阅读说明：本技术 一种交联增强间位芳纶及其制备方法 (Cross-linked reinforced meta-aramid and preparation method thereof ) 是由 关振虹 任仲恺 潘士东 李丹 周绪波 杨文华 于 2019-08-30 设计创作，主要内容包括：本发明提供了一种交联增强间位芳纶及其制备方法,该方法以异氰酸酯类为交联剂,加入催化剂后在一定温度条件下处理一段时间后再水洗、烘干及热定型制备一种高强度间位芳纶；本发明制备出间位芳纶进行交联,其纤维之间结合力增加,具有优良的力学性能及耐高温性能。(The invention provides a cross-linking reinforced meta-aramid fiber and a preparation method thereof, wherein isocyanate is used as a cross-linking agent, a catalyst is added, the mixture is treated for a period of time at a certain temperature, and then the treated mixture is washed, dried and heat-set to prepare the high-strength meta-aramid fiber; the meta-aramid prepared by the method is crosslinked, the bonding force between fibers is increased, and the meta-aramid has excellent mechanical property and high temperature resistance.)

1. The cross-linked reinforced meta-aramid is characterized in that the structural formula is as follows:

Wherein n is more than or equal to 80 and less than or equal to 150, x is more than or equal to 80 and less than or equal to 150, and m is more than or equal to 80 and less than or equal to 150;

R is One or more of them.

2. A preparation method of cross-linked reinforced meta-aramid is characterized by comprising the following steps: placing meta-aramid precursor filaments in an isocyanate organic solution containing a catalyst for standing reaction to obtain the cross-linked meta-aramid; and washing, drying and heat setting the crosslinked meta-aramid to obtain the crosslinked reinforced meta-aramid.

3. The method for preparing the cross-linked reinforced meta-aramid fiber as claimed in claim 2, wherein the isocyanate is one or more of 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate, naphthalene 1, 5-diisocyanate, p-phenylene diisocyanate and triphenylmethane triisocyanate.

4. The method of claim 2, wherein the catalyst is one or two of stannous octoate, lead octoate, cobalt octoate, iron octoate, dibutyltin dilaurate, tetraisobutyl titanate, and triethylenediamine.

5. The method of claim 2, wherein the organic solvent in the organic solution is N, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone, or dimethylsulfoxide.

6. The preparation method of the crosslinked and reinforced meta-aramid fiber as claimed in claim 2, wherein the isocyanate-based organic solution containing the catalyst comprises 1-10% by mass of isocyanate, 0.5-3% by mass of the catalyst and the balance of an organic solvent.

7. The preparation method of the crosslinked and reinforced meta-aramid fiber as claimed in claim 2, wherein the meta-aramid fiber precursor is allowed to stand in an isocyanate organic solution containing a catalyst at a temperature of 40 to 150 ℃ for 5 to 60 min.

8. The preparation method of the crosslinked and reinforced meta-aramid fiber according to claim 2, wherein the crosslinked meta-aramid fiber is washed with water, dried at a temperature of 120 to 180 ℃ until the water content of the meta-aramid fiber is less than 5%, and then heat-set.

9. The preparation method of the crosslinked and reinforced meta-aramid fiber as claimed in claim 2, wherein the heat setting temperature is 200 to 400 ℃, the heat stretching ratio is 1.5 to 4 times, and the heat setting is carried out until the meta-aramid fiber is stably formed.

10. the preparation method of the crosslinked and reinforced meta-aramid fiber as claimed in any one of claims 2 to 9, wherein the meta-aramid fiber precursor is prepared by forming, washing and drying the meta-aramid fiber prepared by wet spinning.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the field of meta-aramid, and particularly relates to cross-linked reinforced meta-aramid and a preparation method thereof.

[ background of the invention ]

the meta-aramid fiber is an excellent high-temperature resistant fiber, and the total amount of the meta-aramid fiber is second to that of the special fiber. The enterprises for producing meta-aramid abroad mainly comprise DuPont, Kitasman and Korea panda, and DuPont takes the lead of realizing the meta-aramidThe method for the commercial production of the aramid fiber,the meta-aramid fiber accounts for more than half of the total global yield of the meta-aramid fiber. Domestic meta-aramid product productivity constantly increases, and product diversity is constantly abundant, and product quality constantly promotes for the meta-aramid of domestic preparation can improve market share and product competitiveness in many high-end fields.

The polyisophthaloyl metaphenylene diamine is a regularly arranged sawtooth-shaped macromolecule, has excellent performances of flame retardance, insulation, radiation resistance, high strength, high modulus and the like due to the self property, and is widely applied to the aspects of safety protection, environmental protection filtration, structural reinforcement, electrical insulation and the like in the industries of energy, traffic, chemical engineering, electronics and the like. The prior strengthening technology aiming at the meta-aramid fiber comprises a chemical method and a physical method. The physical method comprises ultraviolet ray, high-energy radiation, plasma and the like to change the wettability of the fiber, and the chemical method comprises surface activation such as etching, functional group introduction, diffusion and the like, and monomer addition for surface grafting to improve the composition and the structure of the fiber surface; however, in the process of preparing the meta-aramid by using the method, the meta-aramid has low surface energy, lacks of functional groups with chemical activity, has low reactivity, weak fiber transverse bonding force and low transverse strength, so that the meta-aramid is easy to break under the action of compression and shearing force, and the strength of the prepared meta-aramid is difficult to meet in some practical applications.

