How to Make Clear, Waterproof Sunscreen That Doesn't Feel Greasy
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.
Original patent title: “Sunscreen composition”
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. Granted to Carter Wallace Inc in 1989 with 8 claims and 11 forward citations.
Key facts
Coverage
What does this patent actually cover?
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.
The gap
What does this patent 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The inventors discovered that using the methyl ester of hydrogenated wood rosin creates a film that is both water-resistant and non-tacky, solving the classic trade-off between durability and comfort.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Clear sunscreen gels
Water-resistant sunscreen oils
Sport-formula sunscreen liquids
Why it matters
The bigger picture
Before this invention, many sunscreens were thick, white, and greasy, which discouraged frequent use. This patent helped shift the industry toward 'elegant' formulations that were pleasant to wear, which is critical for public health compliance in sun protection. It represents a transition period where cosmetic chemistry began focusing as much on skin feel as on UV protection.
Filed
June 4, 1987
Granted
March 7, 1989
Market context
Who's building on this
Companies in this space
Major personal care companies like Beiersdorf (Nivea), L'Oreal, and Johnson & Johnson have expanded on these early film-forming concepts to create the modern range of invisible, high-SPF sunscreens. The focus has since shifted toward more advanced polymer science to improve wear time and environmental safety.
Market impact
This patent helped standardize the expectation that sunscreens should be invisible and comfortable, moving the market away from thick, white pastes. It enabled the growth of the 'sport' sunscreen category, where water resistance and non-greasy application are essential for active users.
Claim 1 — Plain English
What this patent covers
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.
The clever bit
The inventors discovered that using the methyl ester of hydrogenated wood rosin creates a film that is both water-resistant and non-tacky, solving the classic trade-off between durability and comfort.
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.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Early stage
Citation count
22/40
Moderately cited
Claim breadth
5/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$18K – $58K
Midpoint $36K · expired or expiring · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
8 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Dixon, R. P., & Foxx, M. E. (1989). How to Make Clear, Waterproof Sunscreen That Doesn't Feel Greasy (U.S. Patent No. 4,810,490). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/4810490/tpa-tissue-plasminogen-activator
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How to Make Clear, Waterproof Sunscreen That Doesn't Feel Greasy cover?
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.
Who owns patent US 4810490?
Carter Wallace Inc owns this patent, granted in 1989.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 4810490 cited by?
This patent has been cited by 11 later patents that build on its ideas.
What problem does this patent solve?
Before this invention, many sunscreens were thick, white, and greasy, which discouraged frequent use. This patent helped shift the industry toward 'elegant' formulations that were pleasant to wear, which is critical for public health compliance in sun protection. It represents a transition period where cosmetic chemistry began focusing as much on skin feel as on UV protection.
What does this patent NOT cover?
Does not cover sunscreen formulas that lack the methyl ester of hydrogenated wood rosin.
Patent monitoring