CN112533403A

CN112533403A - High-strength instrument shell and production process thereof

Info

Publication number: CN112533403A
Application number: CN202011476274.XA
Authority: CN
Inventors: 金子豪; 段海涯; 朱坚
Original assignee: Hangzhou Shunhao Metalwork Co ltd
Current assignee: Hangzhou Shunhao Metalwork Co ltd
Priority date: 2021-01-09
Filing date: 2021-01-09
Publication date: 2021-03-19

Abstract

The invention discloses a high-strength instrument shell which comprises a perspective window, a protective sleeve and a polymer shell, wherein the polymer shell comprises the following raw materials in parts by weight: 60-80 parts of PC/ABS alloy, 15-30 parts of composite gel, 1-3 parts of composite anti-aging agent, 0.3-2 parts of coupling agent, 0.3-0.5 part of lubricant, 0.1-0.8 part of antibacterial agent and 1-2 parts of toughening agent; the invention also discloses a production process of the high-strength instrument shell, and the PC/ABS alloy has excellent processability, heat resistance and impact resistance, the composite gel has high heat conduction, corrosion resistance, flame retardance, shielding and other properties, and the composite anti-aging agent can improve the anti-aging capacity and weather resistance of the polymer.

Description

High-strength instrument shell and production process thereof

Technical Field

The invention belongs to the technical field of instrument shell preparation, and particularly relates to a high-strength instrument shell and a production process thereof.

Background

The instrument shell is a scientific and technological product, mainly plays a role in protecting internal elements, generally comprises elements such as a shell, a panel, a lining plate and a support, adopts high-quality aluminum alloy profiles as a main body, has the characteristics of reasonable design, firm structure, attractive appearance and the like, is widely applied to industries such as instruments, electronics, communication, automation, sensors, smart cards, industrial control, precision machinery and the like, and is an ideal box body of high-grade instruments. The surface treatment adopts electrostatic spraying, and the color is white, dark gray, black, army green and the like.

Most of the existing instrument shells are formed by injection molding of ABS engineering plastics, ABS has the characteristics of good mechanical property, good wear resistance and impact resistance, so that ABS is widely applied to instrument shell materials, ABS is opaque granules in ivory color, is nontoxic, tasteless, has an oxygen index of 18.2, belongs to flammable polymers, has high impact strength and surface hardness in a wide temperature range, is high in stability and good in oil resistance, but poor in heat resistance and weather resistance, and can be discolored by ultraviolet rays.

Disclosure of Invention

The invention aims to provide a high-strength instrument shell and a production process thereof.

The technical problems to be solved by the invention are as follows:

in the prior art, the instrument shell has the defects of high brittleness, impact resistance, poor heat resistance and weather resistance, color change caused by ultraviolet rays, poor electromagnetic shielding effect and cracking, aging, even melting and burning and the like in practical application.

The purpose of the invention can be realized by the following technical scheme:

a high-strength instrument shell comprises a perspective window, a protective sleeve and a polymer shell, wherein the perspective window is positioned in the protective sleeve and fixedly connected with the protective sleeve;

the perspective window is made of transparent glass, and the protective sleeve is made of stainless steel materials or aluminum alloy materials;

the polymer shell comprises the following raw materials in parts by weight: 60-80 parts of PC/ABS alloy, 15-30 parts of composite gel, 1-3 parts of composite anti-aging agent, 0.3-2 parts of coupling agent, 0.3-0.5 part of lubricant, 0.1-0.8 part of antibacterial agent and 1-2 parts of toughening agent;

the polymer shell is prepared by the following steps:

adding a PC/ABS alloy into a reaction kettle, heating to 240 ℃ at a heating rate of 5 ℃/min, preserving heat, heating for 6min, adding a composite gel and a toughening agent into the reaction kettle, stirring for 20min under the condition of a rotation speed of 400r/min, adding a coupling agent into the reaction kettle, stirring for 5min at a constant rotation speed, adding a composite anti-aging agent, a lubricant and an antibacterial agent, and continuously stirring for 1.5h to obtain a mixture;

secondly, transferring the mixture into a screw extruder for extrusion granulation, controlling the temperature of each zone from the main feed inlet to the extrusion die head to be 190 ℃ in the first zone, 200 ℃ in the second zone, 200 ℃ in the third zone, 220 ℃ in the fourth zone, 240 ℃ in the fifth zone, 260 ℃ in the third zone, 270 ℃ in the sixth zone and 65Hz in the main machine to obtain the master batch;

and thirdly, drying the master batch in a ventilation drying oven at 90 ℃ for 6 hours, and then performing injection molding by using an injection molding machine at the injection molding temperature of 285 ℃ to obtain the high polymer shell.

