Low-total-chlorine epoxy resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of epoxy resin, and particularly relates to low-total-chlorine epoxy resin and a preparation method and application thereof. The invention provides a preparation method of low-total-chlorine epoxy resin, which comprises the following steps: mixing an epoxy resin organic solution and a dechlorinating agent organic solution in a microchannel reaction device, and carrying out substitution reaction to obtain the low-total-chlorine epoxy resin. The micro-channel reactor is adopted for rapid reaction and dechlorination, the phenomenon that side reactions of the product are increased due to excessive reaction of a conventional reactor is avoided, and the total chlorine content of the obtained product is low.

Description

Technical Field

[0001] This invention belongs to the field of epoxy resin technology, specifically relating to a low total chlorine epoxy resin, its preparation method, and its application. Background Technology

[0002] Epoxy resins possess excellent physical and mechanical properties, chemical stability, chemical resistance, heat resistance, and adhesiveness, making them widely used in various fields. However, chlorine residue is unavoidable during the synthesis of epoxy resins. The total chlorine in epoxy resins generally consists of three parts: ① Hydrolyzable chlorine: hydrolyzes to produce hydrochloric acid, which corrodes circuit and device substrates, leading to decreased reliability or even failure of electronic components and circuits; ② Non-hydrolyzable chlorine: has high polarity, easily generates heat under high-frequency action, increases dielectric loss, and leads to decreased heat resistance and signal attenuation; ③ Inorganic chlorine: increases the conductivity of the epoxy resin matrix, which is detrimental to its application in insulating materials. Excessive chlorine content in epoxy resins can affect product performance; therefore, it is necessary to control the total chlorine content. Low-chlorine epoxy resins are commonly used as raw materials for electronic packaging in the electronics field. With the continuous development of information technology, the requirements for chlorine content in epoxy resins in electronic components, integrated circuits, and chips are becoming increasingly stringent. Currently, the electronics industry, including copper clad laminates, photoresists, and chip adhesives, requires epoxy resins to have a total chlorine content of less than 800 ppm; high-end electronics industries and aerospace fields have even higher requirements for low total chlorine content.

[0003] Currently, the commonly used methods for dechlorination mainly involve reducing the organic chlorine produced by side reactions during epoxy resin synthesis. For example, phase transfer catalysts are used to catalytically hydrolyze organic chlorine into inorganic chlorine, and then a strong alkaline solution is used to remove the hydrogen chloride produced by the hydrolysis of inorganic chlorine, thereby reducing the chlorine content of the epoxy resin. However, epoxy resins prepared by this method still have a high chlorine content, typically 500–2000 ppm. Summary of the Invention

[0004] The purpose of this invention is to provide a low total chlorine epoxy resin, its preparation method, and its application. This invention uses a microchannel reactor for rapid dechlorination, avoiding excessive reaction and increased side reactions in conventional reactors, resulting in a product with low total chlorine content.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for preparing a low-total-chlorine epoxy resin, comprising the following steps: An epoxy resin organic solution and a dechlorinating agent organic solution are mixed in a microchannel reactor to carry out a substitution reaction, thereby obtaining the low total chlorine epoxy resin.

[0006] Preferably, the temperature of the substitution reaction is 50~100℃, and the residence time of the substitution reaction is 10~200s.

[0007] Preferably, the dechlorinating agent in the dechlorinating organic solution includes an alkali metal salt, and the organic solvent in the epoxy resin organic solution includes one or more of toluene, xylene, cyclohexane, n-hexane, tetrahydrofuran, acetone, and butanone; the organic solvent in the dechlorinating organic solution includes one or more of ethanol, toluene, n-hexane, tetrahydrofuran, and acetone.

[0008] Preferably, the mass ratio of epoxy resin to organic solvent in the epoxy resin organic solution is 1:0.5~10, and the mass concentration of the dechlorinating agent organic solution is 0.1~15%; the mass ratio of epoxy resin organic solution to dechlorinating agent organic solution is 5~15:1.

[0009] Preferably, the feed rate of the epoxy resin organic solution is 30~240mL / min, and the feed rate of the dechlorinating agent organic solution is 3~50mL / min.

[0010] Preferably, after the reaction is completed, the process further includes mixing the obtained liquid with water, allowing it to stand and separate into layers, separating and removing the aqueous phase, and sequentially subjecting the oil phase to atmospheric pressure desolvation and negative pressure desolvation to obtain a crude product; and subjecting the crude product to molecular distillation to obtain the low total chlorine epoxy resin.

[0011] Preferably, the temperature for atmospheric pressure desolvation is 100~150℃; the temperature for negative pressure desolvation is 120~170℃, and the vacuum degree is -0.1MPa; the temperature for molecular distillation is 140~150℃.

