MODIFIED MINERAL-BASED FILLER COMPRISING COPPER SALTS

Abstract

The present invention relates to a modified mineral-based filler comprising at least one alkaline earth metal carbonate-comprising material, and at least one water insoluble copper salt comprising the copper mineral malachite in an amount of at least 10 wt.-%, which covers at least partially the surface of the at least one alkaline earth metal carbonate-comprising material, and a method of producing the same.

Claims

1. A modified mineral-based filler comprising at least one alkaline earth metal carbonate-comprising material, and at least one water insoluble copper salt, which covers at least partially the surface of the at least one alkaline earth metal carbonate-comprising material, wherein the at least one water insoluble copper salt comprises the copper mineral malachite in an amount of at least 10 wt.-%, based on the total weight of the at least one water insoluble copper salt.

2. The modified mineral-based filler according to claim 1, wherein the modified mineral-based filler is in form of an aqueous suspension.

3. The modified mineral-based filler according to claim 1, wherein the modified mineral-based filler is a dried modified mineral-based filler, preferably in powder form, and the moisture content of the modified mineral-based filler is between 0.01 and 5 wt.-%, based on the total weight of the dried modified mineral-based filler.

4. The modified mineral-based filler according to claim 1, wherein the at least one alkaline earth metal carbonate-comprising material has a specific surface area (BET) from 1 to 200 m.sup.2/g, as measured using nitrogen and the BET method according to ISO 9277, and/or the total weight of copper on the total surface area of the at least one alkaline earth metal carbonate-comprising material is from 0.001 to 500 mg/m.sup.2.

5. The modified mineral-based filler according to claim 1, wherein the at least one water insoluble copper salt comprises malachite in an amount of at least 15 wt.-%, preferably at least 20 wt.-%, more preferably at least 25 wt.-%, and most preferably at least 30 wt.-%, based on the total weight of the at least one water insoluble copper salt, and/or the water insoluble copper salt further comprises a copper mineral selected from the group consisting of atacamite, deviline, posnjakite, brochantite, copper oxide, and mixtures thereof, and the total amount of these copper minerals including malachite is at least 15 wt.-%, preferably at least 20 wt.-%, more preferably at least 25 wt.-%, and most preferably at least 30 wt.-%, based on the total weight of the at least one water insoluble copper salt.

6. The modified mineral-based filler according to claim 1, further comprising at least one hydrophobising agent, which covers at least partially the surface of the modified mineral-based filler, wherein the total weight of the at least one hydrophobising agent on the total surface area of the modified mineral-based filler is from 0.001 to 10 mg/m.sup.2.

7. The modified mineral-based filler according to claim 6, wherein the specific surface area (BET) of the least one alkaline earth metal carbonate-comprising material is from 1 to 150 m.sup.2/g, preferably from 2 to 60 m.sup.2/g, and more preferably from 2 to 15 m.sup.2/g, as measured using nitrogen and the BET method according to ISO 9277, and/or the total weight of copper on the total surface area of the at least one alkaline earth metal carbonate-comprising material is from 0.001 to 300 mg/m.sup.2, preferably from 0.1 to 100 mg/m.sup.2, and more preferably from 1.5 to 30 mg/m.sup.2, and/or the total weight of the at least one hydrophobising agent on the total surface area of the modified mineral-based filler is from 0.001 to 9 mg/m.sup.2, preferably from 0.01 to 8 mg/m.sup.2, and more preferably from 0.1 to 4 mg/m.sup.2.

8. The modified mineral-based filler according to claim 6, wherein the at least one hydrophobising agent is selected from the group consisting of an aliphatic carboxylic acid having a total amount of carbon atoms from C.sub.4 to C.sub.24 and/or reaction products thereof, a 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 C.sub.2 to C.sub.30 in the substituent and/or reaction products thereof, a phosphoric acid ester blend of one or more phosphoric acid mono-ester and/or reaction products thereof and one or more phosphoric acid di-ester and/or reaction products thereof, polyhydrogensiloxane and reaction products thereof, an inert silicone oil, preferably polydimethylsiloxane, and mixtures thereof.

9. A process for manufacturing a modified mineral-based filler comprising the following steps: (i) providing at least one alkaline earth metal carbonate-comprising material, (ii) providing at least one water soluble copper salt, (iii) contacting the at least one alkaline earth metal carbonate-comprising material of step (i), the at least one water soluble copper salt of step (ii), and optionally water, in one or several steps to form a mixture, and (iv) heating the mixture obtained from step (iii) to a temperature in the range from 30 to 200 C. to form a modified mineral-based filler.

10. The process according to claim 9, wherein the process is a batch or a continuous process, preferably a continuous process.

11. The process according to claim 9 or 10, wherein the mixture formed in step (iii) is an aqueous suspension, and the process further comprises a step (v) of separating the modified mineral-based filler from the aqueous suspension after step (iv).

12. The process according to claim 9, wherein the process further comprises a step (vi) of drying the modified mineral-based filler after step (iv) or step (v), if present, at a temperature in the range from 60 to 200 C., preferably until the moisture content of the modified mineral-based filler is between 0.01 and 5 wt.-%, based on the total weight of the dried modified mineral-based filler.

13. The process according to claim 9, wherein the process further comprises a step of treating the modified mineral-based filler obtained in step (iv) during and/or after step (iv) in one or more steps with at least one hydrophobising agent at a temperature from 30 to 200 C., wherein the at least one hydrophobising agent is added in an amount such that the total weight of the at least one hydrophobising agent on the total surface area of the modified mineral-based filler is from 0.001 to 10 mg/m.sup.2.

14. The process according to claim 9, wherein the at least one water soluble copper salt of step (ii) is provided in form of an aqueous solution or aqueous suspension, preferably the aqueous solution or aqueous suspension comprises carbonate ions, wherein the carbonate ions are derived from a carbonate-comprising compound, which is dissolved in the aqueous solution or aqueous suspension of the at least one water soluble copper salt, or are generated in-situ by treating the aqueous solution or aqueous suspension of the at least one water soluble copper salt with gaseous carbon dioxide.

15. The process according to claim 9, wherein the at least one alkaline earth metal carbonate-comprising material of step (i) is provided in form of an aqueous suspension, preferably the aqueous suspension comprises carbonate ions, wherein the carbonate ions are at least partially derived from a carbonate-comprising compound, which differs from the at least one alkaline earth metal carbonate-comprising material of step (i) and is dissolved in the aqueous suspension, or are generated in-situ by treating the aqueous suspension of the at least one alkaline earth metal carbonate-comprising material with gaseous carbon dioxide.

16. The process according to claim 9, wherein the at least one alkaline earth metal carbonate-comprising material is a calcium carbonate-comprising material, preferably the at least one alkaline earth metal carbonate-comprising material is selected from the group consisting of ground calcium carbonate, preferably marble, limestone and/or chalk, precipitated calcium carbonate, preferably vaterite, calcite and/or aragonite, dolomite, and mixtures thereof, more preferably the at least one alkaline earth metal carbonate-comprising material is selected from the group consisting of dolomitic marble, magnesitic marble, limestone, chalk, and mixtures thereof, and most preferably the at least one alkaline earth metal carbonate-comprising material is ground calcium carbonate.

17. The process according to claim 9, wherein the at least one water soluble copper salt is selected from the group consisting of copper nitrate, copper sulphate, copper acetate, copper chloride, copper bromide, hydrates thereof, and mixtures thereof, preferably selected from the group consisting of copper sulphate, hydrates thereof, and mixtures thereof.

