Low-heat-release high-compression-resistance light epoxy filler capable of being rapidly cured at room temperature and preparation method thereof

Abstract

The invention relates to an epoxy filler and a preparation method thereof, in particular to a low-heat-release high-compression-resistance light epoxy filler capable of being rapidly cured at room temperature and a preparation method of the low-heat-release high-compression-resistance light epoxy filler. The invention aims to solve the problems of large heat release amount, high heat release temperature, low curing speed and insufficient room-temperature curing in the curing process of the existing room-temperature rapid curing type oxygen filler. The invention discloses a low-heat-release high-compression-resistance light epoxy filler capable of being rapidly cured at room temperature. The low-heat-release high-compression-resistance light epoxy filler consists of a component A and a component B The component A is prepared from main body epoxy resin, low-activity epoxy resin, high-hydroxyl novolac epoxy resin, a flexibilizer, a diluent and modified hollow glass microspheres; and the component B is prepared from a low-speed curing agent and a curing accelerator. The filler prepared by the invention can gel in 20-40 minutes, the highest exothermic temperature does not exceed 100 DEG C during room-temperature curing, the density is lower than 0.7 g / cm < 3 > after curing, the room-temperature curing performance and the heating curing performance are equivalent, and the compression strength is greater than 54 MPa.

Description

Technical Field

[0001] The invention relates to an epoxy filler and a preparation method thereof. Background Art

[0002] Room temperature curing low-density filler is a lightweight filler widely used in the aerospace field. It is an auxiliary material for the processing of fully bonded honeycomb structures and various composite material components. It is generally composed of adhesives and hollow microsphere fillers. The main functions of fillers are filling, reinforcement, bonding and sealing. It is mainly used for filling and reinforcing various honeycomb structures, fixed assembly of inserts, filling and reinforcing the frames of honeycomb structures and fiberglass thin shells, and repairing the surfaces of composite materials.

[0003] In order to meet different application scenarios, room temperature curing low-density fillers can be divided into normal curing type and fast curing type. The gel time of normal curing type is generally one to several hours, which is a more common type. Its curing speed is moderate and can meet most daily filling, packaging and other manufacturing scenarios. Fast curing fillers can achieve gelation in a shorter time (such as a few minutes to tens of minutes), which is suitable for occasions that require fast filling and repair and high efficiency, such as some emergency repair scenarios.

[0004] Patent CN114561178B discloses a low-density flame-retardant filling glue and its preparation method. The density of the prepared filling glue is 0.45-0.5g / cm 3 , compression strength ≥15MPa, long gel time at 23°C, 50min-120min, and no record or description of the exothermic phenomenon during the curing of the filling glue. Patent CN116903997A discloses a fast-curing lightweight structural filling and fixing material and its use method. The obtained mixture of 200g of filling and fixing material has a gel time of about 1.5h, a slow curing speed, and the compression strength of the sample obtained by curing at room temperature for 7 days is significantly lower than the strength of heating curing, and the room temperature curing capacity is insufficient. This patent also does not investigate the exothermic phenomenon during the curing of the material. Patent CN113046006A discloses an adhesive and its preparation method and application. The pre-reaction of polyetheramine and epoxy resin and the pre-reaction between isophorone diamine, triethylenetetramine and diphenol propane are used to reduce the reaction activity and reaction heat of the adhesive, thereby achieving the purpose of keeping the maximum exothermic temperature below 80°C during use. The adhesive prepared by this patent has a relatively high density, and the prepolymerization reaction will significantly increase the viscosity of the resin system and shorten the shelf life of the product. Therefore, it is not suitable for the preparation of low-density fillers. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of large heat release, high heat release temperature, slow curing speed and insufficient room temperature curing during the curing process of the existing room temperature fast curing oxygen filler, and to provide a room temperature fast curing, low heat release, high pressure resistance and lightweight epoxy filler and a preparation method thereof.

[0006] A room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler, consisting of component A and component B;

[0007] The component A is prepared from 60 to 80 parts of main epoxy resin, 10 to 20 parts of low-activity epoxy resin, 5 to 15 parts of high-hydroxyl phenolic epoxy resin, 5 to 8 parts of toughening agent, 5 to 20 parts of diluent and 20 to 40 parts of modified hollow glass microspheres;

[0008] The component B is prepared from 10 to 25 parts of a slow curing agent and 3 to 5 parts of a curing accelerator.

