Лако-красочные материалы — производство

Much smaller quantities of thermosetting emulsions are used compared with either thermosetting solution polymers or thermoplastic emulsions. This is because one of the big advantages of emulsion resins of a very high molecular weight is of much less importance for thermosetting systems, where molecular weights are increased by crosslinking. However, emulsion resins having functional groups […]

These are commercially the most important class of vinyl and acrylic polymers for coatings, forming the basis of most decorative paints used today. One of the most common types of emulsion for decorative paint is based on vinyl acetate internally plasticised with about 20 parts of vinyl versatate. Di-butyl or di-octyl maleate or fumarate are […]

Before proceeding into detailed discussion, it is worth revising the differences between solution (in solvent)and emulsion acrylic polymers. Their typical characteristics are compared in Table 7-5. TABLE 7-5: COMPARISON OF THE PROPERTIES OF EMULSION AND SOLUTION ACRYLIC POLYMERS Property Solution Emulsion Molecular weight 10,000-50,000 100,000- 1,000,000 Viscosity very dependent on molecular wt. low and independent […]

Water has a slow evaporation rate, much slower than solvents with a similar boiling range, Solvents such as toluene and xylene evaporate 8-10 times faster. The latent heat of vaporisation is a significant factor when considering solvents for stoving finishes. The heat of vaporisation for water is 540 cal/g and for xylene it is 94 […]

Before considering waterborne resins in detail, it is necessary to consider the unusual properties of water as a solvent. Water is the only naturally occurring liquid and also the only one occurring on earth in three physical states, solid (ice), liquid (water) and gas (water vapour). Water has a molecular weight of 18, but it […]

Waterborne resin systems can be divided roughly into two classes — water soluble and water insoluble. A true water soluble resin is a solution of a single polymer molecule solubilised on its own, and completely surrounded by water. The water insoluble types are emulsions, these consist of a particle (or micelle — see Chapter II […]

I INTRODUCTION Waterborne paints have been used since earliest times, often as solutions of clays in water, dyed with natural materials such as barks, berries, etc. Later pigments were dispersed in gums, glue, egg whites, gelatine or casein. Waterborne materials continued along this line of development until the 1940’s when emulsified drying oils and alkyds […]

A range of commercially available non-isocyanate acrylic systems and the end use sectors for which they are recommended by their manufacturer’s are given in the following table: TABLE 6-6: COMMERCIALLY AVAILABLE NON-ISOCYANATE ACRYLIC SYSTEMS. Supplier Recommended End Use Resin Synocure 880 + 890 series Cray Valley Ltd. Vehicle Refinish, Transport, Maintenance and Plastic Components Setalux […]

by Morrison Barbour BSc and N Tuck PhD BSc Typical formulations and characteristics properties for a range of non-isocyanate coatings are given below. A typical white gloss formulation based on the Michael technology might be for heavy duty, rolling stock and heavy equipment enamels: FORMULATION 6-1: WHITE HIGH GLOSS FINISH WITH EXCELLENTCHEMICAL RESISTANCE PARTI GRIND […]

The original development of non-isocyanate acrylics was targeted in the early 1980’s at the vehicle refinishing market. The products were developed to be direct alternatives to the isocyanate cured acrylics and polyesters used in this market, due to the inherent toxicity problems of the isocyanate crosslinker. However, the slower cure and lower resistance characteristics of […]