SYNTHETIC FIBRE HAVING SILK-LIKE SURFACE LUSTRE AND LIGHT TRANSPARENCY

摘要

1,224,368. Composite silk-like fibres. KANEGAFUCHI BOSEKI K.K., and SNIA VISCOSA SOC. NAZIONALE INDUSTRIA APPLICAZIONI VISCOSA S.p.A. 26 Aug., 1968 [25 Aug., 1967], No. 40690/68. Heading B5B. A synthetic conjugate fibre of the sheath-core type has the following properties: a core component containing at least 0À3% by weight of titanium dioxide in which the maximum particle size is 5Á and at least 50% by weight of the particles have a size less than 1Á, a sheath component containing from 0 to 0À06% by weight of the above titanium dioxide oaf crosssection shown, for example, in Fig. 1, in which the ratio of the area of the core component to the area of the sheath component is in the range 70: 30 to 40: 60, the filament having two to six concave or flat ribs and the degree of deformation, i.e. the ratio of the maximum radius to its minimum radius being in the range 1À25 to 3À0. Such filaments may be made by melt spinning. In the examples the various components given are (1), (2), (3) and (6), core component nylon-6, sheath component nylon-6; (4) core component polyethylene terephthalate, sheath component nylon-6; (5) core component nylon-6, sheath component nylon-6 but both contain 0À2% of a whitening agent; (7) core component nylon-6, sheath component nylon-6 copolymer prepared by copolymerizing #-caprolactam and hexamethylene diammonium isophthalate; (8) core component nylon-66, sheath component the nylon-6 copolymer of Example 7; (9) core component nylon 6, sheath component polyethylene terephthalate; (10) core component the polyethylene terephthalate of Example 4, sheath component the nylon-6 copolymer of Example 7; (11) core component polyethylene terephthalate, sheath component another polyethylene terephthalate having the same intrinsic viscosity; (12) core or sheath component polyethylene terephthalate and sheath or core component polyethylene oxybenzoate; (13) core component polyethylene terephthalate, sheath component a mixture of the same polyethylene terephthalate and polyethylene oxybenzoate. Unless otherwise stated the sheath and core components were of differing intrinsic viscosities. The arrangement of core and sheath component can either be concentric or eccentric depending on whether it is desired to crimp the fibres. At least three ribs are preferred but the shape of the core component of the filament is not critical and it may be of circular or non- circular cross-section. Additives such as dyeing assistants may be incorporated in either or both the sheath or core components and if the dyeing affinities of sheath and core components are different it is possible to dye them different colours. Fibres so made have a silk-like lustre and light transparency.