BYK Additives & Instruments


Dispersing a carbon black pigment

We are trying to disperse CABOT's carbon black XC72R in a standard epoxy system. The material is very fluffy and the the technical data sheet shows an oil absorption number of 174. Are there any of your additives that are suitable?

We recommend doing trials with BYK-9076 and BYK-9077 between 30-40% Additive (delivery form) on pigment, in your case carbon black.

Additive to increase thixothropic behavior and air release

Can I use GARAMITE-1958 thickener for an unsaturated polyester resin to have transparent glow for granite, and what quantity should I put in the system?

GARAMITE-1958 is used as a  rheology additive in unsaturated polyester systems. We have tested several types in our labs, but because GARAMITE-1958 is clay-based, we found a pseudoplastic flow which results in poor air release. In our trials we used 10 % of BYK-R 605 calculated on clay to get more thixotropic behavior, and as defoamer we used BYK-A 555. Alternatively, you should test fumed silica in combination with 20 % BYK-R 605 calculated on silica. You should start with a quantity of 3-5 % of the GARAMITE-1985 and 0.3-0.5% of silica in combination with BYK-R 605.

Solid surface applications

We are going to start producing solid surface from an unsaturated polyester resin. Please suggest your products for (1) air bubble removal (2) better flow of preparation in the mold (3) even color, glossy surface finish, etc. Could you please also suggest the sequence in which to add the products you suggest? Where can we get the material in India (your dealer or agent)? We request you provide further information on making solid surfaces.

We have several additives which will help in solid surface applications, assuming a filler load of approx. 75%: 1) Air release: For best air release we recommend using 1% BYK-A 555 (based on resin). Add the air release additive as soon as possible to prevent the formation of stable air in every following production step. 2) Viscosity and flow: To reduce viscosity and to improve the flow (or increase the amount of filler) you could use 1% - 1.5%  BYK-W 908 or BYK-W 909 (based on resin). Please note that BYK-W 909 is not REACH listed. This additive should be incorporated before the filler. 3) Leveling: To improve the leveling and the surface facing the air, we recommend using 0.5% BYK-370(based on resin).
If you have further questions, do not hesitate to contact us again. If you prefer contacting our agent in India, please refer to find all locations under

TIXOGEL applications

We are a cosmetics company in India and are trying to understand the chemical name and the specifications of Bentone gel yvs. Could you please let us have all technical information on this product by return mail.

Bentone gel is made by using a natural phyllosilicate, which is a powder. Suppliers are for example Elementis and BYK-Chemie. The trade name of the Elementis product is Bentone, the trade name of BYK-Chemie is TIXOGEL.  These additives are used to increase viscosity and to reduce sagging. A gel is made as follows: put 85 g of xylene into a cup and, while stirring with a dissolver, add 10 g of TIXOGEL. Disperse for 5 minutes, add 5 g of ANTI-TERRA-U or BYK-W 966 and disperse for another 5 minutes. Apply the gel on glass and check instantly if the gel is clear and without seeds. Now the dispersion is ready to use. Depending on the application normally 2-3 % of this gel is added. Pre-dispersed gels can be obtained from other additives as well. If the solvent is water, e.g. OPTIGEL can be used to improve the rheological properties.

Additionally with products as GARAMITE or CLAYTONE we offer organically modified phyllosilicates (Organoclays) which are ready to use and can be added directly into the formulation without the need to manufacture a gel.

BYK-410 and BYK-411 in unsaturated systems

Can BYK-410 and BYK-411 function in unsaturated polyester and styrene systems?

In general, BYK-410 and BYK-411 can be used in polyester resins. The limiting factor is the type of curing catalyst. As soon as you cure with cobalt salts, you should not use more than 0.3 % based on resin because the additive will form a complex with the cobalt salts. If you spray the formulation and the desired effect is to increase the sag resistance, the structure build-up after application may be too slow, which limits the achievable film thickness. In this case, other rheology additives should be considered. To prevent settling, 0.3% BYK-410 on resin should be used. If you want to avoid the NMP which BYK-410 and BYK-411 contain as a solvent, BYK-7410 ET  can be used instead. It consists of the same active substance, but contains an amide ether as the carrier.
If you have further questions, do not hesitate to contact us again.