Further, the composite gel is prepared by the following steps:

step S11, adding sulfuric acid and nitric acid into a beaker according to a volume ratio of 3:1, setting a rotating speed of 1200r/min, controlling the temperature to be 60 ℃, magnetically stirring for 20min to obtain a mixed acid solution, adding carbon nanotubes into the mixed acid solution, adding the carbon nanotubes in equal amount for two times, continuously stirring for 2-3h at the constant rotating speed, cooling to room temperature, adding deionized water, stirring for 10min at the rotating speed of 60r/min, vacuum-filtering, washing a filter cake with distilled water until the washing liquid is neutral, freezing for 3-4h at-18 ℃, transferring to a freeze dryer, and freeze-drying for 48h at-45 ℃ to obtain an intermediate 1;

step S12, adding absolute ethyl alcohol into a reactor, adding ammonia water with the mass fraction of 50% and the intermediate 1 into the reactor, performing ultrasonic dispersion for 30min at the frequency of 30-50kHz, setting the rotating speed to be 1500r/min, magnetically stirring for 15min to obtain a suspension, dropwise adding tetraethoxysilane into the suspension, finishing the dropwise adding within 3 min, after finishing the dropwise adding, transferring the suspension to a magnetic stirrer, setting the rotating speed to 1000r/min, stirring for 12h at room temperature, centrifuging at a rotation speed of 5000r/min and a temperature of 20 deg.C for 5min, after centrifuging, pouring off the upper layer waste liquid, adding deionized water for centrifuging again, repeating the centrifuging step for 3-4 times, carrying out vacuum filtration, washing a filter cake for 4-5 times by using an ethanol solution with the mass fraction of 30%, and finally carrying out freeze drying at-45 ℃ for 48 hours to obtain an intermediate 2;

step S13, adding the intermediate 2 and toluene into a beaker, heating in a water bath to 80-85 ℃, then adding a silane coupling agent into the beaker, heating to boiling reflux, keeping the reflux state, reacting for 8-12h, then cooling to room temperature, filtering, washing a filter cake for 2 times by using ethanol and deionized water respectively, and finally freeze-drying to obtain an intermediate 3; adding graphene oxide, the intermediate 3, p-aniline and dimethyl sulfoxide into a reaction kettle, performing ultrasonic dispersion for 10min at the frequency of 35kHz, performing heat preservation reaction for 2h at the temperature of 60 ℃, performing suction filtration, washing a filter cake for 3-5 times by using an ethanol solution with the mass fraction of 35%, and finally drying in a 65 ℃ drying oven to constant weight to obtain an intermediate 4;

step S14, adding aramid fiber, potassium tert-butoxide and dimethyl sulfoxide into a reaction container according to the mass ratio of 2:2:96, magnetically stirring for 48 hours at 40 ℃ to obtain aramid fiber dispersion liquid, adding the intermediate 4 and dimethyl sulfoxide into a beaker according to the mass ratio of 2:98, ultrasonically dispersing for 20 minutes at the frequency of 45kHz to obtain intermediate 4 dispersion liquid, adding the aramid fiber dispersion liquid and the intermediate 4 dispersion liquid into a reaction kettle according to the mass ratio of 20:13-14, and mixing for 30 minutes at the rotation speed of 200 and 300r/min to obtain the composite gel.

Further, in the step S11, the dosage ratio of the mixed acid solution to the carbon nanotubes is 200 mL: 1-3; in the step S12, the dosage ratio of the absolute ethyl alcohol, the ammonia water, the intermediate 1 and the tetraethoxysilane is 500 mL: 16-20 mL: 0.5 g: 20 mL; the dosage ratio of the intermediate 2, the toluene and the silane coupling agent in the step S13 is 1 g: 10mL of: 4-5mL, wherein the silane coupling agent is selected from one of silane coupling agents KH-550, KH-450 or KH-792, and the dosage ratio of the graphene oxide, the intermediate 3, the p-aniline and the dimethyl sulfoxide is 1 g: 1 g: 4 g: 50-80 mL.

Treating a carbon nano tube by a mixed acid solution, leading active groups such as hydroxyl, carboxyl and the like to be introduced on the surface of the carbon nano tube, taking tetraethoxysilane as a raw material, coating silicon dioxide on the surface of an intermediate 1, grafting amino groups on the surface of the silicon dioxide by a silane coupling agent, grafting an intermediate 3 and p-phenylenediamine on the surface of graphene oxide in a dimethyl sulfoxide solution, leading the surface of the graphene oxide to be rich in-OH and-COOH and to generate chemical reactions such as substitution, amide and the like, leading the graphene oxide to be tightly crosslinked with the intermediate 3 and the p-phenylenediamine to obtain an intermediate 4, mixing aramid fibers, potassium tert-butoxide and dimethyl sulfoxide, deprotonating hydrogen atoms of amide groups in the aramid molecules in a strong base solution, weakening hydrogen bonds among polymer chains, preparing the intermediate 4 into a dispersion liquid, and leading the intermediate 4 to be uniformly distributed in gaps among the aramid fibers, a complex gel was obtained.

