3 results about "Intrinsic viscosity" patented technology

Disclosed is a polytrimethylene terephtalate conjugate fiber having high self-crimpability, which is prepared by conjugate-spinning two types of polytrimethylene terephtalates having different intrinsic viscosities in which a difference between the intrinsic viscosities ranges from 0.05 to 0.15 into a side-by-side fiber. Also, the polytrimethylene terephtalate conjugate fiber prepared by the conjugate-spinning undergoes a false twisting process, leading to development of three-dimensional high self crimpability and sufficient bulky property in the resulting fiber.

The invention discloses hygrothermal-aging-resistant polyester, a polyester film and a preparation method of the polyester film. The hygrothermal-aging-resistant polyester is prepared from the following raw material: basic polyester, wherein the intrinsic viscosity of the basic polyester is 0.45 dL / g-0. 65 dL / g, and the concentration of terminal carboxyl groups of the basic polyester is 10 mol / t-18 mol / t. The intrinsic viscosity of the hygrothermal-aging-resistant polyester is 0.65 dL / g to 1.00 dL / g, and the concentration of carboxyl-terminated groups of the hygrothermal-aging-resistant polyester is 5 mol / t to 10.0 mol / t. According to the invention, an inorganic additive is introduced and a two-step method is adopted to prepare the hygrothermal-aging-resistant polyester. The invention also provides a polyester film and a preparation method thereof. The tensile elongation retention rate of a hygrothermal-aging-resistant polyester film sample strip within 72 hours is 75% or above, the hygrothermal aging resistance of the damp-heat aging-resistant polyester film sample strip is improved by 5 times or above compared with the hygrothermal aging resistance of conventional hygrothermal-aging-resistant polyester, and the hygrothermal-aging-resistant polyester film sample strip has the characteristic of remarkable hygrothermal aging resistance.