High refractive index epoxy useful for rapid encapsulation and method of making same

Abstract

The application relates to the technical field of organic chemistry, in particular to a high-refractive epoxy for rapid packaging and a preparation method thereof. The epoxy is an epoxy resin with double epoxy groups, and the epoxy is connected with a benzene ring. The epoxy has the following general structure formula: wherein X is oxygen or sulfur, and R is a hydrogen atom or a methyl group, an ethyl group, an aromatic group or a fluorine-containing C1-C6 alkyl group. The epoxy resin with double epoxy groups and aromatic structures is designed and synthesized, and after being added into a commercial epoxy resin DGEBA system, the curing speed and the refractive index of the resin can be improved as a whole, and the epoxy can be used in the field of rapid semiconductor packaging.

Description

Technical Field

[0001] This invention relates to the field of organic chemistry, specifically to a high-refractive-index epoxy that can be used for rapid encapsulation and its preparation method. Background Technology

[0002] Compared with traditional light sources, light-emitting diodes (LEDs), as a new technology that converts electrical energy into light energy, have advantages such as small size, pure spectrum, fast response speed, high luminous efficiency, long life and clean and pollution-free, and are gradually becoming the mainstream light source.

[0003] LEDs typically consist of two main parts: electronic components and encapsulation materials. The encapsulation material is generally an insulating polymer, with bisphenol A epoxy resin currently being widely used. However, bisphenol A epoxy resin has the following drawbacks, which limit its application to some extent: 1. Low refractive index: most bisphenol A epoxy resins (such as DGEBA) have a refractive index of around 1.53, resulting in relatively low light extraction efficiency; 2. Slow curing speed, affecting production efficiency. Therefore, it is necessary to design an epoxy resin for encapsulation with a high refractive index and fast curing speed. Summary of the Invention

[0004] The technical problem to be solved by this invention is: to develop a high refractive index epoxy that can be used for rapid encapsulation and its preparation method.

[0005] To address the above problems, the technical solution provided by this invention is as follows:

[0006] A high-refractive-index epoxy resin suitable for rapid encapsulation, wherein the epoxy is a diepoxy group epoxy resin with the epoxy linked to a benzene ring, and the epoxy has the following general structural formula:

[0007]

[0008] X is oxygen or sulfur, and R is a hydrogen atom or a methyl, ethyl, aromatic or fluorine-containing C1-C6 alkyl group.

[0009] Preferably, the epoxy is a diepoxydiphenyl ether, where X is oxygen and R is selected from hydrogen, methyl, phenyl and trifluoromethyl.

[0010] Preferably, the application of the above-mentioned epoxy in the epoxy resin DGEBA system is also included.

[0011] Preferably, the method for preparing the above-mentioned diepoxy diphenyl ether comprises the following steps: a. adding hydroxybenzaldehyde, fluorobenzaldehyde, and a base to a solvent, monitoring the reaction until completion, adding the reaction solution to water, and filtering to obtain the product diformaldehyde diphenyl ether; b. adding Corey-Chaykovsky epoxidizing agent and NaH to a solvent, stirring, adding diformaldehyde diphenyl ether, monitoring the reaction until completion, and obtaining the product diepoxy diphenyl ether, as shown in the following reaction formula:

[0012]

[0013] Preferably, in step a, the molar ratio of hydroxybenzaldehyde, fluorobenzaldehyde, and the base is 1:1 to 1.5:1 to 3, the base is potassium carbonate, cesium carbonate, DBU, sodium hydroxide, or potassium hydroxide, the solvent is DMSO or DMF, and the solvent volume (ml) is 10 to 15 times the mass (g) of hydroxybenzaldehyde.

[0014] Preferably, in step b, the molar ratio of Corey-Chaykovsky epoxidizing agent, NaH, and dimethylformaldehyde diphenyl ether is 1-4:1-4:1, the solvent is DMSO or DMF, the solvent volume (ml) is 10-15 times the mass (g) of dimethylformaldehyde diphenyl ether, and the Corey-Chaykovsky epoxidizing agent is trimethylsulfonium iodide.

[0015] Preferably, the epoxy is a diepoxydiphenyl sulfide, where X is sulfur and R is selected from hydrogen, methyl, phenyl and trifluoromethyl.

[0016] Preferably, the application of the above-mentioned epoxy in the epoxy resin DGEBA system is also included.

