CN113429404B - Benzothiadiazole modified imidazole compound, and preparation method and application thereof - Google Patents
Benzothiadiazole modified imidazole compound, and preparation method and application thereof Download PDFInfo
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- CN113429404B CN113429404B CN202110752320.2A CN202110752320A CN113429404B CN 113429404 B CN113429404 B CN 113429404B CN 202110752320 A CN202110752320 A CN 202110752320A CN 113429404 B CN113429404 B CN 113429404B
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- -1 Benzothiadiazole modified imidazole compound Chemical class 0.000 title claims abstract description 47
- 239000005964 Acibenzolar-S-methyl Substances 0.000 title claims abstract description 43
- 238000002360 preparation method Methods 0.000 title abstract description 16
- 239000003822 epoxy resin Substances 0.000 claims abstract description 71
- 229920000647 polyepoxide Polymers 0.000 claims abstract description 71
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 48
- 150000001875 compounds Chemical class 0.000 claims abstract description 13
- 239000002904 solvent Substances 0.000 claims description 14
- 238000002156 mixing Methods 0.000 claims description 8
- 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 claims description 3
- 239000004849 latent hardener Substances 0.000 claims 2
- 238000006243 chemical reaction Methods 0.000 abstract description 33
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 18
- 238000003860 storage Methods 0.000 abstract description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 6
- 125000000217 alkyl group Chemical group 0.000 abstract description 5
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 5
- 239000001257 hydrogen Substances 0.000 abstract description 5
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 5
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 abstract description 3
- 125000004435 hydrogen atom Chemical class [H]* 0.000 abstract 1
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 36
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical group ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 19
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 15
- 238000000034 method Methods 0.000 description 13
- FEOWHLLJXAECMU-UHFFFAOYSA-N 4,7-dibromo-2,1,3-benzothiadiazole Chemical compound BrC1=CC=C(Br)C2=NSN=C12 FEOWHLLJXAECMU-UHFFFAOYSA-N 0.000 description 11
- 238000001035 drying Methods 0.000 description 11
- 238000001914 filtration Methods 0.000 description 11
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- PCLIMKBDDGJMGD-UHFFFAOYSA-N N-bromosuccinimide Chemical compound BrN1C(=O)CCC1=O PCLIMKBDDGJMGD-UHFFFAOYSA-N 0.000 description 8
- 239000012043 crude product Substances 0.000 description 8
- 230000008859 change Effects 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 7
- 238000005406 washing Methods 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- CMLFRMDBDNHMRA-UHFFFAOYSA-N 2h-1,2-benzoxazine Chemical compound C1=CC=C2C=CNOC2=C1 CMLFRMDBDNHMRA-UHFFFAOYSA-N 0.000 description 5
- 229910021595 Copper(I) iodide Inorganic materials 0.000 description 5
- 239000003054 catalyst Substances 0.000 description 5
- LSXDOTMGLUJQCM-UHFFFAOYSA-M copper(i) iodide Chemical group I[Cu] LSXDOTMGLUJQCM-UHFFFAOYSA-M 0.000 description 5
- 239000012299 nitrogen atmosphere Substances 0.000 description 5
- 229910000027 potassium carbonate Inorganic materials 0.000 description 5
- LXBGSDVWAMZHDD-UHFFFAOYSA-N 2-methyl-1h-imidazole Chemical compound CC1=NC=CN1 LXBGSDVWAMZHDD-UHFFFAOYSA-N 0.000 description 4
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 4
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 4
- 239000000706 filtrate Substances 0.000 description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 4
- 150000002460 imidazoles Chemical class 0.000 description 4
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 4
- 238000002390 rotary evaporation Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- FNQJDLTXOVEEFB-UHFFFAOYSA-N 1,2,3-benzothiadiazole Chemical compound C1=CC=C2SN=NC2=C1 FNQJDLTXOVEEFB-UHFFFAOYSA-N 0.000 description 3
