{
  "patent_number": "US 4810490",
  "country": "US",
  "title": "How to Make Clear, Waterproof Sunscreen That Doesn't Feel Greasy",
  "original_title": "Sunscreen composition",
  "summary": "A 1989 patent for a transparent, water-resistant sunscreen formula that uses wood rosin to create a non-sticky, long-lasting protective film on the skin.",
  "what_it_does": "This patent describes a specific chemical recipe for a sunscreen that remains clear and resists washing off in water. The core of the invention is the use of the methyl ester of hydrogenated wood rosin, which acts as a film-forming agent. By mixing this resin with specific solvents like ethanol or mineral oil, emollients like volatile silicone, and UV-absorbing chemicals, the formula creates a thin, durable layer on the skin. This layer stays on even when the wearer is swimming or sweating, while avoiding the heavy, oily feeling common in older sunscreen products.",
  "what_it_does_not_cover": [
    "Does not cover sunscreen formulas that lack the methyl ester of hydrogenated wood rosin.",
    "Does not cover physical sunscreens that use mineral ingredients like zinc oxide or titanium dioxide.",
    "Does not cover non-clear or opaque sunscreen lotions or creams.",
    "Does not cover spray-on delivery mechanisms or aerosolized sunscreen delivery systems."
  ],
  "filed": "1987-06-04",
  "granted": "1989-03-07",
  "expires": null,
  "status": "active",
  "holder": "Carter Wallace Inc",
  "holder_url": "https://patentbrief.org/company/carter-wallace-inc",
  "inventors": [
    {
      "name": "Richard P. Dixon",
      "url": "https://patentbrief.org/inventor/richard-p-dixon"
    },
    {
      "name": "Mary E. Foxx",
      "url": "https://patentbrief.org/inventor/mary-e-foxx"
    }
  ],
  "times_cited": 11,
  "tags": [
    "consumer_electronics",
    "materials"
  ],
  "abstract": "Clear, water-proof sunscreen compositions, including a film-forming resin, a solvent, an ultra-violet sunscreening agent and emollients are disclosed. The compositions when spread on the skin leave an elegant non-greasy, non-tacky film with a superior resistance to removal by water and which provide prolonged high level protection for human skin to ultraviolet radiation.",
  "url": "https://patentbrief.org/patent/us/4810490/tpa-tissue-plasminogen-activator",
  "markdown_url": "https://patentbrief.org/patent/us/4810490/tpa-tissue-plasminogen-activator/md",
  "google_patents_url": "https://patents.google.com/patent/US4810490",
  "relatedPatents": []
}