[0017] Similarly, a method for preparing the above-mentioned diepoxy diphenyl sulfide includes the following steps: a. adding methyl mercaptobenzoate, methyl fluorobenzoate, and a base to a solvent, monitoring the reaction until completion, adding the reaction solution to water, and filtering to obtain methyl diformate diphenyl sulfide; b. subjecting methyl diformate diphenyl sulfide to different reactions to obtain... c. Add Corey-Chaykovsky epoxidizing agent and NaH to the solvent, stir, and then add diformyl diphenyl sulfide ( After the reaction was monitored to complete, the product diepoxydiphenyl sulfide was obtained. The reaction formula is as follows:

[0018]

[0019] Where R is hydrogen, methyl, phenyl, and trifluoromethyl.

[0020] Preferably, in step a, the molar ratio of methyl mercaptobenzoate, methyl fluorobenzoate, and base is 1:1 to 1.5:1 to 3, the base is potassium carbonate, the solvent is DMSO or DMF, and the solvent volume (ml) is 10 to 15 times the mass (g) of methyl mercaptobenzoate.

[0021] Preferably, in step c, the molar ratio of Corey-Chaykovsky epoxidizing agent, NaH, and dicarboxylated diphenyl sulfide is 1–4:1–4:0.5, and the solvent is DMSO or DMF, with a solvent volume (ml) 10–15 times the mass (g) of dicarboxylated diphenyl sulfide. In cases where the Chinese nomenclature of a compound conflicts with its structural formula, the structural formula shall prevail, except where the structural formula contains obvious errors.

[0022] The beneficial effects of this invention are that it designs and synthesizes a class of epoxy resins containing aromatic structures and having biepoxy groups. The biepoxy structure has high activity, and when added to the commercial epoxy resin DGEBA system, the curing speed is faster and the refractive index is increased, which can be used in the field of semiconductor rapid packaging. Detailed Implementation

[0023] The present invention is illustrated below with reference to examples, but is not intended to limit the invention. Any simple substitutions or modifications made to the present invention by those skilled in the art are within the scope of the technical solutions protected by this invention.

[0024] Example 1: Preparation of Compound 1

[0025]

[0026] In the first step, p-hydroxybenzaldehyde (10 g, 0.082 mol), 4-fluorobenzaldehyde (11.2 g, 0.09 mol), and potassium carbonate (22.1 g, 0.16 mol) were dissolved in DMF (100 mL). The reaction was carried out at 120°C for 12 hours until the endpoint was reached, and the reaction was monitored by TLC until completion. While stirring, the solution was added to water (300 mL), filtered, and dried to obtain pure product 1-iii, with a yield of 90% and a purity of 98%.

[0027] In the second step, a certain amount of trimethylsulfonium iodide (36.11 g, 0.177 mol) and NaH (7.1 g, 0.177 mol, 60%) were added to DMSO (100 mL) under ice bath conditions. After stirring for 30 min, the above product dimethylformaldehyde diphenyl ether (10 g, 0.044 mol) was added. The reaction was carried out at room temperature for 4 hours. The reaction was monitored by TLC until it ended. The mixture was quenched in an aqueous solution of ammonium chloride, extracted with ethyl acetate, and the organic phase was dried by rotary evaporation. The product was then recrystallized from n-heptane to obtain the target product 1 with a yield of 70% and a purity of 99%.

[0028] The 1H NMR spectrum of the target product is as follows:1 H NMR (400 MHz, Chloroform- d ) δ 7.36 (d, 4H), 7.24 (d, 4H), 3.83 (t, 2H), 2.96 (m, 2H), 2.71 (m, 2H).

[0029] Example 2: Preparation of Compound 2

[0030]

[0031] In the first step, methyl mercaptobenzoate (10 g, 0.059 mol), methyl 4-fluorobenzoate (10 g, 0.065 mol), and potassium carbonate (16.3 g, 0.118 mol) were reacted in DMF (100 mL) at 120°C for 12 hours until the endpoint was reached, and the reaction was monitored by TLC. While stirring, the solution was added to water (300 mL), filtered, and dried to obtain pure product 2-iii, with a yield of 95% and a purity of 96%.

