Acrylic resin/SiO2 nano composite tanning agent and preparation method thereof

Abstract

The invention relates to an acrylics/ SiO2 nano-composite tanning agent. The nano-composite tanning agent appears to be light yellow or yellow semitransparent ropy liquid, the mass concentration is 20 to 35%, the viscosity is 500 to 1000MPa.s, the pH value is 5 to 8, and the storage stable period is over 12 months. With only 2% (relative to the leather weight) chromium powder, the nano-composite tanning agent can thicken the leather by 124.5%, the shrinkage temperature reaches to 95 DEG C.; compared with a chrome tanned leather, a leather tanned by the nano-composite tanning agent has a tensile strength, peeling strength and elongation at break improved by 51.8%, 8.2% and 13.3% respectively, has no obvious stratification or sedimentation during over 12 months of storage period. Water is used as solvent when prepared, which is low-cost and pollution-free; the preparing technology is simple, the reaction is mild, the polymerization process is easy to control, so that the nano-composite tanning agent is easy to realize industrial production, the synthesized material is inexpensive and easy to obtain as well.

Description

(1) Technical field [0001] The invention belongs to the field of functional polymer synthesis of nanocomposite tanning agents for leather, in particular to an acrylic resin / SiO 2 Nano-composite tanning agent. (2) Background technology [0002] With the transfer of the world's tanning center to Asia, my country has become a major tanning country in the world. However, the environmental pollution caused by tanning has seriously affected the development of the tanning industry. The annual discharge of waste liquid in my country's leather industry is about 70 million tons. Among these pollutants, chromium is the most toxic, but no matter what method is adopted, as long as chromium is involved, it will inevitably cause permanent pollution of chromium ions. The unreduced hexavalent Cr ions attached to leather products will directly cause damage to human skin and induce various diseases, and chromium resources are also in short supply nowadays. The fundamental way to solve the abo...

AI Technical Summary

Problems solved by technology

However, this method is still insufficient in terms of shrinkage temperature, leather thickening and physical and mechanical properties; the second is to use "grafting" technology to graft nanoparticles with special properties onto the tanning agent material molecules, or use surface technology to It is evenly dispersed in the tanning agent, and the tanning process is adjusted according to the properties of the material, so that these particles are evenly dispersed and firmly fixed between the leather fibers to achieve better tanning purposes

For example, Gao Dangge et al. dispersed nanoparticles into the commercialized Lekotan970 retanning agent by ultrasound (Research on the Preparation and Application of Acrylic Resin / Silicon Dioxide Retanning Agent, China Leather, Volume 36, Issue 1, January 2007 ), the nano-retanning agent was prepared by the physical method of blending, but the stability of the obtained product was poor, and the application effect of the product, such as the tensile strength of the skin, was not satisfactory.