Viscosity test
The American Brookfield DV-C digital display rotary viscometer is used to test the viscosity of the coating material and its components, and to screen out the coating material formula with suitable viscosity. The specific operation is: select the No. 0 rotor, and set the rotating speed to 5 r/min (the range is 1-120 cP). Add about 20 g of liquid sample into the Viscosity Cup until the liquid level is below the marking line on the top of the rotor, set the relevant parameters, press the test button and wait for the reading to stabilize before reading the viscosity value. Coating material components whose viscosity is close to or exceeds the range of 120cP are generally not suitable for coating.
Coating Adhesion Test
Coating adhesion is one of the important indicators of coatings, which refers to the strength of the bonding force between the coating and the surface of the substrate. Good adhesion is the prerequisite for the coating to protect the substrate or impart other special properties to the substrate. Use the scratch test of paint and varnish paint film (with GBT/9286-1998 as the test standard) to test the adhesion of the coating, use a utility knife to cut through the coating, and obtain a right-angle grid pattern of equal size, observe The degree to which the coating has peeled off from the PC substrate. The test results are divided into 6 grades: Grade 0—the tested coating is complete without peeling marks; Grade 1—the tested coating is complete, and the peeling marks cannot be obviously more than 5%; Grade 2—the tested coating is complete, and the peeling marks cannot be Obviously more than 15%; Level 3 - The tested coating is intact, and the peeling marks cannot obviously exceed 35%; Level 4 - The tested coating is intact, and the peeling marks cannot obviously exceed 65%; Level 5 - The peeling degree exceeds 65%.
Coated Pencil Hardness Test
The pencil hardness of the coating was tested by the pencil hardness method of paint film (GB/T 6739-1996). The specific method is: fix the coated PC substrate on a horizontal table, use a pencil with known hardness (Mitsubishi pencil with a hardness of 9H-6B in this paper) to form an angle of 45o with the coating film, and draw 5 lines with a length of about 1/4 inch (6.5 mm), about 1/8 inch (3 mm) wide, to see if the coating is scratched. Begin testing with the pencil with the highest hardness until a certain pencil that does not scratch the coating is found. At this time, the hardness of the pencil is the pencil hardness of the coating to be tested.
Coating pendulum hardness test
The British Sheen 707KP pendulum Hardness Tester is used , the pendulum weight is 500g, and two spherical surfaces with a diameter of 8mm at the lower end of the crossbar are supported on the surface of the board to be tested. Select the Persoz measurement mode to test the damping time of the pendulum swing attenuation angle from 12° to 4°. Before the test, it is necessary to calibrate the instrument with a glass standard substrate, then fix the coated PC substrate, and test 5 times at different positions of the coating to obtain the average value to obtain the pendulum hardness of the coating.
Coating scratch resistance test
The scratch resistance of the coating was tested by using the British SheenRef.705 automatic scratch resistance Tester (the measurement standard is GBT 9279-2007). The specific method is: fix the board to be tested on the slide plate, and the slide board drives the board to be tested to move slowly. During the movement, the test needle scratches on the surface of the paint film. During the test, the force applied to the surface of the coating can be changed by changing the weight of the weight above the test needle. Generally, the weight is gradually increased from a lighter weight until the minimum force that penetrates the paint film is found.
Coating light transmittance, haze test
German DIFFUSION SYSTEMS EEL57D haze meter is used to test the transmittance and haze of the coating to analyze the optical properties of the coating.
Coating SEM Characterization
The morphology of the coating surface is photographed by a Japanese JSM-6700F high-resolution scanning electron microscope, which can directly observe the morphology characteristics of the coating surface and analyze the microscopic morphology of the surface.
For more information, please refer to the full text of "Preparation and Properties of PC Surface UV Curing Organic-Inorganic Hybrid Light Diffusion Coating Materials" (Kang Jingling)