18. The process according to claim 9, wherein the process further comprises a step of grinding and/or fractionating and/or classifying the mixture obtained from step (iii) before, during or after step (iv).

19. A modified mineral-based filler obtainable by a process according to claim 9.

20. Use of a modified mineral-based filler according to claim 1 in polymer applications, paper coating applications, paper making, paints, coatings, sealants, printing inks, adhesives, food, feed, pharmaceuticals, concrete, cement, cosmetics, water treatment, engineered wood applications, plasterboard applications, packaging applications and/or agricultural applications, wherein preferably the modified mineral-based filler is a dried modified mineral-based filler.

21. Use of a modified mineral-based filler according to claim 1 as preservative, wherein preferably the modified mineral-based filler is a dried modified mineral-based filler.

22. Use of a modified mineral-based filler according to claim 1 for enhancing and/or mediating antimicrobial activity of a substrate, preferably the antimicrobial activity is against at least one strain of bacteria and/or at least one strain of mould and/or at least one strain of yeast and/or at least one algae, wherein preferably the modified mineral-based filler is a dried modified mineral-based filler.

23. Use of a modified mineral-based filler according to claim 1 for enhancing the electrical conductivity of a substrate, wherein preferably the modified mineral-based filler is a dried modified mineral-based filler.

24. An article comprising a modified mineral-based filler according to claim 1, wherein the article is selected from paper products, engineered wood products, plasterboard products, polymer products, hygiene products, medical products, healthcare products, filter products, woven materials, nonwoven materials, geotextile products, agriculture products, horticulture products, clothing, footwear products, baggage products, household products, industrial products, packaging products, building products, and construction products.

Description

EXAMPLES

1. Measurement Methods

[0192] In the following, measurement methods implemented in the examples are described.

Solid Content

[0193] The suspension solids content (also known as dry weight) was determined using a Moisture Analyser MJ33 (Mettler-Toledo, Switzerland), with the following settings: drying temperature of 150 C., automatic switch off if the mass does not change more than 1 mg over a period of 30 sec, standard drying of 5 to 20 g of suspension.

Water Pick-Up

[0194] The moisture pick up susceptibility of a material as referred to herein is determined in mg moisture/g after exposure to an atmosphere of 10 and 85% relative humidity, respectively, for 2.5 hours at a temperature of +23 C. (2 C.). For this purpose, the sample is first kept at an atmosphere of 10% relative humidity for 2.5 hours, then the atmosphere is changed to 85% relative humidity at which the sample is kept for another 2.5 hours. The weight increase between 10 and 85% relative humidity is then used to calculate the moisture pick-up in mg moisture/g of sample.

Moisture Content

[0195] The moisture content has been determined on a Karl-Fischer Coulometer (C 30 oven:

[0196] Mettler Toledo Stromboli, Mettler Toledo, Switzerland) at 220 C. under nitrogen (flow 80 mL/min, heating time 10 min). The accuracy of the result was checked with a HYDRANAL-Water Standard KF-Oven (Sigma-Adrich, Germany), measured at 220 C.).

X-Ray Fluorescence Analysis (XRF)

[0197] 11.5 g dry sample were pressed to a tablet, using a press at 400 kN. The elemental composition of the sample was measured by sequential, wavelength dispersive X-ray fluorescence (using an ARL PERFORM'X X-ray fluorescence spectrometer, Thermo Fisher Scientific, Inc., USA). The quantification was made by means of a calibration which was especially prepared for calcium carbonate.

Ion Chromatography

[0198] Anions were determined by ion chromatography (882 Compact IC plus, Metrohm).

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Analysis

[0199] The modified mineral based filler was dissolved in a microwave assisted nitric acid based digestion process. The solution was analyzed by ICP-MS (Measured with an ELAN DRC-e from Perking Elmer). Commercially available multi-element calibration solutions were used for quantification of the formed water insoluble copper salts and copper minerals.

X-Ray Diffraction (XRD)

[0200] XRD experiments were performed on the samples using rotatable PMMA holder rings. Samples were analyzed with a Bruker D8 Advance powder diffractometer obeying Bragg's law. This diffractometer consists of a 2.2 kW X-ray tube, a sample holder, a --goniometer, and a VANTEC-1 detector. Nickel-filtered Cu K radiation was employed in all experiments. The profiles were chart recorded automatically using a scan speed of 0.7 per minute in 24. The resulting powder diffraction pattern can easily be classified by mineral content using the DIFFRACsuite software packages EVA and SEARCH, based on reference patterns of the ICDD PDF 2 database. Quantitative analysis of diffraction data refers to the determination of amounts of different phases in a multi-phase sample and has been performed using the DIFFRACsuite software package TOPAS. In detail, quantitative analysis allows to determine structural characteristics and phase proportions with quantifiable numerical precision from the experimental data itself. This involves modelling the full diffraction pattern (Rietveld approach, e.g. described in Bish, D. L. & Howard, S. A., Quantitative Phase Analysis Using the Rietveld Method, J. Appl. Cryst. 21, 1988, 86-91) such that the calculated pattern(s) duplicates the experimental one. The Rietveld method requires knowledge of the approximate crystal structure of all phases of interest in the pattern. However, the use of the whole pattern rather than a few select lines produces accuracy and precision much better than any single-peak-intensity based method.

Brookfield Viscosity

[0201] The Brookfield viscosity was measured by a Brookfield (Type RVT) viscometer at 24 C.3 C. at 100 rpm using an appropriate spindle of the Brookfield RV-spindle set and is specified in mPa.Math.s. Once the spindle has been inserted into the sample, the measurement is started with a constant rotating speed of 100 rpm. The reported Brookfield viscosity values are the values displayed 60 seconds after the start of the measurement. Based on his technical knowledge, the skilled person will select a spindle from the Brookfield RV-spindle set which is suitable for the viscosity range to be measured. For example, for a viscosity range between 200 and 800 mPa.Math.s the spindle number 3 may be used, for a viscosity range between 400 and 1 600 mPa.Math.s the spindle number 4 may be used, and for a viscosity range between 800 and 3 200 mPa.Math.s the spindle number 5 may be used.

pH

[0202] pH was measured on a Mettler-Toledo Seven-Multi device. The pH of a suspension was measured at 24 C.3 C. using a Mettler Toledo Seven Easy pH meter and a Mettler Toledo InLab Expert Pro pH electrode (Mettler Toledo, Switzerland). A three point calibration (according to the segment method) of the instrument was first made using commercially available buffer solutions having pH values of 4, 7 and 10 at 20 C. (from Aldrich). The reported pH values are the endpoint values detected by the instrument (the endpoint is when the measured signal differs by less than 0.1 mV from the average over the last 6 seconds).

Conductivity

[0203] The conductivity of a suspension was measured at 24 C.3 C. using Mettler Toledo Seven Multi instrumentation equipped with the corresponding Mettler Toledo conductivity expansion unit and a Mettler Toledo InLab 730 conductivity probe (Mettler Toledo, Switzerland).

[0204] The instrument was first calibrated in the relevant conductivity range using commercially available conductivity calibration solutions from Mettler Toledo. The influence of temperature on conductivity is automatically corrected by the linear correction mode. The measured conductivities are reported for the reference temperature of 20 C. The reported conductivity values are the endpoint values detected by the instrument (the endpoint is when the measured conductivity differs by less than 0.4% from the average over the last 6 seconds).