[0032] In the second step, methyl diphenyl sulfide (10 g, 0.033 mol) was dissolved in THF (100 mL), and DIBAL-H (50 mL, 0.049 mol, 1 M) was added. The reaction was carried out under N2 conditions at -70 °C for 3 h. The reaction was monitored by TLC until it ended, and then 2 mL of water was added to quench DIBAL-H. The mixture was heated to room temperature, and the solution was added to 100 mL of water. The solution was extracted with ethyl acetate, and the organic phase was concentrated under reduced pressure to obtain 2-iv, with a yield of 83% and a purity of 97%.

[0033] In the third step, a certain amount of trimethylsulfonium iodide (33.46 g, 0.164 mol) and NaH (6.57 g, 0.164 mol, 60%) were added to DMSO (100 mL) under ice bath conditions. After stirring for 30 min, the above product dimethylformaldehyde diphenyl sulfide (10 g, 0.041 mol) was added. The reaction was carried out at room temperature for 4 hours. The reaction was monitored by TLC until it ended. The mixture was quenched in an aqueous solution of ammonium chloride, extracted with ethyl acetate, and the organic phase was dried by rotary evaporation. The product was then recrystallized from n-heptane to obtain the target product 2 with a yield of 73% and a purity of 99%.

[0034] The 1H NMR spectrum of the target product is as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 7.55 (d, 4H), 7.08 (d, 4H), 3.81 (t, 2H), 2.91 (m, 2H), 2.67 (m, 2H).

[0035] Example 3: Preparation of Compound 3

[0036]

[0037] In the first step, methyl diphenyl sulfide diformate (10 g, 0.033 mol) and N,O-dimethylhydroxylamine hydrochloride (6.45 g, 0.066 mol) were added to tetrahydrofuran (100 mL), followed by the addition of tert-butylmagnesium chloride (160 mL, 0.16 mol, 1 M) at room temperature. The mixture was stirred at room temperature for 12 hours. The mixture was then poured into a saturated NaHCO3 solution (100 mL) and extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum to give 3-i, with a yield of 90% and a purity of 98%.

[0038] In the second step, 3-i (10 g, 0.03 mol) was added to 100 mL of dry THF, followed by MeMgBr (3.93 g, 0.033 mol) at 0 °C. The reaction was carried out at 0 °C for 1 h, and the reaction was monitored by TLC until completion. The reaction solution was poured into 100 mL of hydrochloric acid solution, and the mixture was extracted with dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 3-ii with a yield of 93% and a purity of 97%.

[0039] In the third step, a certain amount of trimethylsulfonium iodide (30.19 g, 0.148 mol) and NaH (5.92 g, 0.148 mol, 60%) were added to DMSO (100 mL) under ice bath conditions. After stirring for 30 min, the above product dimethyl phenyl ketone diphenyl sulfide (10 g, 0.037 mol) was added. The reaction was carried out at room temperature for 4 hours. The reaction was monitored by TLC until it ended. The mixture was quenched in an aqueous solution of ammonium chloride, extracted with ethyl acetate, and the organic phase was dried by rotary evaporation. The product was then recrystallized from n-heptane to obtain the target product 3 with a yield of 75% and a purity of 99%.

[0040] The 1H NMR spectrum of the target product is as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 7.56 (d, 4H), 7.10 (d, 4H), 2.95 – 2.88 (m, 2H), 2.71 – 2.64 (m, 2H), 1.7 (s, 6H).

[0041] Example 4: Preparation of Compound 4

[0042]

[0043] First, 3-i (10 g, 0.03 mol) was added to 100 mL of dry THF, followed by PhMgBr (33 mL, 0.033 mol, 1 M) at 0 °C. The reaction was carried out at 0 °C for 1 h, and the reaction was monitored by TLC until completion. The reaction solution was poured into 100 mL of hydrochloric acid solution, and the mixture was extracted with dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 4-i with a yield of 89% and a purity of 95%.

[0044] In the second step, a certain amount of trimethylsulfonium iodide (20.6 g, 0.101 mol) and NaH (4 g, 0.101 mol, 60%) were added to DMSO (100 mL) under ice bath conditions. After stirring for 30 min, the above product bisbenzophenone diphenyl sulfide (10 g, 0.025 mol) was added. The reaction was carried out at room temperature for 4 hours. The reaction was monitored by TLC until it ended. The mixture was quenched in an aqueous solution of ammonium chloride, extracted with ethyl acetate, and the organic phase was dried by rotary evaporation. The product was then recrystallized from n-heptane to obtain the target product 4 with a yield of 65% and a purity of 98%.

