Method for Preparing Multifunctional Composite Modified Masterbatch

A method for preparing a multifunctional composite modified masterbatch, comprising the following steps:

• (1) preparation of a composition A comprising a far-infrared negative ion-carried carrier resin:
• mixing a carrier resin, a curing agent, and a solvent to be uniform to obtain a mixture a;
• preparing a stone needle-tourmaline mixed powder b with a particle size of 1 μm or less by using an ultrafine pulverizer;
• feeding the mixture a and the stone needle-tourmaline mixed powder b into a mixing device to obtain a homogeneous mixed slurry c;
• discharging and stirring the homogeneous mixed slurry c at a heating temperature of 50° C. to 110° C. to obtain a concentrated slurry with a volume of 50% of an original volume;
• and subjecting the concentrated slurry to vacuum filtration to obtain a filter cake with a functional component content of 10% to 20%, and washing and drying the filter cake to obtain the composition A for later use;
• (2) preparation of a surface-modified antibacterial nano-powder B:
• feeding an antibacterial nano-powder with a particle size of 10 nm to 100 nm into a high-speed kneading machine with a temperature set as 70° C. to 120° C. and a rotational speed set as 500 r/min, and adding a surface modifier at an amount of 5 wt % of the antibacterial nano-powder by a metering device;
• adjusting the temperature to 20° C. to 40° C. and the rotational speed to 1,500 r/min, and conducting high-speed mixing for 1 h;
• and reducing the rotational speed to 500 r/min, continuing mixing for another 1 h, and discharging to obtain the surface-modified antibacterial nano-powder B, wherein the antibacterial nano-powder with the particle size of 10 nm to 100 nm is one selected from the group consisting of nano-silver, nano-copper, and nano-zinc and the surface modifier is selected from the group consisting of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltris(β-methoxyethoxy)silane;
• (3) preparation of a compound resin C with a compound flame-retardant function:
• mixing a flame-retardant microcapsule, a flame-retardant agent, and a carrier resin to be uniform in a mixing device, and discharging to obtain the compound resin C, wherein the flame-retardant microcapsule comprises diantimony trioxide, hydrated zinc borate, and dibromomethane in a mass ratio of 1:6:1;
• the flame-retardant agent comprises aluminum hydroxide and whitened red phosphorus in a mass ratio of 4:3;
• and in the compound resin C, a ratio of a total mass of the flame-retardant microcapsule and the flame-retardant agent to a mass of the carrier resin is in a range of 2:23 to 4:21;
• and
• (4) feeding the composition A, the antibacterial nano-powder B, the compound resin C, and a carrier resin into a twin-screw extruder according to a mass ratio of 10:10:20:23, and conducting extrusion and granulation at a processing temperature of 150° C. to 250° C. to obtain the multifunctional composite modified masterbatch with a functional component content of 10% to 20%.