Further, the preparation method of the composite anti-aging agent comprises the following steps:

step S21, adding 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile into a four-neck flask, heating to 70-75 ℃, reacting for 8h under the protection of nitrogen and at the rotating speed of 100-200r/min, transferring the product in the flask into a rotary evaporator for rotary evaporation after the reaction is finished, evaporating the solvent at the temperature of 110-130 ℃, and then cooling and crystallizing to obtain an anti-aging agent A;

and S22, uniformly mixing the anti-aging agent A obtained in the step S21, the nano titanium dioxide and the nano zinc oxide according to the mass ratio of 2:1:1 to obtain the composite anti-aging agent.

Further, in step S21, 10g of 2,2,6, 6-tetramethyl-4-piperidyl stearate, toluene, benzoyl peroxide and azobisisobutyronitrile: 100-150 mL: 0.1 g: 0.1 g.

The 2,2,6, 6-tetramethyl-4-piperidine stearate is used as a functional monomer, benzoyl peroxide and azodiisobutyronitrile are used as initiators, the monomer is polymerized, the problems that a low-molecular anti-aging agent is poor in compatibility with a high-molecular material, easy to migrate, volatilize, exude and poor in oil resistance and the like are solved, the nano zinc oxide and the nano titanium dioxide can well absorb and reflect ultraviolet rays in sunlight, the ultraviolet rays are effectively prevented from entering the high-molecular material, the high-molecular material is protected, the anti-aging agent A, the nano zinc oxide and the nano titanium dioxide are compounded to prepare the organic anti-aging agent and the inorganic anti-aging agent, and the anti-aging capacity and the weather resistance of the polymer are improved in a synergistic.

Further, the coupling agent is one or more of vinyl triethoxysilane, gamma-aminopropyl triethoxysilane, gamma-glycidoxypropyl trimethoxysilane and an aluminate coupling agent which are mixed according to any proportion.

Further, the lubricant is one of silicone oil, white oil, silicone, N-ethylene bis stearamide and calcium stearate.

Further, the toughening agent is one of maleic anhydride grafted linear low density polyethylene and methyl methacrylate-butadiene-styrene terpolymer.

Further, the antibacterial agent is one or two of nano silver oxide and polyhexamethylene guanidine phosphate which are mixed according to any proportion.

Further, a production process of the high-strength instrument shell comprises the following steps:

and sleeving the protective sleeve on the outer side of the perspective window, and then connecting the polymer shell with the protective sleeve through threads to obtain the high-strength instrument shell.

The invention has the beneficial effects that:

1. the invention prepares a high-strength meter shell by a perspective mirror window, a protective sleeve and a high-molecular shell, wherein the protective sleeve is made of stainless steel or aluminum alloy material and has the characteristics of high hardness and wear resistance, the protective sleeve is in threaded connection with the high-molecular shell, so that the meter shell is convenient to maintain and disassemble, a PC/ABS alloy is used as a main material, and the high-strength meter shell is prepared by adding composite gel, composite anti-aging agent and other auxiliary additives, forming by injection molding and demoulding The anti-aging, flame-retardant and heat-dissipation and electromagnetic shielding performance of the instrument shell has excellent performance which can not be compared with the prior instrument shell, and has huge application prospect in the electronic instrument shell.

2. The carbon nano tube and the graphene oxide both have high heat conduction, high electric conduction and corrosion resistance, in order to improve the dispersibility of the carbon nano tube and the graphene oxide in a polymer, an intermediate 4 is prepared through chemical reaction, and finally the intermediate 4 is combined with aramid fiber to prepare the composite gel, wherein the aramid fiber forms a three-dimensional communicated network structure, the intermediate 4 is filled in the network structure to endow the composite gel with good heat conduction performance and electric conduction performance, in addition, because inorganic particles have absorption and reflection effects on electromagnetic waves, the electromagnetic shielding performance of the composite material is further influenced, due to the existence of the carbon nano tube, the silicon dioxide and the graphene oxide, when the composite material is subjected to external stress, the inorganic particles and the polymer form cross-linking points, and the strong and weak interface effect between the particles and a matrix not only increases the crack propagation path, meanwhile, crack shielding is generated, partial stress is dispersed, energy can be absorbed to delay deformation of the composite material, and aramid fiber has the characteristics of ultrahigh strength, high modulus, high temperature resistance, acid and alkali resistance and light weight and has outstanding flame retardance, so that the heat resistance, flame retardance, heat dissipation, electromagnetic shielding and other properties of the polymer shell are improved due to the addition of the composite gel.

