On October 3, 2025, Xingye Leather Technology Co., Ltd. (Stock Code: 002674), a leading enterprise in China’s leather industry, announced that its independently developed "Acetal Amine Retanning Agent for Chrome-Free Tanning and Preparation Method of High-Brightness Leather" has officially been granted a national invention patent. With the patent classification number C14C3/18 (2006.01) I, this achievement marks a new milestone in the company’s core competitiveness within the eco-friendly leather technology sector and offers a fresh technical solution for the industry’s green transition.
It is reported that this patent was jointly developed by four R&D professionals from Xingye Technology—Sun Chuanji, Wang Xiaozhuo, Mao Peng, and Zhou Heng. The application was filed on September 1, 2022, followed by the publication of the application on December 2, 2022. After three years of technical verification and review, the patent has now been formally finalized. In terms of technical principles, the core lies in the innovative preparation process of the acetal amine retanning agent: first, glyoxylic acid reacts with ethylene glycol in a benzene solvent, with p-toluenesulfonic acid added as a catalyst; the solvent is then removed to obtain an activated glyoxylic acid precursor. Next, the precursor reacts with thionyl chloride and N,N-dimethylformamide, followed by purification to produce highly active glyoxylic acid. Finally, this active glyoxylic acid is mixed with mellitic acid and pentaerythrityltetramine, and concentrated sulfuric acid is used to adjust the reaction conditions and pH value—ultimately yielding a retanning agent compatible with chrome-free tanning processes.
The breakthrough of this technology lies in the precise control of the retanning agent’s particle size and dispersion performance, which significantly enhances the adsorption efficiency of collagen fibers in leather for subsequent retanning, filling, and dyeing materials. This not only addresses the long-standing industry pain point of insufficient color brightness in traditional chrome-free tanned leather but also reduces the consumption of chemical raw materials during production and further lowers the costs of environmental treatment. A technical leader at Xingye Technology stated that the process corresponding to this patent has achieved stable results in the laboratory pilot phase; the next step will be to advance pilot-scale production and industrial application. In the future, it is expected to be used in high-end fields such as furniture leather and automotive interior leather, where high requirements for color quality and environmental friendliness are demanded.
As an enterprise long dedicated to leather technology R&D, Xingye Technology has continuously increased its investment in innovation in recent years. According to its 2025 interim report, the company’s R&D expenditure in the first half of the year reached 37.0139 million yuan, a year-on-year increase of 25.5%, while the scale of its R&D team expanded by 15% compared to the previous year. Up to now, the company has filed a total of 187 patents, including 158 invention patents, and holds 97 valid authorized patents (92 of which are invention patents). Prior to this, it had already laid out multiple patents in eco-friendly technology fields such as "dye-free white nappa leather manufacturing" and "seawater-based salt-free pickling and tanning," forming a technology matrix covering chrome-free tanning, clean production, and recycling.
Against the backdrop of the global leather industry’s transition toward "zero chromium emissions," the authorization of this patent holds significant industry-wide significance. Traditional chrome tanning processes face increasingly stringent environmental regulations due to the risk of heavy metal chromium pollution. Although chrome-free tanning technology is recognized as the future development direction, it has long been constrained by issues such as poor color performance and unstable process reliability. The acetal amine retanning agent technology launched by Xingye Technology provides key support for the industrial application of chrome-free tanning processes, while also offering a replicable technical path for other enterprises in the industry. This will help accelerate the transformation of China’s leather industry from "scale leadership" to "technological leadership."
