Repellents methylol compounds

There are reactive softeners, some of which are N-methylol derivatives of long-chain fatty amides (10.241) while others are triazinyl compounds (10.242). The N-methylol compounds require baking with a latent acid catalyst to effect reaction, whereas dichloro-triazines require mildly alkaline fixation conditions. The N-methylol compounds are sometimes useful for combination with crease-resist, durable-press, soil-release and water-repellent finishes. In this context, the feasibility of using silane monomers such as methyltri-ethoxysilane (10.243), vinyltriethoxysilane (10.244), vinyl triace tylsilane (10.245) and epoxypropyltrimethoxysilane (10.246) in crosslinking reactions to give crease-resist properties and softness simultaneously has been investigated [492]. 

Willard and co-workers [21] have shown that the preferred reaction site on cellulose is the primary (Ce) hydroxyl. A/-Methylol compounds can also react with other AT-methylol compounds and form resins by self-condensation. The reaction with cellulose is, therefore, accompanied by the formation of resinous products in varying amounts. Because A/-methylol compounds can react with compounds that have an active hydrogen atom (e.g., alcohols, amines, and carboxylic acids), they are very useful for introducing hydrophobes into the repellent molecule. Because acids catalyze the self-condensation to resins, N-methy-lol compounds are converted with an alcohol, usually methyl alcohol, to ethers, which are more stable and can be reacted with a long-chain fatty acid to form the repellent molecule. 

Chemical reactions other than those of pyridinium and methylol compounds have been explored in an effort to bond the hydrophobic species covalently to the fiber and produce a durable water-repellent finish. 

Because the cure conditions of the polysiloxane water repellents are similar to durable press cross-linking treatments with methylol compounds, polysiloxanes can be coapplied with a durable press finish [80]. The durable press resins enhance the durability of the silicone water repellent [ 78]. 

A -Methylol chemistry, utilized for cross-linking of cellulose, has also been successfully exploited as a means for producing durable water repellents. A/ -Methy-lol compounds are prepared by reacting an amine or amide with formaldehyde ... 

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