- IYRMTTBJJGMXER-UHFFFAOYSA-N 4,7-dibromo-5-methyl-2,1,3-benzothiadiazole Chemical compound BrC1=C(C)C=C(Br)C2=NSN=C21 IYRMTTBJJGMXER-UHFFFAOYSA-N 0.000 description 3
- 239000004593 Epoxy Substances 0.000 description 3
- 230000004913 activation Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000004841 bisphenol A epoxy resin Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000005457 ice water Substances 0.000 description 3
- 238000009776 industrial production Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000003094 microcapsule Substances 0.000 description 3
- 239000011259 mixed solution Substances 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 238000000655 nuclear magnetic resonance spectrum Methods 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- PDQRQJVPEFGVRK-UHFFFAOYSA-N 2,1,3-benzothiadiazole Chemical compound C1=CC=CC2=NSN=C21 PDQRQJVPEFGVRK-UHFFFAOYSA-N 0.000 description 2
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000009210 therapy by ultrasound Methods 0.000 description 2
- 238000005160 1H NMR spectroscopy Methods 0.000 description 1
- UIDDPPKZYZTEGS-UHFFFAOYSA-N 3-(2-ethyl-4-methylimidazol-1-yl)propanenitrile Chemical compound CCC1=NC(C)=CN1CCC#N UIDDPPKZYZTEGS-UHFFFAOYSA-N 0.000 description 1
- ULKLGIFJWFIQFF-UHFFFAOYSA-N 5K8XI641G3 Chemical compound CCC1=NC=C(C)N1 ULKLGIFJWFIQFF-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- FZWLAAWBMGSTSO-UHFFFAOYSA-N Thiazole Chemical compound C1=CSC=N1 FZWLAAWBMGSTSO-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 238000012644 addition polymerization Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 150000008064 anhydrides Chemical class 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000007385 chemical modification Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000004100 electronic packaging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 125000002883 imidazolyl group Chemical group 0.000 description 1
- 238000011534 incubation Methods 0.000 description 1
- 125000004433 nitrogen atom Chemical group N* 0.000 description 1
- 238000010534 nucleophilic substitution reaction Methods 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000010025 steaming Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 150000003573 thiols Chemical class 0.000 description 1
- 229910021381 transition metal chloride Inorganic materials 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D417/00—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00
- C07D417/14—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00 containing three or more hetero rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/50—Amines
- C08G59/5046—Amines heterocyclic
- C08G59/5053—Amines heterocyclic containing only nitrogen as a heteroatom
- C08G59/5073—Amines heterocyclic containing only nitrogen as a heteroatom having two nitrogen atoms in the ring
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Epoxy Resins (AREA)
Abstract
The invention provides a benzothiadiazole modified imidazole compound, a preparation method and application thereof, and belongs to the technical field of epoxy resin curing agents. The structural formula of the compound is shown as formula 1, wherein in the formula 1, N is nitrogen, and R 1、R2、R3 and R 4 are respectively and independently selected from hydrogen, alkyl chain or phenyl. The invention provides a preparation method of a benzothiadiazole modified imidazole compound. The invention also provides application of the compound as a latent curing agent in curing epoxy resin. The compound of the invention is used as a curing agent, has long storage period with a single-component system composed of epoxy resin, can rapidly cure the epoxy resin under the condition of medium and high temperature, and can also be used as a co-curing agent of the epoxy resin with 4' 4-diaminodiphenyl methane, thereby reducing the reaction temperature and improving the reaction rate.
Description
Technical Field
The invention belongs to the technical field of epoxy resin curing agents, and particularly relates to a benzothiadiazole modified imidazole compound, a preparation method and application thereof.
