| With the developing global environmental consciousness, the related policy and law in domestic and abroad become more and more strict, which leads to great environmental protection pressure for domestic coating industry. Because of the national environment law and consumption tax on coating, there is a huge demand for environmental friendly coatings and for the substitute for solvent type coatings in furniture industry. And the focused research may be on the water-based environmental coatings in the future.In this paper, the object is the preparation of water-based wood coating with good performance. Firstly, nano-oxide slurry was made by surface modifier when the modification technology was discussed and then the slurry properties, including TEM topography, disparity and stability were characterized. Then, a series of modified styrene-acrylic emulsion were prepared by using styrene(St), butyl acrylate(BA) and acrylic acid(AA) as main materials and introducing nano-oxide slurry. The influencing factors of the reaction on the emulsion performance were studied and the emulsion was characterized. Finally, the wood coating was made by modified SAE and additives and the wood specimen was paint by the coating. Then the coating hardness, wear-resistance and environmental performance were tested and the comparison between them and the parameters of commercial products was made. And the effect of nano-oxide on the coating film was investigated.The mainly study results were as follow:(1) The slurry particles surface was smooth, neat, homogeneous dispersion when polyacrylamide, polyethylene glycol and octyl phenol ethoxylates were used for the surface modify of nano-alumina and nano-zirconia. Sedimentation test indicated that the slurry had the electrostatic repulsion and steric hindrance with adding the modified, which improved the dispensability and stability of modified nano alumina and zirconia slurry, respectively.(2) It was found out that the emulsion which was made by pre-emulsion seed polymerization process had low gel rate, good thermal stability, high process conversion rate, small emulsion particle sizes and low viscosity and this type latex was suitable for long-term storage. So the pre-emulsion seed polymerization method was select to prepare styrene acrylic emulsion.(3) The effect of polymerization parameters on the emulsion performance was investigated and the optimal conditions were achieved as follows: reaction temperature 85~90℃, reaction time 6 hours, stirring speed 150r/min, soft and hard monomers ratio St/MMA/BA=4/3/1, the amount of emulsifier 3%( SDS:MSDS:SO=10:10:1 mass ratio), and the proper amount of nanooxide was 1.5%.(4) The hardness and wear resistance of coating film was increased when nano-oxide was added, with the dosage from 1wt% to 1.5wt%, and there was little affect on the appearance of the coating and the preparation cost. Although there was little difference of coating film between the two type nano-oxide, nano zirconia had greater impact on the wear resistance of coating film than nano-Al2O3, showed as higher value.(5) When the nanometer oxide content was 1.5%, styrene acrylic water-based wood coatings film hardness was H, abrasion resistance was from 0.071 to 0.079 g / 100 r and TVOC is 150 g/L.Self-made water-based wood coating added with nano-oxide was a type of low-VOC environmentally friendly product and the hardness and wear-resistance of the performance parameters were better than acrylic wood coatings(Nippon), other performance parameters as well as the commercially product. |
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