Cobalt drier is a potent surface drier and oxidizing agent used in the paint and ink industry. It is commonly combined with auxiliary driers. Excessive usage can cause surface wrinkling and increased film brittleness. Proper dosage control is essential for balanced drying, as excessive surface drying may hinder deep film drying. Cobalt octoate acts as a moisture barrier and has minimal sensitivity to atmospheric humidity. It enhances polymerization rate, hardness, and glossiness of the paint film while reducing brittleness. It also accelerates the catalytic reaction of methyl ethyl ketone peroxide (M.E.K) for polymerizing unsaturated polyester resins.
• It is a primary and surface drier
• It is the most powerful at ambient temperatures
• It can lead to discoloration due to its purple color
• It enhances the hardness and glossiness of the paint film
• It acts as accelerator in polymerizing unsaturated polyester resins
Synonyms: cobalt 2-ethylhexanoate and cobalt 2-ethylcaproate
Chemical Formula: Co(C8H15O2)2
Molecular Weight: Approximately 405.3 g/mol
CAS Number: 136-52-7
EC Number: 205-231-1
Properties:
• Odor: Cobalt octoate may have a mild odor
• Solubility: It is soluble in organic solvents such as alcohols, ketones, and esters
• Melting Point: Cobalt octoate does not have a distinct melting point but may solidify at lower temperatures.
For the purpose of determining the cobalt content in drying catalysts, we rely on the ASTM D2373-05 standard test method. This method provides guidelines and procedures to ensure accurate measurement of cobalt in catalysts such as cobalt octoate. Here is how we conduct the analysis:
1. Preparation:
a. We prepare a 0.01 M ethylenediaminetetraacetic acid (EDTA) solution by dissolving the appropriate amount of EDTA in distilled water and adjusting the pH to around 10 using a sodium hydroxide solution.
b. We prepare a buffer solution by dissolving 67 grams of ammonium chloride and 570 mL of ammonium hydroxide in distilled water. We adjust the pH to approximately 10.5 using a sodium hydroxide solution.
c. We calibrate a spectrophotometer at a wavelength of 510 nm using a blank solution (distilled water) and a cobalt standard solution.
2. Sample Preparation:
a. We weigh accurately around 1 gram of the paint drier sample into a 250 mL beaker.
b. We add 100 mL of distilled water to the beaker and stir the mixture until the sample is completely dissolved.
c. We transfer the solution quantitatively to a 250 mL volumetric flask and dilute it to the mark with distilled water.
3. Titration Procedure:
a. We pipette 50 mL of the prepared sample solution into a 250 mL conical flask.
b. We add 10 mL of the buffer solution to the conical flask to adjust the pH.
c. We add 5 drops of xylenol orange indicator to the solution. The indicator will turn yellow.
d. We titrate the solution with the prepared 0.01 M EDTA solution by slowly adding it from a burette while stirring the solution.
e. We continue the titration until the color changes from yellow to a pinkish-red color. The color change indicates the endpoint of the titration.
4. Calculation:
a. We note the volume of the EDTA solution used for the titration.
b. We calculate the cobalt concentration in the sample using the volume of EDTA solution and the concentration of the EDTA solution.
c. We apply any necessary corrections or adjustments specified in the ASTM standard.
5. Repeat and Average:
a. We repeat the entire procedure at least two more times using fresh samples.
b. We record the volume of EDTA solution used for each titration.
c. We calculate the average cobalt concentration from the multiple titrations for better accuracy.
For this purpose, we use the ASTM D1644-01 standard, we follow a step-by-step procedure to determine the nonvolatile matter content of varnishes. Here is how we conduct the analysis:
1. Sample Preparation: We obtain a representative sample of the varnish to be tested. Ensure that the sample is well-mixed and free from any visible contaminants or particles.
2. Weighing: Using a precision balance, we accurately weigh a specific amount of the varnish sample. The amount is typically specified in the standard and may vary depending on the expected nonvolatile matter content.
3. Evaporation: We transfer the weighed sample into a suitable container or weighing dish. The container is then placed in an oven set at a specific temperature, as indicated in the standard. The varnish is allowed to evaporate under controlled conditions to remove the volatile components.
4. Drying: After the evaporation phase, we transfer the container with the dried residue to a desiccator to cool to room temperature. This ensures that any moisture absorbed during cooling is minimized.
5. Weighing Residue: Once the sample has cooled, we reweigh the container with the dried residue using the same precision balance. The weight of the container and residue is recorded for later calculations.
6. Calculation: We calculate the nonvolatile matter content of the varnish by subtracting the weight of the container from the weight of the container with the residue. The difference represents the weight of the nonvolatile matter in the varnish sample.
