A modified epoxy resin and a preparation method thereof, and a glass fiber composite material plate

Abstract

The present invention belongs to the technical field of flame-retardant epoxy resin materials, and specifically relates to a modified epoxy resin and a preparation method thereof, and a glass fiber composite material plate. The present invention provides a modified epoxy resin, which comprises the following preparation raw materials in parts by mass: 500-505 parts of epoxy resin; 500-505 parts of active diluent; 105-120 parts of halogen-free flame retardant; 1-2 parts of nucleophilic catalyst; the halogen-free flame retardant comprises flame retardant DOPO and / or diphenylphosphine oxide; the active diluent comprises polyethylene glycol diglycidyl ether. The modified epoxy resin provided by the present invention has a low viscosity and can be applied to vacuum-assisted molding processes.

Description

Technical Field

[0001] The invention belongs to the technical field of flame-retardant epoxy resin materials, and specifically relates to a modified epoxy resin and a preparation method thereof, and a glass fiber composite material plate. Background Art

[0002] Although epoxy resin is widely used due to its excellent mechanical properties and low cost, its flame retardant and fireproof performance is poor, and its limiting oxygen index is only about 19.8%. Therefore, how to effectively improve the flame retardant performance of epoxy resin has become one of the research hotspots. At present, the improvement of epoxy resin flame retardant performance is mainly achieved by adding flame retardants. Although halogen flame retardants are popular for their high efficiency and flame retardant performance, brominated flame retardants are particularly prominent, but they are eventually abandoned because they release toxic smoke and dioxins when burned.

[0003] Flame retardants tend to be halogen-free, mostly phosphorus, nitrogen, silicon, etc., and can be mainly divided into additive and reactive types according to their existence forms. Although additive flame retardants have a relatively simple addition process and low cost, they have low flame retardant efficiency, poor compatibility with resins, easy precipitation and precipitation, and have a great impact on the mechanical properties of the resin system. Reactive flame retardants are widely used by greatly improving the flame retardant efficiency by connecting flame retardant elements to epoxy molecular chains. However, the addition of reactive flame retardants has a great impact on the viscosity and mechanical properties of the resin. For example, reactive flame retardants are mainly 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), because they increase the molecular weight of the resin matrix and increase the molecular chain, resulting in a high viscosity of the epoxy resin of more than 50,000 cp.s.

[0004] In addition, the vacuum-assisted molding process is a new type of low-cost molding technology for large composite parts. It removes the gas in the fiber pressure under vacuum, uses the flow and penetration of resin to achieve impregnation of fibers and fabrics, and solidifies at a certain temperature to form a certain resin / fiber ratio. This process method has very high requirements for resins. It requires the resin matrix to have low viscosity and be easy to infiltrate the fibers, which is conducive to the molding of large components. Therefore, resins with higher viscosity cannot complete the vacuum-assisted molding process. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a modified epoxy resin and a preparation method thereof, and a glass fiber composite material plate. The modified epoxy resin provided by the present invention has a low viscosity and can be applied to a vacuum assisted molding process.

[0006] In order to solve the above problems, the present invention provides a modified epoxy resin, which includes the following preparation raw materials, measured by mass: 500-505 parts of epoxy resin; 500-505 parts of active diluent; 105-120 parts of halogen-free flame retardant; 1-2 parts of nucleophilic catalyst; the halogen-free flame retardant includes flame retardant DOPO and / or diphenylphosphine; the active diluent includes polyethylene glycol diglycidyl ether.

[0007] Preferably, the epoxy resin comprises bisphenol epoxy resin.

[0008] Preferably, the nucleophilic catalyst comprises triphenylphosphine and / or tetrabutylammonium bromide.

[0009] The present invention also provides a method for preparing the modified epoxy resin described above, comprising the following steps:

[0010] The epoxy resin, the active diluent, the nucleophilic catalyst and the halogen-free flame retardant are mixed under a protective atmosphere, and the obtained mixture is subjected to a cross-linking reaction to obtain the modified epoxy resin.

[0011] Preferably, the mixing temperature is 120-155°C.

