The hottest technology to improve the weatherabili

2022-08-23
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Briefly describe the technology to improve the weather resistance of PVC building materials

the weather resistance of PVC building materials is an important performance index. Its level is related to the weatherability of PVC building materials. Recently, two technologies introduced abroad are worth learning from. The brief introduction is as follows:

first, nano cerium oxide was used to improve the weather resistance. In the past, in order to improve the weather resistance of PVC building materials, ultraviolet absorbers such as benzophenone and benzodiazole were added to vinyl chloride lamp resin. But due to UV absorbers. It is difficult for PVC building materials to maintain high weatherability for a long time because UV absorbers are volatile and deteriorate under the action of light and heat. In addition, degraded UV absorbers will damage the transparency of PVC building materials. Adding nano cerium oxide to the mixture composed of ethylene resin, stabilizer, slip agent, processing aids, modifier, plasticizer, filler, antioxidant and UV absorber or using it to replace UV absorber can greatly improve the weatherability of PVC building materials and maintain good mechanical strength and transparency for a long time

for example, add 1.0 parts of cerium oxide with particle size of 6nm to the mixture composed of 100 parts of polyvinyl chloride (degree of polymerization 1030), 3.9 parts of organotin stabilizer, 0.5 parts of calcium fatty acid, 1.0 parts of acrylate, 5 parts of methyl propionate butadiene styrene modifier, 0.2 parts of polyethylene wax, put it into a mixer for mixing, and then put it into a double roll mill for mixing at 180 ℃ for 3 minutes to make a sheet with thickness of 1mm within ± 2% of the set value. The sheet was compounded, preheated at 180 ℃ for 3 minutes, and pressed under 5MPa pressure for 4 minutes to make a test piece with a thickness of 2mm. The transparency and hue changes were measured by colorimetry and moonlight carbon rod arc irradiation respectively. The results show that using nano cerium oxide as the latest generation of UV absorber, the weather resistance is significantly improved, and the transparency and hue remain basically unchanged for a long time

second, use mixed titanium oxide to improve the weather resistance. Using titanium oxide can improve the weather resistance and hiding power of PVC building materials, prevent fading, and is easy to stain. This titanium oxide is widely used in PVC building materials. However, at present, only rutile anatase titanium oxide is added to the mixture based on vinyl chloride resin, which can not fully improve the weather resistance

the test shows that the mixed titanium oxide composed of rutile and anatase titanium oxide with a ratio of 1.3:1 can give full play to the role of titanium oxide, further improve the weather resistance and hiding power, and better prevent fading. For example, the hue of PVC specimens containing only 0.54 parts of rutile titanium oxide will change after being irradiated by the aging machine for 200 hours, while the hue of PVC specimens containing 0.54 parts of rutile titanium oxide and anatase titanium oxide group can significantly improve the lighting efficiency of lamps, and the hue of PVC specimens composed of mixed titanium oxide will remain unchanged after being irradiated by the aging machine for more than 600 hours. In addition, compared with adding expensive resin and adding agents according to the development orientation of national economic and Technological Development Zone and modern ecological Binjiang New City in the industrial concentration area in the south of the Yangtze River, the production cost of using mixed titanium oxide technology is lower. The above two technologies are simple and feasible, and are suitable for the production of PVC building materials such as a three-dimensional fiber structure, profile, cover material, etc

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