Stain-blocking paints and -impregnations
with NECOWELTM alkyd emulsions

Excellent performance,
first-class application andenvironmental compatibility.
Tailor-made for you.

As a specialist in very efficient alkyd
emulsions for water-based paints
and -impregnations with high stainblocking properties, ASK Chemicals
offers a wide range of solutions for thisarea. In addition to excellent performance,
highly efficient binding agents from ASK
Chemicals also feature very good environmental compa­tibility and top-class application properties. This makes them ideal forswitching from solvent-based to waterbased systems without having any compromise on performance.

Your benefits at a glance: ood product quality thanks to high performanceG
resin systems
 op - class customer service, tailormade
Tmodifications and refinement
 ur alkyd emulsions are based on natural oils
Oand feature a high percentage of renewable raw
materials.
 ECOWEL™ products are VOC-free and meet allNenvironmental-friendliness and occupational healthand safety requirements.

NECOWELTM 4300 and NECOWELTM 4400 —stain-blocking paints and -impregnations
The appearance, easy handling and healthfriendliness are the decisive criteria in theproduction of interior wall paints. A particularchallenge is posed by bleeding substances;these water-soluble coloring agents can evenbe transported to the paint surface throughseveral layers of paint. While conventional resin
dispersions do not exhibit any stain-blocking
properties against these substances, cationicresins can fix this contamination in the paint surface and prevent bleeding. However, usage ofthese resins normally results in reduced paintformulation quality.

Nevertheless, during oxidatively drying process
SVOC in form of hexanal and other aldehydes issplit of. NECOWEL™ 4400 is based on saturated fatty acids having non-yellowing performance and less odor formation.

ASK Chemicals has succeeded in integrating
cationic groups into a more or less anionic alkyd
resin system. The result is a stable paint systemwith outstanding stain-blocking properties against
anionic contamination like water spots, markers
and also wood ingredients like tannin and phenol. Alkaline contamination such as nicotine arealso neutralized and fixed by the acidic groups
in the resin system.

NECOWEL™ 4300 and NECOWEL™ 4400 are
known for their easy and secure handling as wellas their good compability with coating raw materials, filling materials and tinting pastes.

NECOWEL™ 4300 is used in the formulation ofstain-blocking wall paints as well and it is highly
applicable to be used in stain-blocking primers.
The stain-blocking primer has good drying properties and can be coated with a common wall
paint afterwards. No bleeding of water-soluble
substances will occur into the wall paint.

Stain-blocking paints and primers
In order to demonstrate the influence of thebinder on bleed through, a surface painted withwater-based markers was over coated with anacrylate-based paint and a paint based on
NECOWEL™ 4400. Apart from the binder, thepaint formulation was identical. The paint basedon NECOWELTM 4400 delivers a much better
result after one layer than the acrylate-based
paint after two layers.
Alkyd emulsions based on drying fatty acids
tend to exhibit yellowing and odor formation
whereas NECOWEL™ 4300 based on dehydrated castor oil (DCO) is known for its very low
yellowing tendency.

Wall paintbased onacrylates:
1st layer

Wall paintbased onacrylates:
2nd layer

NECOWEL™
4300:
PrimerFigure 1: Application of NECOWEL™ 4300 andNECOWEL™ 4400

NECOWEL™
4400:
Wall paintTannin-blocking impregnation forwood surfaces
It is a well-known problem that dark spots
can appear on the coating surface after awooden surface has been painted. On whitewooden surfaces these stains are especially
noticeable. Bleed-through of water-soluble
wood constituents, such as dyes or tannins,
can normally be prevented if the wood substrate is pre-treated with a coating based ona cationic dispersion or cationic additives.

part (bottom) of the wooden panel can beclearly seen on all panels.
The stain-blocking impregnation based on
NECOWEL™ 4300 prevents the bleedthrough of the wood constituents evenunder extreme weather conditions.

In addition to an excellent stain-blocking
effect against water-soluble impurities,
(A)
(B)
(C)
NECOWEL™ 4300 also exhibits very good
Merbau panel
With a white
After 72 hours
topcoatexposure to thewetting and penetration properties, with thecondensation
result that it is able to penetrate into thewater test
wood fibers well and take effect there.
Figure 2: Application of NECOWEL™ 4300 as
Tannins and other wood constituents aretannin-blocking impregnation
fixed directly in the wood layer and do not
emerge at all from the wood substrate to thesurface. Bleed-through to the painted coating surface is thus prevented, even after
cracking of the wood or after damage tothe coating surface.
The waterborne impregnation is non-filmforming and can be sanded and overpainted after a drying time of approx. 4 hours.
In Figure 2, three Merbau panels from theASK Chemicals laboratory can be seen.
Half of each panel is treated with the stainblocking impregnation to prevent a bleedthrough. The middle sample (B) has been
sanded 4 hours after impregnation andpainted with a white topcoat. The righthand sample (C) has been subjected to acondensation water test for 72 hours after
being painted. The color difference between the treated part (top) and untreatedNECOWEL™ Properties and technical data:

NECOWEL™ – Stain-blocking paints and -impregnations
Product

Type of oilProperties and special features

NECOWEL™ 4300

Spec. fatty
acids

Excellent stain-blocking effect, good application
properties, can be used as a stain-blocking primer
and paintNECOWEL™ 4400

Saturatedfatty acids

Excellent stain-blocking effect, very low smell,no yellowing potential

NECOWEL™ 4300 und 4400 – Benefits• Unique stain-blocking properties• Compability with carbonates• Easy-to-formulate• Good wetting behavior• VOC-freeASK Chemicals GmbH
Reisholzstraße 16 – 1840721 Hilden, Germany
Phone: +49 211 71 103-0
Fax:+49 211 71 103-35
specialties@ask-chemicals.com
www.specialties.ask-chemicals.com

This information is based on our current state of knowledge and does not represent assurance of the properties of the products described. We are only liable for
product-related advice and information within the scope of duties of disclosure included in collateral contractualagreements unless expressly agreed otherwise. (02 / 19)

Technical datasheets and guide formulations are provided
on our website specialties.ask-chemicals.com.