A kind of high-viscosity PBT material for optical cable and preparation method thereof

Abstract

The invention discloses a high-viscosity PBT material for an optical cable and a preparation method thereof. The PBT material is obtained by freezing a part of the PBT resin and then grinding it into powder for use; then mixing the obtained powder PBT with a chain extender in The auxiliary agent in the mixture is premixed, and then the remaining unground granular PBT is added, and the high-viscosity PBT material for optical cables is obtained through heating and melting, mixing reaction, air exhaust, vacuum exhaust, and extrusion granulation. The intrinsic viscosity of the obtained PBT material is above 1.3dL / g, and the viscosity stability is good, which can effectively avoid the bulging phenomenon in the loose tube production line, and has no adverse effect on its mechanical strength and other properties. The method for preparing PBT materials provided by the invention has easy-to-obtain raw materials, simple procedures, no complicated and expensive equipment, and can be completed by a twin-screw extruder. It is an economical and efficient method for producing high-viscosity PBT materials for optical cables. Suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of polyester materials, in particular to a high-viscosity PBT material for optical cables and a preparation method thereof. Background technique [0002] At present, 5G technology is developing rapidly. As the infrastructure in the 5G era, optical cables will play a key role in future development. The industry's requirements for loose tubes of optical cables are also getting higher and higher. Generally, loose tubes are equipped with several parallel optical fibers, which require loose tubes with large diameters, stable apertures, and appropriate rigidity and flexibility. [0003] At present, loose tubes for optical cables and optical fibers are mainly PBT materials. The full name of PBT is polybutylene terephthalate, which has high tensile strength and elongation at break, and can maintain stability in high temperature and humid environments. , Its excellent comprehensive properties make PBT resin widely used in var...

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Problems solved by technology

[0006] However, as optical cable manufacturers have higher and higher requirements for the pultrusion speed of optical cables, the requirements for PBT materials for optical cables are also getting higher and higher. The methods mentioned in the above patents are also facing more and more challenges. The prepared The material cannot meet the increasingly stringent requirements of downstream customers, mainly reflected in the following points: (1) In the process of thickening PBT materials, several additives need to be added. These additives are all in powder form, and some additives The melting point of the PBT optical cable is still relatively low, and it will melt at the mouth of the feeding hopper, which affects the accuracy of the addition, and finally leads to the unevenness of the prepared PBT optical cable material, and the thickness and diameter of the prepared optical cable loose tube. Bulging is prone to occur in some places, causing complaints; (2) Since the proportion of various additives added is relatively small, and they must be mixed in the PBT resin in the form of particles, the specific surface area of ​​PBT particles is small, and the mixing cannot be uniform The effect of dispersion, and thus the viscosity consistency of the viscosified particles cannot be achieved

The viscosity of the high-viscosity PBT resin produced by this method is not easy to control, the color is yellowish, and the molecular chain is unstable and easy to degrade. It is difficult to meet the quality requirements of the current optical cable industry for raw materials.

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