The refractive index of silica is 1.46, which is close to that of film-forming resin and does not affect color of paint film. It migrates to surface of paint film during film forming process, which can lead to expected roughness on surface of paint film and obviously reduce its surface gloss. It is a good matting agent. The matting effect is mainly dependent on three properties of product: porosity, particle size and surface treatment. When using fumed silica, pay attention to match thickness of paint layer. Using fumed silica with very fine particles in thick film paint cannot provide a clean surface with adequate roughness. Conversely, if it is used in thin film paint. Rough atmospheric environment. silica, although its matting effect is very good, but surface roughness of paint film will be unacceptable for most users.
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1. Brief description of Degussa mattifying powder:
Degussa Matting Powder, also known as Silica Matting Agent, is a white dispersed powder or granular appearance and has been used in paint industry for over 40 years. By controlling particle size, particle size distribution and surface properties, Degussa matting powders can provide excellent matting effects for a variety of coatings and printing inks.
ACEMATT is trade name for a range of silica matting agents offered by Evonik Degussa. It has been in use since 1995. Due to different manufacturing processes, following classification methods have been chosen:
T means colloidal silica.
H means precipitated silica.
O stands for surface preparation products.
K means silica.
S stands for silica gel and is only used with ACEMATT TS100.
Degussa is constantly researching and developing a number of new products, and demand for matting powder used in paint industry has grown significantly. The reasons can be summarized as follows: First, adding matting powder to coatings has become a kind of fashion; addition of a second matting powder can reduce gloss of product, so as to improve safety of product.
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Products of Degussa matting powder series:
The production of Degussa matting powder is divided into gas-phase matting powder and deposition matting powder. According to different needs of products, it is divided into the following brands:
ACEMATT HK125, ACEMATT HK400, ACEMATT HK440, ACEMATT OP278, ACEMATT HK450, ACEMATT HK460, ACEMATT OK412, ACEMATT OK 412LC, ACEMATT OK500, ACEMATT OK520, ACEMATT OK607, ACEMATT 36 00, ACEMATT TS100, ACEMATT TC100/20, ACEMATT 3300.
WO2010054953A1 patent examples of Degussa ACEMATT matt effect
2. Introduction to Degussa mattifying powder
Degussa matting powder OK412 matting powder: suitable for inks and paints; easily dispersed matting agent with low electrical conductivity after organic processing; very suitable for cathodic electrophoresis paint as a functional filler.
Opting powder Degussa matting powder OK412LC: Easily dispersible matting agent with low electrical conductivity after organic processing. Particle size 3 µm. It is very practical to use as a functional filler in paint for cathodic electrophoresis.
Degussa Mattifying Powder HK125 Matting Powder: Economical, untreated general purpose matting powder with a wide range of particle sizes. Particle size 4 µm. Used in paints, especially steel coil paints, wood paints and industrial paints.
Degussa Matting Powder HK400: A versatile, untreated mattifier. The average particle size is 3 microns.
Degussa Matting Powder HK440: Raw matting powder produced with new technology. With a very high matt performance, it is particularly suitable for coating systems requiring low and high gloss such as roll coatings, roof coatings and alkyd resin varnishes. The particle size is 5 microns.
Degussa Matting Powder Matt Powder HK450: Produces a raw matting powder with a new manufacturing process. With its high matting efficiency, it is particularly suitable for coating systems requiring low gloss and high gloss such as roll coatings. Particle size 3 µm.
Degussa Matting Powder HK460: Matting agent without pre-treatment. It has high matting efficiency and smooth surface feel, and is a general purpose matting agent with a particle size of 2.5 µm.
Degussa OK500 matting powder: a traditional matting agent, widely used; in some coating systems, use of OK412 will cause problem of increased drying time, which can be avoided using OK500.
Degussa Mattifying Powder OK520 Mattifying Powder: Easily dispersible general purpose mattifying agent after organic processing. Particle size 3 µm. With high matting efficiency and transparency, it is particularly suitable for varnish systems, especially polyurethane systems.
Degussa OK607 Matting Powder: Easily dispersible organically processed matting agent. Its average particle size is very small at 2 microns. Its distinctive particle size gives it a particularly smooth surface, high transparency and a special brilliance. Particularly suitable for thinner coating systems and water-based paint systems.
Degussa mattifying powder TS mattifying powder100: a matting agent produced by vapor phase method without surface treatment. Particle size 4 µm. Excellent matting effect and high transparency, suitable for all paint systems, especially for water-based paints and other paints and topcoats. The conductivity is extremely low, which can improve fluidity and storage stability of powder coatings; it is also suitable for surface treatment of PU/PVC artificial leather and has extremely high matting performance.
Degussa Matting Powder OP278: A matting agent for treatment of organic surfaces. Suitable for plastic semi-finished products such as photosensitive film, cables, plates and tubes without pressure.
Matifying powder Degussa 3300 matting powder: high matting performance, outstanding suspension properties. High transparency, excellent tactile properties, less use of thickeners in water-based coatings, improved scratch resistance, lower viscosity in solvent-based coatings. The particle size is 10 microns and pH value is 7.9.
3. Features of Degussa Matting Powder
1. Narrow particle size distribution, excellent matting effect.
2. High transparency, not easy to mist, because its refractive index is very close to that of most resins, its transparency is very good, especially suitable for processes that require grinding, recoating and finishing.
3. The coating film feels excellent, smooth, scratch-resistant and wear-resistant.
4. High stability under high shear loads.
5. Better chemical resistance, acid and alkali resistance; Due to organic surface treatment of inorganic matting powder, when its treatment layer is damaged, its acid and alkali resistance as well as weather resistance will be fatally affected. acid and alkali resistance and weather resistance can not meet requirements of customers, while organic matting powder itself is an organic substance, so its acid and alkali resistance and weather resistance can meet requirements of formula.
6. Does not affect paint drying or recoat adhesion.
7. There will be no general problems with high viscosity. Does not affect thixotropy, can practically be used as a Newtonian fluid, does not affect paint drying and overcoat adhesion.
8. Used in skin surface treatment, in addition to its mattifying properties, it also has an excellent feel and smoothness.
Strength note: Matte powder is often used in thermoplastic elastomers, especially when customers have high requirements for haze, but because particle size of silica is relatively small, resulting in difficult dispersionWhen particle size is relatively large, dispersion is simple, but matting effect is not particularly perfect, so how to neutralize contradiction between them depends on silica surface treatment and mixing process. Meite has specially developed TPV K1065AN-HIL for premium car floor mats, which has a very good matt finish, is pleasant to touch and relatively wear resistant.
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