Antimicrobial Surface Activity Test

[0205] Fresh bacteria cultures of the bacteria Escherichia coli DSM 1576 and Staphylococcus aureus strains DSM 346 were prepared by dilution streaking onto a tryptic soy agar plate (TSA, no. 236950, Becton Dickinson and Company, USA) and incubation for 16 to 20 h at 35 C.

[0206] To test the antimicrobial surface activity, the Japanese Standard Protocol JIS Z 2801 2000 was followed using fresh bacteria prepared as described above. The plating, counting and evaluation were done according to the Japanese Standard Protocol JIS Z 2801 2000 with the following amendments. To confirm results, studies were performed with a single test piece instead of triplicates. For all coated samples, the bacteria were released after incubation from the test item in a petri dish using a sterile Drigalski spatula to massage the test item with medium, instead of using a stomacher bag and massaging the item by hand. Further for coated samples the test items were not sterilized with 70% ethanol prior analysis.

[0207] As described in the Japanese Standard Protocol JIS Z 2801 2000, the bacterial counts are reported as colony forming units per test item (cfu/test item) with 10 cfu/test item as limit of detection (LOD). Thereof the antimicrobial activity (R) of the test items was calculated as described in the Japanese Standard Protocol JIS Z 2801 2000. For it, after 24 h incubation at 35 C., the average number of viable bacteria on the test item (B) and the untreated control (A) are used to calculate the antimicrobial activity (R) using the following formula: R=log.sub.10(A/B). If zero cfu were detected, a value of 10 cfu/test item was used for calculation of the limit of detection of the antimicrobial activity.

Fungal Growth Resistance Test

[0208] Fresh cultures of fungi (e.g. Aspergillus niger ATCC 6275, Aureobasidium pullulans ATCC 9348, Penicillium funiculosum ATCC 11797) were prepared by inoculation of malt agar plates (malt extract broth, no. 1.05397, Merck KGaA, Germany) containing 1.5 wt.-% agar (no. 05039, Fluka, Switzerland) with spores and/or mycelia of fungi and incubation at 25 C. for until malt agar plate is fully covered with spores (approximately 1 week). Such culture techniques are well known to the skilled person and are described for instance in ASTM D5590-00.

[0209] Malt extract broth (no. 1.05397, Merck KGaA, Germany) was inoculated with loop of spores from a fresh fungal malt agar plate. Spores were dispersed by mixing until no clumps were visible. Test items were cut to 2.5 cm9 cm and immersed into the spore-dispersion, drained and placed into 50 ml bioreactor tubes with a gas permeable filter (e.g. TPP TubeSpin Bioreactors, TPP, Switzerland). Test items in the bioreactors were incubated upright at 28 C. and 90% relative humidity. After different incubation times the percentage of fungal defacement was rated analogous to the rating system of ASTM D3273-D12. [0210] A rating of 10=0 defacement (no growth detectable). [0211] A rating of 9=1 to 10% defacement. [0212] A rating of 8=11 to 20% defacement. [0213] A rating of 7=21 to 30% defacement. [0214] A rating of 6=31 to 40% defacement. [0215] A rating of 5=41 to 50% defacement. [0216] A rating of 4=51 to 60% defacement. [0217] A rating of 3=61 to 70% defacement. [0218] A rating of 2=71 to 80% defacement. [0219] A rating of 1=81 to 90% defacement. [0220] A rating of 0=91 to 100% defacement.

The Antialgal Efficacy Test

[0221] The antialgal efficacy was determined according to the test norm DIN EN 15458:2007 (Paint and varnishesLaboratory test method for testing the efficacy of film preservatives in a coating against algae) using Stichococcus bacillaris as test organism. The principle of the semi-quantitative test method is that the coating sample containing the film preservative, or the untreated control, is placed onto a nutrient agar surface with the coating faced-up. Then the surface is inoculated with a standard algal spore suspension and incubated. At four different time points (after 14, 21, 28 and 35 days) the intensity of the algal growth on the surface of the coating sample and the algal growth on the agar (surrounding the test pieces) is evaluated and compared to the control using the following rating system. [0222] 0: No algal growth on the surface of the coating sample [0223] 1: less algal growth on the coating sample containing modified mineral-based filler compared to sample containing untreated mineral. [0224] 2. equal or more algal growth on the coating sample containing modified mineral-based filler compared to sample containing untreated mineral.

[0225] The test norm was performed in triplicates with a few minor amendments: 1) All coating samples were not conditioned according to EN23270 for 5 days at 23+/2 C. and 50+/5% relative humidity but instead stored for several weeks at 23+/2 C. without controlled humidity. 2) All coating samples were not sterilized prior testing. 3) The size and shape of all coating samples was rectangular (25 mm50 mm) instead of circular (55 mm diameter). The final evaluation was carried out at day 32.

Pigment Whiteness R457

[0226] Pigment whiteness R457 was measured on a tablet (prepared on a press with a pressure of 4 bar for 15 seconds) using an ELREPHO 3000 spectrophotometer (Datacolor AG, Switzerland) according to ISO 2469:1994 (DIN 53145-2:2000 and DIN 53146:2000).

CIELAB Coordinates

[0227] The CIELAB L*, a*, b* coordinates were measured using an ELREPHO 3000 spectrophotometer (Datacolor AG, Switzerland) according to EN ISO 11664-4 and barium sulphate as standard.

Yellow Index

[0228] The CIE coordinates were measured using an ELREPHO 3000 spectrophotometer (Datacolor AG, Switzerland). The yellow index (=YI) was calculated by the following formula:

YI=100*(R.sub.xR.sub.z)/R.sub.y).

2. Preparation of Copper Salt Solutions and Copper Salt Suspensions

Solution 1

[0229] 80 g of deionized water was provided in a beaker glass, and 25 g copper sulphate (anhydrous, Sigma-Aldrich, Spain) was added slowly, under strong stirring. The resulting deep blue mixture was stirred 2 h at room temperature and then filtered. The solid content of the obtained solution was between 20 and 24 wt.-%, based on the total weight of the solution.

Solution 2

[0230] 80 g of deionized water was provided in a beaker glass, and 39 g copper sulphate (pentahydrate, Sigma-Aldrich, Spain) was added slowly, under strong stirring. The resulting deep blue mixture was stirred 2 h at room temperature and then filtered. The solid content of the obtained solution was between 20 and 24 wt.-%, based on the total weight of the solution.

Solution 3:

[0231] 480 g of copper (II) nitrate (trihydrate, Sigma-Aldrich, Spain) was provided in a beaker glass, and 200 g deionised water was added slowly. The resulting deep blue mixture was stirred 2 h at room temperature and then filtered. The solid content of the obtained solution was 41.1 wt.-%, based on the total weight of the solution.

Suspension 1

[0232] 60 g of deionized water was provided in a beaker glass, and 42 g copper sulphate (anhydrous, Sigma-Aldrich, Spain) was added slowly, under strong stirring. The resulting deep blue mixture was stirred 2 h at room temperature and was not fully dissolved. The solid content of the obtained suspension was 42 wt.-%, based on the total weight of the suspension.

3. Preparation of Modified Mineral-Based Filler

[0233] In the following description of the preparation of the Examples and Comparatives Examples the indication of weight in form of parts always refers to parts by weight, unless indicated otherwise.

3.1. Example 1Powder 1

[0234] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 1 part relative to 100 parts CaCO.sub.3 of copper sulphate (45.2 g of solution 1 having 22.1 wt.-% solid content) was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green homogeneous powder was obtained (Powder 1).

