In order to improve adhesion properties of waterborne polyurethane (WPU) inks on biaxially oriented polypropylene (BOPP) films, herein, a liquid polyester polyol BY3003 with long‐branched aliphatic chains was used to prepare WPU latexes suitable for BOPP films printing. The application of BY3003 made the surface tension of the prepared latexes not more than 43 mN/m, while that of traditional WPU latex exceeded 55 mN/m. Accordingly, the T‐peel strength of the inks made from these latexes was all above 0.8 N/15 mm. In addition, post chain extension degree, dimethylol butyric acid content, and NCO/OH molar ratio also had significantly effect on latex and film properties of WPU, especially on the T‐peel strength of the corresponding inks. By optimizing these factors, a WPU latex with surface tension as low as 39.6 mN/m and adhesion fastness over 95% on BOPP film were obtained, and the T‐peel strength of its corresponding ink was up to 2.05 N/15 mm, which is the highest value recorded in the literature as far as we know.

中文翻译：

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高T剥离强度的水性聚氨酯油墨粘合剂的合成及其在双轴取向聚丙烯薄膜印刷中的应用

为了提高水性聚氨酯（WPU）油墨在双轴取向聚丙烯（BOPP）薄膜上的附着性能，本文使用具有长支链脂族链的液态聚酯多元醇BY3003制备适合BOPP薄膜印刷的WPU胶乳。BY3003的使用使制得的乳胶的表面张力不超过43 mN / m，而传统的WPU乳胶的表面张力超过55 mN / m。因此，由这些胶乳制成的油墨的T-剥离强度均高于0.8 N / 15 mm。此外，扩链后的程度，二羟甲基丁酸含量和NCO / OH摩尔比也对WPU的胶乳和薄膜性能，特别是对相应油墨的T-剥离强度有显着影响。通过优化这些因素，表面张力低至39的WPU乳胶。