The present invention relates to sol or gel compositions capable of enhancing the gloss of paints and particularly semi-gloss latex paints.
References to paints and surface coating compositions are often used interchangeably; however, paints are usually used to describe pigmented materials as distinct from clear surface coatings such as lacquers or varnishes. The purposes of paint and surface coatings are aesthetic and/or protective. A coating can enhance the appearance of a substrate in terms of colour and gloss as well as give protection against such problems as weathering or corrosion.
In terms of appearance, particularly gloss properties, paints can be divided into three basic categories, namely, (1) flat paints having a specular gloss of less than about 15 percent reflectance, (2) semi-gloss paints having a specular gloss of about 35 to about 50 percent reflectance, and (3) high-gloss paints having a specular gloss greater than about 70 percent reflectance based upon light having about a 60.degree. angle of incidence. Oil-base paints can easily be formulated into these three categories of paints. However, it is difficult to formulate waterborne paints, particularly water-dispersible (latex) paints having a high specular gloss. The inability to readily formulate semi-gloss and high-gloss latex paints is a significant drawback since oil-base paints are being phased out due to environmental restrictions limiting the volatile organic compounds (VOC) content of paints.