[0012] The present invention also provides a glass fiber composite material plate, which includes the following preparation raw materials, measured by mass: modified epoxy resin: 100 parts; nitrogen-containing curing agent: 20 to 30 parts; defoaming agent: 1 to 3 parts; glycidyl ether diluent: 10 parts; silicon-containing filler: 20 to 30 parts; coupling agent: 1 to 2 parts; glass fiber: 30 to 40 parts.

[0013] Preferably, the silicon-containing filler includes one or more of silicon dioxide, talc and soft silicon.

[0014] Preferably, the glyceryl ether diluent includes one or more of 1,4-butanediol diglycidyl ether, diglycidyl ether glycerol and polyethylene glycol diglycidyl ether.

[0015] The present invention also provides a method for preparing the above-mentioned glass fiber composite material plate, comprising the following steps:

[0016] The modified epoxy resin, the defoaming agent, the glycidyl ether diluent, the silicon-containing filler and the coupling agent are mixed and defoamed to obtain a defoamed resin system;

[0017] The degassed resin system, nitrogen-containing curing agent and glass fiber are mixed and vacuum-assisted molding is performed to obtain a glass fiber composite material plate.

[0018] Preferably, the degassing treatment conditions include: temperature of 90 to 110° C., pressure of -0.05 to -0.15 MPa, and time of 1.8 to 2.2 h.

[0019] The present invention provides a modified epoxy resin, which includes the following raw materials by mass: 500-505 parts of epoxy resin; 500-505 parts of active diluent; 105-120 parts of halogen-free flame retardant; 1-2 parts of nucleophilic catalyst; the halogen-free flame retardant includes flame retardant DOPO and / or diphenylphosphine oxide; the active diluent includes polyethylene glycol diglycidyl ether. In the present invention, the epoxy bond in the epoxy resin forms a stable structure with the halogen-free flame retardant, and the active diluent also contains an epoxy bond and has a longer molecular chain, which can maintain good activity in the system, thereby showing a lower viscosity, and can be applied to vacuum assisted molding process.

[0020] The data of the examples show that the viscosity (50° C.) of the modified epoxy resin provided by the present invention ranges from 1099 to 1210 cp.s. DETAILED DESCRIPTION

[0021] The present invention provides a modified epoxy resin, which comprises the following preparation raw materials in parts by mass:

[0022]

[0023] The halogen-free flame retardant includes flame retardant DOPO and / or diphenylphosphine oxide;

[0024] The reactive diluent includes polyethylene glycol diglycidyl ether.

[0025] In the present invention, the raw materials for preparing the modified epoxy resin include 500 to 505 parts of epoxy resin, preferably 501 to 503 parts, by mass. In the present invention, the epoxy resin preferably includes a bisphenol epoxy resin. In the present invention, the bisphenol epoxy resin is preferably in liquid form. In the present invention, the bisphenol epoxy resin preferably includes a bisphenol A epoxy resin and / or a bisphenol F epoxy resin.

[0026] In the present invention, the raw materials for preparing the modified epoxy resin include 500 to 505 parts of active diluent, preferably 501 to 503 parts by mass. In the present invention, the active diluent includes polyethylene glycol diglycidyl ether.

[0027] In the present invention, the raw materials for preparing the modified epoxy resin include 105 to 120 parts by mass of halogen-free flame retardant, preferably 108 to 118 parts. The halogen-free flame retardant includes flame retardant DOPO and / or diphenylphosphine oxide, more preferably diphenylphosphine oxide. In an embodiment of the present invention, the diphenylphosphine oxide is preferably provided by Shandong Hongchuan Chemical Co., Ltd.

[0028] In the present invention, the raw materials for preparing the modified epoxy resin include 1 to 2 parts of a nucleophilic catalyst, preferably 1.2 to 1.5 parts, by mass. The nucleophilic catalyst preferably includes triphenylphosphine and / or tetrabutylammonium bromide.

[0029] In the present invention, the reason why the modified epoxy resin provided by the present invention has a low viscosity is that after the long molecular chain active diluent modifies DOPO, a stable structure is formed after the epoxy resin modifies DOPO. Since the active diluent has a long molecular chain, it exhibits good flexibility in the system, thereby making the overall viscosity lower.

