Polyurethane clear coats for plastics – high gloss protection from environmental impact

Clear top coats for plastics protect against solvents, UV-damage, dirt and scratching. In addition they can be applied to obtain certain optical effects such as excellent gloss or matting of the desired degree.

Due to their outstanding property profile, polyurethane coatings systems have set the standard for plastic coatings throughout the world. They are crosslinking at low temperatures saving energy and costs. Another reason for their success is that they can be adjusted to the flexibility of the plastic substrate, allowing them to withstand the mechanical stresses of most plastic substrates.

A selection of coating raw materials for waterborne clear coats
Waterbased dispersions:

	Type	Solids in %	% OH on solids	Viscosity mPas at 23°C	Characteristics
Bayhydrol® A 2139/2	Polyester polyacrylate copolymer	48	3.8	1850	In combination with e.g. Bayhydur® 3100 for high-gloss solvent resistant top coats
Bayhydrol® A 2290	Polyester polyacrylate dispersion	45	3.6	< 200	In combination with Bayhydur® 3100 for high-gloss, solvent and tar resistant top coats, overcoatable, good mechanical properties
Bayhydrol® A 2058	Polyacrylate dispersion	42	4.8	1000	In combination with e.g. Bayhydur® 3100 for high-gloss solvent resistant top coats
Bayhydrol® U 241	Polyester polyurethane dispersion	41	2.5	1000	Good pigment wetting, high shearing resistance
Bayhydrol® A 145	Polyester polyurethane dispersion	45	3.3	950	In combination with polyisocyanates for high-gloss two-component polyurethane hydro clearcoats with high film hardness and weather stability
Bayhydrol® A XP 2645	Polyacrylat Dispersion	43	4.5	2000	For waterbased two-component polyurethane hydro clearcoats with good chemical and weather resistance
Bayhydrol® U XP 2750	Polyurethaen Dispersion	43	3.6	1000	For clearcoats and topcoats with very good weather resistance

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	Hardener for waterborne two component polyurethane systems and additive for waterborne high-quality coating systems
Bayhydur® 304	HDI polyisocyanate	100	18.2	4000	Hardener for waterborne two component polyurethane systems and additive for waterborne high-quality coating systems
Bayhydur® XP 2487/1	HDI polyisocyanate	100	20.6	5400	Cross-linker for waterborne two component polyurethane systems, developed for safe processing. Films with high chemical resistance
Bayhydur® XP 2655	HDI Polyisocyanate	100	21.2	3500	Hardener component for waterborne two-component polyurethane systems (easy mixing) and additive for high-quality waterborne coating systems
Bayhydur® XP 2759	IPDL- Polyisocyanate	70	11,0	6500	Hydrophilic crosslinker, in combination with HDI-based grades to enhance drying properties
Desmodur® N 3600	HDI Polyisocyanat (hydrophobic)	100	23.0	1200	Good chemical and weather resistance, good mechanical resistance

Find all Bayhydur® and Bayhydrol® grades in the "Product Search" section.

Some starting formulations for waterborne clear coats

RR PCO 0038e – CC	One-component polyurethane clear coat, for spraying (Bayhydrol® UH 2606)

RR PCO 0022e – CC	Two-component polyurethane clear coat, hard (Bayhydrol® A 145, Bayhydur® 304)

RR PCO 0023e – CC	Two-component polyurethane clear coat, elastic (Bayhydrol® U 241, Bayhydur® 304)