3.2. Example 2Powder 2

[0235] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 0.4 parts relative to 100 parts CaCO.sub.3 of copper sulphate (17.5 g of solution 1 having 22.9 wt.-% solid content) was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green homogeneous powder was obtained (Powder 2).

3.3. Example 3Powder 3

[0236] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 0.1 parts of copper sulphate (4.5 g of solution 1 having 22.1 wt.-% solid content) relative to 100 parts CaCO.sub.3 was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A very slightly green homogeneous powder was obtained (Powder 3).

3.4. Example 4Powder 4

[0237] 0.75 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 3 parts of copper sulphate (4.5 g of suspension 1 having 42 wt.-% solid content) relative to 100 parts CaCO.sub.3 was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A strongly green powder was obtained (Powder 4).

3.5. Example 5Powder 5

[0238] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 0.4 parts of copper sulphate (18.2 g of solution 2 having 22 wt.-% solid content) relative to 100 parts CaCO.sub.3 was introduced and the mixing was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green homogeneous powder was obtained. The powder was then washed with 1 L deionized water, and filtered. A sample of the filtrate and the filter cake was then collected and analysed (XRF). This washing procedure has been repeated 3 times. At the end, the filtered powder was dried in the oven under reduced pressure (Powder 5).

3.6. Example 6Powder 6

[0239] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 1 part of copper sulphate (50 g of solution 2 having 20 wt.-% solid content) relative to 100 parts CaCO.sub.3 was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). Then, 0.6 parts of stearic acid (Omyacid 54, Omya AG, Switzerland) relative to 100 parts CaCO.sub.3 was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green powder was obtained (Powder 6).

3.7. Example 7Powder 7

[0240] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C., Germany). After that time, 0.6 parts of stearic acid (Omyacid 54, Omya AG, Switzerland) and 1 part of copper sulphate (50 g of solution 2 having 20 wt.-% solid content) relative to 100 parts CaCO.sub.3 were introduced and the mixing was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green powder was obtained (Powder 7).

3.8. Example 8Powder 8

[0241] A suspension of 150 g of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) in deionized water (450 mL) was placed in a round bottom flask equipped with a condenser and an addition funnel. The mixture was heated to 90 C. and a previously prepared solution of 35 g of copper sulphate pentahydrate in water (150 ml) was added dropwise to the mixture. The suspension turned green in colour, and heating was continued for another 2 h (with stirring at 500 rpm) after completion of the addition. The heating was then stopped and the suspension was filtered on a Buchner funnel, and washed with 1 L deionized water. The filtrate was colourless, and the filter cake (green powder) was then dried in an oven (80 C., reduced pressure). The obtained green powder (Powder 8) was then analyzed by XRD.

3.9. Example 9Powder 9

[0242] 1.00 kg of a wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 m, BET specific surface area=4.1 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 0.4 parts relative to 100 parts CaCO.sub.3 of copper sulphate (20 g of solution 2 having 20 wt.-% solid content) was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green homogeneous powder was obtained (Powder 9).

3.10. Example 10Powder 10

[0243] 1.00 kg of a wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 m, BET specific surface area=4.1 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 0.05 parts relative to 100 parts CaCO.sub.3 of copper sulphate (2.5 g of solution 2 having 20 wt.-% solid content) was introduced and stirring was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A very slightly green homogeneous powder was obtained (Powder 10).

3.11. Example 11Powder 11

[0244] 400 g of a wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 m, BET specific surface area=4.1 m.sup.2/g) was placed in a mixer (Somakon MP-LB Mixer, Somakon Verfahrenstechnik, Germany), and conditioned by stirring for 10 minutes (2 000 rpm, 120 C.). After that time, 0.02 parts relative to 100 parts CaCO.sub.3 of copper sulphate (8 g of solution 2 previously diluted to 1 wt.-% solids content) was added dropwise over 2 minutes. Stirring and heating was continued for another 20 minutes after completion of the addition (120 C., 2 000 rpm). After that time, the mixture was allowed to cool and the powder collected (Powder 11).

3.12. Example 12Powder 12

[0245] 1 kg of a wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 m, BET specific surface area=4.1 m.sup.2/g) was placed in a 5 L beaker equipped with a mechanical overhead stirrer. 3 L of deionised water was added, and the mixture was heated to 80 C. for 1 h (stirring at approximately 300 rpm). After that time, 243.3 g of the copper nitrate solution 3 (equivalent to 10 parts solid relative to 100 parts CaCO.sub.3) was added dropwise to the mixture via an addition funnel. The resulting suspension was then heated for 2 h at 80 C./300 rpm, and the suspension was then filtered on a Buchner funnel. The filter cake was redispersed (with 3 L deionised water), stirred, and filtered again to wash off soluble salts. The washing procedure was repeated a second time and the filter cake was then dried in an oven (120 C., 7 h) to obtain a green powder after deagglomeration (Powder 12).

3.13. Example 13Powder 13

[0246] 1 kg of a dry ground calcium carbonate from Italy (d.sub.50=1.7 m, BET specific surface area=3.8 m.sup.2/g) was placed in a 5 L beaker equipped with a mechanical overhead stirrer. 3 L of deionised water was added, and the mixture was heated to 70-80 C. (stirring at approximately 300 rpm). Once this temperature was reached, 500 g of a 20 wt.-% copper sulphate solution 2 (equivalent to 10 parts solid relative to 100 parts CaCO.sub.3) was added dropwise to the mixture via an addition funnel. The resulting green suspension was then heated for 3 h at 80 C./300 rpm, and the suspension was then cooled down, and filtered on a Buchner funnel. The filter cake was redispersed (with 2 L deionised water), stirred for 1 h (300 rpm), and filtered again to wash off soluble salts. The washing procedure was repeated a second time and the filter cake was then dried in an oven (110 C., 7 h) to obtain a green powder after deagglomeration (Powder 13).

3.14. Example 14Powder 14

[0247] In a 1 L flask equipped with a condenser and an addition funnel was introduced 220 g of a dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) and 440 g of deionized water. The mixture was stirred (600 rpm) and heated to 100 C. 110 g of a 20 wt.-% solid content copper sulphate solution 2 (equivalent to 10 parts solid relative to 100 parts CaCO.sub.3) was then added dropwise at 100 C. After addition, the green suspension is heated for 3 h at 100 C. under vigorous stirring. The mixture is then cooled and filtered on a Buchner funnel, washed 3 times with 1 L deionised water and dried in oven (90 C., reduced pressure), (Powder 14).

3.15. Example 15Powder 15

[0248] In a 1 L flask equipped with a condenser and an addition funnel was introduced 220 g of a dry ground calcium carbonate from Austria (d.sub.50=7.5 m, BET specific surface area=2.2 m.sup.2/g) and 440 g of deionized water. The mixture was stirred (600 rpm) and heated to 100 C. 110 g of a 20 wt.-% solid content copper sulphate solution 2 (equivalent to 10 parts solid relative to 100 parts CaCO.sub.3) was then added dropwise at 100 C. After addition, the green suspension is heated for 3 h at 100 C. under vigorous stirring. The mixture is then cooled and filtered on a Buchner funnel, washed 3 times with 1 L deionised water and dried in oven (90 C., reduced pressure), (Powder 15).

