CN114015198A - Preparation method of intermediate-temperature cured prepreg epoxy resin with optimized process - Google Patents
Preparation method of intermediate-temperature cured prepreg epoxy resin with optimized process Download PDFInfo
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- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
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Abstract
The invention discloses a preparation method of intermediate-temperature cured prepreg epoxy resin with an optimized process, which comprises the following steps: 1) mixing E-51 epoxy resin, a defoaming agent and a dicyandiamide curing agent, heating to a proper temperature under the condition of stirring, and continuously stirring and dispersing to obtain a uniform mixed solution; 2) adding E-20 epoxy resin and 704 novolac epoxy resin into the mixed solution, heating to a proper temperature under the stirring condition, and continuing to fully stir; 3) naturally cooling the reaction system to a proper temperature under stirring, adding the accelerant and fully stirring; 4) and (4) defoaming the obtained mixture in vacuum to obtain the intermediate-temperature cured prepreg epoxy resin. The method well solves the problem that dicyandiamide is unevenly distributed in the prepreg epoxy resin, the obtained intermediate-temperature cured prepreg epoxy resin has proper viscosity, proper curing temperature, long storage period and good fluidity at the gluing temperature, and the manufacturability requirement of the prepreg resin can be well met.
Description
Technical Field
The invention belongs to the technical field of resin matrix composite prepreg, and particularly relates to a preparation method of intermediate-temperature cured prepreg epoxy resin with an optimized process.
Background
With the development of the automobile industry, the development of new energy, the development of the aerospace field and the like, the use amount of advanced composite materials is increasing day by day. Currently, most fiber reinforced composite articles are made from prepregs. The prepreg is prepared by impregnating continuous fibers or fiber fabrics under the condition of accurately controlling a resin matrix and preparing the material with a certain storage period at room temperature through certain treatment, and can be directly used for manufacturing composite materials. Thus, the quality of the prepreg largely determines the final properties of the composite. At present, the methods for preparing the prepreg mainly include a solution impregnation method and a hot-melt impregnation method. The prepreg prepared by the solution impregnation method has the defects of complicated preparation process, low preparation efficiency and the like. On one hand, the solution impregnation method introduces a large amount of solvent into the matrix resin, which not only easily causes environmental pollution and harms the health of workers, but also causes the resin content to be difficult to control accurately due to the volatilization of the solvent, and the stability of the prepreg batch is poor. On the other hand, the preform obtained by the solution dipping method is easy to form voids and bubbles during molding, and the quality and performance of the product are seriously affected. Therefore, the process of preparing prepreg by solution impregnation method is subject to the disadvantages of the industry. Therefore, with the development of prepreg manufacturing processes, the solution impregnation method has been gradually replaced by the hot melt impregnation method.
The elements involved in prepreg manufacture are a resin matrix system, a fiber system, a process system and prepreg equipment, with the resin system being the most critical. At present, prepreg resins for hot melt methods mainly comprise epoxy resins, cyanate ester resins, benzoxazine, bismaleimide resins, phenolic resins and the like, wherein the epoxy resins have the advantages of good process performance, low curing shrinkage, excellent hydrolysis resistance, corrosion resistance, high stability and the like, and have been widely researched and maturely applied to industrial production. The prepreg can be cured at low temperature, medium temperature and high temperature according to the curing temperature. Compared with low-temperature curing, medium-temperature curing has the advantages of fast curing, high use temperature, relatively good heat resistance and the like; compared with high-temperature curing, the medium-temperature curing forming temperature is low, the internal stress of a workpiece is small, the dimensional stability is better, and the impact strength is higher. Therefore, the development of the epoxy resin system for the medium-temperature curing prepreg is necessary, and the epoxy resin system has good market application prospect.
