Phthalic Anhydride/Trimellitic Anhydride/Glycols Copolymer is a synthetic polymer created from the copolymerization of phthalic anhydride, trimellitic anhydride, and various glycols. This copolymer is known for its excellent film-forming, emulsifying, and stabilizing properties. It is widely used in cosmetic formulations to improve the texture and stability of products, providing enhanced sensory attributes and long-lasting effects. The copolymer helps in creating smooth, even textures in hair and skin care products while also acting as a binder.

Chemical Composition and Structure

The copolymer consists of:

• Phthalic Anhydride: A key component that provides rigidity and enhances the film-forming properties of the copolymer.
• Trimellitic Anhydride: Adds additional functionality and stability to the copolymer, improving its emulsifying capabilities.
• Glycols: Various glycols (such as propylene glycol or butylene glycol) are incorporated to enhance solubility, flexibility, and moisture retention.

The combination of these components results in a copolymer that can effectively improve the performance and sensory qualities of cosmetic formulations.

Physical Properties

• Appearance: Typically a white to off-white powder or solid.

• Solubility: Soluble in water and various organic solvents, facilitating easy incorporation into formulations.

• pH: Generally neutral, making it compatible with a wide range of cosmetic products.

• Odor: Usually odorless or has a very mild scent.

• Stability: Stable under normal storage conditions; should be protected from excessive heat and moisture.

Production Process

1. Synthesis: The copolymer is produced through a condensation reaction between phthalic anhydride, trimellitic anhydride, and selected glycols.

2. Purification: The resulting copolymer is purified to remove any unreacted materials and by-products, ensuring a high-quality product.

3. Formulation: The purified copolymer is then incorporated into various cosmetic formulations, enhancing their texture and stability.

Applications

• Medical: Occasionally used in topical formulations for its emulsifying and stabilizing properties.

• Cosmetics: Commonly found in creams, lotions, hair care products, and makeup for its film-forming and texturizing benefits. It enhances the overall application experience and performance of cosmetic products.

INCI Functions:

Film-forming agent. It produces a continuous ultra-thin film with an optimal balance of cohesion, adhesion and stickiness on the skin or hair to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.

Viscosity Enhancing Agent - non acqueous. Since viscosity is important for increasing the chemical and physical stability of the product, Viscosity Enhancing Agent non acqueous is an important dosage factor in gels, suspensions, emulsions, solutions. Increasing viscosity makes formulations less sedimentary and more homogeneously thickened.

CAS: 186688-25-5

• Industrial Uses: May be employed in formulations requiring effective emulsification and stabilization properties.

Environmental and Safety Considerations

Phthalic Anhydride/Trimellitic Anhydride/Glycols Copolymer is generally considered safe for use in cosmetics when applied according to recommended guidelines, however, data on trimellitic anhydride copolymers are insufficient to determine whether the remaining trimellitic anhydride copolymers are safe for use in cosmetic formulations.(1). It is well tolerated by most skin types; however, numerous cases of contact allergy are reported (2).

Responsible sourcing and formulation practices are essential to ensure that the ingredient is free from harmful contaminants and produced sustainably.

References__________________________________________________________________________

(1) Fiume MM, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler DC, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Gill LJ, Heldreth B. Safety Assessment of Trimellitic Anhydride Copolymers as Used in Cosmetics. Int J Toxicol. 2020 Nov/Dec;39(3_suppl):74S-92S. doi: 10.1177/1091581820958690.

Abstract. The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 6 trimellitic anhydride copolymers as used in cosmetics. These ingredients are related as copolymers in that they all share trimellitic anhydride (ie, 1,2,4-benzenetricarboxylic acid anhydride) as a monomer, are reported to function as film formers in cosmetics, and are reported to be primarily used in nail products. Very limited safety data were available or submitted. The Panel concluded that Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer and Phthalic Anhydride/Trimellitic Anhydride/Glycols Copolymer are safe in nail product formulations in the present practices of use and concentration, but the data are insufficient to make a determination of safety on the use of these 2 ingredients in all other types of cosmetic formulations. The Panel also concluded that the available data are insufficient to make a determination that the remaining trimellitic anhydride copolymers are safe for use in cosmetic formulations.

(2) Moffitt DL, Sansom JE. Allergic contact dermatitis from phthalic anhydride/trimellitic anhydride/glycols copolymer in nail varnish. Contact Dermatitis. 2002 Apr;46(4):236. doi: 10.1034/j.1600-0536.2002.460409.x. PMID: 12081703.

Gach JE, Stone NM, Finch TM. A series of four cases of allergic contact dermatitis to phthalic anhydride/trimellitic anhydride/glycols copolymer in nail varnish. Contact Dermatitis. 2005 Jul;53(1):63-4. doi: 10.1111/j.0105-1873.2005.00456h.x.