By following the ASTM D1644-01 standard, we ensure a standardized and reliable approach to determine the nonvolatile matter content of varnishes. This analysis helps assess the film-forming properties and quality of varnish coatings.
For this purpose, we use the ASTM D1200-10 standard, we follow a step-by-step procedure to determine the viscosity of liquids using the Ford Viscosity Cup. Here is how we conduct the analysis:
1. Cup Selection: We select the appropriate Ford viscosity cup based on the expected viscosity range of the liquid to be tested. The Ford viscosity cups are available in different sizes, denoted by a numerical value.
2. Cup Preparation: We ensure that the Ford viscosity cup is clean and free from any contaminants or residue. If necessary, we clean the cup thoroughly and dry it before proceeding with the analysis.
3. Sample Preparation: We obtain a representative sample of the liquid to be tested. Ensure that the sample is well-mixed and free from any visible particles or contaminants.
4. Cup Filling: We pour a sufficient amount of the liquid sample into the Ford viscosity cup. The cup should be filled to a predetermined level specified in the standard, typically near the top orifice of the cup.
5. Timing: Using a stopwatch or timer, we measure the time it takes for the liquid to completely flow out through the orifice of the Ford viscosity cup. The timing starts as the cup is inverted to allow the liquid to flow.
6. Recording: We record the time it takes for the liquid to flow out completely, typically expressed in seconds. This time is known as the Ford viscosity cup efflux time.
7. Calculation: We use the recorded efflux time to calculate the viscosity of the liquid using a specific formula provided in the ASTM D1200-10 standard. The formula incorporates the cup's calibration constant, which is specific to each cup size.
By following the ASTM D1200-10 standard, we ensure a standardized and reliable approach to determine the viscosity of liquids using the Ford Viscosity Cup. This method is commonly used in industries such as coatings, paints, and adhesives to evaluate the flow properties and consistency of liquid materials.
For this purpose, we use the ASTM D1544-04 standard test method. we follow a step-by-step procedure to determine the color of transparent liquids using the Gardner Color Scale. Here is how we conduct the analysis:
1. Sample Preparation: We obtain a representative sample of the transparent liquid to be tested. Ensure that the sample is properly homogenized and free from any visible particles or contaminants.
2. Apparatus Setup: We set up the spectrophotometer that is calibrated according to the standard's specifications. This instrument is capable of measuring color based on the Gardner Color Scale.
3. Calibration: We calibrate the spectrophotometer using appropriate reference standards provided by the standard or as specified in the procedure. Calibration ensures accurate color measurement and comparison.
4. Sample Placement: We pour a sufficient amount of the sample into a suitable transparent container, ensuring an adequate depth for measurement. The container should be clean and free from any residue that may affect color evaluation.
5. Measurement: We place the container with the sample in the spectrophotometer and follow the instrument's instructions to measure the color. The device quantifies the color based on the Gardner Color Scale, which ranges from a pale yellow (Gardner Color 1) to a dark brown (Gardner Color 18).
6. Data Collection: We record the color measurement obtained from the instrument, typically expressed as a Gardner Color number. This number corresponds to a specific color shade on the Gardner Color Scale.
7. Comparison: We compare the measured Gardner Color number of the sample to the reference values or standards provided in the ASTM D1544-04 standard. This allows us to evaluate the color of the sample and determine its compliance with the specified requirements or industry standards.
By following the ASTM D1544-04 standard, we ensure a standardized and reliable approach to determine the color of transparent liquids using the Gardner Color Scale.
In this table you can find the technical properties of cobalt octoate with different metal content.
Product / Grade | Cobalt Octoate 12 % | Cobalt Octoate 10 % | Cobalt Octoate 8 % | Cobalt Octoate 6 % | Cobalt Octoate 1 % |
Diluent | White Spirits | White Spirits | White Spirits | White Spirits | White Spirits |
Metal Content | 12 ± 0.2 % | 10 ± 0.2 % | 8 ± 0.2 % | 6 ± 0.2 % | 1 ± 0.2 % |
Appearance | Clear Liquid | Clear Liquid | Clear Liquid | Clear Liquid | Clear Liquid |
Color | Dark Violet | Dark Violet | Violet | Violet | Violet |
Solids Content | 61 ± 2 % | 50 ± 2 % | 39 ± 2 % | 25 ± 2 % | 6 ± 2 % |
Density (at 20°C) | 1.01 ± 0.01 | 0.98 ± 0.01 | 0.91 ± 0.01 | 0.88 ± 0.01 | 0.76 ± 0.01 |
Viscosity (at 25°C) (Ford cup 4) | |||||
Standard Barrel Weight (Net. Kg) | 200 | 200 | 180 | 180 | 160 |