外交联型丙烯酸酯乳液压敏胶的制备与性能研究

Synthesis and Properties study of Post cross-linked Acrylic Emulsion Pressure Sensitive Adhesive

摘要:

以丙烯酸丁酯（BA）、醋酸乙烯酯（VAc）、丙烯酸（AA）单体为基础，采用双丙酮丙烯酰胺（DAAM）/己二酸二酰肼（ADH）外交联体系，通过预乳化和半连续加料工艺制备了外交联型丙烯酸酯乳液压敏胶。采用红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)等手段对其进行了表征和分析。并研究了软硬单体配比（BA:VAc）、官能单体（AA）用量及外交联体系（DAAM/ADH）用量对压敏胶性能的影响。结果表明：通过调节软硬单体配比和官能单体用量可以使压敏胶性能达到一个较优的水平。当BA:VAc为85:15，AA的用量为3%时，压敏胶初粘力为17号球，180o剥离强度为504 N/m，室温持粘力>1 month，高温（100oC）持粘力为140min。外交联体系DAAM/ADH的引入可以在对初粘力和180o剥离强度影响较小的情况下显著提高压敏胶的高温持粘力到540min，从而得到高温持粘力优异的外交联型丙烯酸酯乳液压敏胶。

Abstract:

A series of post cross-linked acrylic emulsion adhesives were synthesized by pre-emulsion technology and semi-continuous emulsion polymerization. Butyl acrylate (BA), vinyl acetate (VAc) and acrylic acid (AA) were used as main monomers and diacetone-acryloamide (DAAM) /adipic dihydrazide (ADH) as post cross-linker. Emulsion polymer was characterized by means of fourier transform infrared (FTIR) analysis, transmission electron microscopy(TEM) and thermo-gravimetric analysis (TGA). Polymer structures and the cross-linked between emulsion particles have been characterized by FTIR spectroscopy and TEM photographs, respectively. TGA indicated its potential use in the environment of high temperature. Corresponding pressure sensitive adhesive（PSA）tapes were prepared at a thickness of 50 μm, their properties including tack, 180o peel strength, and shear strength at room temperature and 100 oC and their influence by BA:VAc ratio, AA content and DAAM/ADH content were studied. The results showed best properties were obtained when BA:VAc was 85:15 and AA content was 3%. The tack ball size was 17, 180o peel strength was 504 N/m, room temperature shear strength was more than 1 month, and 100 oC shear strength was 140 min. Further introducing of DAAM/ADH significantly improved 100 oC shear strength of the PSA tapes to 540 min at little sacrifice of their tack property and 180o peel strength, which could be explained by the mechanism of post cross-linking.