Resistance to UV Exposure Through Float Glass
The UV resistance of NTP sealants was confirmed as being adequate for conventional glass glazing. A test piece, as shown in Fig. 5, was prepared, and the adhesion interface was irradiated through the glass in a Xenon tester according to JIS K5600-7-7: Testing methods for paints—Part 7: Long-period performance of film—Section 7: Accelerated Weathering (Exposure to filtered xenon-arc radiation), Japanese Industrial Standards Committee, Tokyo, Japan. After the UV irradiation for a certain period, tensile properties and failure mode were obtained (See Fig. 6 and Table 3). All of the results showed cohesive failure mode after UV irradiation of up to 10000 h, and this finding proves that NTP sealants can have a sufficiently UV resistant adhesion to float glass.
NTP is a polymer having both an organic backbone and terminal silyl groups, therefore we needed to assess the degree of possible degradation of the adhesion interface on a photocatalyst coating and the contamination adjacent to the sealant. Therefore, those two key issues were evaluated under the following headings.