The history of textile waterproofing agents

The history of textile waterproofing agents

At the beginning of the 19th century, waterproof finishing using aluminum soap and paraffin emulsion appeared. This waterproofing agent has good water repellency, but the disadvantage is that it is not resistant to washing. In the 1930s, long carbon chain waterproofing agents appeared. This type of waterproofing agent can react with cellulose macromolecules to form cellulose ether, which has good and long-lasting waterproofing properties.
In 1940, Patnode in the United States issued a patent stating that after treating fabric fibers with dimethyldichlorosilane, the fabric would have good waterproofing effects. However, during the waterproofing process of fluorine-free waterproofing agents, HCl gas will be released, which is harmful to human health.
In 1945, Elliott and others from General Electric Company in the United States soaked fabric fibers in an alkaline aqueous solution and heated them with sodium methylsilanolate. The finished fabric had good waterproofing effects.
In 1947, 3M Company invented PFOA (perfluorooctanoic acid, molecular formula: C8HO2F15).
In the early 1950s, the American company Dow Corning combined hydrogenated polysiloxane with polydimethylsiloxane (PDMS). The treated fabric not only had a very good waterproof effect, but also became soft to the touch.
In 1951,DuPont began purchasing PFOA from 3M Company to produce “Teflon”. C8 waterproofing agent is not only waterproof, but also oil-proof, without affecting the style of textiles, and has begun to become the mainstream of waterproofing agents. Later, the research and application of fluorine-containing waterproofing agents were further developed in the United States and Japan.
In the 1940s, DuPont proposed a complex waterproofing agent, but this type of waterproofing agent was green in color, thus limiting its scope of use. In the late 1940s, silicone waterproofing agents appeared. This type of waterproofing agent is particularly suitable for various synthetic fiber and wool fabrics, and can also be used for cellulose fiber fabrics.

Prohibition of C8 waterproof agent

The production process of C8 waterproofing agent will produce two by-products, PFOA and PFOS, and the harmfulness of these two chemicals has gradually been confirmed.

Table 1  Synthetic process of waterproofing agent Home

Regardless of the electrolysis method or the telomerization method, it is impossible to make the PFOA and PFOS content less than 1.0 μg/m2 after the C8 waterproofing agent is added to the fabric, which determines that the C8 waterproofing agent must be eliminated. On December 17, 2006, the European Parliament and the Council of Ministers jointly issued the Directive on Restrictions on the Sales and Use of Perfluorooctane Sulfonate (2006/122/EC). In 2006, the U.S. Environmental Protection Agency (EPA) issued an ultimatum ordering eight chemical companies including DuPont to stop using perfluorooctanoate (PFOA), the core ingredient needed to make Teflon. Along with DuPont, DuPont Ceramics also received the EPA order. A number of well-known industry giants such as Elastomers Company, Asahi Glass Co., Ltd. of Japan, Ciba Specialty Chemicals of Switzerland and Clariant of Germany.

C6 waterproof agent

The main component of C6 waterproofing agent is PFHS (meth)acrylic perfluorohexyl ethyl ester copolymer, which does not contain PFOA and PFOS. It is the most ideal product to replace C8 waterproofing agent. However, the shorter the carbon chain, the lower its waterproof and oil-proof effect. To achieve the effect of C8 waterproof agent, it is necessary to increase the dosage and cost. There are also many clothing brands that do not accept C6 waterproofing agents and can only use fluorine-free waterproofing agents.

Fluorine-free waterproofing agent

Fluorine-free waterproofing agents can be completely free of PFOA and PFOS, and do not contain PFCS (perfluoroalkyl compounds).They are recognized by more and more brands. However, compared with fluorine-containing waterproofing agents, they have two disadvantages: First, it is not oil-proof; second, the coating has poor fastness and the fibers are easy to slip.

Market demand for waterproofing agents

Carbon six waterproof and anti-fouling agent can give natural fibers, synthetic fibers and blended textiles excellent waterproof, oil-proof and anti-fouling properties. It is also particularly suitable for hydrophobic, oil-repellent and anti-fouling treatment of polyester and blended textiles; it can reach 50% washing resistance. Times or more, and will not affect the style of the fabric and the processing feels soft. It fully meets the use needs of special waterproof fields with washable requirements such as special industrial clothing, tents, and bags; fabrics exported to Europe and the United States comply with relevant standards, such as APEO, PFOA, PFOS and other banned substances.
At present, consumers have higher and higher performance requirements for textiles, and consumers are increasingly inclined to purchase functional textiles, such as fly-knit sports shoes with excellent waterproof effects, jackets with waterproof, cold-proof, warm and other characteristics, Quick-drying clothing that quickly absorbs and wicks away moisture, as well as antibacterial and anti-odor socks, etc.

Why do we need waterproofing and antifouling?

Textiles made of synthetic fibers such as polyester are highly hydrophobic and easily charged with static electricity. They are prone to deposit dirt during daily use, and oily dirt will also adhere firmly to textiles, making it difficult to remove and clean the dirt. Therefore, it is very important for textiles to have durable waterproof properties and anti-static capabilities in daily life and some special industries.

Water repellent principle of waterproofing agent

At present, the mainstream waterproofing market for textiles is carbon 8 and carbon 6 fluorocarbon products. The waterproof performance of this type of waterproofing agent mainly depends on the length of its carbon chain (that is, the fluoride content). The fluoride content embedded in the carbon chain The more fluorine elements, the longer the carbon chain. The longer the carbon chain, the greater the stability between molecules. As the stability becomes stronger, the ability to resist external water and oil stains also increases.
Due to changes in lifestyle, increasing consumer awareness and high-end demand, the demand for waterproof textiles is growing. Especially in the field of workwear, waterproof functions are becoming more and more important.
The widely used waterproofing agents on the market are fluorocarbon waterproofing agents and fluorine-free waterproofing agents. Although fluorocarbon waterproofing agents contain PFOA, POFS and other ingredients that are harmful to the environment and human health, there is currently no complete replacement for fluorocarbon waterproofing agents. Therefore, at present, fluorocarbon waterproof finishing agents are still the “mainstream force” in the textile waterproofing industry. Fluorine-free waterproof finishing agents are currently an alternative to fluorocarbon waterproof finishing agents. Although they are safe and environmentally friendly, they do not have oil-proof and anti-fouling effects. There is news that textiles containing fluorocarbons will be restricted from exporting to countries such as the European Union in 2020. Then, the production and research and development of fluorine-free waterproofing agents will receive more and more attention. With the improvement of research and development technology, fluorine-free waterproofing agents may Will become a product that completely replaces fluorocarbon waterproof finishing agent.
LeMan Polymer Technology Co., Ltd(LeMan)  Textile Auxiliaries launches ecological fluorine-free waterproofing agent products. The perfect value-added option for finishing high-end fabric styles! For more feel requirements, please contact our factory’s technical engineers for customization.