Home Cosmetic Science Talk Formulating Why silicone spray doesn’t make hard or painted surfaces shine?

  • Why silicone spray doesn’t make hard or painted surfaces shine?

    Posted by Gunther on July 18, 2019 at 6:16 pm

    I made the following formulas just to try it

    cyclomethicone D5 66.67%
    dimethicone 350 cst 33.33%

    cyclomethicone D5 98%
    dimethicone 350 cst 2%

    But when sprayed on hard surfaces, like furniture tops, car paint or vinyl, their shine is very short lived, and leave a white residue on vinyl or slightly cracked car paint.
    Why is that? Weren’t silicones supposed to give gloss?

    Is a Si/w  emulsion needed for proper shine?

    Sponge replied 4 years, 4 months ago 3 Members · 5 Replies
  • 5 Replies
  • JonahRay

    July 19, 2019 at 2:32 pm

    Is it due to the volatility of the silicones?

  • Gunther

    July 19, 2019 at 2:41 pm

    JonahRay said:

    Is it due to the volatility of the silicones?

    Just one silicone, cyclomethicone, is volatile
    the other one, dimethicone, isn’t so it was supposed to leave a dimethicone shiny film.

  • JonahRay

    July 19, 2019 at 3:34 pm
  • Gunther

    January 13, 2020 at 3:11 am

    These patents shine light on what’s going on:
    Silicones sink down to the surface crevices
    So either waxes to prevent them from sinking below the surface, or a lot of silicones 20-40% are needed to fill said crevices.

    Furniture polish compositions based on silicone oils also suffer from a phenomenon known as “mottling”. Silicone oils tend to migrate into lower areas on the wood surface, such as imperfections (scratches, chips, etc.). This migration creates dull spots in the polished surface, or mottling. To prevent this migration, wax is added to anchor the silicone molecules to the surface. Ratios of emulsified wax:silicone oil as high as 1:1 have been used to anchor the silicone. However, the emulsified wax contains solid discrete particles which decrease the clarity of the resulting film or finish, and the hardness of the wax particles increases the amount of time and effort to buff the film to a shine.

    Two patents, U.S. Pat. Nos. 6,221,433 and 6,206,956, by Muntz et al., describe siloxane automotive protectant compositions which contain about 10% to 20% by weight of organopolysiloxane and having comparable or improved gloss performance to comparative examples with 20% to 40% by weight of organopolysiloxane. Although these protectant formulations are an improvement over the previous protectants, there is still an opportunity to lower the amount of siloxane in the formulation to levels of less than 10% to achieve a cost savings while maintaining good gloss performance.

  • Sponge

    January 14, 2020 at 5:50 am

    Thanks for posting the excerpts, Gunther. Interesting and certainly not as straightforward as I would have imagined. 

    Dimethicone 350cst is thick but… what about a dimethicone gum? It’s inherent attributes may solve the issues presented. 

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