE25 (comparative) 70 n.d. 34 D-CE26 (comparative) 55.4 12 8 D-E28 (inventive) 78.2 34 14 n.d. = not determined

Examples Series E: Tire Tread Sulfur-Cured SBR Formulations

[0505] Step 1: Internal Mixing

[0506] As a first step, batches of SBR rubber and filler were mixed in a 2 L Banbury internal mixer according to the mixing procedure shown in Table 26 below. The temperature was set at 4000 at the beginning of each mixing, and the temperature raised up to 15000 during the process the temperature, depending on the filler being incorporated.

TABLE-US-00026 TABLE 26 Internal mixing procedure. Time (min:s) Operation Speed (rpm) t = 00:00 Introduction of SBR rubber 50 t = 00:30 Addition of the filler + 1/3 powder 29 50 t = 01:45 Addition of 2/3 of powder 29 + 50 Torilis 6200 (phr) − paraffinic oil t = 02:45 Addition of the curing system 50 (sulfur and accelerators) t = 04:15 Ramp cleaning adjusted t = 06:30 Dumping of the compound adjusted

[0507] Step 2: External Mixing

[0508] For the second step, mixing with the curing system was performed on an external mixer Agila (300×400). All the elastomer precursors were mixed with the same times, cylinder speeds, and cylinder spacing. The cooling system was set to 40° C. and the metal guides were set as to allow the elastomer precursor to occupy 70% of the cylinder surface. The detail proceedings for this process are described in Table 27 below.

TABLE-US-00027 TABLE 27 External mixing procedure. Time Cylinder (min:s) Operation Spacing (mm) t = 00:00 Introduction of the mix from Step 1 1 t = 01:30 Insertion of the curing system 1 (sulfur and accelerators) t = 06:00 3 thin passes 0.5 Calendering sheet, thickness 2 mm 2

[0509] Step 3—Compression Molding

[0510] Sheets of the elastomer composition were produced by compression molding at 160° C. or 180° C. and 100 kg/cm.sup.2 pressure. This way, small 300×300×2 mm plates were made. The curing time, which determines the molding time, was determined through a rheological MDR test.

[0511] The following elastomer compositions of Tables 28 and 29 were obtained following the method described above. All elastomer compositions had an isovolumic amount of fillers. The amount of filler was adjusted to match the volume occupied by 40 phr carbon black (powder 29), depending on the density of the filler (indicated in Tables 28 and 29 with an asterisk).

TABLE-US-00028 TABLE 28 SBR elastomer compositions (phr: parts per hundred). E-CE31 D-E32 D-E33 D-E35 D-E36 D-CE30 Example (comparative) (Inventive) (Inventive) (Inventive) (Inventive) (comparative) SRB - Buna VSL-2538-2 (phr) 137.5 137.5 137.5 137.5 137.5 137.5 Powder 31 55.6* Powder 32 58.4* Powder 33 55.8* Powder 35 44.9* Powder 36 47.8* Powder 29 40 40 40 40 40 40 Powder 30 61.1* Vivatec 500/plasticizer (phr) 16 16 16 16 16 16 Protector - 6PPD (phr) 2 2 2 2 2 2 Protector - Antilux 500 (phr) 2 2 2 2 2 2 ZnO - Silox actif (phr) 3 3 3 3 3 3 Stearic acid - TP2 (phr) 1.5 1.5 1.5 1.5 1.5 1.5 Sulfur (phr) 2 2 2 2 2 2 CBS (phr) 1 1 1 1 1 1 MTBS (phr) 0.5 0.5 0.5 0.5 0.5 0.5

TABLE-US-00029 TABLE 29 SBR elastomer compositions (phr: parts per hundred) E-E10 E-E38 E-E37 Example (Inventive) (Inventive) (Inventive) SRB-Buna VSL-2538-2 (phr) 137.5 137.5 137.5 Powder 10 57.7* Powder 38 57.1* Powder 37 58.2* Powder 29 40 40 40 Powder 30 Vivatec 500/plasticizer (phr) 16 16 16 Protector-6PPD (phr) 2 2 2 Protector-Antilux 500 (phr) 2 2 2 ZnO-Silox actif (phr) 3 3 3 Stearic acid-TP2 (phr) 1.5 1.5 1.5 Sulfur (phr) 2 2 2 CBS (phr) 1 1 1 MTBS (phr) 0.5 0.5 0.5

[0512] The obtained elastomer compositions had the following mechanical properties compiled in Table 30 below.

