Лако-красочные материалы — производство

The basic chemistry and preparation of amino, and phenohc resins is covered extensively in the literature. To make water soluble or water miscible versions of these polymers most activity has concentrated on using the lower molecular weight polymers which are etherified with the lower alcohols (methanol and ethanol). With phenolic resins there are some acid […]

Recent advances in emulsion polymerisation techniques have enabled the development of core /shell polymers, where each dispersed particle is comprised of an inner core of one polymer surrounded by a thin outer shell of another. In the case of a harder core with a softer shell, this would permit film formation to take place at […]

These are aqueous systems using technology which produces a polymer which has a high molecular weight core, hence good physical and chemical resistance properties which is surrounded by an encapsulating polymer. This encapsulating polymer gives the system unique rheology characteristics. ICI, the leaders of this type of polymer, have developed this from their established non-aqueous […]

This is the repeated catalysed addition of monomer to a growing polymer chain and which carries a reactive silyl ketene acetal group. During the addition reaction, the silyl group transfers to the incoming monomer. This generates a new ketene acetal function for reaction with more monomer. Catalysts are bifluoride salts, Lewis acids and various oxyanions. […]

These are emulsions of very small particle size, usually with high acid values which give semi, clear, translucent dispersions after neutralisation. They give coatings with improved gloss and levelling. Hydrosols differ from latices with respect to particle size and the concentration of surfactant used in their manufacture, applications are in water thinned industrial finishes and […]

In addition to the various modifications and development work which are being carried out on the polymers previously described, research into new methods of polymerisation and dispersion manufacture is progressing in an attempt to overcome some of the deficiencies associated with waterborne materials. Some of these developments are outlined below.

The basic chemistry of emulsion-based acrylics is the same as their solution-based counterparts, in the sense that they are both combinations of hard and soft acrylic monomers, the ratios of which will dictate the final film properties. If a hard mar resistant coating with some alcohol and chemical resistance is desired, emulsions polymers with a […]

Anti-foaming agents, preservatives and stabilisers can all be added to latex paints. Polymeric de-foamers of the Bevaloid type are popular, as they combine long life and do not cause wetting or livering troubles. Silicone de-foamers can cause cissing and other surface faults, whilst the nonanol type de-foamers tend to dissolve in the polymer particles and […]

When a latex paint is applied whether by brush or roller, the rate of drying must be reduced to allow time to brush out the paint. High boiling water soluble liquids are added to latices to reduce the rate of evaporation of water. Ethylene and propylene glycols are commonly used at 5-10% of the latex […]

The original water based paints, distempers, were prepared by emulsifying an oil bound paint in water. They had a limited use on porous surfaces where oil absorption into the substrate was reduced in relation to oleoresinous finishes. The replacement of distempers by pigmenting large particle size polyvinyl acetate emulsions, gave faster film drying and better […]