Influence of UV on the self-adhesive properties of silicone pressure-sensitive adhesives

Abstract

The paper presents the results of research on the UV radiation influence on the self-adhesive properties of silicone adhesives. The adhesives were obtained by cross-linking commercial resins (PSA 590, Q2-7566) at the temperature of 110°C, using different amounts (0–3 wt%) of bis(2,4-dichlorobenzoyl) peroxide. Self-adhesive properties of adhesives such as adhesion, tack, and durability before and after aging were determined. The adhesives showed stable self-adhesive properties, however, the PSA 590 adhesive had a higher maximum operating temperature than the Q2-7566 adhesive.

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“…Interestingly, however, higher adhesion was evident here, compared with pretreatment with the pyrosil and Openair ® plasma. Similar to other activation methods, the degradation of the crosslinker in silicone components during artificial aging also plays a role in diminishing adhesive properties [23,24]. Additionally, it could be postulated that the radicals generated from UVC irradiation form more robust bonds with the silicone components, resulting in more stable properties against temperature and humidity [18].…”

“…Another factor, particularly in higher humidit conditions, is the degradation of the crosslinker within silicone components durin artificial aging. This degradation becomes evident as the crosslinker depletes rapidly in the initial days of aging [23,24]. The results of pyrosil pretreatment are shown in Figure 7.…”

“…This suggests that the pretreatment method can affect the hydrolytic degradation of the bonds [22]. Here, the degradation of the crosslinker within silicone components during artificial aging also contributes to the reduction in adhesive stiffness [23,24].…”