[0009] A method for preparing a room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler is specifically completed by the following steps:

[0010] 1. Weigh 60 to 80 parts of main epoxy resin, 10 to 20 parts of low-activity epoxy resin, 5 to 15 parts of high-hydroxyl phenolic epoxy resin, 5 to 8 parts of toughening agent, 5 to 20 parts of diluent, 20 to 40 parts of modified hollow glass microspheres, 10 to 25 parts of slow curing agent and 3 to 5 parts of curing accelerator according to weight;

[0011] 2. Add the main epoxy resin, low-activity epoxy resin, high-hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 60°C to 100°C at a speed of 500r / min to 1000r / min for 1h to 3h, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 50r / min to 200r / min for 20min to 60min, then discharge the material to obtain component A;

[0012] 3. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 500r / min~1000r / min for 1h~2h to obtain component B.

[0013] Principle of the present invention:

[0014] The present invention uses conventional epoxy resin as the main resin, introduces a proper amount of low-activity high-functional epoxy resin, and uses a slow curing agent as the main curing component. With the help of the low activity of the epoxy resin and the curing agent, the concentrated and large-scale heat release during the room temperature curing process of the filler is avoided. The hydroxyl groups on the high-hydroxyl phenolic epoxy resin, the hydroxyl groups on the surface hydroxylated modified hollow glass microspheres, and the curing accelerator jointly promote the appropriate increase in the reaction speed of the system, and the system gel time is regulated to 20min to 40min without significantly affecting the reaction heat release. At the same time, the room temperature late curing ability of the system is guaranteed, so that the room temperature curing performance of the filler is equivalent to the heating curing performance. The low-activity high-functional epoxy resin improves the crosslinking density, the high-hydroxyl phenolic epoxy resin further improves the rigidity of the system, and the surface hydroxylation of the hollow glass microspheres improves the bonding force between the resin and the microspheres. The combined effect of multiple factors gives the filler excellent compressive resistance.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The present invention adopts a multi-angle promotion scheme of a low-activity system to realize the preparation technology of a fast-curing, low-exothermic filler; the present invention adds a certain amount of low-activity, multifunctional glycidylamine epoxy resin to a conventional epoxy resin to obtain a main resin with relatively low activity, and uses a slow curing agent as the main curing component, and adjusts the activity of the system to avoid concentrated and large-scale heat release during the curing of the filler; on this basis, the low-activity system is jointly promoted by means of a high-hydroxyl phenolic epoxy resin, a surface hydroxylated modified hollow glass microsphere, and a curing accelerator, so as to appropriately increase the curing reaction speed, realize the regulation of the gel time and the reaction heat, break through the key technology of fast curing and low heat release, and complete the preparation of a fast curing, low-exothermic filler;

[0017] Second, the filler prepared by the present invention has strong room temperature curing ability, and the performance of the sample obtained by room temperature curing can reach the high performance of the heated cured sample; the room temperature curing ability of the filler depends on the ability of the system to continue to react after gelation; the low-activity epoxy resin used in the present invention has low initial reaction activity and will not produce a large amount of rapid heat release, but because it is a glycidylamine epoxy, it has a strong post-curing ability. At the same time, the use of high-hydroxyl phenolic epoxy resin, surface hydroxylation-modified hollow glass microspheres and curing accelerators also ensures the post-curing ability of the filler, and the room temperature curing effect is consistent with the heating curing effect;

[0018] 3. The filler has excellent compressive resistance; the low-activity epoxy resin used in the raw materials is a multifunctional glycidylamine epoxy resin, and the high-hydroxyl resin is a phenolic epoxy resin with strong rigidity. The modified hollow microspheres can improve the interface bonding force between the filler and the hollow microspheres after surface hydroxylation, and the compressive resistance of the filler is improved from multiple angles;

