Лако-красочные материалы — производство

Generally, for a given binder system, pigmented coatings provide bet­ter corrosion protection than clear systems. Depending upon particle size, shape and amounts used, the barrier properties of pigment coa­tings vary. Lamellar pigments such as aluminum flakes, mica, and micaceous iron oxide improve barrier properties of coatings. Also, certain active anticorrosive pigments intervene with electrochemical corrosion […]

Color and opacity, the important aesthetic attributes of paint, are given by incorporation of pigments. Pigments impart color by selec­tive absorption of visible light, while opacity is obtained by scattering and/or absorption of visible light by pigment particles. Pigments may also affect texture-related appearance characteristics of coatings, such as gloss and sheen. Various special-effects coatings […]

Most coatings are formulated to have two important functions: aes­thetic and protective. Pigments are incorporated into coatings to contribute to both of these functions.

3.1 Introduction Chapter 2 described the vital function of polymers as film formers in paints and coatings. However, successful paint formulation needs to meet other properties such as color and opacity that the binder alone cannot provide. Pigments are one of the most important components of coatings. Colorants are materials used to impart color, which […]

Petroleum oil derived hydrocarbon resins are another important class of hydrocarbon resins worth mentioning. They are derived from unsa­turated hydrocarbon monomers obtained from cracking of petroleum oil. Polymerization of these monomers results in a complex mixture of various low MW copolymers and homopolymers known as petroleum — based hydrocarbon resins. Based on monomer composition in […]

Coumarone indene resins (Figure 2.74) are one important class of hydrocarbon resins. They are mixtures of homopolymers and copoly­mers of coumarone and indene. Coumarone and indene are obtained together in fractional distillation of coal-tar naphtha. They are poly­merized through their unsaturation using either sulfuric acid or metal chloride catalysts. The products are low MW polymers […]

Hydrocarbon resins are primarily composed of cyclic, polycyclic or heterocyclic aliphatic and aromatic structures. Hydrocarbon resins are non-reactive thermoplastic binders, but have low MW compared to other conventional thermoplastic binders such as vinyl, acry­lic, and cellulose esters. They are rarely used as sole binders in coatings, but rather as modifiers. In general, hydrocarbon resins have […]

Ethyl cellulose is the only ether derivative of cellulose that is used as a main binder in which the hydroxyl groups of cellulose are ethe- rified with ethanol. Based on the degree of substitution (~ 2.2 to 2.5) and MW, various grades are marketed. By increasing the degree of substitution, the solubility of ethyl cellulose […]

In order to find a safer non-flammable alternative to nitrocellulose, cellulose esters of lower organic acids have been developed and commercialized. Cellulose acetate is prepared by reacting cellulose with acetic acid or acetic anhydride in the presence of a catalyst. Cellulose acetate has low flammability and better weathering resistance, but is of little interest as […]

Nitrocellulose, also known as cellulose nitrate, was the workhorse thermoplastic binder to produce fast-drying lacquers for many decades. However, its very low solids (~20 %) at spraying viscosity was the main reason for the steep decline of its market share with inception of legislation pertaining to the reduction in VOC emissions. Nitrocellulose is manufactured by […]