Trimethylsiloxysilicate (and) Polypropylsilsesquioxane (Flake Resin)

What is Flake Resin? Trimethylsiloxysilicate (and) Polypropylsilsesquioxane is a product made by Dow chemicals; they call it “DOWSIL™ MQ-1640 Flake Resin”. TKB Trading sells it as “Flake Resin”.

Dow describes this product as “a unique combination of MQ and T propyl silicone resin. This combination of resin technologies has been especially developed to provide both excellent transfer and wash resistance combined with a flexible film and comfort of wear in skin and cosmetics applications. Even with stretching and washing the film formed by this product remained smooth and undamaged. In sunscreens it enhanced the SPF wash off resistance.” (source)

You can find Trimethylsiloxysilicate (and) Polypropylsilsesquioxane in tons of different long-wearing cosmetic products where it improves wear time and rub-off resistance. Examples include Fenty’s Sun Stalk’r Instant Warmth Bronzer, Sephora’s Lip Last Matte Lipstick, ITEM Beauty’s Air Hug Clean Lightweight Full-Coverage Concealer, Kaja’s Don’t Settle Concealer, Tarte’s Quick Dry Matte Lip Paint, and KVD’s Cake Pencil Eyeliner.

Trimethylsiloxysilicate is also manufactured and sold as a stand-alone ingredient (DOWSIL™ MQ-1600 Solid Resin). Trimethylsiloxysilicate (without Polypropylsilsesquioxane) is very commonly used in long-wearing cosmetics for its film-forming and long-wearing properties. Examples include Bobbi Brown’s Long-Wear Gel Eyeliner, Urban Decay’s Primer Potion, Laura Mercier’s Caviar Stick Eye Shadow, Anastasia Beverly Hills’ DIPBROW™ Pomade, and NARS’ Powermatte Lip Pigment.

Both Trimethylsiloxysilicate and Polypropylsilsesquioxane are also available as components of other blended products. For instance, DOWSIL™ 593 Fluid is Dimethicone (and) Trimethylsiloxysilicate and DOWSIL™ 670 Fluid is Cyclopentasiloxane (and) Polypropylsilsesquioxane, and Specsil K-75 is Isododecane (and) Trimethylsiloxysilicate.

Grant Industries Inc. manufactures several solutions of Trimethylsiloxysilicate and Polypropylsilsesquioxane in different solvents: isododecane (Granresin MQI-T50), cyclopentasiloxane (Granresin MQC-T50), and dimethicone (Granresin PHQ-Fluid).

INCI Trimethylsiloxysilicate (and) Polypropylsilsesquioxane
Appearance Dusty, translucent flakes/chunks
Usage rate 1–50% (though you shouldn’t need 50%!)
Texture The flakes are a bit tacky
Scent Nothing noticeable
Solubility Trimethylsiloxysilicate (and) Polypropylsilsesquioxane is soluble in quite a few different liquids including:

Different solvents perform differently; which one you choose will depend on your formulation needs. If you’re unsure, take a look at some commercially available formulations that are similar to what you are planning on making. In my research, I have found that isododecane and cyclomethicone + other cyclo-siloxanes are the most popular choices.

Why do we use Flake Resin in formulations? Trimethylsiloxysilicate (and) Polypropylsilsesquioxane improves the wear time and rub-off resistance of our formulations.
Do you need Flake Resin? If you want to make long-wearing cosmetics I highly recommend it.
Refined or unrefined? Trimethylsiloxysilicate (and) Polypropylsilsesquioxane only exists as a refined product.
Strengths Fantastic film former, great rub-off and water resistance.
Weaknesses I think limited global availability is its biggest weakness. It’s also prone to tackiness if used at high concentrations.
Alternatives & Substitutions for Flake Resin You’ll need another excellent film-former; I’ve had good results with TKB Trading’s Film Fix.
How to Work with It You’ll need to dissolve the Trimethylsiloxysilicate (and) Polypropylsilsesquioxane in a suitable solvent before you can include it in your formulations. Which solvent you choose will depend on your formulation needs.

If you read through the reviews for Flake Resin on TKB Trading you’ll see most users prefer isododecane as their solvent of choice, and TKB Trading also recommends isododecane for the best performance. I have seen products for sale that use cyclomethicone as the solvent. I have yet to find any products for sale that use isopropyl myristate (IPM), C12-15 alkyl benzoate, or MCT as the solvent for Trimethylsiloxysilicate (and) Polypropylsilsesquioxane.

I make my own version of Grant Industries’ Granresin MQI-T50 by weighing equal parts isododecane and Trimethylsiloxysilicate (and) Polypropylsilsesquioxane into a bottle (50% isododecane, 50% flake resin) and work with that. A reviewer named “Astarie D.” on TKB shared that they use an 80/20 mix of Isododecane and flake resin. Remember that isododecane is volatile, so if that’s your solvent you need to be careful heating it.

Film-formers like Trimethylsiloxysilicate (and) Polypropylsilsesquioxane are broken down by oil—that’s why oil cleansers work so well to remove waterproof makeup! With that in mind, it’s not a good idea to put oil in formulations that rely on Trimethylsiloxysilicate (and) Polypropylsilsesquioxane performing well. The oil will diminish the effectiveness of the Trimethylsiloxysilicate (and) Polypropylsilsesquioxane.

For a great starter formulation, try TKB Trading’s free Liquid Lipstick project! It can also be adapted into eyeliners, cream eyeshadows, blushes, and more.

Luisa True Skincare also has a very helpful post on formulating and making liquid lipstick that you can find here. This formulation uses just trimethylsiloxysilicate but does mention polypropylsilsesquioxane as a potential ingredient to include.

Storage & Shelf Life Stored somewhere cool, dark, and dry, Trimethylsiloxysilicate (and) Polypropylsilsesquioxane should last at least two years.
Tips, Tricks, and Quirks As wonderful as Trimethylsiloxysilicate (and) Polypropylsilsesquioxane is for improving the wear time of our cosmetics, it’s not the only ingredient you’ll need in formulation to ensure it is long-wearing. Just because something has excellent rub-off resistance when you scrub at it on your arm doesn’t mean it will wear well on your eyes or mouth for hours 😊 I have had great results pairing it with ingredients like magnesium stearate and magnesium myristate.
Recommended starter amount 30g (1.06oz)
Where to Buy it  TKB Trading sells it as “Flake Resin“. Making Cosmetics sells it as “Silicone Resin“.

Some Formulations that Use Trimethylsiloxysilicate (and) Polypropylsilsesquioxane (Flake Resin)


Posted on

October 7, 2021