硝化棉系塗料之配方與環境相對濕度對塗膜表面裂的影響

The Effect of Formulation and Humidity on the Film Checking of Nitrocellulose Lacquer Film

翁徐得(Shyu-Der Ueng) ； 王松水(Song-Yung Wang)

《林產工業》 8卷4期 (1989/12) Pp. 31-47

摘要

本研究之主要目的在探討硝化棉系塗料不同配方，噴塗環境相對溼度、塗膜厚度及被塗物對塗膜耐冷熱循環割裂性的影響，以改善塗膜的表面割裂性，其結果顯示：（1）對實木的塗裝而言，塗膜割裂的主要原因是木材纖維方向與塗膜之熱膨脹係數相差太大所致。（2）硝化棉系塗料配方中，醇酸樹脂／馬苓酸樹脂之比例4:1比2:1及不加馬苓酸樹脂有較佳的耐割裂性。（3）在80% RH下噴塗之塗膜均比在95% RH及65% RH下噴塗的塗膜有較小的內部應力，塗膜耐割裂性較佳。（4）橡木比松木，徑切面比弦切面，其表面塗膜均有較佳之耐割裂性，噴塗二度底漆將降低塗膜之耐割裂性。（5）塗膜愈厚愈容易割裂，但厚度在396μm以上者其差異就不顯著。（6）塗膜經過冷熱循環試驗時，在50循環後其硬度即緩慢下降，而同一配方在不同溼度下噴塗的塗膜，其硬度則趨於一致。

關鍵字

硝化棉系塗斜 ； 相對溼度 ； 表面裂 ； 塗膜厚度

並列摘要

The main purpose of this study is to investigate the effect of different nitrocellulose lacquor formulas, spray circumstance, film thickness and wood substrates on the film performance of cold check test. The results obtained are as following: 1. The main reson which cause the checking of coating film on the solid wood is the big difference of thermal expansion coefficient between film and wood fiber direction. 2. The formulation ratio of alkyd resin/maleic resin 4:1 has a better cold check test performance than ratio 2:1. 3. Compare to the film sprayed under 65% RH, 80% RH and 95% RH, the 80% RH has a smallest internal stress, and its cold check test performance is the best. 4. In the cold check test performance, oak is better than pine, and the radial section is better than the tangential section, and spraying of sanding sealer will decrease the performance. 5. The thicker is the film, the easier is the checking, but if the film is thicker than 396um, then the effect is not significant. 6. After 50 cycle times cold check test, the hardness of film then will decrease, and the hardness of film, sprayed under different relative humidity, will going to the same.

並列關鍵字

nitrocellulose lacquer ； relative humidity ； film checking ； film thickness