Abstract: In order to develop a kind of polyurethane coatings with high permeability andcollapse resistance for porous wood，a alkyd resin with high hydroxyl value of 168 mgKOH/g was synthesized，and the polyethylene micro-wax powder with refractive index similar to thatof alkyd resin was combined with TDI-TMP and TDI curing agents to prepare the polyurethanecoatings. The effect of different hydroxyl value，ratio of isocyanate group to hydroxyl group［n（— NCO）∶n（— OH）］ on coating collapse resistance and different filling powder selectionand addition amount on coating were investigated. The results showed that the hardness andsolvent swelling resistance of the film increased gradually with the hydroxyl value increasingfrom 105 mgKOH/g to 168 mgKOH/g. When the n（—NCO）∶ n（—OH） increased from 0. 6∶1 to 1. 4∶1，the hardness and solvent swelling resistance of the coating increased linearly.The use of micro wax powder instead of conventional talc powder and transparent powder， improved the filling and good light penetration. After testing and application，it had been proved that the film transparency of the polyurethane coatings was good，no odor drying at normal temperature for 24 hours，basically no collapse after two weeks. It owned short dryingtime，and granular effect. The coatings had good filling property and high permeability，and could be applied to African porous wood to improve the utilization rate and qualityrequirements of African wood.

Key words: high hydroxyl value, African wood, porous wood, anti-collapse, granular powder, high transparency

摘要： 为研制一种多孔木材用高透抗塌陷聚氨酯涂料，通过合成羟值为 168 mgKOH/g的高羟值醇酸树脂，并搭配折光率与醇酸树脂相近的聚乙烯微蜡颗粒粉，再与 TDI-TMP、TDI固化剂制备成聚氨酯涂料。探究了醇酸树脂羟值、氰羟比 [n（—NCO）∶n（—OH）]对涂层抗塌陷性的影响，以及不同填充粉的选择和用量对涂层性能的影响。结果表明：随着羟值从 105 mgKOH/g逐步提升到 168 mgKOH/g，或氰羟比从 0. 6∶1递增到 1. 4∶1时，涂层的硬度和耐溶剂溶胀性程度均会递增。使用微蜡粉代替常规滑石粉和透明粉，提高了填充性且兼顾很好的光线穿透性。经检测和应用证明，该聚氨酯涂料成膜后涂层透明性好，常温干燥 24 h无气味， 2周基本不塌陷，干燥时间短，具有颗粒效果。该涂料填充性好、通透性高，可以应用于非洲多孔木材中，提高非洲木材的使用率和满足质量要求。

关键词: 高羟值, 非洲木材, 多孔木材, 抗塌陷, 颗粒粉, 高透明度

CLC Number: 

• TQ635. 3