Mold, stink, viscosity reduction, delamination… As common paint problems, they occur especially frequently in hot summer, which is a headache! Among them, cellulose thickener, a biodegradable thickening system, whether it can better maintain biological stability has become the key to avoiding coating problems, and it is also a key indicator to measure the pros and cons.
Distinguishing: “Mold” and “Enzyme”：
1.”Mold” The characteristics are obvious and visible to the naked eye, and there are many contacts in daily life. In the paint, it is manifested as: moldy surface, stinky smell, lower pH value, sedimentation and stratification, and lower viscosity. Anti-mildew method: fungicide.
2.”Enzyme” Specifically refers to cellulase, which is invisible but real and has a significant impact on coatings. The performance is: no mildew and no smell, sedimentation and stratification, viscosity reduction. Anti-enzyme methods: high temperature (>100°C) or ultraviolet radiation, biological stability of cellulose thickener.
3.If the viscosity reduction is caused by moldy and smelly paint, it is necessary to confirm whether the fungicide is invalid due to high temperature; if the paint is not moldy or smelly, and the viscosity is simply reduced, it is necessary to pay attention to the biological stability of the cellulose itself.
Analysis: Causes of coating viscosity reduction
1.Bacteria are introduced during the paint production process. Since bacteria need energy to reproduce, and cellulose is composed of glucose, it will be locked as a target food immediately. When the molecular weight of cellulose is too large, the bacteria use cellulase to hydrolyze the cellulose chain segment, and hydrolyze it into small molecular glucose units, and then absorb, reproduce, and accelerate circulation.
2.Paint manufacturers will use fungicides to kill bacteria and interrupt this cycle. However, water sources in nature will still bring in cellulase, and cellulase is also constantly hydrolyzing cellulose segments, but it happens relatively slowly without accelerating the cycle.
3.Anti-enzyme cellulose is not “mildew” but “enzyme”: in a coating system without high temperature and ultraviolet radiation, anti-enzyme can only rely on the biological stability of cellulose itself.
Cellulose thickener is currently the most important type of thickener in paint formulations. Its stability will directly affect the in-can state and application performance of the entire coating. Among them, the biological stability of cellulose thickener should be the most important consideration when customers choose cellulose products. Anxin Chemistry provides a full range of solutions for coatings, and will continue to bring more guidance in the field of coatings. Classic rheological smart choice, leading the water-based trend.
Post time: Apr-26-2024