Лако-красочные материалы — производство

Developing alongside the move to higher solids systems was the trend towards clear over base automotive topcoat systems(6). They consist of a 12 to 15 um dry film, highly pigmented base coat and an overlacquer of approximately 40 |im dry thickness. The base coats are applied at around 12 to 15 % nvc by weight, […]

Additional advances in high solids solution paint systems are achieved through further formulation optimisation which include: a) Lower molecular weight polymers Lower molecular weight acrylics, with a narrow molecular weight distribution are produced using high pressure polymerisation techniques with increased reaction temperature, careful initiator selection and optimised initiator concentration. this period that the thixotropic acrylic […]

A further increase in the solids content of automotive paints came with the advent of acrylic non aqueous dispersions (N. A.D.’s). These were originally developed by I. C.I. in the late 60’s and early 70’s<4)<5). With this development, akin to water based emulsion technology, it became possible to produce higher molecular weight thermoset acrylic particles […]

The paint plants of large automotive manufacturers have been a cause of solvent pollution in the major industrialised countries. Control regulations governing the level of emissions from industrial premises which are coming into force in many countries have given direction to the development in automotive finishing of low V. O.C. coatings. The move from thermoplastic […]

1. Automotive Finishing by Kevin O’Hara LRSC The major application for hydroxy functional thermosetting acrylic is in the field of topcoats for cars and other vehicles. Today and at the moment all the major car manufacturers around the world use paints based on this class of resin. As was discussed in the thermoplastic acrylic chapter […]

The reaction between high acid value acrylics and bisphenol ’A’ glycidyl ether epoxy resins is normally accelerated using a zinc based catalyst such as zinc napthenate or zinc octoate. Levels of catalyst vary between 0.5% and 1.5% (calculated as metal based on solid resin).

Catalysts are used in a number of applications, the type and selection depend on the type of application and the crosslinking chemistry involved. 1. Acid Catalysis The reaction between an hydroxy acrylic and a butylated melamine formaldehyde resin normally proceeds most effectively at 120°C during a 30 minute bake cycle. Higher temperatures can be used, […]

The molecular weights of thermosetting acrylics are considerably lower than their thermoplastic counterparts, since the final crosslinked film is built up during the curing reaction. As a consequence of this difference in molecular weight, the thermosetting types are generally soluble in a wider selection of solvents, e. g. aromatic hydrocarbons, alcohols, esters, ketones and glycol […]

Phthalocyanine green has good fastness and durability and it is used in applications similar to those for phthalocyanine blues. 3. Reds The most widely used red pigments in automotive applications are the quinacridones, due to their good colour and solvent fastness. These vary in shade from scarlet through to violet and maroon. Toluidine and thioindigo […]

Rutile grades of titanium dioxide are used exclusively. Some are treated to enhance both pigment wetting characteristics and exterior durability properties. Formulators should follow the titanium dioxide manufacturers’ recommendations for the selection of suitable grades. 1. Blacks Carbon blacks are used for both black finishes and tinting purposes. In the case of black paint, channel […]