PVC MIXTURE AND METHOD FOR ITS PRODUCTION

摘要

The present invention concerns a PVC mixture and a method for producing PVC which can be converted into plastisols and used in strandard processing processes for paste PVC products. The resulting polyvinyl chloride is produced as a mixture of two or more particle populations produced by various forms of emulsion polymerisation or suspension polymerisation. In this way, paste PVC products with special particle distributions are produced, the production of which has not previously been possible. The particle distributions are particularly favourable because they contain large particles, which produces a low overall particle surface and a small number of particles in the mixture, and because the particle distribution is composed of several particle populations which have a great difference in mean particle sizes, which produces almost optimal packing of the particles when the plastisols are produced. This gives plastisols which are distinguished by low viscosity at both low and high shear rates. Another advantage of the method is that it uses polymerisation techniques which avoid the use of the ionic emulsifiers common in paste PVC products and thus reduces the water absorption of the products and makes them advantageous for use in panelling and roofing materials.