BRB International Silicone Additives, Silanes and Intermediates

Selection and quotation of BRB International materials: Siloen paint additives, heat-resistant resins, Silanil silanes, water repellents, Sempure emulsions, Akasil antifoams and RTV-2 intermediates.

Siloen Additives for Paints and Varnishes

Under the Siloen brand BRB supplies siloxane additives for wetting, levelling, slip, mar resistance and foam control. WA 264 lowers the surface tension of waterborne coatings, LA 271 improves levelling and slip, while SMA 287 and SMA 283 add slip and anti-blocking.

WA 264: wetting at pH 4–10
LA 271: 100% active silicone polyether
SMA 287: 52% aqueous emulsion
DA 291: defoamer for the grind stage

Heat-Resistant Silicone Resins

Silicone resins serve as binders for industrial coatings and marine paints that resist heat, UV, weather and corrosion. Solvent-less SR 833 oligomer cures with ambient moisture and withstands up to 650 °C. Vinyl-functional VMQ resins raise the hardness of clear RTV-2 systems.

SR 833: heat resistance up to 650 °C
SR 833: ambient moisture cure
SR 833: ovens, pipelines, auto parts
VMQ resins: harder RTV-2 systems

Silanil Organofunctional Silanes

Silanil silanes act as adhesion promoters, coupling agents and crosslinkers in paints, sealants, adhesives, wire and cable, fiberglass and foundry resins. The range covers amino silanes 138, 505 and 919, bis-silane 829, epoxy silane 260, mercapto silane 442 and phenyl silane 299.

Silanil 829: six hydrolysable groups
Silanil 505: releases ethanol on hydrolysis
Silanil 442: lower Mooney viscosity
Silanil 299: refractive index 1.468–1.475

Silane Oligomers and Waterborne Silanes

Silanil oligomers release fewer byproducts than monomers. Silanil 1479 is a diamino and alkyl silane co-oligomer for MS polymer and polyurethane adhesives, Silanil 533 ESO is an epoxy oligomer for waterborne systems, and Silanil 581 is an aqueous aminosiloxane from about 40% Silanil 919.

Silanil 1479: less yellowing
Silanil 533 ESO: gamma-glycidoxy groups
Silanil 581: about 40% Silanil 919
Silanil 581: glass fiber binders

Water Repellents for Concrete and Masonry

For building materials Siloen offers silane-siloxane concentrates, water-based emulsions, creams and powders. SR 619 is diluted in solvent to impregnate brick, concrete and plaster, 5022 WR is a masonry emulsion, 882 goes into cement slurry and MXP5 powder into dry mix mortars.

SR 619: dilution 1:11 to 1:15
Siloen 882: 0.1–0.5% of solids
MXP5: powder for dry mix mortars
5022 WR: diluted 1:9 in water

Sempure Silicone Emulsions

Polydimethylsiloxane emulsions serve as mould release agents, polish ingredients, water repellents and lubricants. Sempure 35 and Sempure 60 carry 35% and 60% medium viscosity oil, HV 6500 combines medium and high viscosity oils, and SMA 288 is a 60% anionic emulsion for wood varnishes.

Sempure 35: 35% active
Sempure 60: 60% non-ionic emulsion
LC grades: D4, D5, D6 below 0.1%
SMA 288: 60% anionic emulsion

Akasil and Siloen DA Antifoams

Siloxane-based Akasil antifoams serve water-based, solvent-based and solventless systems. FD and PS series come at 10, 20 and 30% activity, ADP 300 with 100% active content targets non-aqueous systems, 2107 and 7107 serve refinery operations, and DA 293 high PVC paints.

FD and PS series: 10, 20 and 30%
ADP 300: 100% active content
Akasil 2107 and 7107: 30% and 20%
DA 293: paints at PVC 60–85%

Intermediates and RTV-2 Polymers

For silicone formulators BRB supplies polydimethylsiloxanes, H-siloxanes, D4 to D6 cyclics, silanol fluids, gums, HMDZ, Vinyl M2 and vinyl dimethicones. Mono Vinyl fluids from 500 to 10,000 cSt plasticise thermal interface materials, and B300 contains pre-dispersed silica.

OH Fluid: silanol fluids 40 and 70 cSt
HMDO: silicone oil 0.65 cSt
Mono Vinyl: 500 to 10,000 cSt
Vinyl dimethicones: volatiles below 0.5%

Adding Siloen Additives at the Right Paint Stage

The manufacturer specifies the addition stage for each additive. DA 291 defoamer and deaerator goes in at the grind stage under high shear: it is highly incompatible and needs intensive mixing for good distribution. LA 271 is added at the let-down stage or as a post-additive.

WA 263 wetting agent (50% polyether-modified polysiloxane in diethylene glycol monoethyl ether) is recommended in post-addition but can be added at any stage. WA 264 suits systems without co-solvents and has minimal foam stabilization.

In high PVC waterborne paints (PVC 60–85%) DA 293 is added at 0.1–0.5% w/w of the total formulation.

Dosing Water Repellents for Concrete and Masonry

SR 619 is diluted 1:11 up to 1:15 before application in white spirit, or in anhydrous isopropanol near solvent-sensitive materials such as PVC windows; the ratio depends on substrate porosity. The tin catalyst free concentrate resists alkali and suits concrete, sand lime brick and mineral plaster.

Siloen 882 is not water thinnable: it is added under high shear directly into the cement slurry at 0.1–0.5% by weight of the solid content. MXP5 powder goes into dry mix mortars, joint fillers, plasters and grouts and improves durability against freeze-thaw de-icing salt stress.

5022 WR emulsion is diluted 1:9 in demineralized water.

Ethoxy or Methoxy Silane: Choosing by Released Alcohol

Methoxy silanes hydrolyse faster and release methanol, while ethoxy silanes give slower, more controlled hydrolysis, release ethanol and usually have longer shelf stability.

That is why the manufacturer offers the triethoxy epoxy silane Silanil 260 instead of Silanil 258: hydrolysis splits off ethanol, not methanol. The diamino silane Silanil 505 also releases ethanol but reacts as a strong base due to its two amino groups, which the formulation has to allow for.

Silanil 533 ESO oligomer releases less methanol than monomeric epoxy silanes and is more stable in water-based products.

RTV-2 Crosslinking: Vinyl Dimethicones and SiH Crosslinkers

In addition-cured RTV-2 systems vinyl dimethicones react with SiH crosslinkers under platinum-catalyzed hydrosilylation. The SiH content of the crosslinker sets crosslink density: more SiH gives a stiffer network, faster cure and more shrinkage.

Low-viscosity crosslinkers give good flow, uniform cure and longer pot life, high-viscosity ones stiffer networks for structural silicones.

VMQ resins raise the hardness of the cured product, mono-functional Mono Vinyl fluids lower viscosity and hardness without plasticizer migration, and B300 eliminates silica dust when adding reinforcing filler.

BRB International and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of BRB International and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.