During the continuous upgrading process of leather tanning, textile finishing, and polymer modification towards high-performance and functionalization, functional intermediates with both reactive properties and excellent silicone characteristics are becoming key elements for achieving breakthroughs in material performance. Our company's product, carboxyl silicone oil 2520, as a polydimethylsiloxane with terminal carboxyl groups, demonstrates significant industrial application value in areas such as chrome-tanned leather waterproof treatment, polar surface water-repellent modification, polymer chain extension, and fabric hydrophilic softening finishing. It provides efficient modification solutions for the leather, textile, and polymer materials industries.


I. Core Structural Characteristics and Physical Properties of the Product


Product carboxyl silicone oil 2520 is a pale yellow transparent liquid without mechanical impurities. At 25 degrees Celsius, its viscosity is 250 square millimeters per second, and its acid value is 45 milligrams of potassium hydroxide per gram. The effective content is not less than 98.5%. This product is a polydimethylsiloxane with terminal carboxyl functional groups. This structural design makes it a typical reactive organic silicon intermediate. Unlike ordinary silicone oil, the carboxyl groups at the end of this product enable the molecule to react with various polar groups, allowing it to be stably introduced into the target material system through chemical bonds, effectively avoiding the common migration and precipitation problems in physical blending. The high effective content ensures its efficient utilization in applications and provides a stable quality foundation for downstream formulations. Additionally, this product can be made into a microemulsion, and the microemulsion has excellent stability against acids, alkalis, and shear, meeting the requirements of different processing techniques.


II. Core Reaction Characteristics and Performance Advantages


The application value of product carboxyl silicone oil 2520 is rooted in its terminal carboxyl group's chemical reaction capability with the material system. In chrome-tanned leather processing, the carboxyl groups of this product can coordinate or chemically bond with chromium ions and active sites in the leather fibers, firmly introducing the organic silicone chain segments into the leather fiber network, forming a persistent waterproof barrier. Due to the effective components of this product being able to chemically bond with leather fibers, the obtained waterproof effect is resistant to water washing and dry cleaning, belonging to a persistent waterproof finishing.


In polymer modification, this product can be used as a chain extender, introduced during the condensation reaction of polyester and polyamide, to embed organic silicone chain segments in the polymer main chain, imparting the characteristics of organic silicon to the modified polymer - anti-blocking, anti-adhesion, wear-resistant, and scratch-resistant.


In pigment or filler treatment, this product can improve the interface compatibility between inorganic pigments or fillers and organic polymers, enhancing the processing performance and mechanical properties of the composite materials. In fabric finishing, this product can also give the fabric a smooth feel while enhancing hydrophilicity, without yellowing, and can be used for white or light-colored leather or fabric.


III. Wide Application Areas


Product carboxyl silicone oil 2520, with its terminal carboxyl reactive properties and multiple performance gains of organic silicon, can play an important role in the following key application areas, specifically:


1. Long-lasting waterproof treatment of chrome-tanned leather. Based on the reactive properties of the terminal carboxyl groups, this product can impart persistent waterproof properties to the leather during chrome tanning, while also giving the leather certain organic silicon characteristics, such as softness and wear resistance, suitable for waterproof finishing of shoe uppers, clothing leather, and automotive interior leather.


2. Water-repellent treatment of polar surfaces. This product can be used for water-repellent modification of polar material surfaces, forming a stable hydrophobic layer through the bonding of terminal carboxyl groups with the surface active groups of the substrate.


3. Pigment or filler treatment. This product can improve the compatibility between inorganic pigments or fillers and organic polymers, enhancing the dispersion and interface bonding force of the fillers in the composite material formulation.


4. Polymer chain extension and modification. This product can be introduced as a chain extender in polyesters, polyamides and other condensation reactions, enabling the polymer to possess the characteristics of organosilicon - anti-blocking, anti-sticking, wear-resistant, and scratch-resistant, etc.


5. Fabric hydrophilic and soft finishing. This product can be used for fabric finishing, providing a smooth feel while enhancing the water absorption of the fabric. It is suitable for textiles with high requirements for comfort.


4. Packaging specifications and storage conditions


Product carboxyl silicone oil 2520 is provided in 190 kilograms or 950 kilograms drums. It should be stored in the original sealed container under conditions of -20°C to 50°C. The standard validity period is 24 months from the production date.


5. Quality assurance and industrial chain value


Product carboxyl silicone oil 2520 has established a strict quality control system during the production process. Key indicators such as product appearance, viscosity, acid value, and effective components are tested throughout the process to ensure consistency and reliability between batches. As the leather, textile, and polymer materials industries continue to develop towards higher quality and functionality, the demand for end-coupled organic silicon intermediates with reactive activity and long-lasting performance is steadily increasing. This product, with its chemical bonding ability provided by the carboxyl groups, the multiple performance gains brought by the organic silicon chain segments, and stable emulsion quality, is becoming an important raw material option in the fields of leather waterproofing, polymer modification, and fabric finishing, providing strong raw material support for promoting product innovation and technological upgrading in related industries.