O2 scavenging CaCO3 treatment

Abstract

The present invention refers to the use of a surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material as oxygen scavenger; wherein the surface treatment agent is selected from the group consisting of ascorbic acid and/or salts thereof, gallic acid and/or salts thereof, unsaturated fatty acids and/or salts thereof, elemental iron, iron (II)-salts and iron (ID-comprising oxides, iron (II, III)-comprising oxides and mixtures thereof; and wherein the total weight of the surface treatment agent on the total surface area of the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 0.01 to 40 mg/m.sup.2, based on the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material.

Claims

1. A product comprising a surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material as an oxygen scavenger; wherein the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is selected from the group consisting of ground calcium carbonate, marble, dolomitic marble, magnesitic marble, limestone, chalk, precipitated calcium carbonate, vaterite, calcite, aragonite, dolomite, and mixtures thereof; wherein the surface treatment agent is selected from the group consisting of gallic acid and/or salts thereof, elemental iron, iron (II)-salts and iron (II)-comprising oxides, iron (II, III)-comprising oxides and mixtures thereof; and wherein the total weight of the surface treatment agent on the total surface area of the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 2.3 to 40 mg/m.sup.2, based on the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material.

2. The product according to claim 1, wherein the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is selected from the group consisting of ground calcium carbonate, marble, dolomitic marble, magnesitic marble, limestone, chalk, precipitated calcium carbonate, and mixtures thereof.

3. The product according to claim 1, wherein the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is selected from the group consisting of dolomitic marble, magnesitic marble, limestone, chalk, and mixtures thereof.

4. The product according to claim 1, wherein the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is ground calcium carbonate.

5. The product according to claim 1, wherein the specific surface area (BET) of the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 0.5 to 150 m.sup.2/g, as measured using nitrogen and the BET method according to ISO 9277:2010.

6. The product according to claim 1, wherein the specific surface area (BET) of the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 1.5 to 15 m.sup.2/g, as measured using nitrogen and the BET method according to ISO 9277:2010.

7. The product according to claim 1, wherein the total weight of the surface treatment agent on the total surface area of the at least one surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 2.3 to 20 mg/m.sup.2, based on the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material.

8. The product according to claim 1, wherein the total weight of the surface treatment agent on the total surface area of the at least one surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 2.3 to 15 mg/m.sup.2, based on the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material.

9. The product according to claim 1, wherein the moisture pick up susceptibility of the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 0.05 to 20 mg/g.

10. The product according to claim 1, wherein the moisture pick up susceptibility of the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 0.2 to 10 mg/g.

11. The product according to claim 1, wherein the iron is a particulate powder iron having a volume median particle size d.sub.50 ranging from 5 nm to 10 μm.

12. The product according to claim 1, wherein the iron is a particulate powder iron having a volume median particle size d.sub.50 ranging from 30 nm to 500 nm.

13. The product according to claim 1, wherein the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material is additionally treated with another additive, a dispersant, a polyacrylate dispersant, a binder and/or an activating agent.

14. The product according to claim 1, wherein the total volume of oxygen reacted per gram of surface treatment agent is in the range from 0.01 to 10 mL per gram of surface treatment agent per day, wherein the reaction with oxygen is carried out with 500 g dried surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material in a closed desiccator with a volume of 7 L filled with air under normal pressure.

15. The product according to claim 1, wherein the total volume of oxygen reacted per gram of surface treatment agent is in the range from 0.4 to 6 mL per gram of surface treatment agent per day, wherein the reaction with oxygen is carried out with 500 g dried surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material in a closed desiccator with a volume of 7 L filled with air under normal pressure.

16. The product according to claim 1, wherein the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material further comprises at least one supplemental agent which is a hydrophobising agent, which at least partially covers the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material, wherein the total weight of the at least one hydrophobising agent on the total surface area of the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 0.001 to 10 mg/m.sup.2, based on the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material.

17. The product according to claim 1, wherein the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material further comprises at least one supplemental agent which is a hydrophobising agent, which at least partially covers the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material, wherein the total weight of the at least one hydrophobising agent on the total surface area of the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material is from 0.1 to 4 mg/m.sup.2, based on the at least one calcium carbonate-comprising material and/or magnesium carbonate-comprising material.

