BYK Additives & Instruments

Architectural Coatings

Can you suggest some additives to me with regard to the improvement in stain resistance, matting & elongation in interior coating? I am currently working on a water-based pure acrylic matt paint system with ~40 PVC. I want the sheen at 85° gloss head less then 10 units. I am also interested in an adhesion promoter which has good adhesion to masonry surfaces.

Many thanks for your request in our Technical Forum. The property of stain resistance and elongation come in the first instance from the resin and cannot be greatly influenced by the addition of additives. For the matting effect in your water-based acrylic system, we suggest the following additives: CERAFLOUR 920, AQUAMAT 272 either alone or in combination with AQUAMAT 208. A further very important factor is the influence in particle size. The greater the package density of your matting agents, the better your stain resistance will be. We therefore always combine different particle sizes in these formulations. For adhesion to masonary surface, we propose using our BYK-4500. Technical Service Support.

I am preparing some samples to test with an UV / weathering tester. I figured that it is possible to use the desmodur N3400 and N3600 as a clear coating. To harden the desmodur I have used a tin catalyzer. My problem is as follows: When I apply the coating to its surface it will quickly start to crater (Marangoni Effect) - this is an unwanted effect. What can I do to stop this?

To avoid cratering during application, please use a silicone-based additive such as BYK-333 alone or in combination with an acrylic-based additive such as BYK-358 N.
Technical Service Support

We prepare a tint base using DISPERBYK-182 to disperse red iron oxide, yellow iron oxide, and phthalocyanine blue. We notice dark spots in the coating when we blend this tint base with a latex and a white tint base (TiO2 and kaolin clay dispersed with Tamol 731A). The black spots are less evident in the presence of high amounts of hydrophobic cosolvents, and is not observed with all latexes. Could you recommend an alternate dispersant for the colored pigments?

Try using DISPERBYK-185 instead of DISPERBYK-182. Use this additive in combination with DISPERBYK-102. Reduce the pigment content in the formulation. In the let-down of the base paint, put in a wetting agent such as DISPERBYK-187 with a dosage of 0.2-0.4 on total formulation. Do not use a mineral oil-based defoamer in the base paint because it can be the reason for bad colorant acceptance.
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Is there a BYK additive that will help improve household stain resistance in an interior matt wall paint? The paint is based on a 100% acrylic binder with a PVC of 55%. I've tried some flouro-surfactants and ceramic pigments which improve the stain resistance but not nearly enough!

To improve the stain resistance with our additives, you can try a wax emulsion or a combination of a wax emulsion with a silicone-based additive. Try with 2% of AQUACER 539 and AQUACER 513 and make a combination of these waxes with 0.02 BYK-333.
Technical Service Support

I develop alkyd-based varnish for outdoor furniture and to reduce surface tension, improve wetting on oily wood surfuce (some hardwood). I use BYK-337 at a dosage of 0.2-0.25% weight of total formulation. I cannot check for recoatability but I have found some poor adhesion and drying time, so I want to know the influence of BYK-337 on adhesion, drying time, recoatibility, etc. Did I use the right additive for my purposes? Is there possibly a better one? I also develop lacquer base on acrylic thermoplastic, so could you recommend additives for this?

If you are using BYK-337 in an air-drying alkyd and recoat with the same paint, normally you will not have problems with intercoat adhesion and recoatability. If you recoat with a paint without BYK-337, it can happen that you get poor wetting of the first coat. Poor adhesion and longer drying time can be due to the oil you have on the substrate. During the application it can be partly mixed in your paint. BYK-337 is a good choice for your application. If you like to use less active ones with regard to surface tension reduction, you can try using BYK-335 and BYK-320. For thermoplastic acrylics, several additives are possible. As wetting and dispersing additives you can try DISPERBYK-163, DISPERBYK-110, ANTI-TERRA-U, BYK-P 104, ANTI-TERRA-204, depending on the pigmentation you have. As defoamers you can try BYK-088, BYK-055, BYK-066 N. For leveling: BYK-337, BYK-315 N, BYK-331, BYK-310.
Technical Service Support

We have a water-based 70% extender + 5% binder combination filler compound. We are using a dispersant at 0.1% on formula with bermocoll E351CQ @ 0.13%. The batch is done on a sigma mixer. During 3 months of storage we have observed water separation and settling with lump formation which is hard to stir back. Can you suggest your cost-effective additives for this high PVC formula and dosage of bermocoll, and the procedure to disperse the RMs?

