Concentrol, through the Additives and Adhesives divisions, manufactures EMULTROL® and ORDISOL® wax and / or oil emulsions. These two groups of solutions consist of a wide and versatile range of products, which makes it possible to have an impact on many and diverse application sectors. Some of them are of vital importance in the economy, such as the textile, paper, cardboard, latex, cork, paints, inks and food sectors.
At Concentrol, we are in constant research processes to try to find the best possible solution for our clients. In the study presented below, we compared the hydrophobic behaviour of paraffin wax emulsions from two of our reference products with a product from the competition.
Wax emulsions
Wax emulsions are stable mixtures of one or more waxes in water. Waxes can be natural or synthetic. According to the nature of the emulsifying system, they are classified as ionic, non-anionic and cationic, although you can also use a mixture of emulsifiers. We know that aqueous formulations are complex and therefore these additives are free of organic solvents (water-based).
Wax emulsions are used as industrial additives for paints, inks and varnishes, among others. They can be used in formulations of floor treatment products, wood finishes, car care products, paper, paints and coatings, inks and varnishes, fibreglass, textiles, home use, lubricants and mold release agents.
Wax emulsions are offered in the form of fluids to facilitate their use, dosage and incorporation for the greater convenience of our clients.
These products allow us to achieve properties of softness, matt or glossy effect, anti-slip effect, scratch resistance, waterproofing, and hardness. That is, they modify the surface finish to improve and protect the appearance at the interface between the coating and the outside world.
The penetration of water through wall spaces, either by prolonged direct contact or due to humidity, can significantly affect the durability of walls causing structural damage and / or mold appearance, apart from being unhealthy, annoying and unsightly. The use of wax emulsions in paints to increase water repellence is a very common practice.
The emulsions mentioned below are designed to guarantee the best waterproofing performance. They are characterized by an excellent water barrier effect and great covering capacity.
Hydrophobicity study
The present study compares the hydrophobic behaviour of EMULTROL CM-2655 and EMULTROL CM-2469 SPL paraffin wax emulsions with that of a product from the competition (see Table 1).
Table 1 – Characteristics of the emulsions to compare.
Product | Wax melting point (˚C) | % sólids | Emulsifier | pH |
EMULTROL CM-2655 | 59 | 60 | Anionic/non-ionic | 9,5 |
EMULTROL CM-2469 SPL | 66 | 40 | Anionic | 10 |
Competition | 51 | 63 | Anionic/non-ionic | 9 |
Firstly, for the evaluation of the hydrophobic behaviour of each product, a layer of each of the emulsions is applied (30 μm wet) on paper and allowed to dry completely (minimum 12 h at room temperature). Next, a drop of water is dropped on top of this layer, in order to observe the wetting angle (see Figure 1).
The results obtained show that the drops on top of the EMULTROL CM-2655 and EMULTROL CM-2469 SPL products exhibit a higher contact angle than the drop on top of the product from the competition. This behaviour, called the lotus effect, demonstrates superior hydrophobicity in the former two products compared to the latter.
In addition, the behaviour of these drops was evaluated for a few minutes. In Figure 2, it is observed how over time, the drop of water on top of the competitor’s product is absorbed on the paper, indicating a clear re-emulsion of the product. This effect can already be observed from the beginning (see Figure 1).
It should be noted that, after 10 minutes, the drop of EMULTROL CM-2655 product begins to slowly moisten a small area of the paper, without ever being completely absorbed.
Figure 1 – Appearance of water droplets on top of the layers of product on paper
Figure 2 – Appearance of the water drops after 1, 2 and 10 minutes.
To conclude, we believe that the EMULTROL CM-2655 and EMULTROL CM-2469 SPL products are good candidates for use as water repellent additives. At Concentrol we recommend carrying out tests using the complete formulations with the usual resins, as well as making a comparison with the usual additives used by each client.