| 摘要 |
An open-weave endless fabric formed from yarns of a synthetic resin is coated sequentially with a thermosetting phenol-aldehyde resin and a thermosetting amino-aldehyde resin. The preferred synthetic yarn is nylon, but others specified include acrylics, rayon, acetate, triacetate and polyesters. The phenol-aldehyde resin, preferably containing an aldehyde-phenol molar ratio of less than 1 : 1 such as a novolac, is applied to the fabric and partially cured. Resole resins having an aldehyde-phenol molar ratio of at least 1 to 1 may also be used. The amino-aldehyde resin such as melamine-, urea- or substituted urea- or melamine-aldehyde resin may then be applied. The amino-aldehyde resin should contain sufficient available aldehyde to compensate for any deficiency of aldehyde in the phenol-aldehyde resin, thus bringing the molar ratio up to at least 1 : 1. The phenolic component may be any mono- or poly-hydric phenol, preferably mononuclear such as phenol, phloroglucinol, resorcinol, orcinol, and o-, m- and pcresols. The aldehyde may be any aldehyde containing up to 4 carbon atoms, especially formaldehyde: paraformaldehyde and hexamethylenetetramine, acrylic aldehyde and glyoxal may also be used. The amine component may be urea, thiourea, melamine or aniline. Methylated-melamine and -urea resins, and also ethylene urea-formaldehyde resins are also suitable. After curing the coated fabric, the temperature may be raised in order to set the fibre from which the fabric is woven. Specification 827,754 is referred to. |