TABLE-US-00030 TABLE 30 Effect on mechanical properties (series D). M100 Shore Compression Tear Modulus A set resistance/ Sample (MPa) Hardness (%) DELFT (N) E-CE31 1.9 39.2 12 23 (Comparative) E-E32 (Inventive) 3.3 55.7 14 28 E-E33 (Inventive) 1.9 54.8 12 27 E-E35 (Inventive) 1.8 53.8 11 22 E-E36 (Inventive) 1.8 49.8 9 28 E-CE30 0.8 39.2 24 17 (Comparative) E-E10 (Inventive) 0.8 40.4 24 23 E-E38 (Inventive) 0.8 40.4 15 20 E-E37 (Inventive) 3.7 56.4 12 30

Examples Series F: EPDM Elastomer Formulations

Step 1—Internal Mixing

[0513] As a first step, each batch was mixed in a 2 L Banbury internal mixer. The temperature was set at 4000 at the beginning of each mixing, during the process the temperature raised up to 15000 depending on the filler being incorporated. The following process had been used for each batch (Table 31):

TABLE-US-00031 TABLE 31 Internal mixing procedure. Time (min:s) Operation Speed (rpm) t = 00:00 Introduction of EPDM 50 t = 00:50 Addition of the filler 50 t = 02:30 Addition of 2/3 of Powder 17 50 t = 05:30 Addition of 1/3 of Powder 50 17 + paraffinic oil t = 06:30 Ram cleaning 50 t = 08:30 Dropping 50

Step 2—External Mixing

[0514] For the second step, mixing with the peroxide crosslinking agent was performed on a cylinder mixer (300×700). All the elastomer precursors were mixed with the same times, cylinder speeds, and cylinder spacing. The cooling system was set to 4000 and the metal guides were set as to allow the elastomer precursor to occupy 70% of the cylinder surface. The detail proceedings for this process are described in Table 32 below.

TABLE-US-00032 TABLE 32 External mixing procedure. Time Cylinder (min: s) Operation Spacing (mm) t = 00:00 Introduction of the mix from Step 1 2.5 t = 01:30 Insertion of the crosslinking system 2.5 t = 06:00 3 thin passes 0.5 Calendering sheet, thickness 2 mm 2

Step 3—Compression Molding

[0515] Sheets of the elastomer composition were produced by compression molding at 180° C. and 200 bar pressure. This way, small 300×300×2 mm plates were made. The curing time, which determines the molding time, was determined through a rheological test in MDR. The T98 was taken as time of curing for the press plates. The fabrication of the compression set test specimens was done with the same procedure, meaning by compression molding. The curing time used was the addition of 10 min to the T98 as the thickness of these test specimens is higher than the press plates.

EPDM Elastomer Compositions

[0516] The following elastomer compositions of Table 33 were obtained following the method described above. All elastomer compositions had an isovolumic amount of fillers. All fillers were coupled 50/50% with carbon black in volume. Therefore, the carbon black reference batch contains 100 phr of N550. The other batches contain 50 phr of N550 and a slightly variable amount of mineral filler in function of their density, in order to have an amount of mineral filler equivalent to the volume of 50 phr of carbon black (indicated in Table 33 with an asterisk).

TABLE-US-00033 TABLE 33 EPDM elastomer compositions F-CE17 F-CE39 F-E40 F-E42 F-CE43 F-CE21 F-E44 Example (Comparative) (Comparative) (inventive) (Inventive) (Comparative) (Comparative) (Inventive) EPDM Vistalon 2504N from Exxon Mobil 100 100 100 100 100 100  100 (phr) Carbon black - N550 (Powder 17) 100 50 50 50 50 50  50 Powder 39 76.4* Powder 40 72.2* Powder 8 60.8* Powder 9 61.4* Powder 21 80* Powder 44 71.9* Powder 45 Torilis 6200 plasticizer (phr) 10 10 10 10 10 10  10 Peroxide DC40 crosslinking agent (phr) 7 7 7 7 7 7 7 Rhenogran TAC 50% crosslinking 2 2 2 2 2 2 2 coagent (phr)
The obtained elastomer compositions had the properties set out in the following Tables 34, 35 and 36:

TABLE-US-00034 TABLE 34 Shore A hardness of the elastomer compositions. Sample Hardness (Shore A) F-CE17 (comparative) 79.1 F-CE39 (comparative) 84.3 F-E40 (Inventive) 86.1 F-E42 (Inventive) 83.1 F-CE43 (Comparative) 81.4 F-CE21 (Comparative) 78.1 F-E44 (Inventive) 84.2

TABLE-US-00035 TABLE 35 Effect on tensile modulus (M50-modulus at 50% elongation) Sample M50 (MPa) F-CE17 3.7 F-CE39 4.7 F-E40 6.1 F-E42 4.4 F-CE43 3.5 F-CE21 2.8 F-E44 5.8

TABLE-US-00036 TABLE 36 Effect on compression set Sample Compression set (%) F-CE17 7 F-CE39 14 F-E40 7 F-E42 8 F-CE43 19 F-CE21 20 F-E44 8