18. The product according to claim 16, wherein the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material comprises at least one supplemental agent which is a hydrophobising agent 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, polydimethylsiloxane, and mixtures thereof.

19. The product according to claim 17, wherein the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material comprises at least one supplemental agent which is a hydrophobising agent 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, polydimethylsiloxane, and mixtures thereof.

20. The product according to claim 1, wherein the product is selected from the group consisting of polymer compositions, coatings, polymer or paper coatings, food applications, food packaging applications, filters and/or cosmetic applications.

Description

EXAMPLES

1 Measurement Methods

(1) In the following, measurement methods implemented in the examples are described.

(2) Moisture Pick Up Susceptibility

(3) 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.

(4) The moisture pick up susceptibility in mg/g divided by the specific surface area in m.sup.2/g (calculated based on the specific surface area BET) corresponds to the “normalized moisture pick up susceptibility” expressed in mg/m.sup.2 of sample.

(5) Solids Content

(6) 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.

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

(8) Weight median grain diameter and grain diameter mass distribution of a particulate material were determined via the sedimentation process, i.e. an analysis of sedimentation behaviour in a gravitational field. The measurement was made with a Sedigraph™ 5100 or Sedigraph™ 5120.

(9) Volume median grain diameter d.sub.50 and grain diameter volume distribution of a particulate material such as particulate powder iron was evaluated using a Malvern Mastersizer 2000 Laser Diffraction System (Malvern Instruments Plc., Great Britain) using the Mie theory, with a particle refractive index of 1.57 and an absorption index of 0.005. Alternatively, the measurement can be made with a HELOS particle-size-analyser of Sympatec, Germany. The measurement may be considered equivalent to weight distribution assuming a constant density throughout the particle size distribution, and reference is made to the measurement technique.

(10) The method and instrument are known to the skilled person are commonly used to determine particle sizes of fillers and other particulate materials. The measurement was carried out in an aqueous solution comprising 0.1 wt.-% Na.sub.4P.sub.2O.sub.7. The samples were dispersed using a high speed stirrer and in the presence of supersonics.

(11) BET Specific Surface Area of a Material

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

(13) Humidity of Calcium Carbonate

(14) A 10 g powder sample has been heated in an oven at 150° C. until the mass is constant for 20 minutes. The mass loss has been determined gravimetrically and is expressed as wt.-% loss based on the initial sample mass. This mass loss has been attributed to the sample humidity.

(15) Oxygen Scavenging Tests

(16) Oxygen-scavenging tests were performed by placing a defined amount of powder in a closed desiccator equipped with an oxygen measuring device (GOX 100, GHM Messtechnik GmbH) and the total amount of oxygen scavenged by gram of sample (or active substance) estimated, assuming the gas respect the ideal gas law, and neglecting the volume occupied by the powders. Results were expressed as mL O.sub.2/g of powder, or mL O.sub.2/g of active substance.

(17) The following equations were used for the calculations:

(18) $n\left(\mathrm{gas}\right)-\frac{\mathrm{PV}}{R.Math.T}$$n\left(O_2\right)=n\left(\mathrm{gas}\right)\times 20.9/100$$m\left(O_2\right)=n\left(O_2\right)\times M\left(O_2\right)$$V\left(O_{2\mathrm{desiccator}}\right)=V\left(\mathrm{desiccator}\right)\times 20.9/100$

(19) Assuming R=8.314 J.Math.K.sup.−1.Math.mol.sup.−1 T=295 K P=101 300 Pa M(O.sub.2)=32 g.Math.mol.sup.−1 O.sub.2 in air=20.9%

(20) The values presented in the experimental section are calculated as follow:

(21) $O_2\mathrm{scavenged}\left(\mathrm{mL}\text{/}g\mathrm{of}\mathrm{powder}\right)=\frac{20.9-\left(\%O_2\mathrm{measured}\right)}{20.9}\times \frac{V_{O2\mathrm{desiccator}}}{m\left(\mathrm{powder}\right)}{O}_2\mathrm{scavenged}\left(\mathrm{mL}\text{/}g\mathrm{of}\mathrm{surface}\mathrm{treatment}\mathrm{agent}\right)=O_2\mathrm{scavenged}\left(\mathrm{mL}\text{/}g\mathrm{of}\mathrm{powder}\right)\times \frac{m\left(\mathrm{surface}\mathrm{treatment}\mathrm{agent}\right)}{m\left(\mathrm{powder}\mathrm{after}\mathrm{treatment}\right)})$

2 Preparation of the Surface Treated Calcium Carbonate-Comprising Material and/or Magnesium Carbonate-Comprising Material

(22) 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.