[0019] Fourth, by means of raw material selection, proportion adjustment, and beneficial processing methods, the combination of various excellent properties of the filler was finally achieved, and a lightweight epoxy filler with rapid curing at room temperature, low heat release, and high compressive strength was obtained; the obtained filler can gel in 20min to 40min, the maximum heat release temperature during room temperature curing does not exceed 100℃, and the density after curing is less than 0.7g / cm 3 The performance of room temperature curing and heating curing is equivalent, and the compressive strength is greater than 54MPa. DETAILED DESCRIPTION

[0020] Specific implementation method 1: This implementation method is a room temperature fast curing low exothermic high compressive light epoxy filler, which is composed of component A and component B;

[0021] The component A is prepared from 60 to 80 parts of main epoxy resin, 10 to 20 parts of low-activity epoxy resin, 5 to 15 parts of high-hydroxyl phenolic epoxy resin, 5 to 8 parts of toughening agent, 5 to 20 parts of diluent and 20 to 40 parts of modified hollow glass microspheres;

[0022] The component B is prepared from 10 to 25 parts of a slow curing agent and 3 to 5 parts of a curing accelerator.

[0023] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that the room temperature fast curing low exothermic high compressive light epoxy filler can gel in 20min to 40min, the maximum exothermic temperature during room temperature curing does not exceed 100°C, and the density after curing is less than 0.7g / cm 3 , the compression strength is greater than 54MPa. The other steps are the same as those in the first embodiment.

[0024] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that: the main epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin and alicyclic epoxy resin with an epoxy value of 0.25 to 0.75. The other steps are the same as those of specific embodiment 1 or 2.

[0025] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that: the low-activity epoxy resin is one or two of N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dimethyldiphenylmethane and N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-diethyldiphenylmethane; the high-hydroxyl phenolic epoxy resin is one or two of EPALLOY 8240 and EPALLOY 8240E. The other steps are the same as those of specific embodiments 1 to 3.

[0026] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that: the toughening agent is a combination of a rubber toughening agent and a nanoparticle toughening agent, wherein the mass ratio of the rubber toughening agent to the nanoparticle toughening agent is (1 to 5): (5 to 1); the rubber toughening agent is one or more of CTBN, ATBN, HTBN and polysulfide rubber; the nanoparticle toughening agent is one or more of acrylate core-shell nanoparticles and silicone-acrylate core-shell nanoparticles of Japan's Kanebuchi, and P52 silicone core-shell particles of Germany's Wacker International Group Co., Ltd. The other steps are the same as specific embodiments 1 to 4.

[0027] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the diluent is one or more of aliphatic glycidyl ether, aromatic glycidyl ether and polyol glycidyl ether. The other steps are the same as those of specific embodiments 1 to 5.

[0028] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that: the preparation method of the modified hollow glass microspheres is specifically completed according to the following steps:

[0029] 1. Evenly mix H2SO4 solution and H2O2 solution at room temperature to obtain a mixed solution;

[0030] 2. Immersing the hollow glass microspheres into the mixed solution, stirring for a period of time at room temperature, filtering the hollow glass microspheres, and washing with water until neutral to obtain washed hollow glass microspheres;

[0031] 3. Dry the washed hollow glass microspheres for a period of time to obtain surface hydroxylated modified hollow glass microspheres. The other steps are the same as those in the first to sixth embodiments.

[0032] Specific embodiment 8: The difference between this embodiment and specific embodiments 1 to 7 is that the mass fraction of the H2SO4 solution described in step 1 is 98%; the mass fraction of the H2O2 solution described is 30%; the volume ratio of the H2SO4 solution to the H2O2 solution described in step 1 is 70:30; the hollow glass microspheres described in step 2 have a diameter of 10 μm to 120 μm and a density of 0.10 g / cm 3 ~0.60g / cm 3 , hollow glass microspheres with a compressive strength of 1 MPa to 50 MPa; the stirring time at room temperature in step 2 is 30 min to 60 min; in step 2, washing with water until the pH value is 6 to 7. The other steps are the same as those in specific embodiments 1 to 7.

[0033] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that: the slow curing agent is one or more of polyetheramine, polyamide and fatty amine; the curing accelerator is one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, N-(3-aminopropyl)imidazole, 1-methylimidazole, 1-vinylimidazole and 2-ethylimidazole. The other steps are the same as those of specific embodiments 1 to 8.