The curing agents applied to the industrial production at present in the intermediate-temperature curing prepreg resin system are all micro-powder dicyandiamide curing agents, and the original synthesis method is that different types of epoxy resins are mixed according to corresponding proportions, then dicyandiamide curing agent components are added, and dicyandiamide is stirred and dispersed at high temperature. However, dicyandiamide is insoluble in epoxy resin, so that the phenomena of uneven dispersion and agglomeration easily occur in a prepreg epoxy resin system, and if the dicyandiamide curing agent is dispersed uniformly in the prepreg epoxy resin system, only the mechanical stirring speed, the stirring environment temperature or the stirring duration can be increased, so that the energy consumption and the cost for synthesizing the prepreg epoxy resin are greatly increased. Therefore, how to solve the problem of dispersion of dicyandiamide by improving the process method is very significant.
Disclosure of Invention
The invention mainly aims to provide a preparation method of intermediate-temperature cured prepreg epoxy resin with an optimized process aiming at the defects in the prior art. The method well solves the problem that dicyandiamide is unevenly distributed in the prepreg epoxy resin, the obtained intermediate-temperature cured prepreg epoxy resin has proper viscosity, proper curing temperature, long storage period and good fluidity at the gluing temperature, and the manufacturability requirement of the prepreg resin can be well met.
In order to achieve the purpose, the invention adopts the technical scheme that:
the preparation method of the intermediate-temperature curing prepreg epoxy resin with the optimized process comprises the following steps:
1) mixing E-51 epoxy resin, a defoaming agent and a dicyandiamide curing agent, heating to a proper temperature under the condition of stirring, and continuously stirring and dispersing to obtain a uniform mixed solution;
2) adding E-20 epoxy resin and 704 novolac epoxy resin into the mixed solution in the step 1), heating to a proper temperature under the stirring condition, and continuing to fully stir;
3) naturally cooling the reaction system in the step 2) to a proper temperature under stirring, adding an accelerant and fully stirring;
4) and (3) defoaming the mixture obtained in the step 3) in vacuum to obtain the intermediate-temperature cured prepreg epoxy resin.
According to the scheme, in the step 1), 49-51 parts of E-51 epoxy resin, 0.18-0.22 part of defoaming agent and 6.5-7.5 parts of dicyandiamide curing agent are counted by mass; in the step 2), 29-31 parts of E-20 epoxy resin and 19-21 parts of 704 novolac epoxy resin; in the step 3), 1.9-2.1 parts of an accelerator.
According to the scheme, in the step 1), the particle size of the dicyandiamide curing agent is 2-5 um.
According to the scheme, in the step 1), the defoaming agent is an organic silicon defoaming agent.
According to the scheme, in the step 1), the temperature is increased to 95-105 ℃, and stirring and dispersing are carried out for 25-35 min.
According to the scheme, in the step 2), the temperature is increased to 115-125 ℃, and the mixture is fully stirred for 25-35 min.
According to the scheme, in the step 3), the mixture is naturally cooled to 75-85 ℃, and the accelerant is added and then fully stirred for 3-5 min.
According to the scheme, in the step 1), the stirring speed is 450-550 r/min; in the step 2), the stirring speed is 450-550 r/min; in the step 3), the stirring speed is 450-550 r/min.
According to the scheme, in the step 3), the accelerant is dichlorophenyl dimethyl urea.
According to the scheme, in the step 4), the vacuum defoaming conditions are as follows: and (3) carrying out vacuum defoaming for 10-20 min at the temperature of 75-85 ℃.
According to the scheme, in the step 4), the toughened medium-temperature cured prepreg epoxy resin is transferred to a freezer at the temperature of-17 ℃ for freezing storage.
According to the scheme, in the step 1), gas-phase nano SiO is also added2。
Preferably, E-51 epoxy resin and gas phase nano SiO2The mass ratio is (49-51): (0-1), more preferably (49-51): (0.4 to 1).
Preferably, the gas phase nano SiO2The particle size of (A) is 12-16 nm.
The principle of the invention is as follows:
the invention well solves the problem of uneven dispersion of dicyandiamide in the prepreg resin by innovatively improving the synthesis process of the prepreg resin. Firstly, E-51 liquid epoxy resin and dicyandiamide are mixed and heated to a proper temperature, so that the liquid resin E-51 has extremely low viscosity, dicyandiamide can be fully dispersed in the E-51, then another two solid resins are added and fully stirred, and the dicyandiamide is uniformly dispersed in a resin mixture, so that the stirring speed can be reduced, the energy consumption is reduced, the mixing time is shortened, and the efficiency is improved.
Further, the invention adds gas-phase SiO in the step of mixing E-51 liquid epoxy resin and dicyandiamide2The toughness of the whole resin system is improved, and the effect of strengthening and toughening is achieved. Gas phase SiO2Active groups such as hydroxyl groups are enriched on the surface of the particles, and the active groups can perform a physical or chemical crosslinking effect with epoxy resin macromolecular chains, and the specific effects are as follows: on the one hand, gas phase SiO2The introduction of the particles can generate stress concentration in deformation, and the resin matrix around the particles is induced to yield, so that a great deal of deformation work is absorbed, and the silver streak is hindered and passivated in treesThe spreading in the grease serves to prevent destructive cracking. On the other hand gas phase SiO2The elongation deformation under the action of tensile stress is small, so that the interface part of the matrix and the particles is debonded to generate a cavity, further the crack is passivated, and the crack is prevented from expanding or being damaged to generate a toughening effect.
Gas phase nano SiO2Compared with other large-size particle sizes, the particle size is more suitable to be used as a toughening agent due to the characteristics of small particle size, large surface area and more abundant active groups. But gas phase nano SiO2As the toughening agent is often easy to have the conditions of uneven dispersion and particle agglomeration, the gas-phase nano SiO can be well dispersed by matching with the optimized process2And micro-powder dicyandiamide, and can also make gas-phase nano SiO2One side of the resin is adsorbed on the micro-powder dicyandiamide, and the other side of the resin and the epoxy resin play a role in chemical bonding, so that the dicyandiamide is further prevented from settling and agglomerating, the toughness of the whole resin system can be greatly improved, and the reinforcing and toughening effects are achieved.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention well solves the problems of uneven dispersion and easy agglomeration of dicyandiamide in a prepreg epoxy resin system by optimizing the synthesis process of the prepreg epoxy resin, reduces the time for synthesizing the prepreg epoxy resin, improves the production efficiency and has good economic benefit.
2. Further, the invention introduces gas-phase nano SiO2Toughening agent, optimized compounding process, gas phase nano SiO2The toughening and toughening agent is uniformly dispersed in a resin system, has good toughening and reinforcing effects, solves the problem of insufficient toughness of the conventional prepreg epoxy resin, improves the tensile strength of a toughened resin casting body to 74.41MPa by 72.64 percent compared with the original resin system formula before toughening and modifying, well plays a role in reinforcing and toughening, and does not influence the molding process performance of the original prepreg resin system.
Drawings
In FIG. 1, the surface quality of the tensile test specimens of comparative example 1, comparative example 2 and example 1 is shown from left to right.
FIG. 2 is a graph showing the temperature and viscosity relationship of the intermediate-temperature-cured epoxy resin prepreg prepared in example 3.
FIG. 3 is a graph of temperature versus gel time for a mid-temperature cured prepreg epoxy resin prepared in example 3.
Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.
Example 1
The preparation method of the intermediate-temperature curing prepreg epoxy resin with the optimized process comprises the following steps:
1) adding 150g E-51 epoxy resin, 0.6g of organic silicon defoaming agent and 21g of dicyandiamide curing agent micro powder with the particle size of 2-5 um into a three-neck flask, stirring at the rotating speed of 500r/min, heating from room temperature to 100 ℃, and stirring at 100 ℃ for 30 min;
2) adding 90g of E-20 epoxy resin and 60g of 704 novolac epoxy resin into the reaction system in the step 1), then heating the reaction system from 100 ℃ to 120 ℃, and rotationally stirring for 30min at 120 ℃;
3) keeping the reaction system in the step 2) at a rotating speed of 500r/min, naturally cooling to 80 ℃, adding 6g of an accelerant dichlorophenyl dimethyl urea, and stirring for 5 min;
4) transferring the mixture obtained in the step 3) to a vacuum drying oven, defoaming in vacuum for 15min at the temperature of 80 ℃ to obtain the intermediate-temperature cured prepreg epoxy resin, transferring the intermediate-temperature cured prepreg epoxy resin to a freezer at the temperature of-17 ℃, and freezing and storing.
Taking out the product obtained in the embodiment from a refrigerator, placing the product in an oven at 90 ℃ for heating for 10min until solid resin is molten and has better fluidity, then pouring the molten solid resin into a casting body mould of a tensile sample, placing the casting body mould into a vacuum drying oven, defoaming the casting body mould at 80 ℃ for 15min, then placing the casting body mould into a casting body mould at 100 ℃ for heat preservation for 1h, and preserving the heat at 120 ℃ for 3h to obtain the cured resin casting body tensile sample.
The test result shows that the casting body prepared by the intermediate-temperature cured prepreg epoxy resin obtained in the example has good surface quality, as shown in figure 1, the surface has no dicyandiamide particles, and the test result shows that the tensile strength is 43.10 MPa.
Example 2
The preparation method of the epoxy resin for toughening medium-temperature curing prepreg, which is optimized in process, comprises the following steps:
1) adding 150g E-51 epoxy resin, 0.6g of organic silicon defoaming agent, 21g of micro-powder dicyandiamide curing agent with the particle size of 2-5 um and 1.5g of gas-phase nano SiO into a three-neck flask2(the particle size is 12-16 nm), stirring at the rotating speed of 500r/min, heating from room temperature to 100 ℃, and stirring at 100 ℃ for 30 min;
2) adding 90g of E-20 epoxy resin and 60g of 704 novolac epoxy resin into the reaction system in the step 1), then heating the reaction system from 100 ℃ to 120 ℃, and rotationally stirring for 30min at 120 ℃;
3) keeping the reaction system in the step 2) at a rotating speed of 500r/min, naturally cooling to 80 ℃, adding 6g of an accelerant dichlorophenyl dimethyl urea, and stirring for 5 min;
4) transferring the mixture obtained in the step 3) to a vacuum drying oven, and defoaming in vacuum for 15min at 80 ℃ to obtain the intermediate-temperature cured prepreg epoxy resin; it was transferred to a freezer at-17 ℃ and stored frozen.
Taking out the product obtained in the embodiment from a refrigerator, placing the product in an oven at 90 ℃ for heating for 10min until solid resin is molten and has better fluidity, then pouring the molten solid resin into a casting body mould of a tensile sample, placing the casting body mould into a vacuum drying oven, defoaming the casting body mould at 80 ℃ for 15min, then placing the casting body mould into a casting body mould at 100 ℃ for heat preservation for 1h, and preserving the heat at 120 ℃ for 3h to obtain the cured resin casting body tensile sample.
The test result shows that the casting body prepared from the medium-temperature cured prepreg resin obtained in the example has good surface quality and no dicyandiamide particles exist on the surface, and the tensile strength obtained by the test is 56.48 MPa.
Example 3
The preparation method of the epoxy resin for toughening medium-temperature curing prepreg, which is optimized in process, comprises the following steps:
1) 150g E-51 epoxy resin and 0.6g organic silicon defoamer are added into a three-neck flask21g of micro-powder dicyandiamide curing agent with particle size of 2-5 um and 3g of gas-phase nano SiO2(the particle size is 12-16 nm), stirring at the rotating speed of 500r/min, heating from room temperature to 100 ℃, and stirring at 100 ℃ for 30 min;
2) adding 90g of E-20 epoxy resin and 60g of 704 novolac epoxy resin into the reaction system in the step 1), then heating the reaction system from 100 ℃ to 120 ℃, and rotationally stirring for 30min at 120 ℃;
3) keeping the reaction system in the step 2) at a rotating speed of 500r/min, naturally cooling to 80 ℃, adding 6g of an accelerant dichlorophenyl dimethyl urea, and stirring for 5 min;
4) transferring the mixture obtained in the step 3) to a vacuum drying oven, and defoaming in vacuum for 15min at 80 ℃ to obtain the intermediate-temperature cured prepreg epoxy resin; it was transferred to a freezer at-17 ℃ and stored frozen.