2.1 Surface Treatments with Unsaturated Fatty Acids

2.1.1 Example 1

Powder 1

(23) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 30° C.). After that time, 0.6 parts relative to 100 parts CaCO.sub.3 of linoleic acid (6 g, Sigma-Aldrich (Germany), technical grade 60-74%) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 2.3 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 1).

2.1.2 Example 2

Powder 2

(24) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 30° C.). After that time, 1.0 parts relative to 100 parts CaCO.sub.3 of linoleic acid (10 g, Sigma-Aldrich (Germany), technical grade 60-74%) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 3.8 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 2).

2.1.3 Example 3

Powder 3

(25) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 30° C.). After that time, 3 parts relative to 100 parts CaCO.sub.3 of linoleic acid (30 g, Sigma-Aldrich (Germany), technical grade 60-74%) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 11.5 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 3).

2.1.4 Example 4

Powder 4

(26) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 30° C.). After that time, 0.6 parts relative to 100 parts CaCO.sub.3 of oleic acid (6 g, Fluka (Belgium)) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 2.3 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 4).

2.1.5 Example 5

Powder 5

(27) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 30° C.). After that time, 1.0 parts relative to 100 parts CaCO.sub.3 of oleic acid (10 g, Alfa Aesar (Germany), technical grade, 90%) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 3.8 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 5).

2.1.6 Example 6

Powder 6

(28) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 30° C.). After that time, 3 parts relative to 100 parts CaCO.sub.3 of oleic acid (30 g, Fluka (Belgium)) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 11.5 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 6).

2.1.7 Example 7

Powder 7

(29) 1.00 kg of dry ground calcium carbonate from Italy (d.sub.50=1.7 μm, BET specific surface area=3.8 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, 30° C.). After that time, 1.0 parts relative to 100 parts CaCO.sub.3 of oleic acid (10 g, Fluka (Belgium)) was introduced and stirring was continued for another 20 minutes (30° C., 3 000 rpm). This treatment level corresponds to approx. 2.6 mg/m.sup.2. After that time, the mixture was taken out. A hydrophobic white powder was obtained (Powder 7).

2.2 Surface Treatments with Ascorbic Acid

2.2.1 Example 8

Powder 8

(30) 700 g of dry ground calcium carbonate from Italy (d.sub.50=1.7 μm, BET specific surface area=3.8 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, 30° C.). After that time, 1.0 parts relative to 100 parts CaCO.sub.3 of (L)-ascorbic acid (reagent grade, Sigma life science, China, 31 g of a previously prepared 22.6% solid content aqueous solution) was added and stirring was continued for another 20 minutes (100° C., 3 000 rpm). This treatment level corresponds to approx. 2.6 mg/m.sup.2. After that time, the mixture was cooled down and taken out of the mixer. A coloured (beige-yellow) powder was obtained (Powder 8).

2.2.2 Example 9

Slurry 9

(31) To 600 g (100 parts) of wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 μm, BET specific surface area=4.1 m.sup.2/g) in a 2 L bottle was added 440 g water and 0.46 parts of a polyacrylate dispersant (2.76 g of a 42 wt.-% aqueous solution of a 100% sodium-neutralised polyacrylate, M.sub.w=3 500 g/mol, pH=8) is added dropwise under strong stirring (930 rpm) at room temperature (Pendraulik stirrer). Once a stable suspension was obtained, 1.0 part ascorbic acid (6 g, reagent grade, Sigma life science) was added at room temperature (this treatment level corresponds to approx. 2.4 mg/m.sup.2), and stirring was continued for 10 minutes. The mixture became thicker (Slurry 9).

