CN117624838A - Low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and preparation method thereof - Google Patents
Low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and preparation method thereof Download PDFInfo
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- 239000003822 epoxy resin Substances 0.000 title claims abstract description 136
- 229920000647 polyepoxide Polymers 0.000 title claims abstract description 136
- 239000000203 mixture Substances 0.000 title claims abstract description 82
- 238000010521 absorption reaction Methods 0.000 title claims abstract description 26
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 72
- 239000004593 Epoxy Substances 0.000 claims abstract description 41
- 239000002245 particle Substances 0.000 claims abstract description 30
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 14
- 238000006243 chemical reaction Methods 0.000 claims description 24
- QGBSISYHAICWAH-UHFFFAOYSA-N dicyandiamide Chemical group NC(N)=NC#N QGBSISYHAICWAH-UHFFFAOYSA-N 0.000 claims description 19
- 150000004982 aromatic amines Chemical group 0.000 claims description 16
- 238000002156 mixing Methods 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 10
- 239000004202 carbamide Substances 0.000 claims description 9
- 150000003672 ureas Chemical class 0.000 claims description 8
- 125000003700 epoxy group Chemical group 0.000 claims description 7
- 229920006260 polyaryletherketone Polymers 0.000 claims description 7
- 239000004677 Nylon Substances 0.000 claims description 3
- 239000004696 Poly ether ether ketone Substances 0.000 claims description 3
- 239000004695 Polyether sulfone Substances 0.000 claims description 3
- 229920001971 elastomer Polymers 0.000 claims description 3
- 229920001778 nylon Polymers 0.000 claims description 3
- 229920006393 polyether sulfone Polymers 0.000 claims description 3
- 229920002530 polyetherether ketone Polymers 0.000 claims description 3
- 239000005060 rubber Substances 0.000 claims description 3
- 229920013636 polyphenyl ether polymer Polymers 0.000 claims description 2
- 239000004721 Polyphenylene oxide Substances 0.000 claims 1
- 229920006380 polyphenylene oxide Polymers 0.000 claims 1
- 229920005989 resin Polymers 0.000 abstract description 25
- 239000011347 resin Substances 0.000 abstract description 25
- 238000004132 cross linking Methods 0.000 abstract description 6
- 229920001577 copolymer Polymers 0.000 abstract description 2
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 abstract 2
- 238000001723 curing Methods 0.000 description 80
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical class C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 15
- KZTYYGOKRVBIMI-UHFFFAOYSA-N diphenyl sulfone Chemical compound C=1C=CC=CC=1S(=O)(=O)C1=CC=CC=C1 KZTYYGOKRVBIMI-UHFFFAOYSA-N 0.000 description 10
- 239000002131 composite material Substances 0.000 description 8
- 230000008569 process Effects 0.000 description 6
- 238000003860 storage Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 150000004985 diamines Chemical class 0.000 description 5
- PXKLMJQFEQBVLD-UHFFFAOYSA-N bisphenol F Chemical compound C1=CC(O)=CC=C1CC1=CC=C(O)C=C1 PXKLMJQFEQBVLD-UHFFFAOYSA-N 0.000 description 4
- 239000004850 liquid epoxy resins (LERs) Substances 0.000 description 4
- 150000001412 amines Chemical class 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000004841 bisphenol A epoxy resin Substances 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
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- 230000002349 favourable effect Effects 0.000 description 1
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- 238000010438 heat treatment Methods 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000013035 low temperature curing Methods 0.000 description 1
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Abstract
The invention provides a low-heat release, low-water absorption and low-viscosity epoxy resin composition and a preparation method thereof. The epoxy resin composition mainly comprises an epoxy resin mixture, a curing agent, an accelerator and toughening particles. Wherein the epoxy resin mixture comprises two or more low-viscosity epoxy resins (35-60 wt%) and low-epoxy-value flexible epoxy resins (10-35 wt%) and its room-temperature viscosity is not higher than 15000 mPa.s; the curing agent comprises a prepolymerized curing agent (6-18 wt%) and a latent curing agent (1-5 wt%). When the epoxy resin is prepared, the low-viscosity epoxy resin and the low-epoxy-value flexible epoxy resin are pre-polymerized to form a copolymer to improve the compatibility of the resin. The pre-polymerization process reduces the curing exotherm of the composition on the one hand, and increases the crosslinking density of the low exotherm epoxy resin system on the other hand, reducing the water absorption thereof. Finally, components such as a latent curing agent and the like are added to obtain the epoxy resin composition with low heat release, good moisture resistance, low viscosity and high toughness.
Description
Technical Field
The invention relates to the technical field of composite materials, in particular to a low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and a preparation method thereof.
Background
The epoxy resin has excellent mechanical property and good processing and molding manufacturability, and is one of the most widely used resin matrixes in the composite material. With the development of new technical industries in recent years, the requirements of large-size and ultra-thick composite structural parts are becoming more and more widespread. The large-size high-thickness structural member has higher requirements on a resin matrix and a forming process, such as high temperature resistance, high toughness, mild curing reaction, low heat release, medium-temperature curing (130 ℃), and the like. When urea accelerators are adopted in the existing medium-temperature curing dicyandiamide/epoxy resin system, the activity is excited within the range of 100-130 ℃, the reaction and the curing are rapidly carried out, and larger heat is generated, so that on one hand, the partial overheating can cause uneven curing of the product, internal stress is generated, and the quality of the composite material product is influenced; on the other hand, the concentration of the heat release can cause the reaction rate to be too fast and difficult to control.
The existing method for reducing the heat release of the epoxy resin mainly reduces the curing reaction temperature of the epoxy resin through a plurality of low-temperature curing agents, but has higher reactivity, short storage time at room temperature and poor manufacturability, and cannot realize the synchronization of low curing heat release and manufacturability of the resin.
Aiming at the problems, the invention develops the epoxy resin composition with low heat release, low water absorption and low viscosity and the preparation method thereof, ensures the medium-temperature curing condition and manufacturability through the prepolymerization reaction, solves the heat release concentration phenomenon in the curing process, simultaneously remarkably reduces the water absorption of the epoxy resin cured product, and simultaneously has the advantages of low viscosity and high toughness.
Disclosure of Invention
The invention aims to provide a low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and a preparation method thereof, and the prepared epoxy resin composition has the characteristics of low heat release amount in a curing reaction, moisture and heat resistance, long storage time and good manufacturability; in addition, the toughness of the resin system is enhanced by the flexible epoxy resin component and the toughening particles, and a high-toughness low-exothermic epoxy resin composition is provided.
It is another object of the present invention to provide a low exotherm, low water absorption, low viscosity epoxy resin composition useful in the preparation of hot melt prepregs.
The above object of the present invention is mainly achieved by the following technical solutions:
in a first aspect, the present invention provides a low exotherm, low water absorption, low viscosity epoxy resin composition consisting essentially of: epoxy resin mixture, curing agent, accelerator and toughening particles; the epoxy resin mixture comprises a low viscosity epoxy resin and a low epoxy value flexible epoxy resin; the curing agent comprises a pre-polymerization curing agent and a latent curing agent.
Preferably, the pre-polymerization curing agent is an aromatic amine curing agent, and the latent curing agent is a dicyandiamide curing agent, so that the medium-temperature curing and good storability of the resin are realized. The pre-polymerization curing agent is an aromatic amine curing agent, the cross-linking density of the resin system is improved by high-temperature curing, and a part of reaction heat is released in advance; the latent curing agent is dicyandiamide curing agent, and realizes medium-temperature curing and storage.