3.16. Example 16Powder 16

[0249] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 20 minutes (3 000 rpm, 120 C.). After that time, 1.0 parts of copper sulphate (50 g of solution 2 having 20 wt.-% solids content) relative to 100 parts CaCO.sub.3 was introduced and the mixing was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green homogeneous powder was obtained (Powder 16).

3.17. Example 17Powder 17

[0250] 0.9 kg of powder 16 was dispersed in 1.5 L deionized water, stirred at room temperature for 1 hour, and filtered on a Buchner funnel. This washing procedure was repeated 4 times. At the end, the filtered powder was dried in the oven (90 C.) under reduced pressure (Powder 17).

3.18. Example 18Powder 18

[0251] 1.00 kg of dry ground calcium carbonate from Austria (d.sub.50=7.5 m, BET specific surface area=2.2 m.sup.2/g) was placed in a high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 20 minutes (3 000 rpm, 120 C.). After that time, 1.0 parts of copper sulphate (50 g of solution 2 having 20 wt.-% solid content) relative to 100 parts CaCO.sub.3 was introduced and the mixing was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green homogeneous powder was obtained. (Powder 18).

3.19. Example 19Powder 19

[0252] 0.9 kg of powder 18 was dispersed in 1.5 L deionized water, stirred at room temperature for 1 hour, and filtered on a Buchner funnel. This washing procedure was repeated 4 times. At the end, the filtered powder was dried in the oven (90 C.) under reduced pressure (Powder 19)

3.20. Comparative Example 1Powder C1

[0253] Comparative Example 1 is a ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g), without further treatment (Powder C1).

3.21. Comparative Example 2Powder C2

[0254] 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 m, BET specific surface area=2.6 m.sup.2/g) was placed in a closed high speed mixer (MTI Mixer, MTI Mischtechnik International GmbH, Germany), and conditioned by stirring for 10 minutes (3 000 rpm, 120 C.). After that time, 0.6 parts of stearic acid (Omyacid 54, Omya AG, Switzerland) relative to 100 parts CaCO.sub.3 were introduced and mixing was continued for another 20 minutes (120 C., 3 000 rpm). After that time, the mixture was allowed to cool and collected. A slightly green powder was obtained (Powder C2).

3.22. Comparative Example 3Powder C3

[0255] Comparative Example 3 is a wet ground and spray dried calcium carbonate from Carara Italy (d.sub.50=1.6 m, BET specific surface=4.1 m.sup.2/g), without further treatment (Powder C3.).

3.23. Comparative Example 4Powder C4

[0256] Powder C4 is a dry ground calcium carbonate from Italy (d.sub.50=1.7 m, BET specific surface area=3.8 m.sup.2/g).

[0257] The prepared modified mineral-based fillers are summarized in Table 1 below. Furthermore, the physical and chemical properties of selected modified mineral-based fillers were tested. The results are shown in Tables 2 to 5 below.

TABLE-US-00001 TABLE 1 Overview of prepared modified mineral-based fillers. Stearic acid CuSO.sub.4/CuNO.sub.3.sup.a [parts per [wt.-%, based hundred on total parts Moisture Powder weight of CaCO.sub.3] CaCO.sub.3] comments Content C1 1 497 ppm C2 0.6 C3 C4 1 1 2 418 ppm 2 0.4 3 0.1 1 497 ppm 4 3 4 469 ppm 5 0.4 Powder washed with water 6 1 0.6 Successive addition 7 1 0.6 Simultaneous addition 8 15 Wet process 2.37 wt.-% 9 0.4 10 0.05 11 0.02 12.sup.a 10 Wet process 13 10 Wet process 14 10 Wet process 15 10 Wet process 16 1 17 1 Washed powder 18 1 19 1 Washed powder .sup.aSample 12 marked with a) has been prepared by using CuNO.sub.3 the remaining ones are prepared by using CuSO.sub.4 as starting material.

TABLE-US-00002 TABLE 2 Water pick-up and brightness data. Water Brightness pick-up R457 Yellowness CIELAB Powder (mg/g) Rx Ry Rz TAPPI index L* a* b* C1 1.7 95.1 94.8 93.5 93.6 1.7 97.9 0.05 0.90 2 1.9 92.6 93.3 92.5 92.7 0.3 97.4 1.11 0.61 3 1.6 94.4 94.3 93.2 93.3 1.3 97.8 0.27 0.81 13 3.4 n.d. = not determined.

TABLE-US-00003 TABLE 3 XRF analysis of composition of powder 5 after washing with 1-4 L of deionized water (room temperature, 60 minutes) and powder C1. Powder Powder 5 Powder Powder 5 after 1 L after 2 L 5 after 4 L Powder 5 before H.sub.2O H.sub.2O H.sub.2O C1 washing washing washing washing [wt.-%] [wt.-%] [wt.-%] [wt.-%] [wt.-%] CaCO.sub.3 97.7 97.6 97.7 97.7 97.8 other 2.3 2.4 2.3 2.3 2.2 constituents Cu (semiquant *<0.001 0.15 0.15 0.15 0.15 by UNIQUANT) *approx. 0.001% (10 ppm) is the detection limit of the semiquant. XRF analysis.

TABLE-US-00004 TABLE 4a Composition of filtered washing water from powder 5. After 1 L washing After 2 L washing After 4 L washing Sulphate (Ion 688 ppm 195 ppm 29 ppm Chromatogr.) ROR.sup.a): 99.1% Cu (ICP-MS) 0.2 ppm <0.1 ppm <0.1 ppm .sup.aROR means rate of recovery of the measurement.

[0258] 4 samples of 15 g of Powder 8 were suspended in 150 g deionized water in a glass bottle. After 1 h, 24 h, 4 days and 4 weeks, the supernatant was filtered and analysed by ICP-MS and Ion chromatography to determine the amount of copper solubilized.

TABLE-US-00005 TABLE 4b Composition of filtered washing water from powder 8. After 1 h After 24 h After 4 days After 1 month Sulphate (Ion 1436 ppm 1431 ppm 1467 ppm 1485 ppm Chromatogr.) (ROR: 101.2%)a Cu (ICP-MS) 24 ppb 14 ppb 20 ppb 22 ppb aROR means rate of recovery of the measurement.

[0259] As can be gathered from Tables 3 and 4 a significant amount of copper has been incorporated into the calcium carbonate surface. Furthermore, only a minor amount of the copper has been leached after washing.

TABLE-US-00006 TABLE 5a Quantitative Rietveld analyses (XRD) of the powders 1, 4, and 8. CuSO.sub.45H.sub.2O Mineral Formula (reference) Powder 1 Powder 8 Powder 4 Calcite CaCO.sub.3 98.3 84.7 96.1 Gypsum CaSO.sub.42H.sub.2O 0.2 7.8 1.4 Chalcanthite CuSO.sub.45H.sub.2O 100 Brochantite Cu.sub.4SO.sub.4(OH).sub.6 <0.1 2.0 0.8 Malachite Cu.sub.2CO.sub.3(OH).sub.2 0.9 5.5 1.0 other constituents <0.6 <0.2 0.6 Total 100 100 100 100 Data were normalized to 100% crystalline material.

TABLE-US-00007 TABLE 5b Quantitative Rietveld analyses (XRD) of the powders 12, 14, and 15. Mineral Formula Powder 12 Powder 14 Powder 15 Calcite CaCO.sub.3 89.4 84.5 80.1 Gypsum CaSO.sub.42H.sub.2O 7.7 7.6 Chalcanthite CuSO.sub.45H.sub.2O Brochantite Cu.sub.4SO.sub.4(OH).sub.6 3.1 Malachite Cu.sub.2CO.sub.3(OH).sub.2 9.0 6.7 2.4 other constituents 1.6 1.1 6.8 Total 100 100 100 Data were normalized to 100% crystalline material.

