Views: 1092 Author: Site Editor Publish Time: 2018-12-19 Origin: Site
Precipitated Calcium Carbonates (PCCs) are manufactured or synthesized calcium carbonates, w hich can be prepared in many different crystal sizes and shapes. A special category of PCC is the ultrafine PCC, or as it is now more commonly known, the nano PCC. Nano particles are those which are less than 100 nanometers or 0.1 microns in size. To help judge what this means: a human hair is betw een 40 to 120 microns thick. To give you an idea of how small this is you would have to line up 400 ultrafine PCC particles, side by side, to make a line of particles the w idth of the finest human hair. Very small, indeed! Nano Precipitated Calcium Carbonates While the field of nano particle research has exploded in recent years, nano PCCs have been in commercial use for much longer. Shanghai Hy-Sailing Chemical Tech.Co.,LTD has manufactured nano PCCs for more than 30 years. They have been widely used to make Printing Ink,automotive and construction sealants and PVC window profiles. Hy-Sailing's ultrafine PCCs range in particle size from 10nm to 100nm in median particle size. This is an order of magnitude smaller than the so-called ultrafine ground calcium carbonates.
Nano PCCs For Sealant Rheology and Reinforcement With these extremely small particles, true thixotropic structure can be built in a sealant or other moderately to highly filled product in w hich control of viscosity, sag, slump and other rheological properties is needed. These ultrafine PCC particles also act as a semi-reinforcing filler, for strong physical performance. PVC plastisols, urethanes, silicones, polysulfides, and silylated polyethers are some of the types of high performance, long-lived automotive and construction sealants that use nano PCCs. Nano PCCs For Rigid PVCs In rigid polyvinyl chloride, nano PCCs can act as impact modifiers, providing the impact strength, even at very low temperatures, needed for PVC w indow profiles (which are used to form the frame of vinyl w indow s). When formulating with a nano PCC, replacing a larger sized ground calcium carbonate (GCC), the amount of expensive acrylic or chlorinated polyethylene (CPE) impact modifier used can be substantially reduced, saving money. Nano PCCs also give the highest gloss and best surface finish to PVC window profile extrusions.
Other Uses For Nano PCCs Nano PCCs are also used in lithographic or offset inks. In highly filled litho inks, they can serve as the main rheological additive and cost-reducing filler. In lightly filled offset inks, they can extend other more expensive thickeners, as w ell as replace oils and varnishes.
Nano PCCs thicken PVC plastisol silk screen inks. Gravure inks need very low abrasion fillers. Small particle-sized PCC is excellent here. Rheology and filling are also the reasons to use ultrafine PCCs in epoxy and other adhesives, as w ell as in unsaturated polyester gel coats. Other uses include: High strength reinforcement of rubber Detackification and mold release for thin gauge surgical and other medical gloves Nucleating agent in emulsion polymerization Carrier for catalysts, peroxides, fragrances Powder flow control additive for acrylic modifiers and other sticky products.