PATENT CLAIM ANALYSIS

Application Number: 15888024
Application Type: Utility
Filing Date: 2018-02
Publication Date: 2018-06
Patent Classification: ["528", "348000"]

Abstract:
The present invention relates to a preparation method of para-aramid nanofibers, and belongs to the technical field of novel polymer materials. The para-aramid nanofibers prepared in the present invention have a diameter of 10-100 nm, and a length of hundreds of microns. The preparation method includes: adding a certain amount of surfactant in a PPTA low-temperature polymerization process, and controlling aggregation of PPTA molecules along with growth of a PPTA molecule chain, thereby preparing the para-aramid fibers with a uniform size and an adjustable nano-scale diameter under assistance of other means (e.g., a coagulator and high-speed shearing dispersion). The present invention is short in production process and simple in equipment, can realize stable batch production to meet needs of large-scale production of the para-aramid nanofibers, has wide application prospects and can be applied to preparing a lithium-ion battery separator, a high-performance composite material and the like.

Claim (Index 1):
A preparation method of para-aramid nanofibers, comprising:\n (1) modified polymerization: under nitrogen protection, adding a dewatered solvent N-methyl pyrrolidone (NMP) with moisture content lower than 150 ppm into a reaction container; adding solubilizing salt and surfactants while stirring, wherein the solubilizing salt is calcium chloride or lithium chloride; and heating to 80-100\u00b0 C. to dissolve the solubilizing salt and the surfactants to obtain a solution of the solubilizing salt and the surfactants, wherein a concentration of the solubilizing salt is 5-10 wt % and a concentration of the surfactants is 0-3 wt %; then cooling the solution to 0-15\u00b0 C., and adding the p-phenylenediamine into the reaction container for stirring and dissolving, and controlling the concentration of the p-phenylenediamine as 0.1-0.6 mol/l.; continuously cooling the solution to \u22125-5\u00b0 C., and adding terephthaloyl chloride, wherein a molar ratio of the terephthaloyl chloride to the p-phenylenediamine is (1.000-1.010):1; accelerating the stirring speed and continuously reacting for 5-30 minutes, and controlling a reaction temperature to be below 70\u00b0 C.; and stopping stirring when a gel phenomenon occurs in the reaction system before reactants are completely agglomerated, thereby obtaining frozen gel; (2) dispersing into fibers: adding a dispersing agent of N-methyl pyrrolidone into the frozen gel in the above step (1) while high-speed stirring to disperse the frozen gel into a uniform gel solution, wherein a stirring speed and stirring time are regulated according to a dispersion effect and an addition amount of the dispersing agent of N-methyl pyrrolidone is 2-10 times of the solvent used in the above step (1); adding a coagulator into the above gel solution while high-speed stirring, or injecting the above gel solution into a coagulator under high-speed stirring, thereby obtaining a suspension containing the para-aramid nanofibers, wherein the stirring speed and the stirring time are regulated according to a forming effect of the nanofibers, and the use amount of the coagulator is 2-10 times of mass of the dispersing agent; and (3) washing and purification: purifying the suspension in a manner of continuous countercurrent washing or a manner of centrifugal washing to remove the solvent, the surfactants, the solubilizing salt and other impurities, and finally dispersing with water, thereby obtaining the pure aqueous dispersion of the para-aramid nanofibers.

Metadata:
- Claim Count in Document: 5.0
- Percentile: 88.0
- Lexical Diversity: 1.75
- Patent Class: 528.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: True
- Related Applications: ['10556152', '12790236', '13765423', '12450326', '10582119']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.723733979423928
- 35 USC 102 Novelty (BERT): 0.4915506483529645
- Combined Prediction Score: 0.7005156463168316
- Mean Citation Score: 182.005568
- Max Citation Score: 208.48418
- Similarity Product: 135.59503773651838

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 0
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test