[0030] The present invention also provides a method for preparing the modified epoxy resin described above, comprising the following steps:

[0031] The epoxy resin, the active diluent, the nucleophilic catalyst and the halogen-free flame retardant are mixed under a protective atmosphere, and the obtained mixture is subjected to a cross-linking reaction to obtain the modified epoxy resin.

[0032] In the present invention, the protective atmosphere is preferably nitrogen.

[0033] In the present invention, the preparation method of the modified epoxy resin preferably comprises the following steps:

[0034] The epoxy resin and the nucleophilic catalyst are first mixed under a protective atmosphere, the first mixed material obtained and a part of the halogen-free flame retardant are second mixed for primary crosslinking, and the primary crosslinked material obtained and the remaining halogen-free flame retardant are third mixed for re-crosslinking.

[0035] In the present invention, the mass ratio of the epoxy resin to part of the halogen-free flame retardant is preferably 500-505:35-40, more preferably 500-505:36-37. In the present invention, the mass ratio of part of the halogen-free flame retardant to the remaining halogen-free flame retardant is preferably 35-40:70-85, more preferably 36-37:70-85.

[0036] In the present invention, the temperature of the first mixing is preferably 110-125° C., more preferably 120° C. In the present invention, the heating rate to the first mixing temperature is preferably 1° C. / min.

[0037] In the present invention, the temperature of the second mixing is preferably 145-155° C., more preferably 150° C. In the present invention, the heating rate from the temperature of the first mixing to the temperature of the second mixing is preferably 1° C. / min.

[0038] In the present invention, the temperature of the initial crosslinking is preferably the same as the temperature of the second mixing, which will not be repeated. In the present invention, the time of the initial crosslinking is preferably 30 to 60 minutes, more preferably 40 minutes. In the present invention, the initial crosslinking is that the resin is crosslinked with part of the halogen-free flame retardant under the action of a catalyst. This crosslinking reaction is exothermic, so the halogen-free flame retardant is added in batches.

[0039] In the present invention, the temperature of the third mixing is preferably 145-150° C., more preferably 146-147° C. In the present invention, the temperature of the re-crosslinking is preferably the same as the temperature of the third mixing, and will not be repeated. In the present invention, the time of the re-crosslinking is preferably 4-6 hours, more preferably 5 hours.

[0040] In the present invention, the re-crosslinking is that the resin is crosslinked with the remaining halogen-free flame retardant under the action of a catalyst.

[0041] The present invention also provides a glass fiber composite material plate, which comprises the following raw materials by weight:

[0042]

[0043] In the present invention, the raw materials for preparing the glass fiber composite material plate preferably include 100 parts by mass of modified epoxy resin. The modified epoxy resin is the modified epoxy resin described above.

[0044] In the present invention, the raw material for preparing the glass fiber composite material plate preferably includes 20 to 30 parts by mass of a nitrogen-containing curing agent, and more preferably 25 parts. In the present invention, the nitrogen-containing curing agent preferably includes one or more of curing agents 593B, 593 and 650, and more preferably curing agent 593B.

[0045] In the present invention, the raw material for preparing the glass fiber composite material plate preferably includes 1 to 3 parts of defoamer by weight, and more preferably 2 parts. In the present invention, the defoamer preferably includes one or more of defoamers BYK530, B313 and B314, and more preferably defoamer BYK530.

[0046] In the present invention, the raw materials for preparing the glass fiber composite material plate preferably include 10 parts by mass of a glycidyl ether diluent. In the present invention, the glycidyl ether diluent preferably includes one or more of 1,4-butanediol diglycidyl ether, polyethylene glycol diglycidyl ether and diglycidyl ether glycerol, more preferably 1,4-butanediol diglycidyl ether.

[0047] In the present invention, the raw materials for preparing the glass fiber composite material plate preferably include 20 to 30 parts by mass of silicon-containing filler. In the present invention, the filler preferably includes one or more of silicon dioxide, talc and soft silicon, and more preferably silicon dioxide.