2.3 Surface Treatments with Gallic Acid

2.3.1 Example 10

Powder 10

(32) 700 g of dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, 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, 80° C.). After that time, 1.0 parts relative to 100 parts CaCO.sub.3 of gallic acid (Sigma-Aldrich, 35 g of a previously prepared 20% solid content solution in ethanol) was added and stirring was continued for another 10 minutes at 80° C., then for 10 minutes at 100° C. and again 20 minutes at 80° C. (3 000 rpm). This treatment level corresponds to approx. 3.8 mg/m.sup.2. After that time, the mixture was cooled down and taken out of the mixer. A coloured (grey-green) powder was obtained (Powder 10).

2.4 Surface Treatments with Iron

2.4.1 Example 11

Slurry 11

(33) To 600 g (100 parts) of wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 μm, BET specific surface area=4.1 m.sup.2/g) in a 2 L bottle was added 300 g water and 0.23 parts of a polyacrylate dispersant (1.38 g of a 42 wt.-% aqueous solution of a 100% sodium-neutralised polyacrylate, M.sub.w=3 500 g/mol, pH=8) is added dropwise under strong stirring (930 rpm) at room temperature (Pendraulik stirrer). Once a stable suspension was obtained, 1.0 part iron nanopowder (6 g, 60-80 nm particle size, Aldrich (China)) was added at room temperature, and stirring was continued for 10 minutes This treatment level corresponds to approx.

(34) 2.4 mg/m.sup.2. The mixture became grey in colour and a stable slurry was obtained (Slurry 11).

2.5 Comparative Examples

2.5.1 Comparative Example 1

Powder CE1

(35) Powder CE1 is a dry ground calcium carbonate from Italy (d.sub.50=2.6 μm, BET specific surface area=2.6 m.sup.2/g).

2.5.2 Comparative Example 2

Powder CE2

(36) Powder CE2 is a dry ground calcium carbonate from Italy (d.sub.50=1.7 μm, BET specific surface area=3.8 m.sup.2/g).

2.5.3 Comparative Example 3

CE3

(37) CE3 is commercially available linoleic acid (Sigma-Aldrich (Germany), technical grade 60-74%).

2.5.4 Comparative Example 4

Powder CE4

(38) Powder CE4 is commercially available (L)-ascorbic acid crystalline powder (Sigma life science, reagent grade, China).

2.5.5 Comparative Example 5

Slurry CE5

(39) To 600 g (100 parts) of wet ground and spray dried marble from Carrara, Italy (d.sub.50=1.6 μm, BET specific surface area=4.1 m.sup.2/g) in a 2 L bottle was added 300 g water and 0.23 parts of a dispersant agent (1.38 g of a 42 wt.-% aqueous solution of a 100% sodium-neutralised polyacrylate, M.sub.w=3 500 g/mol, pH=8) is added dropwise under strong stirring (930 rpm) at room temperature (Pendraulik stirrer). After ca 10 minutes stirring, a stable slurry was obtained (Slurry CE5).

2.5.6 Comparative Example 6

CE6

(40) Powder CE6 is commercially available oleic acid (Fluka (Belgium)).

(41) TABLE-US-00001 TABLE 1 Overview of prepared surface-treated calcium carbonate-comprising material. BET specific Additive surface (parts) CaCO.sub.3 CaCO.sub.3 Linoleic Oleic (L-ascorbic Gallic elemental Example (parts) (m.sup.2/g) acid acid acid) acid Iron 1 100 2.6 0.6 — — — 2 100 2.6 1 — — — — 3 100 2.6 3 — — — — 4 100 2.6 — 0.6 — — — 5 100 2.6 — 1 — — — 6 100 2.6 — 3 — — — 7 100 3.8 — 1 — — — 8 100 3.8 — — 1 — — 9 100 4.1 — — 1 — — (slurry) 10 100 2.6 — — — 1 — 11 100 4.1 — — — — 1 (slurry) CE1 100 2.6 — — — — — CE2 100 3.8 — — — — — CE3 — — 100 — — — — CE4 — — — — 100 — — CE5 100 4.1 — — — — — (slurry) CE6 — — — 100 — — —