Background
Epoxy resin is a thermosetting resin with excellent mechanical property, chemical corrosion resistance, electrical insulation and adhesive property, and is widely applied in the fields of paint, adhesive, electronic packaging material, composite material and the like. The epoxy resin is generally a low molecular compound at room temperature, and a curing agent is added when the epoxy resin is used, so that a cross-linking reaction occurs to generate a product with a three-dimensional network structure, and the epoxy resin has use value. Therefore, curing agents are indispensable in epoxy resin applications and play even decisive roles to some extent. Many epoxy resin curing agents, such as amines, anhydrides, thiols, phenols, imidazoles and the like, wherein the imidazoles curing agents can be subjected to addition polymerization and also can be subjected to anion catalytic polymerization, so that the crosslinking density and the curing speed of the resin are increased, and the epoxy resin curing agents become important points for research and development at present. However, the unmodified imidazole and epoxy resin systems have to be prepared at present because of too short storage time at room temperature, or else gel can not be used, so that not only is material waste caused, but also the mechanical properties of the composite material are reduced because of too fast heat release of the curing of the epoxy resin. To overcome the disadvantages of the above curing agents, imidazole latent curing agents have been introduced. The latent curing agent is a curing agent which is added to an epoxy resin and which has a certain storage stability at room temperature and which can rapidly undergo a curing reaction under conditions such as heat, light, and pressure.
Heretofore, there have been many studies on the incubation of imidazole-based curing agents, and patent 201810519488.7 discloses a latent curing agent prepared by reacting 1-cyanoethyl-2-ethyl-4-methylimidazole with a transition metal chloride under curing conditions of 150℃for 30 minutes. Although the method can optimize the storage time at room temperature, the reaction of imidazole at the curing temperature can be influenced, the curing time is prolonged, and the requirement of rapid curing in the current industrial production is not met; secondly, a microcapsule technology is used for preparing a latent curing agent, and patent 201911235546.4 discloses a microcapsule-prepared latent curing agent. The method has a plurality of influence factors of microcapsule formation in the preparation process, and the reaction is not easy to control; and after the epoxy resin is cured, microcapsule wall materials remain in the epoxy resin system, so that the physical properties of the materials are affected. Patent 202010289178.8 discloses a benzoxazine epoxy resin copolymer containing phenolic hydroxyl groups and a preparation method thereof, wherein the phenolic hydroxyl groups of the benzoxazine containing phenolic hydroxyl groups are protected by intramolecular hydrogen bonds, the benzoxazine epoxy blend resin containing phenolic hydroxyl groups can be endowed with the characteristics of easy storage and latent curing at room temperature, but the benzoxazine curing temperature is too high, and the benzoxazine epoxy resin copolymer is not beneficial to being applied to actual industrial production.
Disclosure of Invention
The invention aims to provide a benzothiadiazole modified imidazole compound, a preparation method and application thereof, wherein the compound is used as a curing agent, a single-component system consisting of the compound and epoxy resin has long storage period, the epoxy resin can be rapidly cured under the medium-high temperature condition, and the compound can be used as a co-curing agent of bisphenol A epoxy resin (E51) with 4' 4-diaminodiphenyl methane (DDM), so that the reaction temperature is reduced, and the reaction rate is improved.
The invention adopts the technical proposal for solving the problems that:
the invention provides a benzothiadiazole modified imidazole compound, which has a structural formula shown in formula 1:
In the formula 1, N is nitrogen, and R 1、R2、R3 and R 4 are respectively and independently selected from hydrogen, alkyl chain or phenyl.
Preferably, the structural formula of the compound is shown in the formulas 4-6:
The invention provides a preparation method of a benzothiadiazole modified imidazole compound, which comprises the following steps:
Under the action of a catalyst, a solvent and an acid-binding agent, reacting imidazole with a structure shown in a formula 2 with 4, 7-dibromo-2, 1, 3-benzothiadiazole with a structure shown in a formula 3 in a nitrogen atmosphere to obtain a benzothiadiazole modified imidazole compound;
Preferably, the mole ratio of the imidazole with the structure of the formula 2 to the 4, 7-dibromo-2, 1, 3-benzothiadiazole with the structure of the formula 3 is 1: (2-5).
Preferably, the solvent is selected from one of N, N-dimethylformamide, dimethyl sulfoxide or N, N-dimethylacetamide, and the catalyst is cuprous iodide.
Preferably, the acid binding agent is selected from one of anhydrous potassium carbonate, triethylamine, sodium hydroxide or potassium hydroxide.
Preferably, the reaction temperature is 140-155 ℃ and the reaction time is 48-72h.
The invention also provides application of the compound as a latent curing agent in curing epoxy resin.
Preferably, the application comprises: and uniformly mixing the benzothiadiazole modified imidazole compound and the epoxy resin in a solvent to obtain a latent epoxy resin single-component curing system.
Preferably, the application comprises: and uniformly mixing the benzothiadiazole modified imidazole compound, 4 '4-diaminodiphenylmethane and epoxy resin in a solvent to obtain a latent curing agent/4' 4-diaminodiphenylmethane/epoxy resin curing system.
Compared with the prior art, the invention has the following beneficial effects:
1. According to the invention, a chemical modification method is adopted, the benzothiadiazole is introduced into the 1-position nitrogen atom active site of the imidazole ring, and the normal-temperature curing activity of the imidazole curing agent is passivated through the electron-withdrawing effect and the steric hindrance effect of the benzothiadiazole, so that the defect of short applicable period of the imidazole curing agent is overcome, the latency is improved, and the storage period of an epoxy resin single-component system is effectively improved.
2. The diazosulfide modified imidazole compound disclosed by the invention is used as a latent curing agent, has long storage life with a single-component system consisting of epoxy resin, recovers inherent high reactivity of imidazole under medium-high temperature conditions, and can be used for rapidly curing the epoxy resin.
3. The diazosulfide modified imidazole compound provided by the invention is used as a latent curing agent, and can be used as a co-curing agent of epoxy resin together with 4' 4-diaminodiphenyl methane, so that the reaction temperature is reduced, and the reaction rate is improved.
4. The invention prepares the benzothiadiazole modified imidazole compound through nucleophilic substitution reaction, has simple synthesis process, high yield and easily obtained raw materials, and is suitable for industrial production.
Drawings
FIG. 1 is an infrared spectrum of a benzothiadiazole modified imidazole compound prepared in example 1 of the present invention;
FIG. 2 is a nuclear magnetic resonance spectrum of the benzothiadiazole modified imidazole compound prepared in example 1 of the present invention;
FIG. 3 is a nuclear magnetic resonance spectrum of the benzothiadiazole modified imidazole compound prepared in example 6 of the present invention;
FIG. 4 is a graph showing the change in storage modulus, loss modulus, and complex viscosity of the compounds of examples 1 to 4 and comparative example 1 according to the present invention as a curing agent at 60 ℃;
FIG. 5 is a graph showing the scanning differential calorimetric curves of BTD-MZ/E51 obtained in examples 1-4 and comparative example 1 of the present invention with different doping levels;
FIG. 6 is a graph of ln (. Beta./Tp 2) versus 1/Tp 103 for the epoxy resin blend systems obtained in example 5 and comparative example 2 of the present invention using the Kissinger method;
FIG. 7 is a plot of lnβ versus 1/Tp 103 for the epoxy resin blend system of example 5 and comparative example 2 of the present invention using the Ozawa process.
Detailed Description
The invention provides a benzothiadiazole modified imidazole compound, which has a structural formula shown in formula 1:
in the formula 1, N is nitrogen, R 1、R2、R3 and R 4 are respectively and independently selected from hydrogen, alkyl chain or phenyl, wherein the alkyl chain is preferably alkyl of C 1-6;
preferably, the structural formula of the compound is shown in the formulas 4-6:
The invention provides a preparation method of a benzothiadiazole modified imidazole compound, which comprises the following steps:
Reacting imidazole with a structure shown in a formula 2 with 4, 7-dibromo-2, 1, 3-benzothiadiazole with a structure shown in a formula 3 under the action of a catalyst, a solvent and an acid-binding agent in a nitrogen atmosphere, wherein the solvent is preferably selected from one of N, N-dimethylformamide, dimethyl sulfoxide or N, N-dimethylacetamide; the catalyst is preferably cuprous iodide, the acid-binding agent is preferably one of anhydrous potassium carbonate, triethylamine, sodium hydroxide or potassium hydroxide, the reaction temperature is preferably 140-155 ℃, the reaction time is preferably 48-72h, after the reaction is finished, the catalyst is preferably cooled to room temperature, water is added for dilution, filtration, washing and drying to obtain a crude product, the crude product is dissolved in a solvent, ultrasonic filtration is carried out, the filtrate is steamed in a spinning mode, and the diazosulfide modified imidazole compound is obtained after drying; the molar ratio of the imidazole with the structure of the formula 2 to the 4, 7-dibromo-2, 1, 3-benzothiadiazole with the structure of the formula 3 is preferably 1: (2-5), more preferably 1:3.