Improve wetting of glass fiber in RTM project

We presently have an RTM project that has a 60-65 % fiber content, 1" thick pack of uni E glass. We are having problems wetting out the fiber. We have heated the resin and mold to 100°F which has helped. This is an unfilled vinyl ester we are utilizing for testing; we will be going to a styrenated urethan, "plexinate", for production. I have seen BYK-A 515 and BYK-W 985 on your website. What do each of these do? And will they be effective in the plexinate product? Any other thoughts in assisting the wet-out would be appreciated.

You already did a good search on our website. BYK-A 515 would be a good product, but we recommend you to use BYK-A 560 which is an improved version of BYK-A 515. BYK-A 560 will dramatically improve the wetting of the glass fiber and reduce air entrapments and porosity, and it will reduce the injection time of your RTM process! We would recommend to use 0.5 % BYK-A 560 based on resin. BYK-W 985 is another option, but for filled systems only.

BYK-R 605: Point of incorporation, influence on viscosity and rheology in UP resins

Is there any difference between BYK-R 605 being added before and after the fumed silica has been dispersed in an UP resin? Will thixotropy and viscosity be greatly affected?

BYK-R 605 is used as a rheology boosting additive in unsaturated polyester, epoxy and vinylester formulations in combination with fumed silica or organophilic phyllosilicates (organoclays). BYK-R 605 increases hydrogen bonding when combined with hydrophilic fumed silica or organoclays. It is possible to increase the efficiency of the rheology additives so that lower amounts of fumed silica or organoclays must be used. This leads to good anti-sagging properties with improved flow and de-aeration. In vinylester resins, BYK-R 605 activates hydrophilic fumed silica. Low dosages of BYK-R 605 (7 % based on fumed silica) will stabilize fumed silica in laminating resins and prevent the sedimentation during storage. Alternatively we recommend ANTI-TERRA-210 to stabilize fumed silica and to prevent the sedimentation during storage. The amount should be 5-20 % based on fumed silica. To achieve the best performance of ANTI-TERRA-210 and BYK-R 605, they should be added to the UP resin prior to the dispersion of fumed silica.
Post addition is also possible, but the boost effect will be slightly reduced.
We recommend using an air release additive (e.g. BYK-A 555) in combination with the recommended BYK-R 605 or ANTI-TERRA-210 to prevent entrapment of air due to the higher viscosities that will be achieved.

Additive for Retaining Gloss of Polyester Buttons

Please suggest any additive to be added in unsaturated polyester resin for cast / centrifuge button process to retain gloss and non-yellowing after making buttons.

The following additives can be used in button applications. In cast process: Usually air release additives are used, BYK-A 555 is the most powerful product here. If haze is a problem, BYK-A 550 is the one which should be tested. In centrifugation process: Here, BYK-S 706 is used to improve orientation of pearlescent pigments.

Improving paint adhesion on molded SMC parts

How can I improve the paint adhesion on my molded SMC parts?

We can recommend 4-5 phr of BYK-P 9085. This product was developed for low profile and class A SMC systems. It stabilizes the compound and improves flow behavior. Because of its excellent mold release properties in the tool, BYK-P 9085 completely replaces the traditional mold release products. The additive improves the surface quality of the molded part, the paint adhesion and bondability.

Reducing the scrap rate of molded SMC/BMC parts

Is there any possibility of using a BYK additive to reduce the scrap rate of molded parts?

