Лако-красочные материалы — производство

SBS block copolymers degrade primarily via cross-linking. The thermal stability of SBS copolymers can be improved with the addition of a more effective stabilizer system. Figures 7 and 8 show gel formation and discoloration of a SBS copolymer stabilized

with different stabilizer systems after static oven aging at 70°C (158°C). As seen previously in SIS copolymers, a higher-molecular-weight, more effective stabilizer such as AO-3, alone or in combination with a secondary antioxidant, PS-1, provides superior color stability and resistance to gel formation than does the AO-1/PS-1 stabilizer system.

3. Stabilization of Carboxylated Styrene-Butadiene (X-SBR) Latices Carboxylated SBR latices are used as adhesives in applications where durability and flexibility are desired. Some of the major uses for X-SBR latex are in tufted carpet backing, paper coatings, wall and vinyl floor tile adhesives, and pressure-sensitive adhesives. Typically, discoloration is the first measure of the degradation of an X-SBR latex. Discoloration of a dried latex film can often be related to a loss of the physical properties and subsequently, to inferior performance in an adhesive formulation. Figure 9 illustrates the effects of adding an effective antioxidant system to an X-SBR latex on the level of discoloration as a result of static oven aging at 150°C (300°F). The addition of AO-4 alone

and a combination of AO-4 and AO-5 in a 1:1 ratio dramatically increases the resistance to discoloration compared to that of a traditional stabilization system such as AO-6 or AO-7.