3. The 2,2,6, 6-tetramethyl-4-piperidine stearate is used as a functional monomer, benzoyl peroxide and azodiisobutyronitrile are used as initiators, the monomer is polymerized, the problems that a low-molecular anti-aging agent is poor in compatibility with a high-molecular material, easy to migrate, volatilize, exude and poor in oil resistance and the like are solved, the nano zinc oxide and the nano titanium dioxide can well absorb and reflect ultraviolet rays in sunlight, the ultraviolet rays are effectively prevented from entering the high-molecular material, the high-molecular material is protected, the anti-aging agent A, the nano zinc oxide and the nano titanium dioxide are compounded to prepare the organic anti-aging agent and the inorganic anti-aging agent, and the anti-aging capacity and the weather resistance of the polymer are improved in a synergistic.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a high strength instrument housing according to the present invention;

fig. 2 is a schematic side view of a high-strength instrument housing according to the present invention.

The reference numerals in the drawings represent the following: 1. a perspective window; 2. a protective sleeve; 3. a polymer shell.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Referring to fig. 1-2, a high-strength instrument housing includes a perspective window 1, a protective sleeve 2 and a polymer housing 3, wherein the perspective window 1 is located inside the protective sleeve 2, the perspective window 1 is fixedly connected with the protective sleeve 2, an external thread is arranged at one end of the protective sleeve 2 far away from the perspective window 1, the polymer housing 3 is a cylinder with a closed and hollow end, an internal thread matched with the protective sleeve 2 is arranged at the end of the polymer housing 3 far away from the closed end, and the polymer housing 3 is in threaded connection with the protective sleeve 2;

the perspective window 1 is made of transparent glass, and the protective sleeve 2 is made of stainless steel materials;

the polymer shell 3 comprises the following raw materials in parts by weight: 60 parts of PC/ABS alloy, 15 parts of composite gel, 1 part of composite anti-aging agent, 0.3 part of coupling agent, 0.3 part of lubricant, 0.1 part of antibacterial agent and 1 part of toughening agent;

the polymer shell 3 is prepared by the following steps:

secondly, transferring the mixture into a screw extruder for extrusion granulation, and controlling the temperature of each zone from a main feed inlet to an extrusion die head to be 190 ℃ in a first zone, 200 ℃ in a second zone, 220 ℃ in a third zone, 240 ℃ in a fourth zone, 260 ℃ in a fifth zone, 275 ℃ in a sixth zone, and the rotating speed of a main machine to be 65Hz to obtain master batch;

and thirdly, drying the master batch in a ventilation drying oven at 90 ℃ for 6 hours, and then performing injection molding by using an injection molding machine at the injection molding temperature of 285 ℃ to obtain the polymer shell 3.

Wherein the composite gel is prepared by the following steps:

step S11, adding sulfuric acid and nitric acid into a beaker according to a volume ratio of 3:1, setting a rotating speed of 1200r/min, controlling the temperature to be 60 ℃, magnetically stirring for 20min to obtain a mixed acid solution, adding carbon nanotubes into the mixed acid solution, adding the carbon nanotubes in equal amount for two times, continuously stirring for 2h at a constant rotating speed, cooling to room temperature, adding deionized water, stirring for 10min at a rotating speed of 60r/min, performing vacuum filtration, washing a filter cake with distilled water until the washing liquid is neutral, then freezing for 3h at-18 ℃, transferring to a freeze dryer, and performing freeze drying for 48h at-45 ℃ to obtain an intermediate 1;

step S12, adding absolute ethyl alcohol into a reactor, adding ammonia water with the mass fraction of 50% and an intermediate 1 into the reactor, performing ultrasonic dispersion at the frequency of 30kHz for 30min, setting the rotation speed to be 1500r/min, performing magnetic stirring for 15min to obtain a suspension, dropwise adding tetraethoxysilane into the suspension, finishing dropwise adding within 3 min, transferring the suspension onto a magnetic stirrer after finishing dropwise adding, setting the rotation speed to be 1000r/min, performing centrifugal treatment at the rotation speed of 5000r/min and the temperature of 20 ℃ for 5min after stirring for 12h at room temperature, pouring the upper-layer waste liquid after finishing the centrifugal treatment, adding deionized water for centrifuging again, repeating the centrifugal step for 3 times, performing vacuum filtration, washing a filter cake for 4-5 times by using an ethanol solution with the mass fraction of 30%, and finally performing freeze drying at-45 ℃ for 48h to obtain an intermediate 2;