Taking out the product obtained in the embodiment from a refrigerator, placing the product in an oven at 90 ℃ for heating for 10min until solid resin is molten and has better fluidity, then pouring the molten solid resin into a casting body mould of a tensile sample, placing the casting body mould into a vacuum drying oven, defoaming the casting body mould at 80 ℃ for 15min, then placing the casting body mould into a casting body mould at 100 ℃ for heat preservation for 1h, and preserving the heat at 120 ℃ for 3h to obtain the cured resin casting body tensile sample.
The test result shows that the casting body prepared from the medium-temperature cured prepreg resin obtained in the example has good surface quality, no dicyandiamide particles exist on the surface, and the tensile strength obtained by the test is 74.41 MPa.
The dynamic thermo-mechanical analyzer is used for testing the Tg of the epoxy resin of the intermediate-temperature cured prepreg obtained in the embodiment, and the result shows that the Tg is 145.73 ℃, and the Tg is higher, which shows that the heat resistance is good; meanwhile, the gel time at 120 ℃ is tested to be 858s, so that the requirement that the gel time is about 15min at the temperature is met.
The formulations were tested for rheological findings (fig. 2 and 3) that met the rheological performance required for prepreg resin storage and molding processes.
Comparative example 1
The preparation method of the intermediate-temperature cured prepreg epoxy resin in the comparative example is the same as that of the raw material used in example 1, but the stirring speed, the stirring time and the stirring temperature in the synthesis process and the addition sequence of the materials are different, and the specific steps are as follows:
1) adding 150g E-51 epoxy resin, 90g E-20 epoxy resin and 60g 704 novolac epoxy resin into a three-neck flask, and stirring at the rotating speed of 500r/min to raise the temperature from room temperature to 100 ℃;
2) adding 0.6g of organic silicon defoaming agent and 21g of micro-powder dicyandiamide curing agent into the reaction system in the step 1), and stirring the reaction system at the temperature of 100 ℃ at the rotating speed of 500r/min for 30 min;
3) keeping the reaction system in the step 2) at a rotating speed of 500r/min, heating the reaction system from 100 ℃ to 120 ℃, and rotationally stirring the reaction system for 1.5 hours at the temperature of 120 ℃;
4) keeping the reaction system in the step 3) at a rotating speed of 500r/min, naturally cooling to 80 ℃, adding 6g of an accelerant dichlorophenyl dimethyl urea, and stirring for 5 min;
5) transferring the mixture obtained in the step 4) to a vacuum drying oven, and defoaming in vacuum for 15min at 80 ℃ to obtain the intermediate-temperature cured prepreg epoxy resin; it was transferred to a freezer at-17 ℃ and stored frozen.
And taking the product obtained in the comparative example out of a refrigerator, placing the product in an oven at 90 ℃ for heating for 10min until the solid resin is molten and has better fluidity, then pouring the product into a casting body mould of the tensile sample, placing the casting body mould into a vacuum drying oven, defoaming the product at 80 ℃ for 15min, then placing the casting body mould into a casting body mould at 100 ℃ for heat preservation for 1h, and preserving the heat at 120 ℃ for 3h to obtain the cured resin casting body tensile sample.
The test result shows that the large agglomerated dicyandiamide distributed on the surface of the casting body prepared from the medium-temperature cured prepreg resin obtained in the example exists (as shown in fig. 1), the tensile strength is 29.32Mpa, the large agglomerated dicyandiamide particles easily cause stress concentration, and when the large agglomerated dicyandiamide particles are used for preparing a composite material, the mechanical property of the composite material is greatly influenced, so that the application requirement is not met.