The reaction process of the above reaction is as follows:
According to the invention, the preparation of 4, 7-dibromo-2, 1, 3-benzothiadiazole compounds of formula 3, reference ("Synthesis of Benzothiadiazole Derivatives by Applying C–CCross-Couplings"Juha P.Heiskanen,Paola Vivo,Niko M.Saari,Terttu I.Hukka,Tuuva Kastinen,Kimmo Kaunisto,Helge J.Lemmetyinen,and Osmo E.O.Hormi The Journal of Organic Chemistry 2016,81,4,1535-1546), is described. Preferably comprises:
The preparation method comprises the following steps of reacting 2,1, 3-benzothia compounds with N-bromosuccinimide for 3 hours at 60 ℃ by taking concentrated sulfuric acid as a solvent according to a feeding molar ratio of 1:2, wherein the reaction process is as follows:
the invention also provides application of the benzothiadiazole modified imidazole compound as a latent curing agent in curing epoxy resin.
Specifically, the benzothiadiazole modified imidazole compound provided by the invention can be directly used as a latent curing agent, and the using method is as follows: and uniformly mixing the benzothiadiazole modified imidazole compound and the epoxy resin in a solvent to obtain a latent epoxy resin single-component curing system. The epoxy resin is preferably bisphenol A type epoxy resin, more preferably E51; the adding amount of the benzothiadiazole modified imidazole compound is preferably 5-20% of the mass of the epoxy resin, and the solvent is preferably dichloromethane.
The benzothiadiazole modified imidazole compound of the invention can be used as a latent curing agent and can also be mixed with 4' 4-diaminodiphenyl methane to be used as a co-curing agent. The using method comprises the following steps:
And uniformly mixing the benzothiadiazole modified imidazole compound, 4 '4-diaminodiphenylmethane and epoxy resin in a solvent to obtain a latent curing agent/4' 4-diaminodiphenylmethane/epoxy resin curing system. The epoxy resin is preferably bisphenol A type epoxy resin, more preferably E51; the mass ratio of the benzothiadiazole modified imidazole compound to the 4' 4-diaminodiphenyl methane to the epoxy resin is preferably 5.4:18:80, and the solvent is preferably dichloromethane.
The present invention will be described in further detail by the following examples, which are only for the purpose of illustrating the present invention and are not to be construed as limiting the scope of the present invention. Other combinations and various modifications within the spirit of the invention may be made without departing from the spirit or scope of the invention.
Example 1
1. In a 500ml single-necked flask, 15.03g of 2,1, 3-benzothiadiazole, 40.62g of N-bromosuccinimide and 150ml of concentrated sulfuric acid were charged; after being uniformly mixed, the mixed solution reacts in an oil bath at 60 ℃ for 3 hours; after the reaction is finished, cooling to room temperature, washing concentrated sulfuric acid by using an ice water bath, filtering and drying to obtain the 4, 7-dibromo-2, 1, 3-benzothiadiazole.
2. 31.38G of 4, 7-dibromo-2, 1, 3-benzothiadiazole, an excess of imidazole, satisfying a molar ratio of imidazole to 4, 7-dibromo-2, 1, 3-benzothiadiazole of 1:3,2.474g of cuprous iodide, 17.756g of anhydrous potassium carbonate, 120ml of N, N-dimethylformamide, and under nitrogen atmosphere at 150 ℃ for three days; cooling to room temperature after the reaction is finished, adding water to dilute, filtering, washing and drying to obtain a crude product, dissolving the crude product in dichloromethane, carrying out ultrasonic filtration for 30 minutes, steaming filtrate at 45 ℃ in a rotary way, and drying to obtain the benzothiadiazole modified imidazole compound BTD-MZ 2. The structural formula is shown in formula 4:
The infrared spectrogram of the benzothiadiazole modified imidazole compound BTD-MZ 2 prepared in example 1 is shown in fig. 1, wherein curve 1 represents BTD, curve 2 represents BTD-MZ 2,IR(KBr):1631cm-1 c=n stretching vibration is blue shifted and absorption peak is widened; 1399cm -1 C-N stretching vibration.