step S13, adding the intermediate 2 and toluene into a beaker, heating in a water bath to 80 ℃, then adding a silane coupling agent into the beaker, heating to boil and reflux, keeping the reflux state for reacting for 8 hours, then cooling to room temperature, filtering, washing a filter cake for 2 times by using ethanol and deionized water respectively, and finally freeze-drying to obtain an intermediate 3; adding graphene oxide, the intermediate 3, p-aniline and dimethyl sulfoxide into a reaction kettle, performing ultrasonic dispersion for 10min at the frequency of 35kHz, performing heat preservation reaction for 2h at the temperature of 60 ℃, performing suction filtration, washing a filter cake for 3 times by using an ethanol solution with the mass fraction of 35%, and finally drying in a 65 ℃ oven to constant weight to obtain an intermediate 4;

step S14, adding aramid fiber, potassium tert-butoxide and dimethyl sulfoxide into a reaction container according to the mass ratio of 2:2:96, magnetically stirring for 48 hours at 40 ℃ to obtain an aramid fiber dispersion liquid, adding the intermediate 4 and dimethyl sulfoxide into a beaker according to the mass ratio of 2:98, ultrasonically dispersing for 20 minutes at the frequency of 45kHz to obtain an intermediate 4 dispersion liquid, adding the aramid fiber dispersion liquid and the intermediate 4 dispersion liquid into a reaction kettle according to the mass ratio of 20:13-14, and mixing for 30 minutes at the rotating speed of 200r/min to obtain the composite gel.

Wherein the using amount ratio of the mixed acid solution to the carbon nano tube in the step S11 is 200 mL: 1g of a compound; in the step S12, the dosage ratio of the absolute ethyl alcohol, the ammonia water, the intermediate 1 and the tetraethoxysilane is 500 mL: 16mL of: 0.5 g: 20 mL; the dosage ratio of the intermediate 2, the toluene and the silane coupling agent in the step S13 is 1 g: 10mL of: 4mL, wherein the silane coupling agent is a silane coupling agent KH-550, and the dosage ratio of the graphene oxide, the intermediate 3, the p-aniline and the dimethyl sulfoxide is 1 g: 1 g: 4 g: 50 mL.

The preparation method of the composite anti-aging agent comprises the following steps:

step S21, adding 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile into a four-neck flask, heating to 70 ℃, reacting for 8 hours under the protection of nitrogen and at the rotating speed of 100r/min, transferring a product in the flask into a rotary evaporator for rotary evaporation after the reaction is finished, evaporating a solvent at 110 ℃, and then cooling and crystallizing to obtain an anti-aging agent A;

Wherein, in step S21, the contents of 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile are 10 g: 100mL of: 0.1 g: 0.1 g.

The coupling agent is vinyl triethoxysilane, the lubricant is silicone oil, the toughening agent is maleic anhydride grafted linear low density polyethylene, and the antibacterial agent is nano silver oxide.

Example 2

A high-strength instrument shell comprises a perspective window 1, a protective sleeve 2 and a polymer shell 3, wherein the perspective window 1 is positioned inside the protective sleeve 2, the perspective window 1 is fixedly connected with the protective sleeve 2, an external thread is arranged at one end, away from the perspective window 1, of the protective sleeve 2, the polymer shell 3 is a hollow cylinder with a closed end, an internal thread matched with the protective sleeve 2 is arranged at the end, away from the closed end, of the polymer shell 3, and the polymer shell 3 is in threaded connection with the protective sleeve 2;

the polymer shell 3 comprises the following raw materials in parts by weight: 70 parts of PC/ABS alloy, 20 parts of composite gel, 2 parts of composite anti-aging agent, 1 part of coupling agent, 0.4 part of lubricant, 0.5 part of antibacterial agent and 1.5 parts of toughening agent;

the polymer shell 3 is prepared by the following steps:

secondly, transferring the mixture into a screw extruder for extrusion granulation, and controlling the temperature of each zone from a main feed inlet to an extrusion die head to be 185 ℃ in a first zone, 195 ℃ in a second zone, 210 ℃ in a third zone, 230 ℃ in a fourth zone, 250 ℃ in a fifth zone and 272 ℃ in a sixth zone, and the rotating speed of a main machine to be 65Hz to obtain master batch;