[0034] Specific embodiment 10: This embodiment provides a method for preparing a lightweight epoxy filler with low exothermicity and high compressive strength that is rapidly cured at room temperature, which is specifically completed in the following steps:

[0035] 1. Weigh 60 to 80 parts of main epoxy resin, 10 to 20 parts of low-activity epoxy resin, 5 to 15 parts of high-hydroxyl phenolic epoxy resin, 5 to 8 parts of toughening agent, 5 to 20 parts of diluent, 20 to 40 parts of modified hollow glass microspheres, 10 to 25 parts of slow curing agent and 3 to 5 parts of curing accelerator according to weight;

[0036] 2. Add the main epoxy resin, active epoxy resin, high hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 60°C to 100°C at a speed of 500r / min to 1000r / min for 1h to 3h, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 50r / min to 200r / min for 20min to 60min, then discharge the material to obtain component A;

[0037] 3. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 500r / min~1000r / min for 1h~2h to obtain component B.

[0038] The following examples are used to verify the beneficial effects of the present invention:

[0039] Example 1: A room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler is composed of component A and component B. The preparation method is specifically completed according to the following steps:

[0040] 1. Preparation of modified hollow glass microspheres:

[0041] ①. At room temperature, mix 98% H2SO4 solution and 30% H2O2 solution in a volume ratio of 70:30 to obtain a mixed solution;

[0042] The hollow glass microspheres described in step 1① have a diameter of 10 μm to 80 μm and a density of 0.10 g / cm 3 ~0.50g / cm 3, hollow glass microspheres with a compressive strength of 20MPa to 45MPa;

[0043] ②, immerse the hollow glass microspheres in the mixed solution, stir at room temperature for 30 minutes, filter the hollow glass microspheres, and wash with water until the pH value is 6.8 to obtain washed hollow glass microspheres;

[0044] ③, drying the washed hollow glass microspheres at 60°C for 5 h to obtain surface hydroxylated modified hollow glass microspheres;

[0045] 2. Weigh 60g of main epoxy resin, 15g of low-activity epoxy resin, 8g of high-hydroxy phenolic epoxy resin, 6g of toughening agent, 8 parts of diluent, 30 parts of modified hollow glass microspheres, 10 parts of slow curing agent and 3 parts of curing accelerator according to weight;

[0046] The main epoxy resin described in step 2 is: bisphenol A type epoxy resin E51 with an epoxy value of 0.51 produced by Nantong Xingchen Synthetic Materials Co., Ltd.;

[0047] The low-activity epoxy resin described in step 2 is N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dimethyldiphenylmethane;

[0048] The high hydroxyl phenolic epoxy resin described in step 2 is EPALLOY 8240 from Huntsman Company;

[0049] The toughening agent described in step 2 is CTBN and silicone-acrylate core-shell nanoparticles, wherein the mass ratio of CTBN to silicone-acrylate core-shell nanoparticles is 2g:4g; the silicone-acrylate core-shell nanoparticles are purchased from Kanebuchi, Japan;

[0050] The diluent described in step 2 is aliphatic glycidyl ether;

[0051] The slow curing agent described in step 2 is a mixture of polyetheramine D230 from Huntsman and JH-5280 from Shenzhen Jiadida New Material Technology Co., Ltd. in a mass ratio of 2:1; the curing accelerator described in step 2 is 2-methylimidazole;

[0052] 3. Add the main epoxy resin, active epoxy resin, high hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 100°C at a speed of 800r / min for 1h, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 50r / min for 30min, then discharge the material to obtain component A;

[0053] 4. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 500 r / min for 1.5 hours to obtain component B.