[0012] The present invention provides a low total chlorine epoxy resin prepared by the preparation method described above, wherein the total chlorine content of the low total chlorine epoxy resin is less than or equal to 300 ppm.

[0013] Preferably, the low total chlorine epoxy resin has an inorganic chlorine content of less than or equal to 1 ppm, a hydrolyzed chlorine content of less than or equal to 100 ppm, an epoxy equivalent of 170~172 g / eq, and a color of less than or equal to 5 APHA.

[0014] This invention provides the application of the low total chlorine epoxy resin described above in electronic packaging raw materials.

[0015] This invention provides a method for preparing a low-total-chlorine epoxy resin, comprising the following steps: mixing an epoxy resin organic solution with a dechlorinating agent organic solution in a microchannel reactor to carry out a substitution reaction, thereby obtaining the low-total-chlorine epoxy resin. This invention utilizes a microchannel reactor for rapid dechlorination, avoiding the excessive reaction and increased product side reactions associated with conventional reactors. The resulting product has a low total chlorine content, meeting the requirements of high-end electronics for epoxy resins with low total chlorine content. Test results show that the low-total-chlorine epoxy resin prepared using this method has a total chlorine content ≤300ppm, an inorganic chlorine content ≤1ppm, a hydrolyzed chlorine content ≤100ppm, an epoxy equivalent of 170~172g / eq, and a color ≤5APHA, indicating that the preparation method provided by this invention can significantly reduce the total chlorine content of epoxy resin.

[0016] Furthermore, the raw materials used in this invention are readily available and easy to obtain; by adjusting the reaction temperature and controlling the reaction time, a low-total-chlorine epoxy resin is obtained, which has the advantages of rapid reaction, few side reactions, high production capacity, and excellent dechlorination effect. The process has a high safety factor, is environmentally friendly throughout the reaction process, is fast and efficient, can greatly improve production and operation capabilities, and achieve controllable adjustment of epoxy resin indicators, stable quality, and continuous production.

[0017] This invention provides a method for preparing low total chlorine epoxy resin. The low total chlorine liquid epoxy resin has a total chlorine content ≤300ppm, an inorganic chlorine content ≤1ppm, a hydrolyzed chlorine content ≤100ppm, an epoxy equivalent of 170~172g / eq, and a color ≤5APHA, indicating that the preparation method provided by this invention can significantly reduce the total chlorine content of epoxy resin. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the preparation method of the low total chlorine epoxy resin of the present invention. Detailed Implementation

[0019] This invention provides a method for preparing a low-total-chlorine epoxy resin, comprising the following steps: An epoxy resin organic solution and a dechlorinating agent organic solution are mixed in a microchannel reactor to carry out a substitution reaction, thereby obtaining the low total chlorine epoxy resin.

[0020] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0021] In one embodiment of the present invention, the epoxy resin organic solution has an epoxy equivalent (EEW) of 186.5 g / eq; a total chlorine content of 1634 ppm, a hydrolyzed chlorine content of 238 ppm, an inorganic chlorine content of 4.6 ppm, and a color of 14 APHA; the organic solvent in the epoxy resin organic solution includes one or more of toluene, xylene, cyclohexane, n-hexane, tetrahydrofuran, acetone, and butanone, specifically toluene; the mass ratio of epoxy resin to organic solvent in the epoxy resin organic solution can be 1:0.5~10, more preferably 1:1.2~3, specifically 1:1.25 or 1:2; preferably, the epoxy resin organic solution is preheated to a temperature of 35~70℃, more preferably 45~55℃, specifically 50℃.

[0022] In one embodiment of the present invention, the dechlorinating agent in the organic solution includes an alkali metal salt, and more preferably a tert-butoxide salt, specifically potassium tert-butoxide in this embodiment; the organic solvent in the organic solution includes one or more of ethanol, toluene, n-hexane, tetrahydrofuran, and acetone, specifically ethanol; the mass concentration of the organic solution is 0.1-15%, specifically 10-15%; preferably, the organic solution is preheated to a temperature of 35-70°C, more preferably 45-55°C, specifically 50°C.