[ summary of the invention ]

The invention aims to overcome the defects of the prior art and provides a cross-linked reinforced meta-aramid and a preparation method thereof; the preparation method aims to solve the problems that meta-aramid fiber is low in surface energy, weak in transverse bonding force of fiber and low in transverse strength, so that breakage is easily caused under the action of compression and shearing force.

in order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

A cross-linked reinforced meta-aramid fiber has a structural formula:

wherein n is more than or equal to 80 and less than or equal to 150, x is more than or equal to 80 and less than or equal to 150, and m is more than or equal to 80 and less than or equal to 150;

R is One or more of them.

A preparation method of cross-linked reinforced meta-aramid comprises the following steps: placing meta-aramid precursor filaments in an isocyanate organic solution containing a catalyst for standing reaction to obtain the cross-linked meta-aramid; and washing, drying and heat setting the crosslinked meta-aramid to obtain the crosslinked reinforced meta-aramid.

The invention is further improved in that:

Preferably, the isocyanate is one or more of 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate, naphthalene 1, 5-diisocyanate, p-phenylene diisocyanate and triphenylmethane triisocyanate.

Preferably, the catalyst is one or two of stannous octoate, lead octoate, cobalt octoate, iron octoate, dibutyltin dilaurate, tetraisobutyl titanate and triethylenediamine.

Preferably, the organic solvent in the organic solution is N, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone, or dimethylsulfoxide.

Preferably, the isocyanate organic solution containing the catalyst contains 1-10% by mass of isocyanate, 0.5-3% by mass of the catalyst and the balance of an organic solvent.

Preferably, the standing reaction temperature of the meta-aramid protofilament in the isocyanate organic solution containing the catalyst is 40-150 ℃, and the time is 5-60 min.

Preferably, after the cross-linking treatment, the meta-aramid fiber is washed by water, dried at the temperature of 120-180 ℃ until the water content of the meta-aramid fiber is less than 5%, and then heat setting is carried out.

Preferably, the heat setting temperature is 200-400 ℃, the heat stretching multiple is 1.5-4 times, and the meta-aramid fiber is stably formed after heat setting.

Preferably, the meta-aramid protofilament is prepared by forming, washing and drying meta-aramid prepared by wet spinning.

Compared with the prior art, the invention has the following beneficial effects:

The invention discloses a cross-linked reinforced meta-aramid, which is characterized in that isocyanate is adopted for cross-linking in conventional meta-aramid so that covalent bond interaction is realized among molecular chains, acting force among the molecular chains and fiber compactness are increased, relative sliding displacement among the molecular chains can be reduced in the fiber stretching and deformation processes, the rigidity of the molecular chains of the fiber is improved, and the breaking tensile strength of the fiber is improved.

the invention also discloses a preparation method of the cross-linked reinforced meta-aramid, which is characterized in that the existing meta-aramid is treated by using an isocyanate organic solution containing a catalyst at a certain temperature, so that amido bonds and hydrogen on amino groups in the original molecular chains are subjected to bonding reaction with isocyanate groups, and covalent bonds are formed between adjacent molecular chains. Then, preparing the high-strength meta-aramid through the procedures of washing, drying and heat setting; in the preparation process, the solvent enables the fiber to swell, the isocyanate and the catalyst with certain concentration ensure that reactants can enter between molecular chains to react with the molecular chains, and the reaction is fully carried out at certain temperature and for certain time.

[ description of the drawings ]

FIG. 1 is a flow chart of the preparation process of the present invention.

[ detailed description ] embodiments

the invention is further described in detail by combining the specific process and the attached drawing, and provides a cross-linking reinforced meta-aramid and a preparation method thereof.

The reaction formula of the processed meta-aramid fiber process is as follows:

in the molecular formula, R is:

One or more of them.

Referring to fig. 1, the specific preparation process of the crosslinked reinforced meta-aramid fiber comprises the following steps:

step 1, preparing meta-aramid through wet spinning

Forming, washing and drying the meta-aramid spinning solution to obtain meta-aramid precursor fibers; the meta-aramid can be directly prepared by CN201510915358 or CN 200910259778.

Step 2, placing meta-aramid precursor fibers in an isocyanate organic solution containing a catalyst for treatment

Standing the meta-aramid precursor fiber in an isocyanate organic solution containing a catalyst at 40-150 ℃ for 5-60 min to obtain a treated meta-aramid fiber spun yarn; the isocyanate organic solution containing the catalyst comprises 1-10% by mass of isocyanate, 0.5-3% by mass of the catalyst and the balance of an organic solvent. The isocyanate is one or more of 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate (MDI), naphthalene 1, 5-diisocyanate (NDI), p-phenylene diisocyanate (PPDI) and triphenylmethane triisocyanate (PMDI), and when the isocyanate is more than one, the isocyanate can be mixed according to any proportion.

The catalyst is one or two of stannous octoate, lead octoate, cobalt octoate, iron octoate, dibutyltin dilaurate, tetraisobutyl titanate and triethylenediamine, and when the two catalysts are used, the two catalysts can be mixed according to any proportion.

The organic solvent in the organic solution is one of N, N-dimethylacetamide (DMAc), N-Dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO) and the like.

Step 3, washing, drying and heat setting the processed meta-aramid to prepare high-strength meta-aramid; the drying temperature is 120-180 ℃, and the drying is carried out until the moisture content of the fibers in the meta-aramid is less than 5%; the heat setting temperature is 200-400 ℃, the heat stretching multiple is 1.5-4 times, and the meta-aramid fiber is stably formed after heat setting.

The prepared meta-aramid fiber is crosslinked, the bonding force between fibers is increased, and the meta-aramid fiber has excellent mechanical property and high temperature resistance.

The process is further described below with reference to specific examples: