阅读说明：本技术 一种高耐磨低温固化导电银浆及其制备方法 (High-wear-resistance low-temperature curing conductive silver paste and preparation method thereof ) 是由 杨丁娥 李禹函 于 2021-08-02 设计创作，主要内容包括：一种高耐磨低温固化导电银浆及其制备方法,它涉及一种手机电子到导电材料。它首先进行环氧树脂的改性合成,然后改性环氧树脂和多官能团环氧树脂在70～75℃烘烤4小时以上,将银粉在120℃下烘烤12小时以上,接着将烘烤后的改性树脂和银粉混合均匀,混合时间为30～40分钟,混合温度20～30℃,然后将一定量的气相二氧化硅、增韧剂、固化剂和固化促进剂,分别加入搅拌均匀,搅拌时间30～40分钟,温度20～30℃,然后用三辊机研磨两遍,然后加入真空搅拌反应釜中搅拌抽真空90分钟,搅拌温度控制在20～30℃,过滤灌装制得产品。本发明具有固化温度低且制备过程环保,适用范围广,同时其导电银浆还具备强度高、耐磨性能好、可靠性高和存储稳定的特点。(A high-wear-resistance low-temperature curing conductive silver paste and a preparation method thereof relate to a mobile phone electronic-to-conductive material. Firstly, modifying and synthesizing epoxy resin, baking the modified epoxy resin and polyfunctional epoxy resin at 70-75 ℃ for more than 4 hours, baking silver powder at 120 ℃ for more than 12 hours, then uniformly mixing the baked modified resin and the silver powder for 30-40 minutes at the mixing temperature of 20-30 ℃, then respectively adding a certain amount of fumed silica, a toughening agent, a curing agent and a curing accelerator into a vacuum stirring reaction kettle, uniformly stirring for 30-40 minutes at the temperature of 20-30 ℃, grinding twice by using a three-roll machine, then stirring and vacuumizing for 90 minutes in the vacuum stirring reaction kettle, controlling the stirring temperature at 20-30 ℃, filtering and filling to obtain the product. The conductive silver paste has the characteristics of low curing temperature, environment-friendly preparation process, wide application range, high strength, good wear resistance, high reliability and stable storage.)

1. The high-wear-resistance low-temperature curing conductive silver paste is characterized in that: the low-temperature resistant toughened segmented polyurethane resin comprises, by weight, 10-30 parts of low-temperature resistant toughened segmented polyurethane resin, 10-20 parts of high-temperature resistant epoxy resin, 5-10 parts of a toughening agent, 3 parts of a diluent, 10-20 parts of a curing agent, 5-10 parts of an accelerator, 1-5 parts of fumed silica and 80-85 parts of silver powder.

2. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the low-temperature resistant toughened block polyurethane resin is self-made resin, and the preparation method comprises the following steps: the method comprises the following steps: putting one equivalent of aminopropyl double-end-capped polydimethylsiloxane, hydroxypropyl double-end-capped polydimethylsiloxane or hydrogenated double-end hydroxyl polybutadiene with the number average molecular weight of 1000-5000 g/mol into a reactor;

step two: stirring at 110 ℃ and-0.1 MPa for dewatering for 1 hour, and cooling to 80 ℃;

step three: and (5) after the second step is finished, adding two equivalents of isophorone diisocyanate (IPDI) into the reactor, adding two equivalents of di-methylimidazole until the NCO is completely consumed, and monitoring the NCO by reflection mode Fourier transform infrared.

3. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the high-temperature-resistant epoxy resin is JER604 epoxy resin.

4. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the toughening agent is CTBN modified epoxy resin.

5. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the curing agent is one or two of latent modified imidazole and modified amine curing agent.

6. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the accelerant is one or two of latent modified urea and modified amine curing agents.

7. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the fumed silica is hydrophobic fumed silica.

8. The high-wear-resistance low-temperature curing conductive silver paste as claimed in claim 1, wherein: the particle size of the silver powder is 0.5-3.0 micrometers, and the particle size distribution D90 is less than 2.5 micrometers.

9. A preparation method of high-wear-resistance low-temperature curing conductive silver paste comprises the following steps of:

step (1): modifying and synthesizing epoxy resin;

step (2): baking 10-30 parts of modified epoxy resin and 10-20 parts of polyfunctional epoxy resin at 70-75 ℃ for more than 4 hours, and baking silver powder at 120 ℃ for more than 12 hours;

and (3): after the step (2) is completed, uniformly mixing the baked epoxy resin and the baked silver powder for 30-40 minutes at the mixing temperature of 20-30 ℃;

step (4), after the step (3) is completed, respectively adding 1-10 parts of fumed silica, 5-10 parts of a toughening agent, 20-30 parts of a curing agent and 1-6 parts of a curing accelerator, uniformly stirring for 30-40 minutes at 20-30 ℃, and then grinding twice by using a three-roll machine;

and (5) after the step (4) is finished, adding the mixture into a vacuum stirring reaction kettle, stirring and vacuumizing for 90 minutes, controlling the stirring temperature to be 20-30 ℃, and filtering and filling to obtain the product.

Technical Field

The invention relates to the technical field of conductive materials in the field of electronic communicators, in particular to high-wear-resistance low-temperature curing conductive silver paste and a preparation method thereof.

Background

At present, the traditional mobile phone antenna can only be applied below 4G mobile phone communication, and can not meet the development requirement of 5G. The PDS antenna is gradually accepted and applied by the market as an updated product of the 5G mobile phone antenna. The PDS is a (pad printing) process for printing a mobile phone antenna, in which conductive silver paste is applied to the surface of a workpiece, and then the silver paste is printed by multiple layers to form a conductive three-dimensional circuit. The PDS has the advantages that circuits can be directly printed, special laser modified materials are not needed, and the cost can be greatly reduced. The structure parts which are difficult to process in the antenna design, such as corners, and the structure of the through hole can realize circuit conduction. The key material is low-temperature conductive silver paste, low-temperature curing is required due to the property (no high temperature resistance, and not more than 80 ℃) of the used material, and high wear resistance is required due to the contact elastic sheet of the conductive circuit.

The existing products in the market have the problems of poor wear resistance, high curing temperature, low speed, high impedance after curing and the like, and are difficult to meet the requirements of high efficiency, high reliability and the like of electronic production, so that the requirements of the market are met, the wear resistance and the adhesive force of the cured silver paste are improved through formula adjustment, good conduction performance can be achieved, and the conductive silver paste with the conductive function has important significance.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art, and provides high-wear-resistance low-temperature curing conductive silver paste and a preparation method thereof, wherein the high-wear-resistance low-temperature curing conductive silver paste has the characteristics of low curing temperature, environment-friendly preparation process and wide application range, and meanwhile, the conductive silver paste has the characteristics of high strength, good wear resistance, high reliability and stable storage, and can be stored for more than 6 months when placed in a refrigerator at the temperature of 2-8 ℃.

In order to achieve the purpose, the invention adopts the following technical scheme: the high-wear-resistance low-temperature curing conductive silver paste comprises, by weight, 10-30 parts of low-temperature-resistant toughening block polyurethane resin, 10-20 parts of high-temperature-resistant epoxy resin, 5-10 parts of a toughening agent, 3 parts of a diluent, 10-20 parts of a curing agent, 5-10 parts of an accelerator, 1-5 parts of fumed silica and 80-85 parts of silver powder.

Further, the low temperature resistant toughened segmented polyurethane resin is a self-made resin, and the preparation method comprises the following steps:

the method comprises the following steps: putting one equivalent of aminopropyl double-end-capped polydimethylsiloxane, hydroxypropyl double-end-capped polydimethylsiloxane or hydrogenated double-end hydroxyl polybutadiene with the number average molecular weight of 1000-5000 g/mol into a reactor;

step two: stirring at 110 ℃ and-0.1 MPa for dewatering for 1 hour, and cooling to 80 ℃;

step three: and (5) after the second step is finished, adding two equivalents of isophorone diisocyanate (IPDI) into the reactor, adding two equivalents of di-methylimidazole until the NCO is completely consumed, and monitoring the NCO by reflection mode Fourier transform infrared.

Further, the high-temperature resistant epoxy resin is JER604 epoxy resin.

Further, the toughening agent is CTBN modified epoxy resin.

Further, the accelerator is one or two of latent modified urea and modified amine curing agents.

Further, the fumed silica is hydrophobic fumed silica.

Further, the particle size of the silver powder is 0.5-3.0 microns, and the particle size distribution D90 is less than 2.5 microns.

A preparation method of high-wear-resistance low-temperature curing conductive silver paste comprises the following steps of:

step 1: modifying and synthesizing epoxy resin;

step 2: baking 10-30 parts of modified epoxy resin and 10-20 parts of polyfunctional epoxy resin at 70-75 ℃ for more than 4 hours, and baking silver powder at 120 ℃ for more than 12 hours;

and step 3: after the step 2 is completed, uniformly mixing the baked epoxy resin and the baked silver powder for 30-40 minutes at the mixing temperature of 20-30 ℃;

step 4, after the step 3 is completed, respectively adding 1-10 parts of fumed silica, 5-10 parts of a toughening agent, 20-30 parts of a curing agent and 1-6 parts of a curing accelerator, uniformly stirring for 30-40 minutes at the temperature of 20-30 ℃, and then grinding twice by using a three-roll machine;

and 5, after the step 4 is finished, adding the mixture into a vacuum stirring reaction kettle, stirring and vacuumizing for 90 minutes, controlling the stirring temperature to be 20-30 ℃, and filtering and filling to obtain the product.

The working principle of the invention is as follows:

firstly, modifying and synthesizing epoxy resin, baking the modified epoxy resin and polyfunctional epoxy resin at 70-75 ℃ for more than 4 hours, baking silver powder at 120 ℃ for more than 12 hours, then uniformly mixing the baked modified resin and the silver powder for 30-40 minutes at the mixing temperature of 20-30 ℃, then respectively adding a certain amount of fumed silica, a toughening agent, a curing agent and a curing accelerator into a vacuum stirring reaction kettle, uniformly stirring for 30-40 minutes at the temperature of 20-30 ℃, grinding twice by using a three-roll machine, then adding the mixture into the vacuum stirring reaction kettle, stirring and vacuumizing for 90 minutes, controlling the stirring temperature at 20-30 ℃, and finally filtering and filling to obtain the product.

After the technical scheme is adopted, the invention has the beneficial effects that:

the high-wear-resistance low-temperature conductive silver paste prepared by the invention has the characteristics of low curing temperature, environment-friendly preparation process and wide application range, and meanwhile, the conductive silver paste has the characteristics of high strength, good wear resistance, high reliability and stable storage, and can be stored for more than 6 months when placed in a refrigerator at the temperature of 2-8 ℃.

Drawings

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

FIG. 1 is a schematic flow diagram of the present invention.

Description of reference numerals: step 1, step 2, step 3, step 4, step 5.

Detailed Description

Example one

Referring to fig. 1, the technical solution adopted by the present embodiment is: the low-temperature resistant toughened polyurethane resin comprises, by weight, 25 parts of low-temperature resistant toughened block polyurethane resin, 20 parts of high-temperature resistant epoxy resin, 8 parts of a toughening agent, 3 parts of a diluent and 20 parts of a curing agent, wherein the curing agent is modified amine produced by Japanese monosodium glutamate fine chemistry, FXR-1020, 5 parts of an accelerator, 3 parts of fumed silica and 85 parts of silver powder.

The low-temperature resistant toughened block polyurethane resin is self-made resin, and the preparation method comprises the following steps:

the method comprises the following steps: charging one equivalent of aminopropyl di-terminated polydimethylsiloxane, hydroxypropyl di-terminated polydimethylsiloxane or hydrogenated hydroxy-terminated polybutadiene with a number average molecular weight of 1000g/mol into a reactor;

step two: stirring at 110 ℃ and-0.1 MPa for dewatering for 1 hour, and cooling to 80 ℃;

step three: and (5) after the second step is finished, adding two equivalents of isophorone diisocyanate (IPDI) into the reactor, adding two equivalents of di-methylimidazole until the NCO is completely consumed, and monitoring the NCO by reflection mode Fourier transform infrared.

The high-temperature-resistant epoxy resin is JER604 epoxy resin.

The toughening agent is CTBN modified epoxy resin, and HyPox RA840 is selected.

The accelerant is PN-H

The fumed silica is hydrophobic fumed silica, namely Degussa R202.

The silver powder has the particle size of 0.5-3.0 micrometers, the particle size distribution D90 is smaller than 2.5 micrometers, and the silver powder is a Kunminbman electronic material CPS-0154.