To make an extender slurry I would disperse with dissolver 20 min. or longer until I reach the fineness I need for the application. We do not know the sigma mixer. Disperse only in water with a dispersing additive such as BYK-154 or BYK-151 and the thickener and put in the resin after dispersing. A cellulose-based thickener is the cheapest one. In our product line you can test BYK-425. I do not know whether the dosage of the Bermocoll is right because we do not have expierence with such types of additives. The reason for your problems could be poor dispersing, not using dispersing additive and/or too low a dosage of Bermocoll, or that this is not the right additive for this application at all.
Technical Service Support

Please instruct me regarding the dispersion of pigment in an aqueous system, especially emulsion acrylic. I tried to use BYK-346 to improve the wetting surface for wood coatings by emulsion acrylic, but the results did not come up to my expectations.

To produce emulsion paint: Put water in a container, mix in a defoamer such as BYK-023, put in a dispersing additive such as BYK-154. Under stirring with dissolver, put in TiO2 and extenders. Disperse for 20 min. at high speed. Check if the fineness is good for your application. Complete the paint with the emulsion, thickener, preservative, co-solvent, defoamer. If BYK-346 is not good enough for substrate wetting, it could be that you have not used the right dosage, or the co-solvent content is too low. Then change to BYK-348. An alternative option is to use BYK-DYNWET 800 N instead. A combination with a silicone-based additive such as BYK-333 can also help.
Technical Service Support

At the moment our primer is made up of PVA and aqueous synthetic pigments, it is OK for porous surfaces but is very thin and poor in color and runs quite quickly when applied to the likes of MDF or any non-porous surface. I would appreciate any technical help you could give regarding additives that could provide our primer with a better coverage and body.

As a wetting and dispersing additive, we recommend BYK-154. For good defoaming, BYK-012 added to the grinding, and BYK-028 added to the let-down should be used. A leveling additive such as BYK-345 is not helpful because of foam stabilization. With BYKETOL-WS, the leveling can be improved in many systems.
Technical Service Support

How can we prevent foam formation while applying solvent-borne high-solid deco paints? Thanks in advance for your answer & kind regards!

Our best defoamers for solvent-borne alkyd paints are BYK-066 N, BYK-052 and BYK-065. Start your trials with a dosage of 0.3-0.5% on total formulation. Also the use of the right wetting and dispersing additive helps in reducing foam formation. Try DISPERBYK-107 and use as little rheological modifier as possible.
Technical Service Support

Which is the most suitable additive to improve colorant acceptance in acrylic based emulsion paints? Darkening of the shade was noticed when doing a rub-up test with a combination of violet and yellow oxide colorant paste in the paint base. There is a range of paints with varying PVCs, so please make your recommendation PVC-specific.

The following wetting and dispersing additives and dosages are recommended in order to improve the color acceptance for acrylic emulsion paints. Dosage: % delivery form on total white paint - DISPERBYK-187 (0.5-2.0) -BYK-151 (1.0-3.0) - BYK-154 (1.0-3.0) - DISPERBYK-192 (1.0-3.0) - DISPERBYK-102 (0.5-2.0) (in our experience, pre-diluted and incorporation with higher speed) - DISPERBYK-2095 (1.0-3.0) - DISPERBYK-2096 (1.0-3.0). Please control the drying property in each case and test all additives, independent of PVC.
Technical Service Support

We are experiencing problems when adding universal, glycol-based colorants (specially black) to alkyd bases. A major kick-out (seeding) problem occurs just after adding 12 ounces of colorant to a clear alkyd base. The problem is present even when adding less than 2 ounces of black colorant, independently of doing a mild, slow stirring or a vigorous shaking of the paint. Based on these results, the possible microfoam origin of the defect has been discarded. A reading on the Hegman gauge results in 1 Hegman in all cases. The sprayed panels look badly seeded (uniform seeding) all over. I wonder if an additive like DISPERBYK-108 could help to compatibilize the universal colorants with the oil-based vehicle. I would like to hear any comment you may have regarding this.

We have only lab expierence in improving colorant acceptance of white alkyd bases. One possibility is to use DISPERBYK-108 in the grinding, the other is to use DISPERBYK-109 as post-addition additive. To improve colorant acceptance in a clear, please try DISPERBYK-108, ANTI-TERRA-U, DISPERBYK-187, DISPERBYK-102, DISPERBYK-109, BYK-220 S 0.5-1.5% on total formulation. Or is it possible to put extra additive in the black colorant? Then try DISPERBYK-102. It is also important that there are not any great differences in viscosity of paint and colorant. You will also achieve an improvement if you put in the colorant first and add the alkyd slowly under stirring. The worst result will be obtained if you have a low viscosity alkyd and a high-pigmented high-viscosity colorant and put the colorant on top of the alkyd base and start stirring after 5 minutes. Try to optimize the conditions.
Technical Service Support

Could you tell whether propylene carbonate can be used as material of bentonites and is there any relationship between them?