Wherein the composite gel is prepared by the following steps:

step S11, adding sulfuric acid and nitric acid into a beaker according to a volume ratio of 3:1, setting a rotating speed of 1200r/min, controlling the temperature to be 60 ℃, magnetically stirring for 20min to obtain a mixed acid solution, adding carbon nanotubes into the mixed acid solution, adding the carbon nanotubes in equal amount for two times, continuously stirring for 2.5h at the constant rotating speed, cooling to room temperature, adding deionized water, stirring for 10min at the rotating speed of 60r/min, vacuum-filtering, washing a filter cake with distilled water until a washing solution is neutral, freezing for 3.5h at-18 ℃, transferring to a freeze dryer, and freeze-drying for 48h at-45 ℃ to obtain an intermediate 1;

step S12, adding absolute ethyl alcohol into a reactor, adding ammonia water with the mass fraction of 50% and an intermediate 1 into the reactor, performing ultrasonic dispersion for 30min at the frequency of 40kHz, setting the rotation speed to be 1500r/min, performing magnetic stirring for 15min to obtain a suspension, dropwise adding tetraethoxysilane into the suspension, finishing dropwise adding within 3 min, transferring the suspension onto a magnetic stirrer after finishing dropwise adding, setting the rotation speed to be 1000r/min, performing centrifugal treatment for 5min at the rotation speed of 5000r/min and the temperature of 20 ℃ after stirring for 12h at room temperature, pouring upper-layer waste liquid after finishing centrifuging, adding deionized water for centrifuging again, repeating the centrifuging step for 3 times, performing vacuum suction filtration, washing a filter cake for 4 times by using an ethanol solution with the mass fraction of 30%, and finally performing freeze drying for 48h at the temperature of minus 45 ℃ to obtain an intermediate 2;

step S13, adding the intermediate 2 and toluene into a beaker, heating in a water bath to 82 ℃, then adding a silane coupling agent into the beaker, heating to boil and reflux, keeping the reflux state for reaction for 10 hours, then cooling to room temperature, filtering, washing a filter cake for 2 times by using ethanol and deionized water respectively, and finally freeze-drying to obtain an intermediate 3; adding graphene oxide, the intermediate 3, p-aniline and dimethyl sulfoxide into a reaction kettle, performing ultrasonic dispersion for 10min at the frequency of 35kHz, performing heat preservation reaction for 2h at the temperature of 60 ℃, performing suction filtration, washing a filter cake for 4 times by using an ethanol solution with the mass fraction of 35%, and finally drying in a 65 ℃ oven to constant weight to obtain an intermediate 4;

step S14, adding aramid fiber, potassium tert-butoxide and dimethyl sulfoxide into a reaction container according to the mass ratio of 2:2:96, magnetically stirring for 48 hours at 40 ℃ to obtain an aramid fiber dispersion liquid, adding the intermediate 4 and dimethyl sulfoxide into a beaker according to the mass ratio of 2:98, ultrasonically dispersing for 20 minutes at the frequency of 45kHz to obtain an intermediate 4 dispersion liquid, adding the aramid fiber dispersion liquid and the intermediate 4 dispersion liquid into a reaction kettle according to the mass ratio of 20:13, and mixing for 30 minutes at the rotating speed of 250r/min to obtain the composite gel.

Wherein the using amount ratio of the mixed acid solution to the carbon nano tube in the step S11 is 200 mL: 2g of the total weight of the mixture; in the step S12, the dosage ratio of the absolute ethyl alcohol, the ammonia water, the intermediate 1 and the tetraethoxysilane is 500 mL: 18mL of: 0.5 g: 20 mL; the dosage ratio of the intermediate 2, the toluene and the silane coupling agent in the step S13 is 1 g: 10mL of: 4mL, wherein the silane coupling agent is a silane coupling agent KH-550, and the dosage ratio of the graphene oxide, the intermediate 3, the p-aniline and the dimethyl sulfoxide is 1 g: 1 g: 4 g: 60 mL.

step S21, adding 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile into a four-neck flask, heating to 72 ℃, reacting for 8 hours under the protection of nitrogen and at the rotating speed of 150r/min, transferring a product in the flask into a rotary evaporator for rotary evaporation after the reaction is finished, evaporating a solvent at the temperature of 110-;

Wherein, in step S21, the contents of 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile are 10 g: 120mL of: 0.1 g: 0.1 g.

