Tosylamide/formaldehyde resin

Tosylamide/formaldehyde resin

Names
Systematic IUPAC name poly[4-methylbenzenesulfonamide-alt-methanal]
Other names Toluenesulfonamide/formaldehyde resin Formaldehyde-p-toluenesulfonamide copolymer Santolite MHP Santolite MS
Identifiers
CAS Number	25035-71-6
ECHA InfoCard	100.132.132
EC Number	607-493-7
PubChem CID	159985
CompTox Dashboard (EPA)	DTXSID80933988
Properties
Chemical formula	(C8H9NO2S)n(n ≤ 10)
Molar mass	Variable (400–1900 g·mol−1)
Melting point	82 °C (180 °F; 355 K) [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Tosylamide/formaldehyde resin (TSFR) is a polymeric resin used as a plasticizer and secondary film-forming agent in nail polishes. While it was still in use as of 2023, ^[update] its use has been diminishing in favor of hypoallergenic alternatives, due to the prevalence of reactions causing allergic contact dermatitis of the eyelids, face, and neck.

Production

TSFR is produced by condensing p-tosylamide  [ de ] (often impure, containing o-tosylamide  [ de ]) with formaldehyde. It consists of a mixture of short oligomers with repeating unit −N(Ts)CH₂−, terminated by −NHTs or −N(Ts)CH₂OH groups. ^[2]

Allergenicity

Nail polishes containing TSFR were first introduced in 1939, becoming a major cause of allergic contact dermatitis of the eyelids, face, and neck. ^{[3] [4]} Allergic responses are caused by the water-soluble contaminants 5-tosyl-1,3,5-dioxazinane (TsN(−)(CH₂OCH₂OCH₂−)) and 3,5-ditosyl-1,3,5-oxadiazinane (TsN(−)(CH₂N(Ts)CH₂OCH₂−)), rather than formaldehyde, which is only present in trace quantities (<0.5%). ^{[3] [4] [5]}

Since the early 2010s, the prevalence of allergic reactions to TSFR has decreased, due to the widespread use of hypoallergenic alternatives such as tosylamide/epoxy resin (first introduced in the late 1980s ^[6] ), cellulose acetate butyrate, and polyester resins (e.g. 2,2,4-Trimethyl-1,3-pentanediol  [ de ]–isophthalic acid–trimellitic anhydride). ^[7]

References

1. "Formaldehyde-p-toluenesulfonamide copolymer". CAS Common Chemistry . American Chemical Society.
2. Chiva, V.; Lecacheur, M.; Faure, R.; Gallo, R.; Wimmer, E. (15 July 1993). "Structure of Toluene Sulfonamide Formol Resins: Molecular Models from Mechanistic Schemes and Analytical Results". Journal of Applied Polymer Science. 49 (3): 461–467. doi:10.1002/app.1993.070490310.
3. Hausen, B. M.; Milbrodt, M.; Koenig, W. A. (September 1995). "The allergens of nail polish: (I). Allergenic constituents of common nail polish and toluenesulfonamide-formaldehyde resin (TS-F-R)". Contact Dermatitis. 33 (3): 157–164. doi:10.1111/j.1600-0536.1995.tb00537.x.
4. Park, Michelle E.; Zippin, Jonathan H. (January 2014). "Allergic Contact Dermatitis to Cosmetics". Dermatologic Clinics. 32 (1): 6. doi:10.1016/j.det.2013.09.006.
5. "Tosylamide/Formaldehyde Resin". Cosmetics Info. Personal Care Products Council. 2023-10-20. Archived from the original on 2024-01-10. Retrieved 2025-01-06.
6. Sandewicz, Robert W. (2017). "Formulation of Nail Care Products". In Dayan, Nava (ed.). Handbook of Formulating Dermal Applications. Hoboken, New Jersey : Beverly, Massachusetts : Scrivener Publishing: John Wiley & Sons, Inc. pp. 539–590. ISBN   9781119364238.
7. Lee, Senhong; Maor, Danit; Palmer, Amanda; Nixon, Rosemary L. (September 2018). "Declining prevalence of allergic contact dermatitis caused by tosylamide/formaldehyde in nail polish" . Contact Dermatitis. 79 (3): 184–185. doi:10.1111/cod.13020. Archived from the original on 26 May 2022. Retrieved 8 January 2025.