Enhanced Cosmetic Ink Composition for Improved Stability, Print Quality, and Safety

The present invention relates to a novel cosmetic ink composition that exhibits improved stability, print quality, and safety, addressing the limitations of existing ink compositions in thermal and piezo inkjet printing applications.

The original patent, 'Stable cosmetic ink composition', disclosed an ink composition suitable for high-frequency printing via thermal and/or piezo inkjet printheads. However, the original composition may still exhibit settling and syneresis, compromising print quality and shelf life. Furthermore, the composition may contain volatile organic compounds (VOCs) that pose safety concerns. The present invention addresses these limitations by introducing novel components and formulations that improve the stability, print quality, and safety of the cosmetic ink composition.

The enhanced cosmetic ink composition comprises a particulate material having a Particle Size Distribution D50 of about 100 nm to about 2,000 nm, a (meth)acrylic acid homopolymer or salt thereof, and a rheology modifier. The composition exhibits improved stability by maintaining a storage modulus of at least 10 Pa and a loss modulus of at most 5 Pa after 30 days of static storage. Additionally, the composition may include a stabilizing agent selected from surfactants, polymers, and combinations thereof to further improve shelf life. The composition also exhibits improved print quality by reducing the amount of settling and syneresis. In another embodiment, the composition is designed to reduce VOCs to less than 10 ppm, ensuring improved safety. A system for printing cosmetic inks, comprising a printhead, an ink reservoir, and a temperature control unit, may also be employed to maintain a temperature of from about 20°C to about 30°C, preventing degradation of the ink composition.

The present invention introduces novel components and formulations that improve the stability, print quality, and safety of the cosmetic ink composition, distinguishing it from the original patent. The specific combination of a particulate material with a (meth)acrylic acid homopolymer or salt thereof, and a rheology modifier, along with the addition of a stabilizing agent and/or VOC-reducing components, provides an inventive step over the prior art.

Alternative embodiments of the inventive concept may include varying the type and amount of particulate material, using different (meth)acrylic acid homopolymers or salts, or incorporating additional additives to further enhance stability and print quality. The composition may also be adapted for use in different printing applications, such as textile or packaging printing.

The enhanced cosmetic ink composition has significant commercial potential in the beauty and personal care industry, as well as in other industries where high-quality, safe, and reliable printing is essential. The invention may be particularly attractive to companies seeking to develop innovative, sustainable, and environmentally friendly printing solutions.