Advantages of using ACEMATT® matting agents in coating formulations

Blog Archive | 4 minutes  | Author: Kulvinder Kaur , MChem.

ACEMATT® matting agents, from Evonik Industries AG, have been market leading technologies for the last few decades. There is a wide selection of grades to choose from, which enable them to be effective in a variety of coating types e.g. aqueous, non-aqueous, 100%, UV etc. It is definitely true that matt finishes come in and out of fashion as design trends change. Matt finishes are often regarded as being synonymous with high quality, which is likely one reason behind the popularity of matting agents in recent years.

These silica-based matting agents change the surface roughness of a coating; switching light reflection from a specular to diffuse paradigm (see Figure 1). This is achieved whilst having a minimal effect on transparency and colour tone. There are many different options when it comes to roughening up a surface, so why are the ACEMATT® products such a popular choice?

Figure 1. (left) Specular light reflection on a smooth, glossy, surface. (right) diffuse light reflection on a matt surface. ACEMATT® is one such method to achieve surface roughness in a coating.

Gloss values can be determined at an angle of 20°, 60° or 85° on a reflectometer. When we are talking about a matting effect the sample will be evaluated at the angles of 60° and 85°. Values of less than 10 gloss units (GU) are considered matt, while values higher than 70 GU are considered gloss. When the value drops below 10 GU on a 60° measurement, then it is time to move the measurement angle to 85° - in order to properly differentiate your coating. Not all matting agents are able to effectively reduce sheen (85° - 60° reflectometer value). Most fillers that stick out of the surface will give a matt value when looking at 60° but it is an altogether different story when looking at the higher angle of 85°. ACEMATT® is an excellent option for reducing sheen, giving a deep matt effect from all angles.

Matting, transparency and colour are related variables. If you are looking for a matt finish with a high transparency, then ACEMATT® TS 100 is a great place to start.

ACEMATT® is easy to process through use of a dissolver or high-speed stirrer, often requiring a relatively short dispersion time. It can be incorporated at any stage of production, which means that post formulation gloss adjustments can be easily made.

ACEMATT® grades have a narrow particle size distribution which ensures haptic and optical homogeneity in the surface finish. Fine cut of the grindometer values ensure highly matt surfaces with smooth finishes. When formulated with particular polyurethane binders, ACEMATT® can also improve the soft touch feel. This is frequently employed in leather coatings for car and furniture seating. Anti-blocking can benefit the integrity of fabric rolls as elevated temperatures often cause these to stick together in transit.

Increasing the loading of ACEMATT® has a low impact on the rheological properties of the system. This makes it much easier when reformulating your coating for a matt finish. Products with an organic surface treatment have excellent suspension stability, even in low viscosity systems. Such surface treated grades can be found under the ACEMATT® “OK” series e.g. ACEMATT OK 412, as well as the ACEMATT® 3300 and ACEMATT® 3600 grades. Non-treated grades can be made more stable to sedimentation (especially in clear coatings) through the use of a suitable fumed silica e.g. AEROSIL® R 972.

There are a number of factors which can influence the effectiveness of a matting agent and these are looked at in the brochure “ACEMATT® - Matting agents for the coating industry”.

Lawrence Industries is the UK and IE distributor for the ACEMATT® range. We will help you find the right solution for your matt formulation. Call us on 01827 314151, or submit a form through the website to start the conversation.

Author: Kulvinder Kaur , MChem.

Kulvinder studied Chemistry at the University of Leicester, where she obtained a first class degree. She looks after all of the industry sections across England and Wales.