Propylene carbonat is used as a polar activator for bentonites. In our opinion, you obtain a better gel and better performance in the paint when using a wetting and dispersing additive such as ANTI-TERRA-204, ANTI-TERRA-U, BYK-P 104 or others instead of propylene carbonate. Bentonites are in powder form, and only a few have a special treatment so that they can be incorporated directly in the paint. With the others a gel has to be formulated before usage to avoid seeding and uncontrolled viscosity increase during storage.
Technical Service Support

As you know and have told me already, the base of bentone is bentonite (inorganic material). Is there any gelling agent with organic base, so that when we fire it at 800°C it won't leave any residue?

Additives of ours which are used to make a bentonite gel are ANTI-TERRA-U or ANTI-TERRA-204, and others. The gel has the following formulation: solvent 85 g, bentonite 10 g, additive 5 g. Put the solvent in a container, stir with a dissolver, put in bentonite under stirring, disperse it for 10 min. at high shear. Put in the additive under stirring and disperse for 2-5 min. Apply on glass to check if you have a proper gel without seeding. If our additives are completely burned at 800°C, I cannot say why because we have not made thermograpic analyses up to such temperatures.
Technical Service Support

Please recommend a suitable additive for making a solvent-based medium oil alkyd to resist foam in processing.

As defoamer for medium alkyd you should test our BYK-066 N and BYK-052.
Technical Service Support

In a long oil alkyd-based system we have some difficulties in the dispersion of some difficult pigments. These are carbon black and phthalocyanine for example. Can you offer us a non-polymeric and high polymeric weight dispersant for this application?

For dispersing pigments in long oil alkyd you can try DISPERBYK-108, DISPERBYK-115, DISPERBYK-116, DISPERBYK-174, DISPERBYK-164 and DISPERBYK-182. I recommend you first do a compatibility test in your alkyd resin and in a clear coat formulated by your resin. Put 5% of the additive in each and check which one gives a clear solution without seeding. Use these ones in dispersing your pigments.
Technical Service Support

We are producing waterbased paints. In most cases it is only white combined with tinters, but sometimes we need also iron oxide pigments. What is the best product?

DISPERBYK-199 provides a strong viscosity reduction in the mill base combined with an excellent pigment wetting. The color acceptance of the white base is very good even with universal tinters. The product can be used for Iron oxide pigments, also for transparent iron oxide types.

I am looking for an environmentally friendly deaerator for epoxy flooring systems. My coating has to pass AgBB.

BYK-1794 is a VOC free polymer defoamer with strong spontaneous deaeration / defoaming properties in 100% solid systems. In epoxy floorcoatings AgBB standard as well as Swiss and French regulations are fulfilled.

I have been using mineral oil defoamers for a long time. Nowerdays my customers are more critical and are complaining fogging and bad smell.

BYK-014 shows an excellent defoaming performance in various dispersions such as acrylates or VAE´s (vinyl acetate ethylene). BYK-014 is emission-free and creates no fogging. It is recommended for water-borne interior and exterior dispersions in a PVC range from 30 to 85 and it is suitable for a wide pH range from 3 to 12. Being quite universal BYK-014 works equally well in plasters and adhesives. It has no negative influence on yellowing, color acceptance or odor. BYK-014 is highly economical and easy to incorporate.

Our product portfolio is changing more and more to VOC-free coatings. We need an additive for a universal coating which provides good substrate wetting on solid wood, on primers, and on old coatings.

BYK-349 is a silicone surfactant especially developed for VOC-free coatings. The advantage of this additive is highly efficient spreading, substrate wetting and leveling. Strong reduction of surface tension combined with very low foaming tendency are the key benefits.

I am looking for a polymer defoamer which does not need high sheer force. It has to be VOC-free.

BYK-1710 is a polymer defoamer with hydrophobic particles. The defoaming properties are spontaneous and excellent. The additive is VOC-free (<1500 ppm headspace GC) and fufills common directives. BYK-1710 is easy to incorporate, and therefore can be used at all stages of production process.