(42) TABLE-US-00002 TABLE 2 Water pick-up. Example Water pick-up (mg/g) CE1 1.8 CE2 2.8 2 0.7 4 0.4 5 0.5 6 0.7 7 0.6

3 Coating Colours Preparation and Paper Coating

Examples 12 to 13 (E12-E13) and Comparative Example 12 (CE12)

(43) Coating colours containing 100 parts of CaCO.sub.3 (w/w) and 6 or 12 parts (dry/dry) of a synthetic binder based on styrene-butadiene copolymers (Styronal D628 (BASF, Germany)) were then prepared with slurries according to Examples 9, 11 and Comparative Example 5 and coated on both sides of superYUPO® foils from Fischer Papier AG, Switzerland (thickness 80 μm, size: 18×26 cm.sup.2, 62 g/m.sup.2, polypropylene) and dried on a belt-drier (150° C.). After coating, the sheets were immediately stored in a closed plastic bag to limit oxygen exposure until use. The composition of the coating colours and coating weights are summarized in Table 3 below.

(44) TABLE-US-00003 TABLE 3 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] CE12 CE5 100 6 64.8 107.8 E12 E9 100 12 56.7 89.3 E13 E11 100 6 65.6 106.1

4 Oxygen Scavenging Tests

4.1 Tests on Powders

(45) Oxygen-scavenging tests were performed by placing a defined amount of powder in a well closed desiccator equipped with an oxygen measuring device (GOX 100, GHM Messtechnik GmbH, Germany). The relative amount of oxygen in air is regularly recorded and the total amount of oxygen scavenged by gram of sample estimated, assuming the gas respect the ideal gas law, and neglecting the volume occupied by the powder. Results are expressed as mL O.sub.2/g of powder.

4.1.1 Example 14

(46) 500 g of the powder from Example 1 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 2.3 mg/m.sup.2.

(47) TABLE-US-00004 TABLE 4 Oxygen scavenging test. Time [h] 0 2 4 6 7.5 22 25 31 47 55 70 O.sub.2 [%] in 20.9 20.8 20.7 20.4 20.2 18.9 18.6 18 17.5 16.9 16.9 desiccator O.sub.2 scavenged 0 0.014 0.028 0.07 0.098 0.28 0.322 0.406 0.476 0.56 0.56 (mL/g powder) O.sub.2 scavenged 0 2.35 4.70 11.74 16.44 46.98 54.03 68.12 79.87 93.96 93.96 (mL/g linoleic acid)

(48) The results of Example 14 are also shown in FIGS. 1 and 2.

4.1.2 Example 15

(49) 500 g of the powder from Example 2 were placed in a sealed 7 L desiccator, and the O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 3.8 mg/m.sup.2.

(50) TABLE-US-00005 TABLE 5 Oxygen scavenging test. Time [h] 0 1 2.5 3.5 4.6 5.5 6.5 7.75 O.sub.2 [%] in desiccator 20.9 20.8 20.7 20.6 20.4 20.3 20.2 20 O.sub.2 scavenged (mL/g 0 0.014 0.028 0.042 0.07 0.084 0.098 0.126 powder) O.sub.2 scavenged (mL/g 0 1.41 2.83 4.24 7.07 8.48 9.90 12.73 linoleic acid) Time [h] 23 24 28 32.5 47.3 51 56 120 O.sub.2 [%] in desiccator 16.8 16.6 16 15.3 14.7 14.4 14.2 13.6 O.sub.2 scavenged (mL/g 0.574 0.602 0.686 0.784 0.868 0.91 0.938 1.022 powder) O.sub.2 scavenged (mL/g 57.98 60.81 69.29 79.19 87.68 91.92 94.75 103.23 linoleic acid)

(51) The results of Example 15 are also shown in FIGS. 1 and 2.

4.1.3 Example 16

(52) 500 g of the powder from Example 3 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 11.5 mg/m.sup.2.

