Purpose

Styrene–isoprene–styrene (SIS) block copolymer-based pressure-sensitive adhesives (PSAs) are used in many applications with various additives. These PSAs can provide proper adhesion and high cohesive strength in tape formulations. Potential advantages of increasing the content of LP are that the PSAs become more flexible, resulting in easier deforming along the body surface shape, which improves adhesion to the skin surface. However, it is important to maintain an appropriate balance between SIS copolymer and LP because an excessive amount of LP may reduce the adhesiveness and cohesive strength of the PSAs. Here we investigated the effect of varying percentages of liquid paraffin (LP) on SIS copolymer-based PSA formulations with the proportion of alicyclic saturated hydrocarbon resin fixed at 30%.

Methods

These formulations were assessed for their adhesion and peeling characteristics by measuring their viscoelasticity in the linear range and using peel adhesion and texture analysis tests. In addition, we evaluated the intermolecular interactions in these PSAs using differential scanning calorimetry and Fourier transform infrared spectroscopy.

Results

As the LP/SIS ratio exceeded 2.5, the adhesion performance of PSA declined. However, the 180° peel adhesion test and texture analysis revealed that peel adhesion decreased nonlinearly with increasing LP/SIS copolymer ratio. The adhesion distance remained unchanged, and no cohesive breakdown of the probe was observed when the LP/SIS copolymer ratio exceeded 2.5.

Conclusion

These results provide valuable information for regulating adhesion and peel characteristics of tape formulations by varying their LP/SIS copolymer ratio as the amount of adhesive agent remains fixed.

中文翻译：

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液体石蜡对医用胶带配方压敏胶特性的影响

目的

基于苯乙烯-异戊二烯-苯乙烯 (SIS) 嵌段共聚物的压敏粘合剂 (PSA) 与各种添加剂一起用于许多应用。这些压敏胶可以在胶带配方中提供适当的粘合力和高内聚强度。增加LP含量的潜在优势是PSA变得更加柔韧，从而更容易沿着身体表面形状变形，从而提高对皮肤表面的粘附力。然而，保持 SIS 共聚物和 LP 之间的适当平衡很重要，因为过量的 LP 可能会降低 PSA 的粘合性和内聚强度。在这里，我们研究了不同百分比的液体石蜡 (LP) 对基于 SIS 共聚物的 PSA 配方的影响，其中脂环族饱和烃树脂的比例固定为 30%。

方法

通过测量它们在线性范围内的粘弹性并使用剥离粘附力和质地分析测试来评估这些制剂的粘附力和剥离特性。此外，我们使用差示扫描量热法和傅里叶变换红外光谱评估了这些 PSA 中的分子间相互作用。

结果

当LP/SIS比率超过2.5时，PSA的粘合性能下降。然而，180°剥离粘合力测试和质地分析表明，随着LP/SIS共聚物比例的增加，剥离粘合力呈非线性下降。当LP/SIS共聚物比率超过2.5时，粘附距离保持不变，并且没有观察到探针的内聚破坏。

结论

这些结果为通过在粘合剂量保持固定的情况下改变 LP/SIS 共聚物比例来调节胶带配方的粘合和剥离特性提供了有价值的信息。