[0045] The 1H NMR spectrum of the target product is as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 7.55-7.46 (m,8H), 7.31-7.22 (m, 6H), 7.08 (d, 4H), 3.31 (m, 4H).

[0046] Example 5: Preparation of Compound 5

[0047]

[0048] In the first step, methyl diphenyl sulfide (10 g, 0.033 mol) and TMSCF3 (5.86 g, 0.041 mol) were added to 100 mL of toluene. Anhydrous tetrabutylammonium fluoride THF solution was added at -78 °C, and the mixture was slowly heated to room temperature and stirred for 18 h. The reaction was monitored by TLC until it ended. Finally, the mixture was quenched in hydrochloric acid aqueous solution, and the organic phase was concentrated under reduced pressure to obtain 5-i with a yield of 90% and a purity of 96%.

[0049] In the second step, a certain amount of trimethylsulfonium iodide (21.6 g, 0.106 mol) and NaH (4.3 g, 0.106 mol, 60%) were added to DMSO (100 mL) under ice bath conditions. After stirring for 30 min, the above-mentioned diphenyl sulfide bis(trifluoromethyl)phenyl ketone (10 g, 0.026 mol) was added. The reaction was carried out at room temperature for 4 hours. The reaction was monitored by TLC until it ended. The mixture was quenched in an aqueous solution of ammonium chloride, extracted with ethyl acetate, and the organic phase was dried by rotary evaporation. The product was then recrystallized from n-heptane to obtain the target product 5 with a yield of 72% and a purity of 97%.

[0050] The 1H NMR spectrum of the target product is as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 7.58 (d, 4H), 7.13 (d, 4H), 3.48 – 3.44 (m, 2H), 2.98 – 2.95 (m, 2H).

[0051] Example 6: Preparation of Compound 6

[0052]

[0053] In the first step, methyl mercaptobenzoate (10 g, 0.059 mol), methyl 3-fluorobenzoate (10 g, 0.065 mol), and potassium carbonate (16.3 g, 0.118 mol) were reacted in DMF (100 mL) at 120°C for 12 hours until the endpoint was reached, and the reaction was monitored by TLC. While stirring, the solution was added to water (300 mL), filtered, and dried to obtain the pure product 6-iii, with a yield of 93% and a purity of 98%.

[0054] In the second step, 6-iii (10 g, 0.033 mol) was dissolved in THF (100 mL), and DIBAL-H (49 mL, 0.049 mol, 1 M) was added. The reaction was carried out under N2 conditions at -70 °C for 3 h. The reaction was monitored by TLC until it ended, and then 2 mL of water was added to quench DIBAL-H. The mixture was heated to room temperature, and the solution was added to 100 mL of water. The solution was extracted with ethyl acetate, and the organic phase was concentrated under reduced pressure to obtain 6-iv with a yield of 80% and a purity of 95%.

[0055] In the third step, a certain amount of trimethylsulfonium iodide (33.46 g, 0.164 mol) and NaH (6.6 g, 0.164 mol, 60%) were added to DMSO (100 mL) under ice bath conditions. After stirring for 30 min, the product of the second step above, dimethylformaldehyde diphenyl sulfide (10 g, 0.041 mol), was added. The reaction was carried out at room temperature for 4 hours. The reaction was monitored by TLC until it ended. The mixture was quenched in an aqueous solution of ammonium chloride, extracted with ethyl acetate, and the organic phase was dried by rotary evaporation. The product was then recrystallized from n-heptane to obtain the target product 6 with a yield of 71% and a purity of 99%.

[0056] The 1H NMR spectrum of the target product is as follows: 1 H NMR (400 MHz, Chloroform- d) δ 7.55 (d, 2H),7.37 (d, 1H), 7.25-7.18 (m, 2H), 7.08-7.06 (m, 3H), 3.87 – 3.82 (t, 2H), 3.13– 3.08 (m, 2H), 2.75 – 2.72 (m, 2H).

[0057] The refractive indices of the epoxy compounds in Examples 1-6 are shown in the table below.

[0058] 1 2 3 4 5 6 Refractive index 1.62 1.65 1.63 1.68 1.64 1.65 Example

[0059] Experimental example:

[0060] 1. Mix DGEBA and curing agent (DDM) thoroughly for several minutes at stoichiometric equilibrium (molar ratio of epoxy groups to amino hydrogens = 1:1), then pour the mixture into a silicone rubber mold. The curing reaction is carried out in air at 140°C for 1 hour, 2 hours, and 3 hours.