(53) TABLE-US-00006 TABLE 6 Oxygen scavenging test. Time [h] 0 2 4 5.5 20 29 44 68 O.sub.2 [%] in desiccator 20.9 20.8 20.5 20.3 17.8 14.8 8.1 0.4 O.sub.2 scavenged (mL/g powder) 0 0.014 0.056 0.084 0.434 0.854 1.792 2.87 O.sub.2 scavenged (mL/g linoleic acid) 0 0.48 1.92 2.88 14.90 29.33 61.54 98.56 n.b.: the test was stopped after 68 h as all oxygen in the sealed desiccator had been consumed.

(54) The results of Example 16 are also shown in FIGS. 1 and 2.

4.1.4 Example 17

(55) 500 g of the powder from Example 4 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 2.3 mg/m.sup.2.

(56) TABLE-US-00007 TABLE 7 Oxygen scavenging test. Time [h] 0 2 5 24 52 74 100 164 172 190 O.sub.2 [%] in 20.9 20.9 20.9 20.8 20.6 20.6 20.5 20.2 19.8 19.8 desiccator O.sub.2 scavenged 0 0 0 0.014 0.042 0.042 0.056 0.098 0.154 0.154 (mL/g powder) O.sub.2 scavenged 0 0 0 2.35 7.05 7.05 9.40 16.44 25.84 25.84 (mL/g oleic acid) Time [h] 194 198 220 239 243 268 334 340 356 364 386 O.sub.2 [%] in 19.7 19.6 19.5 19.3 19 18.8 18.2 18.1 18.1 17.8 17.2 desiccator O.sub.2 scavenged 0.168 0.182 0.196 0.224 0.266 0.294 0.378 0.392 0.392 0.434 0.518 (mL/g powder) O.sub.2 scavenged 28.19 30.54 32.89 37.58 44.63 49.33 63.42 65.77 65.77 72.82 86.91 (mL/g oleic acid)

(57) The results of Example 17 are also shown in FIGS. 3 and 5.

4.1.5 Example 18

(58) 500 g of the powder from Example 5 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 3.8 mg/m.sup.2.

(59) TABLE-US-00008 TABLE 8 Oxygen scavenging test. Time [h] 1 4 22 28 31 46 55 72 79 168 200 217 O.sub.2 [%] in 20.9 20.8 20.7 20.6 20.5 20.4 20.1 19.7 19.2 17.6 17 17.1 desiccator O.sub.2 scavenged 0 0.014 0.028 0.042 0.056 0.07 0.112 0.168 0.238 0.462 0.546 0.532 (mL/g powder) O.sub.2 scavenged 0 1.41 2.83 4.24 5.66 7.07 11.31 16.97 24.04 46.67 55.15 53.74 (mL/g oleic acid)

(60) The results of Example 18 are also shown in FIGS. 3 and 5.

4.1.6 Example 19

(61) 500 g of the powder from Example 6 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 11.5 mg/m.sup.2.

(62) TABLE-US-00009 TABLE 9 Oxygen scavenging test. Time [h] 0 2.5 4 5.5 22 29 46 50 52 69 O.sub.2 [%] in 20.9 20.9 20.8 20.7 20.6 20.6 20.5 20.4 20.3 20.2 desiccator O.sub.2 scavenged 0 0 0.014 0.028 0.042 0.042 0.056 0.07 0.084 0.098 (mL/g powder) O.sub.2 scavenged 0 0 0.48 0.96 1.44 1.44 1.92 2.40 2.88 3.37 (mL/g oleic acid) Time [h] 77 100 166 172 188 196 218 O.sub.2 [%] in 19.8 19.4 17.6 17.4 17.1 16.1 15.6 desiccator O.sub.2 scavenged 0.154 0.21 0.462 0.49 0.532 0.672 0.742 (mL/g powder) O.sub.2 scavenged 5.29 7.21 15.87 16.83 18.27 23.08 25.48 (mL/g oleic acid)

(63) The results of Example 19 are also shown in FIGS. 3 and 5.

4.1.7 Example 20

(64) 500 g of the powder from Example 7 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 2.6 mg/m.sup.2.