Comparative example 2
The preparation method of the intermediate-temperature cured prepreg epoxy resin in the comparative example is the same as that of the raw material used in example 1, but the stirring speed, the stirring time and the stirring temperature in the synthesis process and the addition sequence of the materials are different, and the specific steps are as follows:
1) adding 150g E-51 epoxy resin, 90g E-20 epoxy resin and 60g 704 novolac epoxy resin into a three-neck flask, and stirring at the rotating speed of 1000r/min to raise the temperature from room temperature to 100 ℃;
2) adding 0.6g of organic silicon defoaming agent and 21g of micro-powder dicyandiamide curing agent into the reaction system in the step 1), and stirring the reaction system at 100 ℃ for 30min at the rotating speed of 1000 r/min;
3) keeping the reaction system in the step 2) at a rotating speed of 1000r/min, heating the reaction system from 100 ℃ to 120 ℃, and rotationally stirring the reaction system for 1.5 hours at 120 ℃;
4) keeping the reaction system in the step 3) at the rotating speed of 1000r/min, naturally cooling to 80 ℃, adding 6g of promoter dichlorophenyl dimethyl urea, and stirring for 5 min;
5) transferring the mixture obtained in the step 4) to a vacuum drying oven, and carrying out vacuum defoamation for 15min at the temperature of 80 ℃;
6) and (3) transferring the product finally obtained after vacuum defoaming in the step 5), namely the toughened modified medium-temperature cured prepreg resin product, to a freezer at the temperature of-17 ℃, and freezing and storing.
Taking the product obtained in the example out of a refrigerator, placing the product in an oven at 90 ℃ for 10min to heat until the solid resin is molten and has better fluidity, then pouring the molten solid resin into a casting body mould of a tensile sample, then placing the casting body mould in a vacuum drying oven, defoaming the casting body mould at 80 ℃ for 15min, then placing the casting body mould in a vacuum drying oven, preserving the temperature for 1h at 100 ℃, and preserving the temperature for 3h at 120 ℃ to obtain a cured resin casting body tensile sample.
The test result shows that the casting body prepared from the medium-temperature cured prepreg resin obtained in the example has good surface quality and tensile strength of 42.89Mpa, and can be used for practical use, but the process requires a large rotating speed, long synthesis time, large energy consumption and poor economic benefit.
The results show that the preparation method can well solve the problem of uneven dispersion of dicyandiamide, the synthesis process time and energy consumption are reduced, the toughening agent is added to play a role in well toughening and reinforcing, and the prepared prepreg epoxy resin has excellent performance.
It is apparent that the above embodiments are only examples for clearly illustrating and do not limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications are therefore intended to be included within the scope of the invention as claimed.
Claims (10)
1. A preparation method of intermediate-temperature curing prepreg epoxy resin with an optimized process is characterized by comprising the following steps:
1) mixing E-51 epoxy resin, a defoaming agent and a dicyandiamide curing agent, heating to a proper temperature under the condition of stirring, and continuously stirring and dispersing to obtain a uniform mixed solution;
2) adding E-20 epoxy resin and 704 novolac epoxy resin into the mixed solution in the step 1), heating to a proper temperature under the stirring condition, and continuing to fully stir;
3) naturally cooling the reaction system in the step 2) to a proper temperature under stirring, adding an accelerant and fully stirring;
4) and (3) defoaming the mixture obtained in the step 3) in vacuum to obtain the intermediate-temperature cured prepreg epoxy resin.
2. The preparation method of claim 1, wherein in the step 1), 49-51 parts of E-51 epoxy resin, 0.18-0.22 part of defoaming agent and 6.5-7.5 parts of dicyandiamide curing agent are counted by mass; in the step 2), 29-31 parts of E-20 epoxy resin and 19-21 parts of 704 phenolic epoxy resin; in the step 3), 1.9-2.1 parts of an accelerator.
3. The preparation method according to claim 1, wherein in the step 1), the temperature is raised to 95-105 ℃, and the stirring and the dispersing are carried out for 25-35 min.
