1 Definition, Purpose and Significance
2 related standards
Appendix B of HG/T2576-94 Alkyd Enamels of All Colors
5.4.1.18 in HG/T2454-2006 solvent-based polyester coating (two-component)
HG/「3828-2006 Indoor water-based wood coatings 6.4.21
3 Key points of inspection methods
3.1 Record B in HG/T2576-94 various colors of alkyd enamel
3.1.1 Test Principle
Determine the color of the paint film after the accelerated test. The degree of change is calculated from the measured tristimulus value, which represents the change tendency of the paint film color of the white paint in dark and high-humidity air.
D=(1.28X-1,06Z)/Y
3.1,2 Instruments and equipment
Photoelectric colorimetric measuring device. (Related instrument: Colorimeter)
3.1.3 Key points of inspection methods
First, the sample is coated on a glass plate, placed in a desiccator filled with saturated potassium sulfate solution after dry operation, taken out after a certain period of time, and the three-stimulus value X, Y, Z of the color of the coating film is measured. Then calculate the panorama value (D) according to the formula
D=(1.28X-1.06Z)/Y
It is also possible to put ammonia water with a concentration of 2-5% at the bottom of the dryer to make the paint film experience a certain period of time in the steam generated by the desiccant water, then take it out for inspection, and visually observe or measure the degree of yellowing. It is recommended to carry out the test together with a coating test panel with known resistance to degradation for reference.
5.4.1.18 in 3.2HG/]1'2454-2006 solvent-based polyurethane coating (two-component)
6.4.21 of HG/T3828-2006 indoor water-based wood coatings
3.2.1 Instruments and equipment
Colorimeter;
Fluorescent UV aging machine.
3.2.2 Key points of inspection methods
According to the provisions of IS011507:1997. Using UVA(340) lamp as the light source, the test panel is placed in the test conditions, which can meet the fluorescent ultraviolet aging of the black panel temperature of (60±3)℃, irradiance of 0.68W/(m2nm), dry phase (no condensation) In the machine, the whole process was kept under continuous light for 1158h. Take it out after the test, compare it with the test plate without light, and measure the color change (△E*) with a Colorimeter. (Related instruments: constant temperature and humidity Test Chamber)