[0048] In the present invention, the raw materials for preparing the glass fiber composite material plate preferably include 1 to 2 parts of coupling agent by weight. In the present invention, the coupling agent preferably includes one or more of BYK530, B-313 and B314, and more preferably BYK530.

[0049] In the present invention, the raw material for preparing the glass fiber composite material plate preferably includes 30 to 40 parts of glass fiber, more preferably 35 parts, by mass. In the present invention, the aspect ratio of the glass fiber is preferably 1:0.5 to 2, more preferably 1:1.5. In the present invention, the diameter of the glass fiber is preferably 10 to 20 μm, more preferably 15 to 20 μm.

[0050] In the present invention, the glass fiber composite material plate is combined with phosphorus-silicon-nitrogen for synergistic flame retardancy, so that the flame retardancy of the obtained glass fiber composite material plate meets the v0 standard of UL-94.

[0051] The present invention also provides a method for preparing the above-mentioned glass fiber composite material plate, which preferably comprises the following steps:

[0052] The modified epoxy resin, the defoaming agent, the glycidyl ether diluent, the silicon-containing filler and the coupling agent are mixed and defoamed to obtain a defoamed resin system;

[0053] The degassed resin system, nitrogen-containing curing agent and glass fiber are mixed and vacuum-assisted molding is performed to obtain a glass fiber composite material plate.

[0054] The invention mixes modified epoxy resin, defoamer, glycidyl ether diluent, silicon-containing filler and coupling agent, and performs defoaming treatment to obtain a defoamed resin system.

[0055] In the present invention, the mixing method is preferably stirring, and the stirring is preferably performed in a high-speed disperser. The present invention does not specifically limit the mixing parameters, as long as the materials can be mixed uniformly.

[0056] In the present invention, the conditions for the degassing treatment preferably include: the temperature is preferably 90 to 110°C, more preferably 100°C, the pressure is preferably -0.05 to -0.15 MPa, more preferably -0.1 MPa, and the time is preferably 1.8 to 2.2 h, more preferably 2 h.

[0057] After obtaining the defoamed resin system, the present invention mixes the defoamed resin system, a nitrogen-containing curing agent and glass fibers, and performs vacuum-assisted molding to obtain a glass fiber composite material plate.

[0058] In the present invention, the vacuum-assisted molding process is preferably carried out in a mold with glass fiber laid.

[0059] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0060] Example 1

[0061] Under nitrogen protection, 505 g of liquid bisphenol A epoxy resin and 505 g of polyethylene glycol diglycidyl ether were placed in a four-necked bottle, the temperature was raised to 120° C. at a rate of 1° C. / min, and 1 g of tetramethylammonium chloride was added to obtain a first mixed material;

[0062] The first mixed material was heated to 150°C at a rate of 1°C / min, 37g of phosphorus-containing flame retardant DOPO was added, initial crosslinking was performed at 150°C, and after keeping the temperature for 40 minutes, 81g of phosphorus-containing flame retardant DOPO was continuously added, re-crosslinking was performed at 150°C, and the temperature was kept for 4 hours to obtain a modified epoxy resin.

[0063] Example 2

[0064] Under nitrogen protection, 500 g of liquid bisphenol A epoxy resin and 500 g of polyethylene glycol diglycidyl ether were placed in a four-necked bottle, the temperature was raised to 120° C. at a rate of 1° C. / min, and 1 g of tetramethylammonium chloride was added to obtain a first mixed material;

[0065] The first mixed material was heated to 145°C at a rate of 1°C / min, 36g of diphenylphosphine oxide was added, and initial crosslinking was performed at 145°C. After heat preservation for 40 minutes, 73g of diphenylphosphine oxide was continuously added, and re-crosslinking was performed at 145°C for 6 hours to obtain a modified epoxy resin.

[0066] Example 3

[0067] Under nitrogen protection, 503 g of liquid bisphenol A epoxy resin and 503 g of polyethylene glycol diglycidyl ether were placed in a four-necked bottle, the temperature was raised to 120° C. at a rate of 1° C. / min, and 1 g of tetramethylammonium chloride was added to obtain a first mixed material;

[0068] The first mixed material was heated to 148°C at a rate of 1°C / min, 36g of diphenylphosphine oxide was added, and initial crosslinking was performed at 148°C. After heat preservation for 40 minutes, 72g of diphenylphosphine oxide was continuously added, and re-crosslinking was performed at 148°C and heat preservation for 6 hours to obtain a modified epoxy resin.

[0069] Example 4

[0070] Under nitrogen protection, 501 g of liquid bisphenol F epoxy resin and 501 g of polyethylene glycol diglycidyl ether were placed in a four-necked bottle, the temperature was raised to 120° C. at 1° C. / min, and 1 g of tetramethylammonium chloride was added to obtain a first mixed material.

[0071] The first mixed material was heated to 146°C at a rate of 1°C / min, 36g of diphenylphosphine oxide was added, and initial crosslinking was performed at 146°C. After keeping the temperature for 40 minutes, 72g of diphenylphosphine oxide was added, and re-crosslinking was performed at 146°C. The temperature was kept for 6 hours to obtain a modified epoxy resin.

[0072] Comparative Example 1

[0073] Under nitrogen protection, 500 g of liquid bisphenol A epoxy resin was placed in a four-necked bottle, the temperature was raised to 120° C. at a rate of 1° C. / min, and 1 g of triphenylphosphine was added to obtain a first mixed material;

[0074] The first mixed material was heated to 150° C. at a rate of 1° C. / min, 35 g of phosphorus-containing flame retardant DOPO was added, and initial crosslinking was carried out at 150° C. for 40 min, and then 86 g of DOPO was added, and re-crosslinking was carried out at 150° C. for 4 h to obtain a modified epoxy resin.

[0075] Comparative Example 2

[0076] Under nitrogen protection, 499 g of liquid bisphenol F epoxy resin was placed in a four-necked bottle, the temperature was raised to 120° C. at a rate of 1° C. / min, and 1 g of tetramethylammonium chloride was added to obtain a first mixed material;

[0077] The first mixed material was heated to 150°C at a rate of 1°C / min, 36g of phosphorus-containing flame retardant DOPO was added, initial crosslinking was performed at 150°C, and the mixture was kept warm for 40 minutes. 79g of DOPO was added, and re-crosslinking was performed at 150°C. The mixture was kept warm for 5 hours to obtain a modified epoxy resin.

[0078] Comparative Example 3

[0079] Comparative Example 3 is a conventional bisphenol A epoxy resin, the common brand on the market is E51, and the molecular weight is about 370.

[0080] The present invention tests the epoxy equivalent, hydrolyzable chlorine, viscosity and other parameters of the modified epoxy resins prepared in Examples 1 to 4 and Comparative Examples 1 to 3. The test method is carried out in accordance with national standards GB / T 4612, GB / T 4618.2 and GB / T 22314. The test results are shown in Table 1.

[0081] Table 1 Performance test results of modified epoxy resins prepared in Examples 1 to 4 and Comparative Examples 1 to 3

[0082]

[0083] From the data in Table 1, it can be seen that the modified epoxy resins prepared in Examples 1 to 4 have good fluidity in the temperature range of 25 to 65° C. and are suitable for the vacuum-assisted molding process of composite materials. Comparative Examples 1 to 2 are not suitable for the vacuum-assisted molding process due to their excessive viscosity.

[0084] Application Example 1

[0085] 100 parts of the modified epoxy resin prepared in Example 1, 10 parts of the diluent 1,4-butanediol diglycidyl ether, 25 parts of silicon dioxide, 2 parts of the defoamer BYK530, and 1 part of the coupling agent BYK530 were uniformly dispersed and stirred, and then degassed at -0.1 MPa and 100° C. for 2 hours. The degassed epoxy resin system was uniformly mixed with 25 parts of the curing agent 593B, and then vacuum-introduced into a mold with 35 parts of glass fibers laid, and vacuum-assisted molding was performed to obtain a glass fiber composite material plate.

[0086] Application Example 2

[0087] The only difference from Application Example 1 is that the modified epoxy resin prepared in Example 1 is replaced by the modified epoxy resin prepared in Example 2.

