| What is it? | Isododecane (and) Acrylates/Dimethicone Copolymer is a film former that imparts non-transfer and water-resistant properties to our cosmetics. The active ingredient is Acrylates/Dimethicone Copolymer in a base of isododecane. The volatile isododecane base means Isododecane (and) Acrylates/Dimethicone Copolymer dries down quickly, leaving a sturdy protective film.
Innospec and Shin-Etsu Silicones of America both manufacture a product with this INCI. The Innospec product is called Specsil K-50; the Shin-Etsu product is called KP-550. Both manufacturers state their product is 40% active (60% isododecane). Acrylates/Dimethicone Copolymer does not appear to be as popular as Trimethylsiloxysilicate (and) Polypropylsilsesquioxane (Flake Resin) in commercial cosmetics. It seems to be primarily used in waterproof sunscreens, but I have found it in products like Revlon’s ColorStay Satin Ink Liquid Lipstick, Neutrogena’s Hydro Boost Hydrating Tint, Mented’s Lip Liners, and e.l.f. cosmetics’ 16hr Camo Concealer. I’ve noticed that most commercially available products that include Acrylates/Dimethicone Copolymer also include trimethylsiloxysilicate. |
| INCI | Isododecane (and) Acrylates/Dimethicone Copolymer |
| Appearance | Viscous clear liquid |
| Usage rate | 0.5–10%
I have not found anything from Cosmetics Info/the CIR indicating that this is a safety-based limit; it appears to be more of an efficacy-based range. |
| Texture | Clear viscous fluid |
| Scent | Nothing much. |
| Solubility | Oil, isododecane. |
| Why do we use it in formulations? | Isododecane (and) Acrylates/Dimethicone Copolymer helps extend the wear time of our formulations by forming a durable, clear film that imparts water, wash-off, and transfer resistance. |
| Do you need it? | I recommend it if you are interested in making long-wearing cosmetics. |
| Refined or unrefined? | Isododecane (and) Acrylates/Dimethicone Copolymer only exists as a refined product. |
| Strengths | Effective, easy-to-use film former for imparting water and transfer resistance to cosmetic formulations. |
| Weaknesses | Lack of global availability. |
| Alternatives & Substitutions | A solution of Trimethylsiloxysilicate (and) Polypropylsilsesquioxane (Flake Resin) and isododecane would be a good place to start. |
| How to Work with It | Include Isododecane (and) Acrylates/Dimethicone Copolymer in cosmetic formulations. It should not be heated much as isododecane is volatile and heat sensitive.
I recommend pairing Isododecane (and) Acrylates/Dimethicone Copolymer with other adhesion boosting ingredients like magnesium myristate and magnesium stearate for the best results. Film-formers like Acrylates/Dimethicone Copolymer 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 film-formers to perform well. The oil will diminish the effectiveness of the Acrylates/Dimethicone Copolymer. |
| Storage & Shelf Life | Stored somewhere cool, dark, and dry, Isododecane (and) Acrylates/Dimethicone Copolymer should last at least three years. |
| Tips, Tricks, and Quirks | Both Innospec and Shin-Etsu Silicones of America sell Acrylates/Dimethicone Copolymer in a variety of different bases/solvents, including dimethicone, cyclopentasiloxane, and butyl acetate. There are no entries on UL Prospector for Acrylates/Dimethicone Copolymer as a standalone ingredient. |
| Recommended starter amount | 30mL (1fl oz) |
| Where to Buy it | I have only found Isododecane (and) Acrylates/Dimethicone Copolymer for sale to home crafters from TKB Trading. |
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