Yes, BYK-P 9065 was developed for LS SMC/BMC systems. Therefore, if you use 2-2.5 phr and remove the conventional mold release product, you will reduce the scrap rate. This is because of decreased shrinkage which will lead to less warpage, an increased gloss and reduced haze, and improved color homogeneity and surface appearance of molded parts. Another benefit will be that there is no separation of the LS SMC/BMC compounds, which leads to reduced cobwebbing. No sanding is necessary after molding for parts to be painted or bonded. BYK-P 9065 is fixed in the cured resin matrix and does not migrate to the surface of the finished parts.

Preventing fogging in BMC headlamps

I have problems with fogging in BMC headlamps. What can I do to prevent this?

You can use 3-4 phr of BYK-P 9051 and remove the conventional mold release products from your formulation. BYK-P 9051 is an additive to facilitate processing of BMC/DMC. It also has mold release properties. The product does not contribute to fogging. In BMC for headlamp reflectors, it minimizes fogging of the molded parts and is becoming a standard in the industry.

Additive for flame retardancy and viscosity reduction in SMC systems

I need to fill my SMC formulation up to 350 phr of ATH to achieve a specific flame retardancy. Therefore, I have tremendous problems with the viscosity so that it is impossible to produce an SMC on the machine. Is there an additive that can help?

Basically, we have 2 wetting and dispersing additives. BYK-W 9010 is solvent-free and contains 100% active substance for wetting and dispersing of fillers (and inorganic pigments) where solvents must be avoided. We also have BYK-W 996 which is an universal and cost-effective wetting and dispersing additive for almost all applications. It is particularly effective in systems highly-filled with ATH. In your case, where an extremely high amount is needed, we can also recommend a combination of 1:1 (BYK-W 996 : BYK-W 9010). This is possible where high amounts of an additive are required, as in your situation.

Wetting and dispersing additive for unsaturated polyester systems

Can you please suggest a wetting and dispersing agent for an unsaturated polyester resin? We are loading 20-30 % of barytes in resin.

For your purpose I would propose the use of our wetting and dispersing additive BYK-W 980. BYK-W 980 is a solution of a salt of unsaturated polyamine amides and acidic polyester and it improves the dispersion of a wide range of the most common fillers in UP resins. It reduces the viscosity, so that a higher filler loading is possible, and it helps to prevent sedimentation.

Additive to improve substrate wetting of a gel coat

I am looking for an appropriate wetting agent for a resin-based gel coat application. I believe it used to be BYK-909 but I could be wrong.

For this application we recommend the following additives: BYK-330, BYK-A 525, BYK-306.

Improving carbon fiber wetting in SMC compound

How can I improve the carbon fiber wetting in my SMC compound?

Tests show an excellent wetting of C-fibers in formulations when the additive BYK-9076  is used. BYK-9076 is also a good wetting and dispersing agent for acidic and neutral carbon blacks.

Improving the bonding of two Class-A SMC parts

I need to improve the bonding of two Class-A SMC parts. Do you have any additive which can help here?

The usage of BYK-P 9085 will improve the bondability of the molded parts. BYK-P 9085 was developed for Low Profile and Class A SMC systems. BYK-P 9085 completely replaces the traditional mold-release products.

Avoiding wet areas on the surface of SMC compound and cob webbing

When I take off the carrier film of my SMC compound I found wet areas on the surface of the compound and have problems with cob webbing. What can I do?

Using BYK-9076 will prevent phase separation of all kinds of mixtures of UP resin with thermoplastic components. This means the wet areas which are caused by separations will not show up as also the cob webbing, which is caused by separated thermoplastic components, will disappear.

Wetting out glass fiber in SMC systems

When I increase the filler load of CaCO3 in my SMC formulation I get problems in wetting out the glass fiber. Could be the reason that the viscosity is too high?

BYK-W 9011 will improve the wetting and dispersing of a wide range of the most commonly used fillers such as calcium carbonate. It will reduce compound viscosity so that a higher filler loading is possible. Additionally will the reduced viscosity improve the fiber impregnation. The improved wetting and dispersing of fillers will result in a better homogenity of the compound and will also improve the batch to batch reproducibility.