Good Dispersion, Strong Hiding Power
PVC as the material of the plastic sandals, Gaotong mine shoes, rain boots, slippers and soles, due to the limitations of PVC materials and footwear technology progress and development reasons, PVC shoes are increasingly reduced, more polyurethane and SBS and other elastomer materials replaced. But the current domestic market there are still some PVC shoe products appear, and some also on the PVC performance was modified. Here only a brief introduction to such products.
First, the formula design points
PVC shoes are foam and no foam two, there are two different injection molding and molding methods, but the main design principles of the formula is basically the same.
1, PVC resin: SG-2,3 resin-based, but also the use of SG-4,5 type, which depends mainly on the performance requirements of shoes products. For PVC resin indicators, the general requirements of the apparent density is slightly smaller, plasticizer absorption is higher, less fish, uniform particle size.
2, plasticizer: the addition of large, generally in the 60 ~ 80PHR, mainly to DOP, DBP-based, appropriate with DOS cold plasticizer and cheap oil and chlorinated paraffin and so on. Sometimes, as needed, also use citric acid esters and other environmentally friendly plasticizers.
3, stabilizer: opaque products mainly lead salt compound stabilizer mainly to three salt, two salt supplemented with metal soap. Transparent products more organic tin and calcium and zinc composite stabilizer based. Depending on the variety, the amount added is very different.
4, Lubricants: General stearic acid and paraffin-based, can also use polyethylene wax or oxidized polyethylene wax.
5, the blowing agent: for the need for foam products, foaming agent is essential. The foaming agent which is often used is azodicarbonamide (AC foaming agent), 0.5 to 1.0 PHR of the molded foamed product, and 5 to 6 phr of the molded foamed product.
6, pearl matter: pearl sandals need to add pearlite formula. Pearlescent pearlescent powder and pearl pulp two. Such as B605 pearl powder, the chemical name is bismuth oxychloride, the molecular formula BiOCl, is a basic bismuth salt, under certain conditions of synthesis, a strong refractive power, and PVC miscibility, good dispersion, hiding power, In the plastic molding process is not easy to break down, and in the plastic products on the surface of the pearl rainbow luster, increase the product beautiful. Pearlescent commonly used brand is P35 synthetic candle pulp, it is alkaline lead carbonate particles, with nitrocellulose - butyl acetate and DBP as a dispersant made of slurry.