4. The preparation method according to claim 1, wherein in the step 2), the temperature is raised to 115-125 ℃, and the mixture is fully stirred for 25-35 min; and in the step 3), naturally cooling to 75-85 ℃, adding the accelerant, and fully stirring for 3-5 min.
5. The preparation method according to claim 1, wherein in the step 1), the stirring speed is 450-550 r/min; in the step 2), the stirring speed is 450-550 r/min; in the step 3), the stirring speed is 450-550 r/min.
6. The preparation method according to claim 1, wherein in the step 1), the particle size of the dicyandiamide curing agent is 2-5 um, and the defoaming agent is an organic silicon defoaming agent; in the step 3), the accelerant is dichlorophenyl dimethyl urea; in the step 4), the vacuum defoaming conditions are as follows: and (3) carrying out vacuum defoaming for 10-20 min at the temperature of 75-85 ℃.
7. The preparation method according to claim 1, wherein in the step 1), gas-phase nano SiO is also added2。
8. The method of claim 7, wherein the E-51 epoxy resin and the gas phase nano SiO2The mass ratio is (49-51): (0 to 1).
9. The method of claim 8, wherein the E-51 epoxy resin and the gas phase nano SiO are2The mass ratio is (49-51): (0.4 to 1).
10. The method of claim 7, wherein the gas phase of nano SiO2The particle size of (A) is 12-16 nm.
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| CN202111386631.8A CN114015198B (en) | 2021-11-22 | 2021-11-22 | Preparation method of intermediate-temperature curing prepreg epoxy resin with optimized process |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115627002A (en) * | 2022-10-25 | 2023-01-20 | 台州市黄岩区武汉理工高性能复合材料技术研究院 | Formula, preparation method and application of epoxy prepreg |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018005045A1 (en) * | 2016-06-27 | 2018-01-04 | Dow Global Technologies Llc | Storage stable epoxy prepregs from dicyandiamide solutions and methods for making the same |
| CN109535660A (en) * | 2018-12-18 | 2019-03-29 | 深圳航天科技创新研究院 | A kind of fire-retardant prepreg resin of the rapid curing that viscosity is controllable and preparation method thereof |
| CN110105847A (en) * | 2019-05-31 | 2019-08-09 | 咸阳辉煌电子磁性材料研究所 | A kind of epoxide powder coating and preparation method thereof |
| CN110105709A (en) * | 2019-03-06 | 2019-08-09 | 武汉理工大学 | The method of toughening agent modified epoxy resin toughness |
| CN112694714A (en) * | 2020-12-18 | 2021-04-23 | 广东盈骅新材料科技有限公司 | Epoxy resin composition, prepreg, laminate, and printed wiring board |
-
2021
- 2021-11-22 CN CN202111386631.8A patent/CN114015198B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018005045A1 (en) * | 2016-06-27 | 2018-01-04 | Dow Global Technologies Llc | Storage stable epoxy prepregs from dicyandiamide solutions and methods for making the same |
| CN109535660A (en) * | 2018-12-18 | 2019-03-29 | 深圳航天科技创新研究院 | A kind of fire-retardant prepreg resin of the rapid curing that viscosity is controllable and preparation method thereof |
| CN110105709A (en) * | 2019-03-06 | 2019-08-09 | 武汉理工大学 | The method of toughening agent modified epoxy resin toughness |
| CN110105847A (en) * | 2019-05-31 | 2019-08-09 | 咸阳辉煌电子磁性材料研究所 | A kind of epoxide powder coating and preparation method thereof |
| CN112694714A (en) * | 2020-12-18 | 2021-04-23 | 广东盈骅新材料科技有限公司 | Epoxy resin composition, prepreg, laminate, and printed wiring board |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115627002A (en) * | 2022-10-25 | 2023-01-20 | 台州市黄岩区武汉理工高性能复合材料技术研究院 | Formula, preparation method and application of epoxy prepreg |
| CN115627002B (en) * | 2022-10-25 | 2024-02-13 | 台州市黄岩区武汉理工高性能复合材料技术研究院 | Epoxy prepreg formula and preparation method and application thereof |
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