The nuclear magnetic resonance spectrum of the benzothiadiazole modified imidazole compound BTD-MZ 2 prepared in example 1 is shown in figure 2.
And (3) carrying out ultrasonic treatment on the obtained benzothiadiazole modified imidazole compound BTD-MZ 2 and E51 epoxy resin in methylene dichloride according to the mass ratio of 5:100 so as to uniformly mix, carrying out rotary evaporation at 45 ℃, and vacuumizing to obtain a latent epoxy resin single-component curing system. Can be stored at 60deg.C for over 850min (as shown in FIG. 4), with substantially no change in viscosity. The initial curing reaction exotherm temperature was 145.9℃and the peak at the highest point was 172.5℃to 194.2℃at which the exotherm ended (see FIG. 5).
Example 2
The preparation method and conditions of this example are the same as in example 1, except that: when the method is applied, the mass ratio of the diazosulfide modified imidazole compound BTD-MZ 2 to the E51 epoxy resin is 10:100, and the latent epoxy resin single-component curing system is obtained. Can be stored at 60deg.C for over 850min (as shown in FIG. 4), with substantially no change in viscosity. The exothermic temperature of the initial curing reaction was 145.7℃and the highest peak position was 167.9℃to 190.5℃as measured by DSC (see FIG. 5).
Example 3
The preparation method and conditions of this example are the same as in example 1, except that: when the method is applied, the mass ratio of the diazosulfide modified imidazole compound BTD-MZ 2 to the E51 epoxy resin is 15:100, and the latent epoxy resin single-component curing system is obtained. Can be stored at 60deg.C for over 850min (as shown in FIG. 4), with substantially no change in viscosity. The exothermic temperature of the initial curing reaction was 145℃and the peak position was 162.3℃at the highest temperature, and the exothermic was completed at 178℃as measured by DSC (see FIG. 5).
Example 4
The preparation method and conditions of this example are the same as in example 1, except that: when the method is applied, the mass ratio of the diazosulfide modified imidazole compound BTD-MZ 2 to the E51 epoxy resin is 20:100, and a latent epoxy resin single-component curing system is obtained. Can be stored at 60deg.C for 850min or longer (as shown in b diagram of FIG. 4), and has substantially no change in viscosity. The exothermic temperature of the initial curing reaction was 143 as measured by DSC. The exotherm ended at 7℃with a peak position of 158.9 ℃to 171.4℃as shown in FIG. 5.
Example 5
The preparation method and conditions of this example are the same as in example 1, except that: in application, the benzothiadiazole modified imidazole compound BTD-MZ 2, 4 '4-diaminodiphenyl methane and E51 type epoxy resin are mechanically stirred according to the mass ratio of 5.4:18:80 so as to be uniformly mixed, and then the mixture is vacuumized at 45 ℃ to obtain a latent curing agent/4' 4-diaminodiphenyl methane/epoxy resin curing system. The activation energy of the reaction was 50KJ/mol as measured by Kissinger 'smethod (FIG. 6) and 51.57KJ/mol as measured by Ozawa's method (FIG. 7) as measured by DSC.
Comparative example 1
Uniformly mixing 2-ethyl-4-methylimidazole and E51 epoxy resin in a 100ml beaker according to the mass ratio of 5.61:100, and vacuumizing to obtain a non-latent epoxy resin and curing agent system. The change in storage modulus, loss modulus and complex viscosity of the system obtained in comparative example 1 at 60℃is shown in FIG. 4, panel a. The exothermic temperature of the initial curing reaction was 85.7℃and the highest peak position was 103℃as measured by DSC, and the exothermic was completed from 121.1℃as shown in FIG. 5.