(65) TABLE-US-00010 TABLE 10 Oxygen scavenging test. Time (h) 0 24 48 64 72 88 96 160 168 184 192 216 240 O.sub.2 [%] in 20.9 20.7 20 19.6 19.3 19.1 18.9 17.7 17.5 17.3 17 16.6 15.9 desiccator O.sub.2 scavenged 0 0.028 0.126 0.182 0.224 0.252 0.28 0.448 0.476 0.504 0.546 0.602 0.7 (mL/g powder) O.sub.2 scavenged 0 0 12.73 18.38 22.63 25.45 28.28 45.25 48.08 50.91 55.15 60.81 70.71 (mL/g oleic acid) Time (h) 264 328 336 352 360 376 384 400 408 432 504 O.sub.2 [%] in 15.3 15.1 15 14.9 14.6 14.7 14.6 14.6 14.5 14.4 14.4 desiccator O.sub.2 scavenged 0.784 0.812 0.826 0.84 0.882 0.868 0.882 0.882 0.896 0.91 0.91 (mL/g powder) O.sub.2 scavenged 79.19 82.02 83.43 84.85 89.09 87.68 89.09 89.09 90.51 91.92 91.92 (mL/g oleic acid)

(66) The results of Example 20 are also shown in FIGS. 4 and 6.

4.1.8 Example 21

(67) 500 g of the powder from Example 8 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 2.6 mg/m.sup.2.

(68) TABLE-US-00011 TABLE 11 Oxygen scavenging test. Time [h] 0 16 20 24 40 45 48 64 72 O.sub.2 [%] in desiccator 20.9 19.4 19 18.5 17.7 17.4 17.2 16.6 16.2 O.sub.2 scavenged 0 0.21 0.266 0.336 0.448 0.49 0.518 0.602 0.658 (mL/g powder) O.sub.2 scavenged 0 21.21 26.87 33.94 45.25 49.49 52.32 60.81 66.46 (mL/g ascorbic acid) Time [h] 136 168 192 312 O.sub.2 [%] in desiccator 15.5 15 14.9 15.1 O.sub.2 scavenged 0.756 0.826 0.84 0.812 (mL/g powder) O.sub.2 scavenged 76.36 83.43 84.85 82.02 (mL/g ascorbic acid)

(69) The results of Example 21 are also shown in FIGS. 7 and 8.

4.1.9 Example 22

(70) 500 g of the powder from Example 10 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. This treatment level corresponds to approx. 3.8 mg/m.sup.2.

(71) TABLE-US-00012 TABLE 12 Oxygen scavenging test. Time [h] 0 24 48 72 168 312 360 480 524 740 938 O.sub.2 [%] in 20.9 20.7 20.6 20.6 20.3 20.2 20 19.9 19.8 19.8 19.9 desiccator O.sub.2 0 0.028 0.042 0.042 0.084 0.098 0.126 0.14 0.154 0.154 0.14 scavenged (mL/g powder) O.sub.2 0 2.83 4.24 4.24 8.48 9.90 12.73 14.14 15.56 15.56 14.14 scavenged (mL/g gallic acid)

(72) The results of Example 22 are also shown in FIG. 9.

4.1.10 Comparative Example 7

(73) 500 g of the powder from example CE1 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. No noticeable change in O.sub.2 levels could be noticed after 2 weeks.

(74) TABLE-US-00013 TABLE 13 Oxygen scavenging test. Time (h) 0 3 20 24 72 144 168 192 216 240 O.sub.2 [%] in 20.9 20.9 20.9 20.8 20.9 20.9 20.9 20.8 20.9 20.9 desiccator O.sub.2 absorbed 0 0 0 0.014 0 0 0 0.014 0 0 (mL/g powder)

(75) The results of comparative Example 7 are also shown in FIG. 1.

4.1.11 Comparative Example 8

(76) 500 g of the powder from example CE2 were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly. No noticeable change in O.sub.2 levels could be noticed after 2 weeks.

4.1.12 Comparative Example 9

(77) 14.5 g of linoleic acid (CE3) were put in a 50 mL beaker and placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly.

(78) TABLE-US-00014 TABLE 14 Oxygen scavenging test. Time (h) 0 3 20 24 72 144 168 192 216 O.sub.2 [%] in 20.9 20.9 20.6 20.4 19.6 17.6 16.6 15.6 14.9 desiccator O.sub.2 0 0 1.45 2.41 6.28 15.93 20.76 25.59 28.97 scavenged (mL/g linoleic acid)

(79) The results of comparative Example 9 are also shown in FIG. 2.