4. Slurries of Modified Mineral-Based Filler and Paper Coating

Examples 20 to 37 (E20-E37) and Comparative Examples 5-12 (CE5 to 12)

[0260] Slurries were prepared on a Pendraulik stirrer, by stirring mixtures of the compositions indicated in Table 6 below for 10 minutes at room temperature with 930 rpm.

TABLE-US-00008 TABLE 6 Composition of produced filler slurries. Solid Brookfield Powder Water DA content viscosity Conductivity Example Powder [parts] [parts] [parts] [wt.-%] [m .Math. Pas] pH [mS/cm] CE5 C1 100 50 0.23 66.8 62 10.0 0.97 CE6 C3 100 50 0.23 66.2 211 10.2 1.10 CE7 C4 100 50 0.23 66.5 208 10.1 1.12 E20 1 100 62.5 0.32 61.2 786 9.0 3.18 E21 2 100 50 0.23 66.1 530 8.4 2.13 E22 3 100 50 0.23 65.4 76.2 9.5 1.48 E23 4 100 75 0.23 56.5 154 8.4 2.35 E24 5 100 60 0.23 61.5 53.2 9.9 1.25 E25 9 100 50 0.23 66.1 526 8.6 2.22 E26 10 100 50 0.23 66.4 62.4 9.7 1.23 E27 11 100 50 0.23 66.1 64.4 9.9 1.21 E28 13 100 50 0.23 661 8.4 2.74 DA = dispersing agent (100% sodium-neutralised polyacrylate, M.sub.w = 3 500 g/mol, pH = 8).

[0261] Coating colours containing 100 parts of CaCO.sub.3 (w/w) and 6 parts (dry/dry) of Styronal D628 (BASF, Germany) were then prepared with slurries according to Examples 20 to 28 and Comparative Examples 5, 6 and 7 and coated on superYUPO foils from Fischer Papier AG, Switzerland (thickness 80 m, size: 1826 cm, 62 g/m.sup.2, polypropylene). The composition of the coating colours and coating weights are summarized in Table 7 below.

TABLE-US-00009 TABLE 7 Coating colour preparation and coating weight. Coating colour composition Coating CaCO.sub.3 Styronal D628 Solid content weight Example Slurry [parts] [parts, dry/dry] [wt.-%] [g/m.sup.2] CE8 CE5 100 6 60 29.7 CE9 CE6 100 6 60 22.5 CE10 CE7 100 6 60 23.0 CE11.sup.a CE6 100.sup.b 6 60 22.4 CE12.sup.a CE6 100.sup.c 6 60 22.3 E29 E20 100 6 60 25.6 E30 E21 100 6 60 26.0 E31 E22 100 6 60 22.3 E32 E23 100 6 55 22.9 E33 E24 100 6 60 26.1 E34 E25 100 6 60 22.0 E35 E26 100 6 60 23.2 E36 E27 100 6 60 23.1 E37 E28 100 6 60 22.7 .sup.a0.23 parts of 100 sodium-neutralised polyacrylates (M.sub.w = 3 500 g/mol, pH = 8) added as dispersing agent; .sup.buntreated calcium carbonate but blended with 0.05 parts basic copper(ii)carbonate (powder available from Sigma Aldrich, Germany); .sup.cuntreated calcium carbonate but blended with 0.02 parts basic copper(ii)carbonate (powder available from Sigma Aldrich, Germany);

5. Polymers Containing Modified Mineral-Based Fillers

Examples 38 and 39 (E38 and E39) and Comparative Example 12 (CE12)

[0262] Filled polymer sample have been produced in two steps:

[0263] In a first step, the filler and the polymer (ExxonMobil LLDPE 1001, ExxonMobile Chemical, USA) were compounded on a roll mill (Collin 150, Walzwerk 150400, Germany) with 125 g of material (80:20 polymer and carbonate) using the conditions given in Table 8 below.

TABLE-US-00010 TABLE 8 Compounding conditions. Composition CaCO.sub.3 powder 25 g Exxon Mobil plastic 1001 100 g (LLDPE Low density polyethylene) Roll speed 20 upm Speed difference (typical) 35% Thickness: 0.7/0.8 mm Temperature 180 C.

[0264] LLDPE was injected first, followed by the CaCO.sub.3 powder once the LLDPE had melted. Once a homogeneous mixture was obtained, the melt was removed from the rolls and added again (operation repeated 5 times).

[0265] Once removed from the rolls, the foils were treated in a second step in a Press (Collin P 300 P, Dr. Collin, Germany). 62 g of polymer were cut in pieces and pressed between 2 metal plates to obtain sheets of the following dimensions: 1691692 mm.sup.3. The used press program is summarised in Table 9.

TABLE-US-00011 TABLE 9 Press conditions. Temperature [ C.] Time [s] Pressure [bar] 190 120 20 190 60 200 cooling 60 200

TABLE-US-00012 TABLE 10 Summary of samples and compositions. CuSO.sub.4 in powder Powder Example Powder [parts per 100 parts CaCO.sub.3] [g] LLDPE [g] CE12 C2 0 25 100 E39 6 1 25 100 E40 7 1 25 100

[0266] The surface of the obtained polymer sheets was flat and homogenous.

6. Preparation of Paint Coating Samples

[0267] The paint formulations have been prepared according to the methods known to the skilled person (European Coatings Handbook Dr. Thomas Brock/Dr. Michael Groteklaes/Dr. Peter Mischke, Curt R. Vincentz Verlag, Hannover, ISBN 3-87870-559-X).

[0268] For Indoor paint formulation, the following ingredients were combined in the stated order and amounts.

[0269] 260 g deionised water, 1 g Calgon N Neu (ICL Performance Products, Tel-Aviv, Israel), 5 g Bermocoll Prime 3500 (Akzo Nobel, Amsterdam, Netherlands), 1 g 10 wt.-% sodium hydroxide (CAS NO. 1310-73-2), 3 g Byk 038 (Byk, Wesel, Germany), 3 g Ecodis P50 (Coatex, Genay, France), 100 g TiONA 595 (Cristal Global, Jeddah, Saudi Arabia), 30 g Optiwhite (Burgess Pigment, Sandersville, Ga. USA), 80 g Omyacarb Extra-CL (Omya International AG, Oftringen, Switzerland), 80 g Omya-Calcimatt-AV (Omya International AG, Oftringen, Switzerland), 165 g modified mineral-based filler or corresponding untreated mineral, 2 g Byk 038 (Byk, Wesel, Germany), 120 g Mowilith LDM 1871 53 wt.-% solid content (Celanese, Irving, Tex. USA), 68 g deionised water.

[0270] For outdoor paint formulation, the following ingredients were combined in the stated order and amounts.

