Polyurethane wall coatings - More than protection

Wall coatings not only protect against moisture and aggressive substances, such as acidic gases, but they need to be compatible with the physical requirements of the building. Polyurethane based coatings offer interesting advantages for both interior and exterior wall coatings. Polyurethane systems can provide specific properties to the wall coating, e.g. a particularly good chemical and/or solvent resistance. Therefore polyurethane wall coatings provide a very durable protection for a very long time.

Polyurethane-based coatings are characterized by a specifically adaptable "hard-soft-segmentation" which results in good flexibility over a large range of temperatures. Consequently, small cracks can be bridged better compared to coating systems based on other raw materials. Moreover, polyurethane coatings show a good solvent and chemical resistance which provides durable protection for a long, long time. With correct formulation they are more or less watervapor permeable and show only little take-up of water.

Select raw materials for wall coatings:

Solventbased:

	Type	Solids in %	% NCO or OH on solids	Viscosity mPas at 23°C	Characteristics
Desmophen® 651 MPA/X	Polyester	67	8.2 OH	25000	Outstanding lightfastness, gloss and weather resistance, very high chemical resistance, high wear resistance.
Desmodur® N 75 MPA/X	HDI biuret	75	22.0 NCO	250	Good gloss, chemical and weather resistance, lightfast, good mechanical resistance.
Desmodur® E 1361 MPA/X	TDI Prepolymer	61	11.1 NCO	500	Resistant against moisture, oils, fuels and aggressive chemicals. For the impregnation of substrates of mineral construction material

Waterbased:

Dispersion:

	Type	Solids in %	% OH on solids	Viscosity mPas at 23°C	Characteristics
Bayhydrol® A 242	Polyacrylate	42	4.0	200	For waterborne two-component polyurethane coatings with good and balanced properties.

Polyisocyanate crosslinker for waterbased dispersions:

	Type	Solids in %	% NCO on solids	Viscosity mPas at 23°C	Characteristics
Bayhydur® 3100	HDI Polyisocyanate	100	17.4	2800	Easy to emulsify (hydrophilic) into the water phase.

Some suitable starting formulations

RR 5406	Pigmented primer for wall and facade coatings, e.g. on concrete, plaster, etc. (Desmodur® N 75 MPA/X)
RR 5445	Low-solvent penetration primer for mineral substrates (Bayhydur® 3100)
RR 5436	Low-solvent, pigmented, matte topcoat for mineral substrates (Desmodur® N 3400)
RR 5446	Waterborne, pigmented, satin-finish topcoat for mineral substrates (Bayhdrol® A 242 / Bayhydur® 3100 / Desmodur® N 3400)

Take a look at this information also:

“General remarks on Desmodur®/Desmophen®-starting formulations for 2K polyurethane wall coatings”

Easy-to-clean Systems

Bayer MaterialScience offers raw materials for easy-to-clean wall coatings also. They are often required in public areas, day care centers, athletic facilities etc., where the application of conventional latex paints is oftentimes not sufficient. The effects and the application of easy-to-clean coatings are subject to many conditions and every situation requires an individual discussion. Please contact our experts for easy-to-clean systems in order find the proper solution for you.