Preferably, the low-viscosity epoxy resin has medium epoxy group content, so that the mechanical property of the system is ensured; the low-epoxy-value flexible epoxy resin has lower room temperature viscosity (not higher than 15000 mPa.s) and lower epoxy value (not higher than 0.3), so that on one hand, the heat release amount of a curing reaction is reduced, on the other hand, the viscosity of a system is reduced, and the manufacturability of the resin is improved. The modified epoxy resin with strong hydrophobicity is preferable, and can be one or a combination of polyurethane modified epoxy resin, organosilicon modified epoxy resin, difunctional epoxy resin and modified bisphenol A epoxy resin.
The epoxy resin composition is prepared by pre-polymerizing the low-viscosity epoxy resin and the low-epoxy-value flexible epoxy resin in a pre-polymerization process to form a copolymer, so that the resin compatibility is improved. On the one hand, the reaction releases a part of reaction heat in advance, so that the heat release amount of the composition is reduced, and on the other hand, the crosslinking density is improved through high-temperature curing, so that the water absorption rate is reduced. The polymerization reaction degree needs to be controlled by time, temperature and the dosage of the pre-polymerization curing agent, so as to meet the requirements of resin manufacturability and low heat release.
In a second aspect, the present invention provides a process for preparing a low exotherm, low water absorption, low viscosity epoxy resin composition comprising the steps of:
(1) Fully mixing the low-viscosity epoxy resin and the low-epoxy-value flexible epoxy resin to obtain a mixture A;
(2) Adding a prepolymerization curing agent into the mixture A, and uniformly mixing to obtain a mixture B;
(3) Prepolymerizing the mixture B at a proper temperature to obtain a prepolymer C;
(4) The latent curing agent, the accelerator and the toughening particles are added into the prepolymer C, and the mixture is mixed to obtain the epoxy resin composition with low heat release, low water absorption and low viscosity.
Preferably, the mass ratio of the low-viscosity epoxy resin to the low-epoxy-value flexible epoxy resin to the pre-polymerization curing agent to the latent curing agent to the accelerator to the toughening particles is (35-60): (10-35): (6-18): (1-5): (0.2-1): (5-15), and the sum of the percentages of the components is 100wt%. When the components are proportioned according to the proportion, the resin system can be ensured to be cured smoothly and completely in a medium temperature range, the heat release amount and the viscosity of the system can be reduced, and the toughness and manufacturability of the resin system are improved.
The low viscosity epoxy resin in the step (1) may be a bisphenol A type liquid epoxy resin, such as E-51, E-52, E-54, or bisphenol F type liquid epoxy resin. The room temperature viscosity of the low epoxy value flexible epoxy resin is not higher than 15000 mPa.s, and the epoxy value is not higher than 0.3. The mass ratio of the low-viscosity epoxy resin to the low-epoxy-value flexible epoxy resin is (35-60): (10-35) and the mixing temperature is 70-120 ℃.
Preferably, the temperature of the mixing in steps (1) and (2) is 70 to 120 ℃.
Preferably, the prepolymerized curing agent in the step (2) is an aromatic amine curing agent, and the mass fraction is 6-18 wt%;
preferably, the reaction temperature of the prepolymerization in the step (3) is 150-180 ℃, and the time of the prepolymerization is 1-4 h.
Preferably, the latent curing agent in the step (4) is dicyandiamide curing agent, and the mass ratio of the epoxy resin mixture, the pre-polymerization curing agent and the latent curing agent is 70: (6-18): (1-5).
Preferably, the temperature of the mixing in the step (4) is 60-80 ℃ and the mixing time is 0.2-1 hour.
Preferably, the accelerator is a substituted urea accelerator, preferably a less reactive, slow curing accelerator component for catalyzing a latent curing agent to reduce the curing temperature. The mass fraction of the accelerator is 0.2-1 wt%, and the accelerator is purchased from Shanghai complex high new material company.
Preferably, the toughening particles are one or a combination of nylon particles, rubber particles, polyether-ether-ketone, polyaryletherketone, polyphenyl ether and polyether sulfone, and the mass fraction of the toughening particles is 5-15 wt%. The particle size of the toughening particles is 5-30 mu m, so that on one hand, the free volume inside the resin can be reduced, the water absorption rate of the resin can be reduced, and on the other hand, the toughness of the resin can be improved.
The invention has the beneficial effects that:
(1) The flexible epoxy resin with ultralow viscosity and low epoxy value is favorable for reducing the heat release amount of the overall curing reaction, reducing the viscosity of the resin and improving the manufacturability of the resin; on the other hand, the toughness of the resin is improved from the molecular level through the flexible chain segments, so that the resin has higher bending strength and compression strength after impact.
(2) The low-viscosity epoxy resin and the low-epoxy-value flexible epoxy resin are subjected to a prepolymerization reaction to form a prepolymer, so that the compatibility of the prepolymer can be effectively improved, and phase separation is avoided; meanwhile, part of epoxy groups can be reacted in advance in the prepolymerization process, so that the heat release amount of the curing reaction of the final epoxy resin composition is reduced; the prepolymer can control the viscosity of the prepolymer system by the reaction temperature, time and reactant proportion, and regulate the manufacturability.
(2) The invention adopts the amine curing agent of high temperature reaction to effectively improve the crosslinking density of the system and reduce the water absorption rate of the low-heat-release resin system. The intermediate temperature curing of the system is completed by utilizing the latent dicyandiamide curing agent, and the prepared epoxy resin composition has long storage period and better stability at room temperature.
Detailed Description
Embodiments of the invention and features of embodiments may be combined with each other and the described embodiments are some, but not all, embodiments of the invention.
According to some preferred embodiments, a low exotherm, low water absorption, low viscosity epoxy resin composition is characterized in that the epoxy resin composition comprises an epoxy resin mixture, a curing agent, an accelerator and toughening particles, the epoxy resin mixture is composed of a low viscosity epoxy resin and a low epoxy value flexible epoxy resin, wherein the viscosity of the low epoxy value epoxy resin is not higher than 15000 mpa.s, the epoxy value is lower than 0.3 (for example, may be 0.3, 0.25, 0.2, 0.15), and when the epoxy value is higher, the epoxy groups in the epoxy resin are increased, so that the heat release of the epoxy resin curing reaction is increased.
The invention adopts the flexible epoxy resin with low epoxy value, can reduce the heat release amount of the curing reaction of the epoxy resin system, and controls the mass ratio of the low-viscosity epoxy resin to the low-epoxy value epoxy resin to be (35-60): (10-35). When the addition amount of the flexible epoxy resin with a low epoxy value is lower than the range, the viscosity of the epoxy resin system is increased, the process performance of the epoxy resin composition is deteriorated, the content of epoxy groups is increased, and the heat release amount is increased; when the addition amount of the low epoxy value flexible epoxy resin is more than the above range, the glass transition temperature of the epoxy resin system is greatly lowered and the heat resistance is deteriorated.
In the invention, the low-viscosity epoxy resin and the low-epoxy-value flexible epoxy resin are firstly mixed to obtain the mixture A, then the mixture A reacts with the amine curing agent, and if the low-viscosity epoxy resin and the amine curing agent are only reacted for prepolymerization, the low-epoxy-value flexible epoxy resin, the second curing agent, the accelerator and the toughening particles are added in the second stage, so that the resin curing is split.
The mass ratio of the epoxy resin mixture to the aromatic amine curing agent is 70: (6-18). When the amount of the aromatic amine curing agent is higher than the range, the degree of the prepolymerization reaction is increased, the viscosity of the prepolymer is increased due to a large amount of intermolecular crosslinking, and the prepolymer cannot be mixed with the latent curing agent, the accelerator and the toughening particles, so that the manufacturability of the resin is affected; if the addition amount of the aromatic amine curing agent is lower than the proportion, more epoxy groups remain in the prepolymer component, which is not beneficial to reducing the curing exotherm of the epoxy resin system.
The aromatic amine curing agent and the dicyandiamide curing agent are combined, so that the moisture and heat resistance and mechanical property of the epoxy resin system can be ensured; meanwhile, the prepared epoxy resin composition can be slowly cured at medium temperature, the heat release amount is low, the storage is more stable, and the storage period of the resin is prolonged.
The invention also provides a preparation method of the low-heat-release epoxy resin composition, which comprises the following steps:
(1) The low viscosity epoxy resin and the low epoxy value flexible epoxy resin are mixed to obtain a mixture A, and the stirring temperature is preferably 70-120 ℃ for 0.2-1 hour.
(2) And adding an aromatic amine curing agent into the mixture A to obtain a mixture B.
(3) Heating the mixture B to 150-180 ℃ for prepolymerization for 1-4 h to obtain a prepolymer C.
(4) And adding dicyandiamide curing agent, accelerator and toughening particles into the prepolymer C, and mixing to obtain the epoxy resin composition with low heat release, low water absorption and low viscosity, wherein the stirring temperature is 60-80 ℃ and the stirring time is 0.2-1 hour.
According to some more preferred embodiments, the temperature of the prepolymerization in step (3) may be 150 ℃, 160 ℃, 170 ℃ or 180 ℃, when the prepolymerization temperature is too low, the prepolymerization is difficult to proceed or the process is too slow; when the temperature is higher than 180 ℃, the prepolymerization reaction is too severe, and the heat release is concentrated, so that prepolymer gel can be caused; if the polymerization time in the step (3) is too long, the viscosity of the system may be increased, which may affect the manufacturability of the epoxy resin composition.
The invention is further illustrated below with reference to examples.
Example 1
(1) 50 parts of a low-viscosity epoxy resin (bisphenol A type epoxy resin E-51) and 20 parts of a low-epoxy-value flexible epoxy resin (epoxy value 0.15) were stirred at 80℃for 1 hour to obtain a mixture A;
(2) Adding 10 parts of aromatic amine curing agent (diamine diphenyl sulfone (DDS)) into the mixture A in the step (1), and carrying out prepolymerization for 3 hours at 120 ℃ to obtain a prepolymer C;
(3) 4 parts of dicyandiamide curing agent (Dicy), 1 part of substituted urea accelerator (UR 300) and 15 parts of polyaryletherketone particles are added into the prepolymer C, and stirred at 50 ℃ to obtain the low heat release epoxy resin composition.
The curing exotherm of the low exotherm epoxy resin composition described above as measured by DSC is shown in Table 1. The epoxy resin composition and the T800-grade carbon fiber are compounded to form a prepreg, and the compression strength and the water absorption rate of the composite plate after impact are obtained after layering and curing are shown in Table 1.
Example 2
(1) 48 parts of a low-viscosity epoxy resin (bisphenol A type epoxy resin E-51) and 27 parts of a low-epoxy value flexible epoxy resin (epoxy value 0.15) were stirred at 80℃for 1 hour to obtain a mixture A;
(2) Adding 10 parts of aromatic amine curing agent (diamine diphenyl sulfone (DDS)) into the mixture A in the step (1), and prepolymerizing for 4 hours at 160 ℃ to obtain a prepolymer C;
(3) 4 parts of dicyandiamide curing agent (Dicy), 1 part of substituted urea accelerator (UR 300) and 10 parts of polyaryletherketone toughening particles are added into the prepolymer C, and the mixture is uniformly mixed at 50 ℃ to obtain the low-heat-release epoxy resin composition.
Example 3
Example 3 is substantially the same as example 2 except that: the prepolymerization time in the step (2) was shortened to 2h.
Example 4
(1) 48 parts of a low viscosity epoxy resin (bisphenol A type epoxy resin E-51) and 5 parts of an aromatic amine curing agent (diamine diphenyl sulfone (DDS)) were mixed to obtain a mixture A.
(2) Prepolymerizing the mixture A at 160 ℃ for 4 hours to obtain a prepolymer B;
(3) 27 parts of low-epoxy-value flexible epoxy resin (with an epoxy value of 0.15), 9 parts of dicyandiamide curing agent (Dicy), 1 part of substituted urea accelerator (UR 300) and 10 parts of toughening particles (polyaryletherketone) are added into the prepolymer B in the step (2), and stirred for 1 hour at 50 ℃ to obtain the low-heat-release epoxy resin composition.
Example 5
(1) 50 parts of a low-viscosity epoxy resin (bisphenol A type epoxy resin E-51) and 30 parts of a low-epoxy value liquid epoxy resin (epoxy value 0.3) were stirred at 80℃for 1 hour to obtain a mixture A;
(2) Adding 15 parts of aromatic amine curing agent (diamine diphenyl sulfone (DDS)) into the mixture A in the step (1), and carrying out prepolymerization for 3 hours at 160 ℃ to obtain a prepolymer C;
(3) To the prepolymer C, 4 parts of dicyandiamide-based curing agent (Dicy) and 1 part of substituted urea accelerator (UR 500) were added, and stirred at 50℃to obtain a low-exothermic epoxy resin composition.
Comparative example 1
The composition of comparative example 1 was the same as in example 1, except that the prepolymerization reaction of step 2 was not carried out: the epoxy resin composition is prepared by uniformly mixing 48 parts of low-viscosity epoxy resin (bisphenol A type epoxy resin E-51), 27 parts of low-epoxy-value liquid epoxy resin (epoxy value 0.15), 10 parts of aromatic amine curing agent (diamine diphenyl sulfone (DDS)), 4 parts of dicyandiamide curing agent (Dicy), 1 part of substituted urea accelerator (UR 300) and 10 parts of polyaryletherketone toughening particles at 80 ℃.
Comparative example 2
The comparative example is substantially the same as example 2 except that: the low-viscosity epoxy resin (bisphenol A type epoxy resin E-51) in the step (1) was replaced with bisphenol F type epoxy resin having a lower room temperature viscosity, and the epoxy value was 0.58.
TABLE 1
As can be seen from a comparison of the examples and comparative examples in table 1, the incorporation of a low epoxy value flexible epoxy resin into the system can effectively reduce the amount of epoxy groups involved in the reaction, thereby reducing the amount of heat released from curing. Meanwhile, the addition of the low-viscosity flexible epoxy resin component can reduce the viscosity of the epoxy resin composition, improve the manufacturability of the epoxy resin composition, introduce movable flexible connection sections on the molecular scale and improve the toughness of the system. Incomplete prepolymerization, no prepolymerization, or the use of a highly reactive accelerator (e.g., UR 500) can result in concentrated exotherms for curing the epoxy resin composition, increasing the exotherm for curing the system. The content of the curing agent, the prepolymerization time and the prepolymerization temperature are key factors for controlling the prepolymerization reaction degree in the prepolymerization process, and the polymerization reaction degree is increased on the premise of ensuring the viscosity and the manufacturability of the resin system, so that the curing heat is released as much as possible in the stage. From the water absorption test result of the composite material, it can be speculated that the pre-polymerization reaction of the aromatic amine curing agent on the epoxy resin composition at a relatively high temperature can improve the crosslinking degree of the system and ensure the moisture-heat resistance and mechanical property of the system.
As can be seen from the result of the compressive strength of the composite slab after impact, the low-heat-release epoxy resin composition has good toughness, and the introduction of the flexible epoxy resin component and the toughening particles enhances the toughness of the system on different scales, so that the compressive strength of the composite slab after impact is greatly enhanced. This is mainly due to the soft segments in the cured product, and the interpenetrating network of the thermoplastic polymer formed at the resin matrix and interface.
Finally, it should be noted that: the foregoing is merely illustrative of the preferred embodiments of the invention, and it is to be understood that modifications and equivalents may be made by those skilled in the art without departing from the principles of the invention, which are intended to be regarded as illustrative of the invention.
Claims (10)
1. A low exothermic, low water absorption, low viscosity epoxy resin composition comprising an epoxy resin mixture, a curing agent, an accelerator, and toughening particles; the epoxy resin mixture comprises a low viscosity epoxy resin and a low epoxy value flexible epoxy resin; the curing agent comprises a pre-polymerization curing agent and a latent curing agent.
2. The low exotherm, low water absorption, low viscosity epoxy resin composition according to claim 1, wherein the low viscosity epoxy resin has a medium epoxy group content, guaranteeing mechanical properties of the system; the room temperature viscosity of the low epoxy value flexible epoxy resin is not higher than 15000 mPa.s, and the epoxy value is not higher than 0.3.
3. The low exotherm, low water absorption, low viscosity epoxy resin composition according to claim 1, wherein the pre-polymerized curing agent is an aromatic amine curing agent and the latent curing agent is a dicyandiamide curing agent.
4. The low exothermic, low water absorption, low viscosity epoxy resin composition according to claim 1, wherein the mass ratio of the low viscosity epoxy resin to the low epoxy value flexible epoxy resin is (35-60): (10-35), the mass ratio of the epoxy resin mixture to the pre-polymerization curing agent to the latent curing agent is 70: (6-18): (1-5).
5. The low exothermic, low water absorbing, low viscosity epoxy resin composition according to claim 1, wherein the accelerator is a substituted urea accelerator, the mass fraction of the accelerator being 0.2-1 wt%.
6. The low exothermic, low water absorption, low viscosity epoxy resin composition according to claim 1, wherein the toughening particles have a particle size of 5-30 μm, and the toughening particles are at least one of nylon particles, polyetheretherketone, polyaryletherketone, polyphenylene oxide, polyethersulfone, and rubber particles.
7. A method for preparing a low exothermic, low water absorption, low viscosity epoxy resin composition comprising the steps of:
(1) Fully mixing the low-viscosity epoxy resin and the low-epoxy-value flexible epoxy resin to obtain a mixture A;
(2) Adding a prepolymerization curing agent into the mixture A, and uniformly mixing to obtain a mixture B;
(3) Prepolymerizing the mixture B at a proper temperature to obtain a prepolymer C;
(4) And adding a latent curing agent, an accelerator and toughening particles into the prepolymer C, and mixing to obtain the low-heat-release, low-water-absorption and low-viscosity epoxy resin composition.
8. The method according to claim 7, wherein the temperature of the mixing in steps (1) and (2) is 70 to 120 ℃; the prepolymerization curing agent in the step (2) is an aromatic amine curing agent with the weight percent of 6-18 percent; the reaction temperature of the prepolymerization in the step (3) is 150-180 ℃, and the time of the prepolymerization is 1-4 h.
9. The method according to claim 7, wherein the latent curing agent in the step (4) is 1 to 5wt% of dicyandiamide-based curing agent; the temperature of the mixing in the step (4) is 60-80 ℃, and the mixing time is 0.2-1 hour.
10. The preparation method of claim 7, wherein the accelerator in the step (4) is a substituted urea accelerator, the mass fraction is 0.2-1 wt%, and the toughening particles are at least one of nylon particles, rubber particles, polyether ether ketone, polyarylether ketone, polyphenyl ether and polyether sulfone, and the mass fraction is 5-15 wt%.
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| CN202311504885.4A CN117624838A (en) | 2023-11-13 | 2023-11-13 | Low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and preparation method thereof |
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| CN202311504885.4A CN117624838A (en) | 2023-11-13 | 2023-11-13 | Low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and preparation method thereof |
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| CN202311504885.4A Pending CN117624838A (en) | 2023-11-13 | 2023-11-13 | Low-heat-release, low-water-absorption and low-viscosity epoxy resin composition and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117624838A (en) |
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2023
- 2023-11-13 CN CN202311504885.4A patent/CN117624838A/en active Pending
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