4.1.13 Comparative Example 10

(80) 10 g of (L)-ascorbic acid crystalline powder (Sigma life science, reagent grade, China, powder CE4) were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly.

(81) TABLE-US-00015 TABLE 15 Oxygen scavenging test. Time [h] 0 24 88 120 144 168 O.sub.2 [%] in desiccator 20.9 20.8 20.6 20.5 20.5 20.4 O.sub.2 scavenged (mL/g 0 0.7 2.1 2.8 2.8 3.5 ascorbic acid)

(82) The results of comparative Example 10 are also shown in FIGS. 7 and 8.

4.1.13 Comparative Example 11

(83) 14.5 g of oleic acid (CE6) were placed in a sealed 7 L desiccator, and O.sub.2 amount was recorded regularly.

(84) TABLE-US-00016 TABLE 16 Oxygen scavenging test. Time (h) 0 3 20 24 72 144 168 192 216 O.sub.2 [%] in 20.9 20.9 20.8 20.8 20.7 20.6 20.5 20.4 20.3 desiccator O.sub.2 0 0 0.48 0.48 0.97 1.45 1.93 2.41 2.90 scavenged (mL/g oleic acid)

(85) The results of comparative Example 11 are also shown in FIGS. 5 and 6.

4.2 Tests on Coated Papers

4.2.1 Example 23

Paper from E12 (with Ascorbic Acid)

(86) 80 strips (5×18 cm.sup.2) of coated paper E12 are cut in smaller pieces (each strip was cut in 4) and placed in a sealed 2.9 L desiccator, and O.sub.2 amount was recorded regularly. The estimated amount of coating (by weight) used for this test was 64 g.

(87) TABLE-US-00017 TABLE 17 Oxygen scavenging test. Time [h] 0 15 18 21 24 40 44 120 168 O.sub.2 [%] in 20.9 19.7 19.4 19 18.7 17.8 17.6 17.3 17.3 desiccator O.sub.2 scavenged 0 0.54 0.68 0.86 1.00 1.41 1.450 1.63 1.63 (mL/g coating)

(88) The results of Example 23 are also shown in FIG. 10.

4.2.2 Example 24

Paper from E13 (with Elemental Iron)

(89) 80 strip (5×18 cm.sup.2) of coated paper E13 are cut in smaller pieces (each strip was cut in 4) and placed in a sealed 2.9 L desiccator, and O.sub.2 amount was recorded regularly. The estimated amount of coating (by weight) used for this test was 77 g.

(90) TABLE-US-00018 TABLE 18 Oxygen scavenging test. Time [h] 0 17 25 48 120 168 192 288 332 404 O.sub.2 [%] in 20.9 20.8 20.7 20.6 20.5 20.4 20.4 20.4 20.4 20.3 desiccator O.sub.2 0 0.037 0.075 0.113 0.151 0.188 0.188 0.188 0.188 0.226 scavenged (mL/g coating)

(91) The results of Example 24 are also shown in FIG. 10.

4.2.3 Comparative Example 13

Paper from CE12 (Comparative Example)

(92) 108 strips (5×18 cm.sup.2) of coated paper CE12 are cut in smaller pieces (each strip was cut in 4) and placed in a sealed 2.9 L desiccator, and O.sub.2 amount was recorded regularly. The estimated amount of coating (by weight) used for this test was 84 g.

(93) TABLE-US-00019 TABLE 19 Oxygen scavenging test. Time [h] 0 24 48 120 168 216 288 O.sub.2 [%] in 20.9 20.9 20.8 20.8 20.8 20.8 20.8 desiccator O.sub.2 0 0 0.035 0.035 0.035 0.035 0.035 scavenged (mL/g coating)

(94) The results of comparative Example 13 are also shown in FIG. 10.

(95) All of the examples show that high O.sub.2 scavenging values can be achieved with the surface-treated calcium carbonate-comprising material and/or magnesium carbonate-comprising material. Thus, the reaction with O.sub.2 can be enhanced by using the treatment agent, possibly through an increased available surface area.