Textiles with chitosan core-shell particles

The present invention describes a novel antibacterial treatment on textile materials employing polymeric core-shell particles dispersing in water. These particles are prepared from a surfactant-free emulsion polymerization based on the method of U.S. Pat. No. 6,573,313 and possess average particle sizes in the assortment of 100 to 1000 nm in diameter. When applied to a textile article, the particles form a uniform coating, which prevents the growth of bacteria and germs. The treatment doesn’t affect the fabric mechanical properties, hand feeling and appearance. Antibacterial action on cotton is preserved even after 50 times of residence laundering.


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In comparison with artificial fibers, natural textiles, like those manufactured from cellulose and protein fibers, are a lot more vulnerable to microbe attack because of their hydrophilic porous construction and moisture transport characteristics. The use ofantibacterial agents to stop or retard the growth of bacteria on fabric content has been becoming a standard finishing method for fabric goods, especially for those used in hospitals, hotels, sports and personal care industries. However, there isan increasing general concerns for potential effects of antibacterial finishing on environmental and biological systems. An perfect textile antibacterial finishing should not only kill undesirable germs and stop the spread of diseases, but also besafe and environmentally benign. What’s more, the antibacterial function should be maintained for as many cycles via a home laundering procedure as possible.

Obtained from the shells of crabs, shrimps and other crustaceans, chitosan (CTS) is a non-toxic, biodegradable and biocompatible natural polymer, and has been utilized as a biopolymer and natural substance in pharmaceutical, health, papermakingand food processing industries. Due to its polycationic nature, chitosan possesses great antibacterial property against different fungi and bacteria. However, direct coating of chitosan onto textile articles has endured from four major drawbacks: 1)Chitosan doesn’t dissolve in water but rather only dissolve in acidic aqueous solution. Thus, a considerable quantity of acid is utilized during the chitosan completing process. This can cause many environmental issues as a result of strong odor and corrosiveproperty of acids. 2) The aqueous solution containing dissolved chitosan usually is rather viscous, thus the completing process is hard to deal with. 3) Chitosan is a rigid substance. It impacts the fabric hand after coating. 4) Chitosan has strongwater-absorption ability due to the existence of several polar groups. Hence the water-repellency of chitosan-treated textile goods is significantly decreased.

Chitosan-containing particles with core-parts and shell-parts have been reported by Kuwahara et al in two U.S. patents (U.S. Pat. Nos. 6,359,032 and 6,252,003) used for different applications like coloring and deodorizing agents. But, thechitosan molecules on the particle surface are not permanent due to the bodily absorption property, thus can be easily released with ecological changes like pH.

Thus today, textiles with chitosan particles have not been able to satisfactorily supply an antibacterial activity of any permanence without significant drawbacks.

IP reviewed by Plant-Grow agriculture technology news