A preparation method of high-wear-resistance low-temperature curing conductive silver paste comprises the following steps of:

step 1: modifying and synthesizing epoxy resin;

step 2: baking 25 parts of modified epoxy resin and 10 parts of polyfunctional epoxy resin at 70 ℃ for 4 hours, and baking silver powder at 120 ℃ for 12 hours;

and step 3: after the step 2 is completed, uniformly mixing the baked epoxy resin and the baked silver powder for 30 minutes at the mixing temperature of 20 ℃;

step 4, after the step 3 is completed, respectively adding 3 parts of fumed silica, 8 parts of flexibilizer, 20 parts of curing agent and 5 parts of curing accelerator, uniformly stirring for 30 minutes at the temperature of 20 ℃, and then grinding twice by using a three-roll machine;

and 5, after the step 4 is finished, adding the mixture into a vacuum stirring reaction kettle, stirring and vacuumizing for 90 minutes, controlling the stirring temperature at 20 ℃, filtering and filling to obtain the product.

The experimental test shows that the product has the parameters of the test shear strength of 15Mpa, the test curing temperature of 80 ℃ for 30 minutes, the storage period of 40 ℃ for more than 24 hours and the wear resistance of more than 5000 times.

Example two

The low-temperature resistant toughened polyurethane resin comprises, by weight, 23 parts of low-temperature resistant toughened block polyurethane resin, 8 parts of high-temperature resistant epoxy resin, 5 parts of a toughening agent, 1 part of a diluent and 20 parts of a curing agent, wherein the curing agent is modified amine produced by Japanese monosodium glutamate fine chemistry, FXR-1020, 3 parts of an accelerator, 3 parts of fumed silica and 80 parts of silver powder.

The low-temperature resistant toughened block polyurethane resin is self-made resin, and the preparation method comprises the following steps:

the method comprises the following steps: charging one equivalent of aminopropyl di-terminated polydimethylsiloxane, hydroxypropyl di-terminated polydimethylsiloxane or hydrogenated hydroxy-terminated polybutadiene with a number average molecular weight of 1500g/mol into a reactor;

step two: stirring at 110 ℃ and-0.1 MPa for dewatering for 1 hour, and cooling to 80 ℃;

step three: and (5) after the second step is finished, adding two equivalents of isophorone diisocyanate (IPDI) into the reactor, adding two equivalents of di-methylimidazole until the NCO is completely consumed, and monitoring the NCO by reflection mode Fourier transform infrared.

The high-temperature-resistant epoxy resin is JER604 epoxy resin.

The toughening agent is CTBN modified epoxy resin, and HyPox RA840 is selected.

The accelerant is PN-H

The fumed silica is hydrophobic fumed silica, namely Degussa R202.

The silver powder has the particle size of 0.5-3.0 micrometers, the particle size distribution D90 is smaller than 2.5 micrometers, and the silver powder is a Kunminbman electronic material CPS-0154.

A preparation method of high-wear-resistance low-temperature curing conductive silver paste comprises the following steps of:

step 1: modifying and synthesizing epoxy resin;

step 2: baking 23 parts of modified epoxy resin and 8 parts of polyfunctional epoxy resin at 80 ℃ for 4 hours, and baking silver powder at 120 ℃ for 12 hours;

and step 3: after the step 2 is completed, uniformly mixing the baked epoxy resin and the baked silver powder for 40 minutes at the mixing temperature of 20 ℃;

step 4, after the step 3 is completed, respectively adding 3 parts of fumed silica, 5 parts of toughening agent, 20 parts of curing agent and 3 parts of curing accelerator, uniformly stirring for 30 minutes at the temperature of 20 ℃, and then grinding twice by using a three-roll machine;

and 5, after the step 4 is finished, adding the mixture into a vacuum stirring reaction kettle, stirring and vacuumizing for 90 minutes, controlling the stirring temperature at 20 ℃, filtering and filling to obtain the product.

The parameters of the product measured by experiments are that the test shear strength is 13Mpa, the measured curing temperature is 80 ℃ for 35 minutes, the storage period at 40 ℃ is over 24 hours, and the wear resistance is over 5000 times.

The above description is only for the purpose of illustrating the technical solutions of the present invention and not for the purpose of limiting the same, and other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention without departing from the spirit and scope of the technical solutions of the present invention.