Example 3

the polymer shell 3 comprises the following raw materials in parts by weight: 80 parts of PC/ABS alloy, 30 parts of composite gel, 3 parts of composite anti-aging agent, 2 parts of coupling agent, 0.5 part of lubricant, 0.8 part of antibacterial agent and 2 parts of toughening agent;

the polymer shell 3 is prepared by the following steps:

Wherein the composite gel is prepared by the following steps:

step S11, adding sulfuric acid and nitric acid into a beaker according to a volume ratio of 3:1, setting a rotating speed of 1200r/min, controlling the temperature to be 60 ℃, magnetically stirring for 20min to obtain a mixed acid solution, adding carbon nanotubes into the mixed acid solution, adding the carbon nanotubes in equal amount for two times, continuously stirring for 3h at a constant rotating speed, cooling to room temperature, adding deionized water, stirring for 10min at a rotating speed of 60r/min, vacuum-filtering, washing a filter cake with distilled water until the washing liquid is neutral, freezing for 4h at-18 ℃, transferring to a freeze dryer, and freeze-drying for 48h at-45 ℃ to obtain an intermediate 1;

step S12, adding absolute ethyl alcohol into a reactor, adding ammonia water with the mass fraction of 50% and an intermediate 1 into the reactor, performing ultrasonic dispersion at the frequency of 50kHz for 30min, setting the rotation speed to be 1500r/min, performing magnetic stirring for 15min to obtain a suspension, dropwise adding tetraethoxysilane into the suspension, finishing dropwise adding within 3 min, transferring the suspension onto a magnetic stirrer after finishing dropwise adding, setting the rotation speed to be 1000r/min, performing centrifugal treatment at the rotation speed of 5000r/min and the temperature of 20 ℃ for 5min after stirring for 12h at room temperature, pouring out upper-layer waste liquid after finishing the centrifugal treatment, adding deionized water for centrifuging again, repeating the centrifugal step 4 times, performing vacuum filtration, washing a filter cake for 5 times by using an ethanol solution with the mass fraction of 30%, and finally performing freeze drying at the temperature of minus 45 ℃ for 48h to obtain an intermediate 2;

step S13, adding the intermediate 2 and toluene into a beaker, heating in a water bath to 85 ℃, then adding a silane coupling agent into the beaker, heating to boil and reflux, keeping the reflux state for reaction for 12 hours, then cooling to room temperature, filtering, washing a filter cake for 2 times by using ethanol and deionized water respectively, and finally freeze-drying to obtain an intermediate 3; adding graphene oxide, the intermediate 3, p-aniline and dimethyl sulfoxide into a reaction kettle, performing ultrasonic dispersion for 10min at the frequency of 35kHz, performing heat preservation reaction for 2h at the temperature of 60 ℃, performing suction filtration, washing a filter cake for 5 times by using an ethanol solution with the mass fraction of 35%, and finally drying in a 65 ℃ oven to constant weight to obtain an intermediate 4;

step S14, adding aramid fiber, potassium tert-butoxide and dimethyl sulfoxide into a reaction container according to the mass ratio of 2:2:96, magnetically stirring for 48 hours at 40 ℃ to obtain an aramid fiber dispersion liquid, adding the intermediate 4 and dimethyl sulfoxide into a beaker according to the mass ratio of 2:98, ultrasonically dispersing for 20 minutes at the frequency of 45kHz to obtain an intermediate 4 dispersion liquid, adding the aramid fiber dispersion liquid and the intermediate 4 dispersion liquid into a reaction kettle according to the mass ratio of 20:14, and mixing for 30 minutes at the rotating speed of 300r/min to obtain the composite gel.

Wherein the using amount ratio of the mixed acid solution to the carbon nano tube in the step S11 is 200 mL: 3g of the total weight of the mixture; in the step S12, the dosage ratio of the absolute ethyl alcohol, the ammonia water, the intermediate 1 and the tetraethoxysilane is 500 mL: 20mL of: 0.5 g: 20 mL; the dosage ratio of the intermediate 2, the toluene and the silane coupling agent in the step S13 is 1 g: 10mL of: 5mL, wherein the silane coupling agent is a silane coupling agent KH-550, and the dosage ratio of the graphene oxide, the intermediate 3, the p-aniline and the dimethyl sulfoxide is 1 g: 1 g: 4 g: 70 mL.

step S21, adding 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile into a four-neck flask, heating to 75 ℃, reacting for 8 hours at a rotating speed of 200r/min under the protection of nitrogen, transferring a product in the flask into a rotary evaporator for rotary evaporation after the reaction is finished, evaporating a solvent at 130 ℃, and then cooling and crystallizing to obtain an anti-aging agent A;

Wherein, in step S21, the contents of 2,2,6, 6-tetramethyl-4-piperidine stearate, toluene, benzoyl peroxide and azodiisobutyronitrile are 10 g: 150mL of: 0.1 g: 0.1 g.

Comparative example

The comparison example is a common polymer instrument shell on the market.