[0054] Example 2: A room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler is composed of component A and component B, and the preparation method is specifically completed according to the following steps:

[0055] 1. Preparation of modified hollow glass microspheres:

[0056] ①. At room temperature, mix 98% H2SO4 solution and 30% H2O2 solution in a volume ratio of 70:30 to obtain a mixed solution;

[0057] The hollow glass microspheres described in step 1① have a diameter of 30 μm to 60 μm and a density of 0.20 g / cm 3 ~0.60g / cm 3 , hollow glass microspheres with a compressive strength of 15MPa to 40MPa;

[0058] ②, immerse the hollow glass microspheres in the mixed solution, stir at room temperature for 45 minutes, filter the hollow glass microspheres, and wash with water until the pH value is 6.8 to obtain washed hollow glass microspheres;

[0059] ③, drying the washed hollow glass microspheres at 80°C for 3h to obtain surface hydroxylated modified hollow glass microspheres;

[0060] 2. Weigh 80g of main epoxy resin, 18g of low-activity epoxy resin, 12g of high-hydroxyl phenolic epoxy resin, 7g of toughening agent, 11 parts of diluent, 35 parts of modified hollow glass microspheres, 18 parts of slow curing agent and 4 parts of curing accelerator according to weight;

[0061] The main epoxy resin described in step 2 is: bisphenol A type epoxy resin E44 with an epoxy value of 0.44 produced by Nantong Xingchen Synthetic Materials Co., Ltd.;

[0062] The low-activity epoxy resin described in step 2 is N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-diethyldiphenylmethane;

[0063] The high hydroxyl phenolic epoxy resin described in step 2 is EPALLOY 8240E from Huntsman Company;

[0064] The toughening agent described in step 2 is a mixture of HTBN and silicone-acrylate core-shell nanoparticles, wherein the mass ratio of HTBN to silicone-acrylate core-shell nanoparticles is 3:4; the silicone-acrylate core-shell nanoparticles are purchased from Kanebuchi, Japan;

[0065] The diluent described in step 2 is an aromatic glycidyl ether;

[0066] The slow curing agent described in step 2 is polyamide WSCM-4118 produced by Zhejiang Wansheng Co., Ltd.;

[0067] The curing accelerator described in step 2 is 2-ethyl-4-methylimidazole;

[0068] 3. Add the main epoxy resin, active epoxy resin, high hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 100°C at a speed of 700r / min for 2h, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 100r / min for 40min, then discharge the material to obtain component A;

[0069] 4. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 600 r / min for 1 hour to obtain component B.

[0070] Example 3: A room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler is composed of component A and component B, and the preparation method is specifically completed according to the following steps:

[0071] 1. Preparation of modified hollow glass microspheres:

[0072] ①. At room temperature, mix 98% H2SO4 solution and 30% H2O2 solution in a volume ratio of 70:30 to obtain a mixed solution;

[0073] The hollow glass microspheres described in step 1① have a diameter of 10 μm to 100 μm and a density of 0.20 g / cm 3 ~0.50g / cm 3 , hollow glass microspheres with a compressive strength of 25MPa to 40MPa;

[0074] ②, immersing the hollow glass microspheres into the mixed solution, stirring at room temperature for 49 minutes, filtering the hollow glass microspheres, and washing with water until the pH value is 6.2 to obtain washed hollow glass microspheres;

[0075] ③, drying the washed hollow glass microspheres at 70°C for 4.5h to obtain surface hydroxylated modified hollow glass microspheres;

[0076] 2. Weigh 75g of main epoxy resin, 15g of low-activity epoxy resin, 10g of high-hydroxyl phenolic epoxy resin, 8g of toughening agent, 7 parts of diluent, 38 parts of modified hollow glass microspheres, 25 parts of slow curing agent and 3 parts of curing accelerator according to weight;

[0077] The main epoxy resin described in step 2 is: bisphenol A type epoxy resin E54 with an epoxy value of 0.54 produced by Nantong Xingchen Synthetic Materials Co., Ltd.;

[0078] The low-activity epoxy resin described in step 2 is N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dimethyldiphenylmethane;

[0079] The high hydroxyl phenolic epoxy resin described in step 2 is EPALLOY 8240 from Huntsman Company;

[0080] The toughening agents described in step 2 are ATBN and P52 organosilicon core-shell particles, wherein the mass ratio of ATBN to P52 organosilicon core-shell particles is 6g:2g; the P52 organosilicon core-shell particles are purchased from Wacker International Group Co., Ltd. of Germany;

[0081] The diluent described in step 2 is an aromatic glycidyl ether;

[0082] The slow curing agent described in step 2 is R-2256 polyetheramine from Rich (Guangdong) Technology Co., Ltd.;

[0083] The curing accelerator described in step 2 is 2-methylimidazole;

[0084] 3. Add the main epoxy resin, active epoxy resin, high hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 85°C at a speed of 800 r / min for 2.5 hours, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 120 r / min for 45 minutes, then discharge the material to obtain component A;

[0085] 4. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 800 r / min for 1.5 hours to obtain component B.

[0086] Example 4: A room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler is composed of component A and component B, and the preparation method is specifically completed according to the following steps:

[0087] 1. Preparation of modified hollow glass microspheres:

[0088] ①. At room temperature, mix 98% H2SO4 solution and 30% H2O2 solution in a volume ratio of 70:30 to obtain a mixed solution;

[0089] The hollow glass microspheres described in step 1① have a diameter of 20 μm to 100 μm and a density of 0.20 g / cm 3 ~0.40g / cm3 , hollow glass microspheres with a compressive strength of 15MPa to 45MPa;

[0090] ②, immersing the hollow glass microspheres in the mixed solution, stirring at room temperature for 48 minutes, filtering the hollow glass microspheres, and washing with water until the pH value is 6.1 to obtain washed hollow glass microspheres;

[0091] ③, drying the washed hollow glass microspheres at 70°C for 3.5h to obtain surface hydroxylated modified hollow glass microspheres;

[0092] 2. Weigh 65g of main epoxy resin, 14g of low-activity epoxy resin, 15g of high-hydroxy phenolic epoxy resin, 8g of toughening agent, 5 parts of diluent, 38 parts of modified hollow glass microspheres, 16 parts of slow curing agent and 3 parts of curing accelerator according to weight;

[0093] The main epoxy resin described in step 2 is: bisphenol F type epoxy resin 830 with an epoxy value of 0.59 produced by Nantong Xingchen Synthetic Materials Co., Ltd.;

[0094] The low-activity epoxy resin described in step 2 is N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dimethyldiphenylmethane;

[0095] The high hydroxyl phenolic epoxy resin described in step 2 is EPALLOY 8240E from Huntsman Company;

[0096] The toughening agent in step 2 is a mixture of HTBN and P52 organosilicon core-shell particles, wherein the mass ratio of HTBN to P52 organosilicon core-shell particles is 5g:3g; the P52 organosilicon core-shell particles are purchased from Wacker International Group Co., Ltd. of Germany;

[0097] The diluent described in step 2 is an aromatic glycidyl ether;

[0098] The slow curing agent described in step 2 is R-2257 polyetheramine from Rich (Guangdong) Technology Co., Ltd.;

[0099] The curing accelerator described in step 2 is 2-ethyl-4-methylimidazole.

[0100] 3. Add the main epoxy resin, active epoxy resin, high hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 90°C at a speed of 800r / min for 2.5h, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 150r / min for 50min, then discharge the material to obtain component A;

[0101] 4. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 800 r / min for 1.5 hours to obtain component B.

[0102] Comparative Example 1: The difference between this embodiment and Example 1 is that in step 2, 75g of main epoxy resin, 8g of high hydroxyl phenolic epoxy resin, 6g of toughening agent, 8 parts of diluent, 30 parts of modified hollow glass microspheres, 10 parts of slow curing agent and 3 parts of curing accelerator are weighed by weight.

[0103] Comparative Example 2: The difference between this example and Example 1 is that the curing agent in step 2 is triethylenetetramine curing agent. The other steps and parameters are the same as those in Example 1.

[0104] Comparative Example 3: The difference between this embodiment and embodiment 1 is that in step 2, 68 g of main epoxy resin, 15 g of low-activity epoxy resin, 6 g of toughening agent, 8 parts of diluent, 30 parts of unmodified hollow glass microspheres, 10 parts of slow curing agent and 3 parts of curing accelerator are weighed by weight. The other steps and parameters are the same as those in embodiment 1.

[0105] Comparative Example 4: The difference between this embodiment and embodiment 1 is that in step 2, 60g of main epoxy resin, 15g of low-activity epoxy resin, 8g of high-hydroxyl phenolic epoxy resin, 6g of toughening agent, 8 parts of diluent, 30 parts of modified hollow glass microspheres, and 10 parts of slow curing agent are weighed by weight. The other steps and parameters are the same as those in embodiment 1. The other steps and parameters are the same as those in embodiment 1.

[0106] The following performance tests are conducted on the room temperature fast curing low exothermic high compressive light epoxy fillers prepared in Examples 1 to 4 and the epoxy fillers in Comparative Examples 1 to 4:

[0107] Weigh 100g of filler according to the ratio of component A and component B, and test the gel time and maximum exotherm temperature of the filler after mixing. Refer to GB / T 2567-2021 to test the compression properties of the filler after room temperature curing (25℃ / 7d) and heating curing (70℃ / 3h). The results are shown in Table 1:

[0108] Table 1 Performance test table of each filler

[0109]

[0110]

[0111] As can be seen from Table 1, the low-density fillers prepared in Examples 1 to 4 have a short gel time, can be cured quickly, and have a low maximum exothermic temperature, not exceeding 100° C. After curing, the fillers have good room temperature curing ability and compression performance, and the performance of room temperature curing is basically the same as that of heating curing.

[0112] The performance analysis was conducted in combination with the performance of Comparative Examples 1 to 4 and Example 1, and the specific results are as follows:

[0113] (1) Combining the technical solutions of Comparative Example 1 and Example 1, it can be seen from the data in the table that the maximum exothermic temperature of the filler prepared in Comparative Example 1 is significantly higher than that of the filler prepared in Example 1, and the room temperature curing ability is weak, and the compression performance after room temperature curing is significantly lower than the compression performance after heating curing. This shows that in the technical solution of the present application, the addition of low-activity epoxy resin can reduce the maximum exothermic temperature of the filler system, making the curing process more gentle, and at the same time can also give the filler system excellent room temperature curing ability, and room temperature curing can achieve the performance of heated curing fillers.

[0114] (2) Combining the technical solutions of Comparative Examples 1 and 2 with Example 1, it can be seen from the data in the table that the gel time of the filler prepared in Comparative Example 2 is shortened to 18 minutes, which is too short and is not conducive to construction operation. The maximum exothermic temperature is much higher than that of the fillers prepared in Example 1 and Comparative Example 2. This shows that in the technical solution of the present invention, adding a slow curing agent in combination with other components can appropriately prolong the gel time of the filler while ensuring rapid curing, reduce the maximum exothermic temperature of the filler system, make the curing process more stable, and prevent curing scorching.

[0115] (3) Combining the technical solutions of Comparative Example 3 and Example 1, it can be seen from the data in the table that the gel time of the filler prepared in Comparative Example 3 is longer, the maximum exothermic temperature is lower, and the room temperature curing ability is weaker. The compression performance after room temperature curing is significantly lower than the compression performance after heating curing. At the same time, the compression performance of the filler after heating curing is also lower than that of Example 1. This shows that in the technical solution of the present invention, the addition of high-hydroxyl phenolic epoxy resin and surface hydroxylated hollow microspheres can promote the low-activity system, appropriately accelerate the curing reaction speed, and achieve the regulation of gel time and reaction exotherm and the improvement of post-curing ability. At the same time, the phenolic epoxy resin with strong rigidity and the modified hollow microspheres with surface hydroxylation are both conducive to the improvement of compression performance.

[0116] (4) Combining the technical solutions of Comparative Examples 3 and 4 with those of Example 1, it can be seen from the data in the table that although the maximum exothermic temperature of the filler prepared in Comparative Example 4 is only 65°C, the gel time is too long, exceeding 50 minutes, and the compression performance after room temperature curing is much lower than that of heating curing. This shows that in the technical solution of the present invention, the accelerator plays a more critical role in regulating the gel time and reaction exotherm and improving the post-curing ability.

Claims

1. A room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler, characterized in that The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler is composed of component A and component B; The component A is prepared from 60 to 80 parts of main epoxy resin, 10 to 20 parts of low-activity epoxy resin, 5 to 15 parts of high-hydroxyl phenolic epoxy resin, 5 to 8 parts of toughening agent, 5 to 20 parts of diluent and 20 to 40 parts of modified hollow glass microspheres; The component B is prepared from 10 to 25 parts of a slow curing agent and 3 to 5 parts of a curing accelerator.

2. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The room temperature fast curing low exothermic high compressive light epoxy filler can gel in 20min to 40min, the maximum exothermic temperature does not exceed 100°C when curing at room temperature, and the density after curing is less than 0.7g / cm 3 , the compression strength is greater than 54MPa.

3. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The main epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin and alicyclic epoxy resin with an epoxy value of 0.25 to 0.

75.

4. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The low-activity epoxy resin is one or both of N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dimethyldiphenylmethane and N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-diethyldiphenylmethane; the high-hydroxyl phenolic epoxy resin is one or both of EPALLOY 8240 and EPALLOY 8240E.

5. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The toughening agent is a combination of a rubber toughening agent and a nanoparticle toughening agent, wherein the mass ratio of the rubber toughening agent to the nanoparticle toughening agent is (1-5):(5-1); the rubber toughening agent is one or more of CTBN, ATBN, HTBN and polysulfide rubber; the nanoparticle toughening agent is one or more of acrylate core-shell nanoparticles, silicone-acrylate core-shell nanoparticles and P52 silicone core-shell particles.

6. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The diluent is one or more of aliphatic glycidyl ether, aromatic glycidyl ether and polyol glycidyl ether.

7. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The preparation method of the modified hollow glass microspheres is specifically completed according to the following steps:

1. Evenly mix H2SO4 solution and H2O2 solution at room temperature to obtain a mixed solution; 2. Immersing the hollow glass microspheres into the mixed solution, stirring for a period of time at room temperature, filtering the hollow glass microspheres, and washing with water until neutral to obtain washed hollow glass microspheres; 3. Drying the washed hollow glass microspheres for a period of time to obtain surface hydroxylated modified hollow glass microspheres.

8. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 7, characterized in that The mass fraction of the H2SO4 solution in step 1 is 98%; the mass fraction of the H2O2 solution is 30%; the volume ratio of the H2SO4 solution to the H2O2 solution in step 1 is 70:30; the hollow glass microspheres in step 2 have a diameter of 10 μm to 120 μm and a density of 0.10 g / cm 3 ~0.60g / cm 3 , hollow glass microspheres with a compressive strength of 1 MPa to 50 MPa; the stirring time at room temperature in step 2 is 30 min to 60 min; and the water washing in step 2 is performed until the pH value is 6 to 7.

9. The room temperature fast curing, low exothermic, high compressive strength lightweight epoxy filler according to claim 1, characterized in that The slow curing agent is one or more of polyetheramine, polyamide and fatty amine; the curing accelerator is one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, N-(3-aminopropyl)imidazole, 1-methylimidazole, 1-vinylimidazole and 2-ethylimidazole.

10. The method for preparing a room temperature fast curing low exothermic high compressive light epoxy filler as claimed in claim 1, characterized in that The preparation method is specifically completed according to the following steps:

1. Weigh 60 to 80 parts of main epoxy resin, 10 to 20 parts of low-activity epoxy resin, 5 to 15 parts of high-hydroxyl phenolic epoxy resin, 5 to 8 parts of toughening agent, 5 to 20 parts of diluent, 20 to 40 parts of modified hollow glass microspheres, 10 to 25 parts of slow curing agent and 3 to 5 parts of curing accelerator according to weight; 2. Add the main epoxy resin, low-activity epoxy resin, high-hydroxyl phenolic epoxy resin, toughening agent and diluent into a mixing device, stir and mix at 60°C to 100°C at a speed of 500r / min to 1000r / min for 1h to 3h, then add the modified hollow glass microspheres, stir and mix at room temperature and a stirring speed of 50r / min to 200r / min for 20min to 60min, then discharge the material to obtain component A; 3. Add the slow curing agent and curing accelerator into the mixing equipment, stir and mix at room temperature and a stirring speed of 500r / min~1000r / min for 1h~2h to obtain component B.

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