Common knowledge of paint: factors influencing the gloss of paint film

Core tip: the gloss of paint film is an important index for decorative coatings It is difficult to have a precise definition of gloss Generally speaking, it is the ability of the paint film surface to reflect the light projected on it to the mirror surface The greater the amount of reflected light, the higher the gloss, which is called specular gloss In addition, the ratio of the reflected light intensity to the diffused light intensity of the mirror is also an indicator of the glossiness The gloss depends not only on the reflectivity, but also on this contrast For example, the black paint film and the white paint film with the same reflectivity generally have better gloss There are many factors affecting the luster, mainly Shenyang steel structure fireproof coating construction expert punde Building Fire Engineering Co., Ltd Recommended introduction: since its establishment, Shenyang punde Construction Fire Engineering Co., Ltd has cultivated a group of professional construction teams with excellent equipment, rich experience and serious responsibility with advanced and scientific management methods and strict engineering quality assurance and after-sales service system It has undertaken a number of fire system installation projects, which has been praised by customers Every idea and special requirement of you will be fully considered by us and fully realized in the construction technology, which will become the cornerstone of our successful long-term development We are looking forward to your invitation, to provide you with quality services and high-quality technical support! All construction coatings have passed ISO9001 Paint Home News: the gloss of paint film is an important indicator for decorative paint It is difficult to have a precise definition of gloss Generally speaking, it is the ability of the paint film surface to reflect the light projected on it to the mirror surface The greater the amount of reflected light, the higher the gloss, which is called specular gloss In addition, the ratio of the reflected light intensity to the diffused light intensity of the mirror is also an indicator of the glossiness The gloss depends not only on the reflectivity, but also on this contrast For example, the black paint film and the white paint film with the same reflectivity generally have better gloss There are many factors affecting the gloss, mainly including the following two factors: first, the gloss is related to the smoothness of the paint surface If the surface of the same material is a mirror, the specular reflection occurs, and the reflection in the direction of the reflection angle is the strongest If the surface is uneven, the random reflection will occur, which weakens the light intensity in the direction of the reflection angle The pigment floating on the surface of the paint film will inevitably affect the smoothness of the plane, so the content, particle size, distribution, specific gravity of the pigment have an important impact on the gloss of the paint film 2、 When the surface has the same smoothness, the gloss is related to the molecular properties of the film, especially to the molecular refractive index (R), as shown in the following formula: r = {(n2-1) / (N2 + 1)} × M / D, where m is the molecular weight, D is the density, and N is the refractive index The R value reflects the characteristics of molecular structure The higher the R value, the higher the luster Generally, the molecules with unsaturated bond have higher R value, and the R value with conjugate system is higher, which is one of the reasons why the gloss of alkyd resin coating is higher than that of dry oil; the gloss of acrylate and styrene copolymer coating (styrene acrylic coating) is higher than that of acrylate and vinyl acetate copolymer coating (ethylene propylene coating) and unsaturated polyester coating It can be seen from the above two main factors that affect the gloss that, in order to obtain high gloss paint film, first of all, the paint should have good leveling, the pigment volume concentration of the paint should not be high, the pigment particles should not be too fine, and the specific gravity should not be too small In this way, the pigment can form gradient distribution in the paint film during the film formation process, and the surface pigment is less, which does not affect the smoothness The compatibility of various components in the coating formulation is good, and there is no precipitation problem in the film forming process The polymer with higher molecular refractive index should be selected as the film-forming material It has been found that when the volume concentration of pigment is low, the longer the alkyd oil is, the better the luster is When the volume concentration of pigment is high, the longer the oil is, the better the luster is This may be because the molecular refractive index of the former film-forming substance itself contributes a lot to the luster, and the latter case is that the leveling of the paint contributes a lot to the luster, because the length of oil means that there are more benzene rings and the oil has a long meaning Taste of long-chain fat content, good liquidity Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,