The polymer housings of examples 1-3 and the meter housing of the comparative example were tested for performance, with the following test criteria: tensile strength: ASTM 638, tensile Rate 5 mm/min; flexural modulus: ASTM D790, bending Rate 2 mm/min; electromagnetic shielding effect: ASTM D4935, test range: 30MHz-30GHz, flame retardant rating: UL 94, heat distortion temperature test: ASTM D648, rate of temperature rise 5 ℃/6min, bacteriostatic: QBT 2591; the test results are shown in the following table:

numbering	Example 1	Example 2	Example 3	Comparative example
					Tensile Strength (MPa)	150	163	152	74
Flexural modulus (MPa)	25400	25800	25200	11500
					Electromagnetic shielding effect 2mm (dB)	68	69	68	40
Flame retardant rating	V-0	V-0	V-0	V-1
					Heat distortion (. degree.C.)	200	218	222	136
Bacteriostasis rate (Escherichia coli and staphylococcus aureus)）（%）	99.5	99.6	99.4	91.2

As can be seen from the above table, the instrument housings of examples 1 to 3 are superior to comparative examples in mechanical property test, electromagnetic shielding effect, flame retardant rating, antibacterial activity and heat resistance test, and it is demonstrated that the instrument housings prepared by the present invention have not only excellent mechanical properties, but also flame retardant, antibacterial and electromagnetic shielding properties, and can be widely applied to the field of electronic instruments.

The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.

Claims

1. A high-strength instrument shell is characterized by comprising a perspective window (1), a protective sleeve (2) and a polymer shell (3), wherein the perspective window (1) is positioned inside the protective sleeve (2), the perspective window (1) is fixedly connected with the protective sleeve (2), an external thread is arranged at one end, away from the perspective window (1), of the protective sleeve (2), the polymer shell (3) is a cylinder with one closed end and is hollow, an internal thread matched with the protective sleeve (2) is arranged at one end, away from the closed end, of the polymer shell (3), and the polymer shell (3) is in threaded connection with the protective sleeve (2);

the perspective window (1) is made of transparent glass, and the protective sleeve (2) is made of stainless steel materials or aluminum alloy materials;

the polymer shell (3) comprises the following raw materials in parts by weight: 60-80 parts of PC/ABS alloy, 15-30 parts of composite gel, 1-3 parts of composite anti-aging agent, 0.3-2 parts of coupling agent, 0.3-0.5 part of lubricant, 0.1-0.8 part of antibacterial agent and 1-2 parts of toughening agent;

the polymer shell (3) is prepared by the following steps:

and thirdly, drying the master batch in a ventilation drying oven at 90 ℃ for 6h, and then performing injection molding by using an injection molding machine at the injection molding temperature of 285 ℃ to obtain the polymer shell (3).

2. A high strength instrument housing of claim 1, wherein said composite gel is formed by the steps of:

3. The instrument housing as claimed in claim 2, wherein the ratio of the mixed acid solution to the carbon nanotubes in step S11 is 200 mL: 1-3; in the step S12, the dosage ratio of the absolute ethyl alcohol, the ammonia water, the intermediate 1 and the tetraethoxysilane is 500 mL: 16-20 mL: 0.5 g: 20 mL; the dosage ratio of the intermediate 2, the toluene and the silane coupling agent in the step S13 is 1 g: 10mL of: 4-5mL, wherein the silane coupling agent is selected from one of silane coupling agents KH-550, KH-450 or KH-792, and the dosage ratio of the graphene oxide, the intermediate 3, the p-aniline and the dimethyl sulfoxide is 1 g: 1 g: 4 g: 50-80 mL.

4. The high strength instrument housing of claim 1, wherein the method of making the composite aging resistor comprises the steps of:

5. The high-strength instrument housing as claimed in claim 4, wherein in step S21, the contents of 2,2,6, 6-tetramethyl-4-piperidyl stearate, toluene, benzoyl peroxide and Azobisisobutyronitrile (AIOB) are 10 g: 100-150 mL: 0.1 g: 0.1 g.

6. The high strength instrument shell of claim 1, wherein the coupling agent is one or more of vinyltriethoxysilane, gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, and aluminate coupling agents mixed in any proportion.

7. The high strength instrument housing of claim 1, wherein the lubricant is one of silicone oil, white oil, silicone, N-ethylene bis stearamide, and calcium stearate.

8. The instrument shell as claimed in claim 1, wherein the toughening agent is one of maleic anhydride grafted linear low density polyethylene and methyl methacrylate-butadiene-styrene terpolymer, and the antibacterial agent is one or two of nano silver oxide and polyhexamethylene guanidine phosphate mixed in any proportion.

9. The process for producing a high-strength instrument housing as claimed in claim 1, wherein the steps are as follows:

sheathing the protective sleeve (2) on the outer side of the perspective window (1), and then connecting the polymer shell (3) with the protective sleeve (2) in a threaded manner to obtain the high-strength instrument shell.