竹焦油為基質之戶外用二液型聚胺基甲酸酯木材塗料之研製

Manufacture of Bamboo Tar-based 2-Package Polyurethane Outdoor Wood Coatings

張家偉(Chia-Wei Chang) ； 盧崑宗(Kun-Tsung Lu)

《林產工業》 31卷2期 (2012/06) Pp. 89-99

https://doi.org/10.6561/FPI.2012.31(2).1

摘要

本研究之二液型竹焦油PU塗料是以竹焦油為基質，混合吹製型蓖麻油後作為主劑（polyol），於NCO/OH=1.0（莫耳比）下，與硬化劑（hardener）包括芳香族甲苯二異氰酸酯（toluene diisocyanate, TDI）衍生物（polymeric TDI, PTDI）與脂肪族之六亞甲基二異氰酸酯（hexamethylene diisocyanate, HDI）衍生物（Polymeric HDI, PHDI）等，分別調配成頭度底漆（wood sealer）、二度底漆（sanding sealer）及面漆（top coat），其中二度底漆分別添加14、28及42%（對主劑重量比）之硬脂酸鋅。試驗結果顯示，頭度底漆配方為蓖麻油／竹焦油=80/20（重量比），硬化劑為PTDI，具優良之耐衝擊性、附著性及塗膜強度，能符合木材用頭度底漆之需求。二度底漆配方為蓖麻油／竹焦油=60/40（重量比），硬化劑為PTDI，硬脂酸鋅添加量為28%，其乾磨容易性佳且附著性優良，能合乎木材塗料需求。在蓖麻油／竹焦油=60/40（重量比）下，以PTDI為硬化劑之面漆的乾燥時間較短，具較佳之塗膜硬度及拉伸強度，玻璃轉移（glass transition, Tg）溫度高達83.7℃，能符合木材用面漆之需求，但其耐光性較差；而以PHDI為硬化劑者之附著性優良，耐光性佳，但強度不足，其Tg溫度僅6.7℃，需加以改善才能合乎面漆需求。又上述所有塗膜經冷熱循環10cycles後，塗膜均無異狀，顯示各種塗料之塗膜耐久性均極優良。經過底漆、二度底漆及面漆噴塗之實木試材經戶外耐候試驗及土壤之耐腐朽試驗之結果發現，塗裝試材具良好之耐候及耐腐朽性。又添加1%二月桂酸二丁基锡（dibutyltin dilaurate, DBTDL）作為催化劑，可提升使用PTDI作硬化劑之竹焦油PU面漆之塗膜性質。為增進面漆之表面硬度，額外以異佛耳酮二異氰酸酯（isophorone diisocyanate, IPDI）之三量體（polymeric IPDI, PIPDI）代替PHDI作為硬化劑可有效提升竹焦油PU面漆之塗膜性質，但乾燥時間會延長，頇添加催化劑DBTDL以符合戶外建築塗料之需求。

關鍵字

竹焦油 ； 吹製型蓖麻油 ； 聚胺基甲酸酯 ； 木材塗料

並列摘要

The two-package polyurethane (PU) wood sealer, sanding sealer and top coat were obtained by mixed polyols which were combined bamboo tar with blown castor oil and the hardeners which were derived from toluene diisocyanate (PTDI) and hexamethylene diisocyanate (PHDI) by a NCO/OH molar ratio of 1.0. In addition, the sanding sealers contained different zinc stearate weight ratio of 14, 28, and 42% respectively. The experimental results indicated that the formulation of blown castor oil/bamboo tar =80/20 (by weight) and a hardener of PTDI for wood sealer had an excellent impact resistance, adhesion, strength of film which is adequate to be used as wood sealer for wood finishing. The formulation of blown castor oil/bamboo tar =60/40 (by weight), a hardener of PTDI and the added amount of zinc stearate of 28% for sanding sealer which had an superior ability of dried-sanding and adhesion which is adequate to be used as sanding sealer. In addition, the top coat with blown castor oil/bamboo tar=60/40 (by weight) and containing PTDI which had a short drying time and a superior hardness, adhesion and tensile strength of films and possessed a Tg of 83.7℃ which is adequate to be used as wood top coat for wood finishing, however, it had poor lightfasrness. As a reversed result, although the top coat which contained PHDI had a superior lightfastness and adhesion of film, but its poor film strength and a low Tg temperature of 6.7℃ must be further improved. Furthermore, all of above films exhibited excellent durability which passed 10 cycles of hot and cold cycles test. The outdoor weathering test and decay resistance test in soil showed that the specimens with wood sealer, sanding sealer and top coat finishing had an excellent weathering resistance and decay resistance. Meanwhile, the film properties of PU top coat contained PTDI could be improved by adding 1% DBTDL catalyst. The film properties of PU top coat also could be enhanced by replacing PHDI with another hardener, PIPDI (derived from isophorone diisocyanate, IPDI), while the drying time would be extended, and it must add DBTDL catalyst for the outdoor architectural coating demand.

並列關鍵字

Bamboo tar ； Blown castor oil ； Polyurethane ； Wood coating