Covestro Bayhydrol A 145 Waterborne acrylic polyol dispersion High-gloss varnish Color paint and anti-corrosion primer

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Type	Water-diluted hydroxyacrylic dispersion
Form of Supply	about 45%in water/solvent naphtha100/2-Butoxyethanol solution, neutralized with dimethylethanolamine, the ratio is about 45.6 : 4:4：1.4
Purpose	Admixture with aliphatic polyisocyanates to prepare waterborne two-component clear and topcoats for automotive refinishing, heavy vehicle finishing and industrial painting. Mixed with amino resins or blocked polyisocyanates to prepare waterborne one-component industrial baking coatings

Product Specifications

Features

Value

Measurement unit

Method

Content of non-volatile components

(1g/1h/125℃/Convection oven)

General performance

Bayhydrol® A 145 is a dispersion of hydroxyl-functional polyacrylic acid which can be diluted with water to the application viscosity. The viscosity of this product depends mainly on the pH value. Since the pH may decrease during storage, the viscosity may decrease accordingly. Its viscosity can be restored to its original value by adding a small amount of 10% dimethylethanolamine aqueous solution.
Bayhydrol® A 145 has good pigment wetting and high shear stability. Experiments have proved that bead mills are suitable for use as grinding equipment. Only pigments and fillers with small water-soluble components can be used. Considering the wide variety of pigments and fillers available, the compatibility of the products should be tested when using them. Leveling and substrate wetting can be improved by adding eg BYK® 380 or 348.
Experiments have shown that BYK® 011 is suitable as a defoamer.
Construction and paint dispensing equipment can be cleaned with water, alkaline detergent or isopropanol.

Two-component industrial coatings
Bayhydrol® A 145 can be mixed with aliphatic polyisocyanate to prepare a high-gloss topcoat that can be dried at room temperature or force-dried at 80°C. The cured film is tough with good one-coat adhesion and good water and solvent resistance. If properly formulated, eg mixed with Bayhydur® 3100 in an NCO/OH ratio of 1.5:1, the pot life is about 3 hours. The pH value of the prepared paint should be 7.8~8.3.
When mixing Bayhydur or Desmodur ® into the millbase, a thickener is added to ensure high shear. Experiments have shown that about 0.3% of Acysol® RM 8 (based on solid base) can be added to formulations based on Bayhydrol® A 145.

One-component industrial baking coating
Bayhydrol® A 145 is used in combination with melamine resins to prepare baking coatings with a co-solvent content of less than 5% at the application viscosity. The system cures in just 30 minutes at 120°C.

The mixing ratio of Bayhydrol® A 145 to amino resin is generally 80:20 (both on a solid basis). Considering that there are many kinds of amino resins, the miscibility of the products should be tested when using them. As a hydroxyl-functional binder, Bayhydrol® A 145 is also suitable as a coreactant for waterborne aliphatic polyisocyanates such as Bayhydur® BL 5140 and BL 5235.
The ratio of OH:NCO should be 1:1.
To ensure the storage stability of those one-component coating systems based on Bayhydrol® A 145, the pH is adjusted to approx. 8.5 during preparation.

Save
Stored in the original sealed container at 5~23℃, Bayhydrol® A 145 has a storage stability of at least 6 months. Bayhydrol® A 145 freezes below 0°C and damage is not excluded. So it should be stored antifreeze.

Safety: Hazard Identification
Flammable. Harmful to aquatic life, may cause long-term adverse effects in the aquatic environment.
The Safety Data Sheet (304240) should be read carefully. It includes labelling, transport, storage, product use, product safety and ecological information.

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