[0271] 150 g deionised water, 3 g Bermocoll EHM 200 (Akzo Nobel, Amsterdam, Netherlands), 2 g 24 wt.-% ammonia (CAS NO. 7664-41-7), 3 g Coapur 2025 (Coatex, Genay, France), 1 g Calgon N Neu (ICL Performance Products, Tel-Aviv, Israel), 5 g Borchigen DFN (OMG Borchers GmbH, Langenfeld, Germany), 10 g Di(propylene glycol) butyl ether (CAS NO. 29911-28-2), 10 g Texanol (Eastman Chemical Company, Kingsport, Tenn., United States), 3 g Byk 038 (Byk, Wesel, Germany), 200 g TiONA 595 (Cristal Global, Jeddah, Saudi Arabia), 20 g Alusil ET (PQ Corporation, Malvern, Pa., United States), 70 g Finntalc M2OSL (Mondo Minerals, Amsterdam, Netherlands), 140 g modified mineral-based filler or corresponding untreated mineral, 2 g Byk 038 (Byk, Wesel, Germany), 330 g Mowilith LDM 7717, 46 wt.-% solid content (Celanese, Irving, Tex. USA), 50 g deionised water.

7. Antimicrobial Activity Tests

Example 41Antimicrobial Activity of Paper Coatings

[0272] The antimicrobial activity of selected paper samples comprising a coating layer containing the modified mineral-based filler of the present invention, which were prepared according to Examples E29 to E36, was tested as described in the measurement method section above.

[0273] Tables 11 and 12 show the cfu counts per test item and the calculated antimicrobial activity against S. aureus (Table 11) and E. coli (Table 12) of the coated paper samples E29 to E36 as well as of comparative samples CE8 to CE12 (untreated test items and blends). The term LOD in Tables 11 and 12 refers to the limit of detection.

TABLE-US-00013 TABLE 11 Antimicrobial activity against S. aureus of surface coated paper samples. Antimicrobial cfu/test item activity Test item Set I II III Average R LOD untreated test item CE8 1 2.0E+05 2.0E+05 2.1E+05 2.0E+05 N/A N/A (before incubation) untreated test item CE8 1 1.3E+05 1.8E+05 1.7E+05 1.6E+05 0.00 4.21 Paper from E31 1 1.0E+01 1.0E+01 1.0E+01 1.0E+01 4.21 4.21 Paper from E33 1 1.0E+01 1.0E+01 1.0E+01 1.0E+01 4.21 4.21 Paper from E30 1 1.0E+01 1.0E+01 1.0E+01 1.0E+01 4.21 4.21 untreated test item CE8 2 1.5E+05 1.4E+05 1.2E+05 1.4E+05 N/A N/A (before incubation) untreated test item CE8 2 8.8E+04 1.0E+05 8.3E+04 9.1E+04 0.00 3.96 Paper from E30 2 1.0E+01 1.0E+01 1.0E+01 1.0E+01 3.96 3.96 Paper from E29 2 1.0E+01 1.0E+01 1.0E+01 1.0E+01 3.96 3.96 Untreated test item CE8 3 1.6E+05 1.6E+05 (before incubation) untreated test item CE8 3 1.1E+05 1.1E+05 0.00 4.05 Paper from E31 3 1.0E+01 1.0E+01 4.05 4.05 Paper from E33 3 1.5E+01 1.5E+01 3.87 4.05 Paper from E30 3 1.0E+01 1.0E+01 4.05 4.05 untreated test item CE8 4 1.3E+05 1.3E+05 N/A N/A (before incubation) untreated test item CE8 4 7.0E+04 7.0E+04 0.00 3.85 Paper from E30 4 1.0E+01 1.0E+01 3.85 3.85 Paper from E29 4 1.0E+01 1.0E+01 3.85 3.85 untreated test item CE9 5 1.9E+05 1.8E+05 1.9E+05 1.9E+05 N/A N/A (before incubation) untreated test item CE9 5 2.6E+05 2.1E+05 2.1E+05 2.3E+05 0.00 4.35 Paper from E34 5 1.0E+01 1.0E+01 1.2E+01 4.5E+01 3.70 4.35 Paper from E35 5 1.0E+01 1.0E+01 1.0E+01 1.0E+01 4.35 4.35 untreated test item (CE9) 1 1.3E+05 1.3E+05 1.3E+05 1.3E+05 N/A N/A (before incubation) untreated test item (CE9) 1 2.0E+05 2.1E+05 1.5E+05 1.8E+05 0.00 4.26 Paper from E35 1.0E+01 1.0E+01 1.0E+01 1.0E+01 4.26 4.26 Paper from E36 2.0E+01 1.0E+01 2.5E+01 1.8E+01 4.00 4.26 Paper from CE11 1.2E+03 9.5E+02 1.0E+02 7.5E+02 2.39 4.26 Paper from CE12 1.5E+05 1.3E+05 8.8E+04 1.2E+05 0.18 4.26 N/A: Not applicable, results from four independent sets of experiments are shown, each set with its own untreated test items as control. For each test item, experiments were performed once in triplicates and once using a single test item.

TABLE-US-00014 TABLE 12 Antimicrobial activity against E. coli of surface coated paper samples. Antimicrobial cfu/test item activity Test item Set I II III Average R LOD untreated test item CE8 1 3.2E+05 3.4E+05 3.3E+05 3.3E+05 N/A N/A (preincubation) untreated test item CE8 1 2.6E+07 2.5E+07 2.7E+07 2.6E+07 0.00 6.41 Paper from E31 1 5.4E+02 1.0E+01 1.0E+01 1.9E+02 5.14 6.41 Paper from E33 1 1.0E+01 1.0E+01 1.0E+01 1.0E+01 6.41 6.41 Paper from E30 1 1.0E+01 1.0E+01 1.0E+01 1.0E+01 6.41 6.41 untreated test item CE8 2 3.6E+05 3.7E+05 3.6E+05 3.6E+05 N/A N/A (preincubation) untreated test item CE8 2 4.2E+06 4.4E+06 9.4E+06 6.0E+06 0.00 5.78 Paper from E30 2 1.0E+01 1.0E+01 1.0E+01 1.0E+01 5.78 5.78 Paper from E29 2 3.5E+01 1.0E+01 1.0E+01 1.8E+01 5.51 5.78 N/A: Not applicable; results from two independent sets of experiment are shown, each set with its own untreated test items as control.

Example 42Fungal Growth Resistance of Paper Coatings

[0274] The antifungal activity of selected paper samples comprising a coating layer containing the modified mineral-based filler of the present invention, which were prepared according to Examples E18 to E22, was tested as described in the measurement method section above.

[0275] Tables 13a to 13d below show the rating of fungal defacement for each test item.

TABLE-US-00015 TABLE 13a Fungal defacement of different surface coated paper samples by Aspergillus niger (ATCC 6275) in a fungal growth resistant test after 19 days incubation at 28 C. and 90% relative humidity performed in two different sets. Test item Set Rating.sup.1 % defacement.sup.1 untreated test item CE8 1 4 51% to 60% Paper from E29 1 10 0% Paper from E32 1 10 0% untreated test item CE8 2 5 41% to 50% Paper from E33 2 10 0% Paper from E30 2 8 11% to 20% .sup.1According to ASTM D3273-D12; N/A: Not applicable.

TABLE-US-00016 TABLE 13b Fungal defacement of different surface coated paper samples by Aspergillus niger (ATCC 6275) in a fungal growth resistant test after 32 days incubation at 28 C. and 90% relative humidity performed in triplicates. Test item Rating.sup.1 Average Rating.sup.1 Average % defacement.sup.1 untreated test 2, 2, 2 2 80% item CE8 Paper from E29 9, 9, 9 9 10% Paper from E30 9, 9, 8 8.7 13% Paper from E31 8, 8, 8 8 20% Paper from E32 9, 9, 9 9 10% Paper from E33 9, 9, 9 9 10% .sup.1According to ASTM D3273-D12, average from triplicates.

