>> What difficulties will be encountered in UV-resistant modification of PVC resin?
Due to the strong polarity of the PVC molecular chain, usually it needs higher processing temperature, and need to add plasticizers to reduce its intermolecular gravitational force, and thus increase the flexibility of the products.
However, when under thus heat, oxygen and light conditions, PVC materials will be very easy to get rid of HCl, constantly triggering the decomposition of the material, macroscopically will be manifested as PVC materials become brittle, discoloration and loss of mechanical properties. Therefore, in order to maintain the quality of PVC resin in their processing and usage stage, plastic modification is very necessary, and the most direct method is to add UV absorbers and stabilizers to the resin for modification.
Most stabilizers and UV absorbers on the market are less compatible with polar plastics, and because of their alkaline groups such as piperidine, they react easily with the acids generated during resin processing, which greatly reduces the stabilizing effect of the additives and even produces an antagonistic effect, lowering the performance of the material.
>> How to improve the UV resistance of acidic system resins, like PVC?
OMNISTAB UV312 is an oxalanilide UV absorber suitable for polar and acidic system resins. It exhibits strong absorbance of UVB-band UV rays in the range of 250-350nm.
UV absorption spectrum of OMNISTAB UV312
OMNISTAB UV312 can be used alone, and excellent synergistic effect could be achieved when it used with antioxidants (hindered phenols, phosphites) and low alkaline HALS stabilizers (e.g. OMNISTAB LS119). The recommended dosage is 0.1-1.0%.
>> Main applications of OMNISTAB UV312:
1. Automotive:
Important functional and decorative parts in automobile interior - automobile dashboard, is the bracket for installing various types of automobile instruments.
OMNISTAB UV312 is particularly suitable as the main UV absorber for low VOC system ABS/PVC dashboards, providing light stabilization under long-term UV radiation conditions.
2. Coating:
When OMNISTAB UV312 added to powder coatings and solvent-based coatings can further improve the weatherability of the coatings, so as to maintain the decorative properties.
3、Industrial paint:
OMNISTAB UV312 can be applied to industrial paints with high performance and durability requirements, and helps to inhibit cracking, blistering, delamination, and discoloration.
Besides, OMNISTAB UV312 can be applied to PU, PA, PMMA, PC and cellulose esters. UV312 protects polymers and organic pigments from UV radiation and helps to maintain the original appearance and physical properties of molded products, films, sheets and fibers.
>> Advantages of OMNISTAB UV312:
--Low chroma, no effect on product color and transparency.
--Low volatility and good thermal stability.
--Excellent chemical resistance, it could be applied in polar and acidic systems.
--Effective in reducing the rate of yellowing of materials even in conditions with metal catalyst residues.
--No cross-influence with other modifiers (alkaline and metal catalysts, optical brighteners, etc.).