[0061] 2. Mix DGEBA and the above products (product 1 diepoxydiphenyl ether or product 2 diepoxydiphenyl sulfide) (molar ratio of epoxy groups = 1:1) with the curing agent (DDM) at stoichiometric equilibrium (molar ratio of epoxy groups to amino hydrogen = 1:1) for several minutes, then pour into a silicone rubber mold. The curing reaction is carried out in air at 140°C for 1 hour, 2 hours, and 3 hours.

[0062] 3. Determine the epoxy value of the epoxy-cured product according to GB / T 1677-2008.

[0063] 1h 2h 3h DGEBA+DDM 1.1 0.84 0.65 DGEBA+ Product 1+DDM 0.85 0.63 0.6 DGEBA+Product 2+DDM 0.81 0.61 0.59

[0064] 4. Comparison of curing times

[0065] DGEBA+DDM DGEBA+ Product 1+DDM DGEBA+Product 2+DDM Curing time 53min 22min 18min

[0066] As seen in the examples, after adding the product of the present invention, the curing time of epoxy resin is shortened, the epoxy value is reduced, and the reaction is more thorough.

[0067] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A high refractive index epoxy useful for rapid encapsulation, characterized in that, The epoxy is an epoxy resin having a bicyclic epoxy group, the epoxy is attached to a benzene ring, and the epoxy has the general structure ， X is sulfur and R is methyl, ethyl, phenyl or fluorine-containing C1-C6 alkyl.

2. The high refractive index epoxy useful for rapid encapsulation according to claim 1, wherein, The epoxy is a bicyclic epoxy group diphenyl sulfide, X is sulfur, and R is selected from the group consisting of methyl, phenyl and trifluoromethyl.

3. Process for the preparation of the bis-epoxy diphenyl sulfide as claimed in claim 2, characterized in that, The method comprises the following steps: a. adding methyl mercaptobenzoate, methyl fluorobenzoate and a base into a solvent, monitoring the end of the reaction, adding the reaction liquid into water, and performing suction filtration to obtain methyl diformate diphenyl sulfide; b. performing reaction on the methyl diformate diphenyl sulfide to obtain ; c. adding Corey-Chaykovsky epoxidation reagent and NaH into a solvent, stirring, adding , and monitoring the end of the reaction to obtain a product, bis-epoxy diphenyl sulfide, and the reaction formula is as follows: wherein, for step b, when R is selected from methyl, phenyl, the step b comprises reacting the methyl diformate diphenyl sulfide with N, O-dimethylhydroxylamine hydrochloride, tert-butyl magnesium chloride, and the resulting product is further subjected to Grignard reaction with MeMgBr or PhMgBr to obtain ; for step b, when R is selected from trifluoromethyl, the methyl diformate diphenyl sulfide is subjected to trifluoromethylation reaction to obtain .

4. The method of claim 3, wherein, The mol ratio of the step a methyl mercaptobenzoate, methyl fluorobenzoate and base is 1:1-1.5:1-3, the base is potassium carbonate, cesium carbonate, DBU, sodium hydroxide, potassium hydroxide, the solvent is DMSO or DMF, the solvent volume ml is 10-15 times of the mass g of methyl mercaptobenzoate; the Corey-Chaykovsky epoxidation reagent, NaH, The mol ratio of the step a methyl mercaptobenzoate, methyl fluorobenzoate and base is 1:1-1.5:1-3, the base is potassium carbonate, cesium carbonate, DBU, sodium hydroxide, potassium hydroxide, the solvent is DMSO or DMF, the solvent volume ml is 10-15 times of the mass g of methyl mercaptobenzoate; the Corey-Chaykovsky epoxidation reagent, NaH, The mol ratio of the step a methyl mercaptobenzoate, methyl fluorobenzoate and base is 1:1-1.5:1-3, the base is potassium carbonate, cesium carbonate, DBU, sodium hydroxide, potassium hydroxide, the solvent is DMSO or DMF, the solvent volume ml is 10-15 times of the mass g of methyl mercaptobenzoate; the Corey-Chaykovsky epoxidation reagent, NaH, 5. Use of the high refractive index epoxy of claim 2 in an epoxy resin DGEBA system.

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