TABLE-US-00017 TABLE 13c Fungal defacement of different surface coated paper samples by Aureobasidium pullans (ATCC 9348) in a fungal growth resistant test after 32 days incubation at 28 C. and 90% relative humidity performed in triplicates. Test item Rating.sup.1 Average Rating.sup.1 Average % defacement.sup.1 untreated test 9, 9, 9 9 10% item CE8 Paper from E29 10, 10, 9 9.7 3% Paper from E30 10, 10, 10 10 0% Paper from E31 10, 10, 9 9.7 3% Paper from E32 10, 10, 10 10 0% Paper from E33 10, 10, 10 10 0% .sup.1According to ASTM D3273-D12, average from triplicates.

TABLE-US-00018 TABLE 13d Fungal defacement of different surface coated paper samples by Penicillium funiculosum (ATCC 11797) in a fungal growth resistant test after 32 days incubation at 28 C. and 90% relative humidity performed in triplicates. Test item Rating.sup.1 Average Rating.sup.1 Average % defacement.sup.1 untreated test 8, 6, 6 6.7 33% item CE8 Paper from E29 10, 9, 9 9.3 7% Paper from E30 10, 10, 9 9.7 3% Paper from E31 10, 10, 10 10 0% Paper from E32 9, 9, 9 9 10% Paper from E33 10, 10, 10 10 0% .sup.1According to ASTM D3273-D12, average from triplicates.

Example 43Antimicrobial Surface Activity of Polymers

[0276] The antimicrobial activity of selected polymer samples the modified mineral-based filler of the present invention, which were prepared according to Example E40, was tested as described in the measurement method section above.

[0277] Table 14 shows the cfu counts per test item and the calculated antimicrobial activity against S. aureus of polymers containing modified mineral-based fillers of the present invention Results from two independent sets of experiment are shown, each set with its own untreated test items (CE13) as control. For each test item, experiments were performed once in triplicates and once using a single test item.

TABLE-US-00019 TABLE 14 Antimicrobial activity against S. aureus in a polymers containing modified mineral based fillers. Antimicrobial cfu/test item activity Test item Set I II III Average R LOD untreated test item CE13 1 1.8E+05 1.8E+05 1.8E+05 1.8E+05 N/A N/A (before incubation) untreated test item CE13 1 2.2E+05 1.5E+05 1.7E+05 1.8E+05 0.00 4.26 Polymer from E40 1 6.9E+04 5.6E+04 3.5E+03 4.3E+04 0.63* 4.26 untreated test item CE13 2 1.6E+05 1.6E+05 (before incubation) untreated test item CE13 2 2.8E+04 2.8E+04 0.00 3.44 Polymer from E40 2 2.4E+03 2.4E+03 1.06 3.44 N/A: Not applicable; LOD: Limit of Detection; *Statistical significant difference compared to untreated test item (p < 0.05, t-test two tailed, homoscedastic).

[0278] The following paint coating samples were prepared. The formulations were spread onto a black reinforced foil (PVC) with 0.15 mm thickness and dried for at least 1 week.

[0279] CE14: Indoor paint formulation using untreated calcium carbonate (CE1) as untreated mineral.

[0280] E44: Indoor paint formulation using powder 14 as modified mineral-based filler.

[0281] E45: Indoor paint formulation using powder 17 as modified mineral-based filler.

[0282] E46: Indoor paint formulation using powder 16 as modified mineral-based filler.

[0283] CE15: Outdoor paint formulation using untreated calcium carbonate (calcium carbonate from Austria, d.sub.50=7.1 nm, BET=2.2 m.sup.2/g) untreated mineral.

[0284] E47: Outdoor paint formulation using powder 19 as modified mineral-based filler.

[0285] E48: Outdoor paint formulation using powder 18 as modified mineral-based filler.

[0286] E49: Outdoor paint formulation using powder 15 as modified mineral-based filler.

Example 50Antimicrobial Activity of Paint Coatings Containing Modified Mineral-Based Filler

[0287] The antimicrobial activities of paint coating samples containing modified mineral-based filler of the present invention, were tested as described in the measurement method section above.

[0288] Tables 15 shows the cfu counts per test item and the calculated antimicrobial activity against S. aureus (Table 15) of the indicated paint coating samples as well as of comparative samples (untreated test items). The term LOD in Tables 15 refers to the limit of detection.

TABLE-US-00020 TABLE 15 Antimicrobial activity against S. aureus of paint formulations containing modified mineral-based filler. Antimicrobial cfu/test item activity Test item I II III Average R LOD untreated test item CE15 2.7E+05 2.6E+05 2.6E+05 2.6E+05 N/A N/A (before incubation) untreated test item CE15 5.0E+04 5.5E+04 4.0E+04 4.8E+04 0.00 3.68 E48 1.0E+01 2.0E+01 1.0E+01 1.3E+01 3.55 3.68 E47 1.0E+01 1.0E+01 1.0E+01 1.0E+01 3.68 3.68 E49 1.0E+01 1.0E+01 1.0E+01 1.0E+01 3.68 3.68 untreated test item CE14 2.3E+05 2.4E+05 2.5E+05 2.4E+05 N/A N/A (before incubation) untreated test item CE14 1.2E+04 3.5E+03 4.5E+03 6.5E+03 0.00 2.81 E46 1.0E+01 1.0E+01 1.0E+01 1.0E+01 2.81 2.81 E45 1.0E+01 1.0E+01 1.0E+01 1.0E+01 2.81 2.81 E44 1.0E+01 1.0E+01 1.0E+01 1.0E+01 2.81 2.81

Example 51Antialgal Activity of Modified Mineral-Based Filler

[0289] The antialgal efficacy of various types of coatings containing modified mineral-based filler of the present invention, which were prepared according to Examples E33 and E29 was determined according to the test norm described above. Table 16 shows the results of the test.

TABLE-US-00021 TABLE 16 Antimicrobial activity against the green algae Stichococcus bacillaris of coatings containing modified mineral-based filler. Rating of triplicates at different time points Test item Day 14 Day 21 Day 28 Day 32 untreated test item* 2, 2, 2 2, 2, 2 2, 2, 2 2, 2, 2 (Paper from CE8) Paper from E33 1, 1, 1 1, 1, 1 1, 1, 1 1, 1, 1 Paper from E29 1, 1, 2 2, 1, 1 1, 1, 1 1, 1, 1 The rating of the untreated test item is by definition 2.

Results

[0290] Example 41 shows the antimicrobial surface activity of dried paper coatings against gram positive bacteria (S. aureus) and gram negative bacteria (E. coli). All test samples containing the inventive modified mineral based filler (papers E29 to E36) showed a very strong antimicrobial activity. In almost any case, the antimicrobial activity reaches and most likely exceeds the limit of detection of the test assay. This antimicrobial surface activity is also apparent in polymers containing the inventive modified mineral-based filler (Example 43). The activity though is lower in polymers than on the paper coatings which are filled to a higher degree with the inventive modified mineral-based filler than the polymers.

[0291] Example 42 exemplifies the antimicrobial surface activity of dried paper coatings against fungal defacement under humid conditions due to microbial activity of three different fungi (Aspergillus niger ATCC 6275, Aureobasidium pullulans ATCC 9348, Penicillium funiculosum ATCC 11797). All test samples containing the inventive modified mineral based filler (Papers E29 to E36) showed a reduced or even absent defacement of the coating compared to the sample containing untreated calcium carbonate (paper from CE8) (see Tables 13a-d).