Comparative example 2
Uniformly mixing 4 '4-diaminodiphenylmethane and E51 epoxy resin in a 100ml beaker according to the mass ratio of 20:80, and vacuumizing to obtain a 4' 4-diaminodiphenylmethane/epoxy resin and curing agent system. The activation energy of the reaction was 46.30KJ/mol as measured by the Kissinger's method (FIG. 6) and 49.34KJ/mol as measured by Ozawa' smethod (FIG. 7) as measured by DSC.
Example 6
1. In a 500ml single-necked flask, 15.03g of 2,1, 3-benzothiadiazole, 40.62g of N-bromosuccinimide and 150ml of concentrated sulfuric acid were charged; after being uniformly mixed, the mixed solution reacts in an oil bath at 60 ℃ for 3 hours; after the reaction is finished, cooling to room temperature, washing concentrated sulfuric acid by using an ice water bath, filtering and drying to obtain the 4, 7-dibromo-2, 1, 3-benzothiadiazole.
2. 31.38G of 4, 7-dibromo-2, 1, 3-benzothiadiazole, an excess of 2-methylimidazole, and a molar ratio of 2-methylimidazole to 4, 7-dibromo-2, 1, 3-benzothiadiazole of 1 were charged into a 500ml three-necked flask: 3,2.5g of cuprous iodide, 17.8g of anhydrous potassium carbonate and 120ml of N, N-dimethylformamide are reacted for three days under nitrogen atmosphere at 150 ℃; cooling to room temperature after the reaction is finished, adding water to dilute, filtering, washing and drying to obtain a crude product, dissolving the crude product in dichloromethane, carrying out ultrasonic filtration for 30 minutes, carrying out rotary evaporation on filtrate at 45 ℃, and drying to obtain the benzothiadiazole modified imidazole compound BTD-2MMZ 2. The structural formula is shown in formula 5:
The infrared spectrum of the benzothiadiazole modified imidazole compound BTD-2MMZ 2 obtained in example 6 is shown in FIG. 3, IR (KBr) is that 2922cm -1 -C-H stretching vibration, 1592,1493,1413cm -1 C=N, C=C stretching vibration generates blue movement; 1371cm -1 C-N telescopic vibration, and nuclear magnetic hydrogen spectrum data are as follows: 1H NMR:(CDCl3 ) a (delta 7,71,2H); b (δ 7.54,2H); c (delta 8.10,2H); d (delta 2.427,6H).
And (3) carrying out ultrasonic treatment on the benzothiadiazole modified imidazole compound BTD-2MMZ 2 and the E51 epoxy resin in methylene dichloride according to the mass ratio of 15:100 so as to uniformly mix, carrying out rotary evaporation at 45 ℃, and vacuumizing to obtain the latent epoxy resin single-component curing system. Can be stored at 60deg.C for over 880min without change in viscosity. The initial curing reaction exotherm temperature was 144.3℃with the highest peak at 159.7℃and the exotherm ending at 175.0 ℃.
Example 7
1. In a 500ml single-necked flask, 16.53g of 5-methylbenzo-2, 1, 3-thiazole, 40.62g N-bromosuccinimide and 150ml of concentrated sulfuric acid were charged; after being uniformly mixed, the mixed solution reacts in an oil bath at 60 ℃ for 3 hours; cooling to room temperature after the reaction is finished, washing concentrated sulfuric acid by ice water bath, filtering and drying to obtain the 5-methyl-4, 7-dibromo-2, 1, 3-benzothiadiazole.
2. 31.38G of 5-methyl-4, 7-dibromo-2, 1, 3-benzothiadiazole and a proper amount of 2-methylimidazole were put into a 500ml three-necked flask, and the molar ratio of 2-methylimidazole to 5-methyl-4, 7-dibromo-2, 1, 3-benzothiadiazole was 1:3,2.5g of cuprous iodide, 17.8g of anhydrous potassium carbonate and 120ml of N, N-dimethylformamide are reacted for three days under nitrogen atmosphere at 150 ℃; cooling to room temperature after the reaction is finished, adding water to dilute, filtering, washing and drying to obtain a crude product, dissolving the crude product in dichloromethane, carrying out ultrasonic filtration for 30 minutes, carrying out rotary evaporation on filtrate at 45 ℃, and drying to obtain the benzothiadiazole modified imidazole compound MBTD-2MMZ 2. The structural formula is shown in formula 6:
The synthetic dosing of the curing agent of examples 1-6 and comparative example 1, and the DSC test results of the curing agent with bisphenol A epoxy resin (E51) system are summarized in Table 1.