[0088] Application Example 3

[0089] The only difference from Application Example 1 is that the modified epoxy resin prepared in Example 1 is replaced by the modified epoxy resin prepared in Example 3.

[0090] Application Example 4

[0091] The only difference from Application Example 1 is that the modified epoxy resin prepared in Example 1 is replaced by the modified epoxy resin prepared in Example 4.

[0092] Comparative application example 1

[0093] The only difference from Application Example 1 is that the modified epoxy resin prepared in Example 1 is replaced by the modified epoxy resin prepared in Comparative Example 1.

[0094] Comparative Application Example 2

[0095] The only difference from Application Example 1 is that the modified epoxy resin prepared in Example 1 is replaced by the modified epoxy resin prepared in Comparative Example 2.

[0096] Comparative Application Example 3

[0097] The only difference from Application Example 1 is that the modified epoxy resin prepared in Example 1 is replaced by the modified epoxy resin prepared in Comparative Example 3.

[0098] The glass fiber composite material plates prepared by the corresponding examples 1 to 4 and the comparative application examples 1 to 3 of the present invention were tested for mechanical properties and flame retardant properties, wherein the tensile properties were tested with reference to GB / T1447-2005, the bending properties were tested with reference to DQS40-99A, the impact properties were tested with reference to QJ1632-89, and the elongation at break was tested with HG / T2580-94. The flame retardant property test method was based on GB / T2406.1-2008 and UL-94 standards, and the glass fiber composite material plates were tested for oxygen index and vertical combustion using Suzhou Yangyi Walch 5402A horizontal vertical combustion test machine. The test results of mechanical properties and flame retardant properties are shown in Table 2.

[0099] Table 2 Test results of mechanical properties and flame retardant properties of application examples 1 to 4 and comparative application examples 1 to 3

[0100]

[0101] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A glass fiber composite material plate, characterized in that: The preparation includes the following raw materials by weight: Modified epoxy resin: 100 parts; Nitrogen-containing curing agent: 20~30 parts; Defoaming agent: 1~3 parts; Glycidyl ether diluent: 10 parts; Silicon-containing filler: 20~30 parts; Coupling agent: 1~2 parts; Glass fiber: 30~40 parts; The modified epoxy resin is prepared from the following raw materials in parts by mass: Epoxy resin 500~505 parts; Active diluent 500~505 parts; 105~120 parts of halogen-free flame retardant; 1~2 parts of nucleophilic catalyst; The halogen-free flame retardant is flame retardant DOPO and / or diphenylphosphine oxide; The active diluent is polyethylene glycol diglycidyl ether; The epoxy resin is a bisphenol epoxy resin; The nucleophilic catalyst is triphenylphosphine and / or tetrabutylammonium bromide.

2. The glass fiber composite material plate according to claim 1, characterized in that: The preparation method of the modified epoxy resin comprises the following steps: The epoxy resin, the active diluent, the nucleophilic catalyst and the halogen-free flame retardant are mixed under a protective atmosphere, and the obtained mixture is subjected to a cross-linking reaction to obtain the modified epoxy resin.

3. The glass fiber composite material plate according to claim 2, characterized in that: The mixing temperature is 120-155°C.

4. The glass fiber composite material plate according to claim 1, characterized in that: The silicon-containing filler includes one or more of silicon dioxide, talcum powder and soft silicon.

5. The glass fiber composite material plate according to claim 1, characterized in that: The glycidyl ether diluent includes one or more of 1,4-butanediol diglycidyl ether, polyethylene glycol diglycidyl ether and diglycidyl ether glycerol.

6. The method for preparing the glass fiber composite material plate according to any one of claims 1 to 5, characterized in that: The following steps are involved: The modified epoxy resin, the defoaming agent, the glycidyl ether diluent, the silicon-containing filler and the coupling agent are mixed and defoamed to obtain a defoamed resin system; The degassed resin system, nitrogen-containing curing agent and glass fiber are mixed and vacuum-assisted molding is performed to obtain a glass fiber composite material plate.

7. The preparation method according to claim 6, characterized in that: The degassing treatment conditions include: temperature of 90-110° C., pressure of -0.05-0.15 MPa, and time of 1.8-2.2.

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