TABLE 1 epoxy latent curing System test results
The table shows that the benzothiadiazole modified imidazole compound provided by the invention has good latency when being used as an epoxy resin latency curing agent, and can effectively improve the storage performance; and the curing rate under high temperature curing conditions is substantially the same as that of the unmodified imidazole curing agent.
The amount of the curing agent added to the epoxy resin was changed (examples 1 to 4), the curing reaction temperature was shifted to the low temperature direction with the increase of the content of the curing agent, and the curing time was shortened.
The results of DSC testing of the curative synthetic feeds of example 5 and comparative example 2, and the curative and bisphenol A epoxy resin (E51) system are summarized in Table 2.
TABLE 2 epoxy Co-curing System test results
As can be seen from Table 2, the benzothiadiazole modified imidazole compound of the present invention was able to lower the reaction temperature as a latent curing agent for epoxy resins and as a co-curing agent for E51 with 4' 4-diaminodiphenylmethane.
The benzothiadiazole modified imidazole compound provided by the invention is used as a latent curing agent of epoxy resin and a co-curing agent of 4 '4-diaminodiphenyl methane E51, so that the reaction activation energy is reduced, and the 4' 4-diaminodiphenyl methane E51 is catalyzed.
The above description is only of several preferred embodiments of the present invention, and modifications and variations of the present invention will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (3)
1. The application of the benzothiadiazole modified imidazole compound as a latent curing agent in curing epoxy resin is characterized in that the structural formula of the compound is shown in the formulas 4-6:
2. use of a benzothiadiazole modified imidazole compound according to claim 1 as a latent hardener for curing epoxy resins, comprising: and uniformly mixing the benzothiadiazole modified imidazole compound and the epoxy resin in a solvent to obtain a latent epoxy resin single-component curing system.
3. Use of a benzothiadiazole modified imidazole compound according to claim 1 as a latent hardener for curing epoxy resins, comprising: and uniformly mixing the benzothiadiazole modified imidazole compound, 4 '4-diaminodiphenylmethane and epoxy resin in a solvent to obtain a latent curing agent, and a curing system of the 4' 4-diaminodiphenylmethane and the epoxy resin.
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| CN110591113A (en) * | 2019-10-22 | 2019-12-20 | 江西理工大学 | Cobalt-based metal-organic framework with fluorescence recognition performance and preparation method thereof |
| CN110872308A (en) * | 2018-09-04 | 2020-03-10 | 北京大学深圳研究生院 | Near-infrared organic luminescent material based on benzo-dithiadiazole derivative |
| CN111100265A (en) * | 2019-12-30 | 2020-05-05 | 南京德高材料科技有限公司 | (E) -1, 2-di (2-thienyl) ethylene and benzothiadiazole-based polymer, and preparation method and application thereof |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110872308A (en) * | 2018-09-04 | 2020-03-10 | 北京大学深圳研究生院 | Near-infrared organic luminescent material based on benzo-dithiadiazole derivative |
| CN110591113A (en) * | 2019-10-22 | 2019-12-20 | 江西理工大学 | Cobalt-based metal-organic framework with fluorescence recognition performance and preparation method thereof |
| CN111100265A (en) * | 2019-12-30 | 2020-05-05 | 南京德高材料科技有限公司 | (E) -1, 2-di (2-thienyl) ethylene and benzothiadiazole-based polymer, and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| "Dicarboxylate-dependent structural diversity in amino-functionalized complexes: From mononuclear to multinuclear coordination polymer";Zhang, Xin;《Inorganic Chemistry Communications》;第第69卷卷;Supplementary material 4, 第2页第2段 * |
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