[0023] In one embodiment of the present invention, the microchannel reaction device includes a heat exchange device, a feed channel, a mixing device, and a microchannel reactor. The heat exchange device is located outside the microchannel reaction device and is used to heat the microchannel reactor. The feed channel, the mixing device, and the microchannel reactor are connected sequentially. The epoxy resin organic solution and the dechlorinating agent organic solution are respectively fed into the mixing device through the feed channel for mixing. The mixed material flows into the microchannel reactor for reaction. The present invention uses the heat exchange device to raise the temperature to the reaction temperature. During the heating process, a protective gas is used to purge the microchannel reaction device. The protective gas includes nitrogen. When the temperature reaches the reaction temperature, the present invention feeds the epoxy resin organic solution and the dechlorinating agent organic solution into the mixing device through the feed channel for mixing. The feed rate of the epoxy resin organic solution is 30~240 mL / min, further 50~120 mL / min, specifically 53.4 mL / min, 53.9 mL / min, or 107.8 mL / min. The feed rate of the dechlorinating agent organic solution is 3... The flow rate is ~50 mL / min, further preferably 5~15 mL / min, specifically 6.1 mL / min, 6.6 mL / min, or 12.2 mL / min; the mass ratio of the epoxy resin organic solution to the dechlorinating agent organic solution is 5~15:1, further preferably 8~12:1, specifically 9.7:1 or 10.9:1; after uniform mixing, the mixture is subjected to a substitution reaction in the microchannel reactor, the temperature of the substitution reaction is 50~100℃, specifically 70~80℃; the residence time of the substitution reaction is 10~200s, specifically 30~60s.

[0024] In one embodiment of the present invention, after the substitution reaction is completed, the process further includes: post-treatment of the solution obtained from the substitution reaction, the post-treatment including: mixing the obtained solution with water, allowing it to stand and separate into layers, separating and removing the aqueous phase, and sequentially performing atmospheric pressure desolvation and negative pressure desolvation on the oil phase to obtain a crude product; and performing molecular distillation on the crude product to obtain the low total chlorine epoxy resin. The mass ratio of the solution obtained from the substitution reaction to water is 6~10:1, the mixing is carried out under stirring conditions, the stirring time is 20~180 min, further can be 20~40 min, specifically 30 min; the atmospheric pressure desolvation temperature is 100~150℃, specifically 100~110℃; the negative pressure desolvation temperature is 120~170℃, specifically 140~150℃, the vacuum degree of the negative pressure desolvation is -0.1MPa; and the molecular distillation temperature is 140~150℃.

[0025] The present invention provides a low total chlorine epoxy resin prepared by the preparation method described above, wherein the total chlorine content of the low total chlorine epoxy resin is less than or equal to 300 ppm, the inorganic chlorine content is less than or equal to 1 ppm, the hydrolyzed chlorine content is less than or equal to 100 ppm, the epoxy equivalent is 170~172 g / eq, and the color is less than or equal to 5 APHA.

[0026] This invention provides the application of the low total chlorine epoxy resin described above in electronic packaging raw materials.

[0027] Figure 1 This is a schematic flowchart illustrating the preparation method of low-total-chlorine epoxy resin according to Example 1 of the present invention. The present invention employs a microchannel reactor. Epoxy resin and dechlorinating agent raw materials are fed into a mixing device through a mixing channel at a certain feed rate for mixing. The reaction takes place in the microchannel reactor. By adjusting the reaction temperature and controlling the reaction residence time, the total chlorine content in the epoxy resin is controlled, resulting in a low-total-chlorine epoxy resin. To further illustrate the present invention, the technical solutions provided by the present invention are described in detail below with reference to embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0028] Example 1 (1) Take 800g of epoxy resin and put it into a 3000mL four-necked bottle. Add 1000g of toluene to prepare a toluene solution of epoxy resin. Preheat to 50℃ and set aside for use. (2) Prepare a 15% potassium tert-butoxide ethanol solution by mixing 24.78g of potassium tert-butoxide with anhydrous ethanol solution, and preheat it to 50°C for later use. (3) The microchannel reactor is heated to the reaction temperature of 80°C using an externally installed heat exchanger. During the heating process, the microchannel reactor is purged with nitrogen. When the temperature reaches the preset reaction temperature, the toluene solution of the epoxy resin is pumped into the mixing device through the feed channel at a flow rate of 53.9 mL / min using a horizontal flow pump. At the same time, the ethanol solution of potassium tert-butoxide is pumped into the mixing device through the feed channel at a flow rate of 6.1 mL / min using a horizontal flow pump. After being mixed evenly by collision, the mixture is introduced into the microchannel reactor and reacted for 60 seconds. The mass ratio of the toluene solution of the epoxy resin to the ethanol solution of potassium tert-butoxide is 10.9:1. (4) After the reaction is completed, the material is discharged and collected into a four-necked flask with 300g of water added beforehand. The mixture is stirred for 30min and poured into a separatory funnel to stand and separate into layers. After separating the aqueous phase, the oil phase is heated at room temperature and atmospheric pressure to desolvate. When the desolvation temperature reaches 105℃, the temperature is lowered to 80℃. The system is slowly evacuated to -0.1MPa and the desolvation is continued under negative pressure until the temperature reaches 150℃. At this point, there is basically no material feeding. The product is kept at this temperature and evacuated for 20min. The temperature is then lowered, and the obtained product is separated by molecular distillation at 145℃ to separate the macromolecular impurities and residual trace amounts of inorganic chlorine to obtain the low total chlorine epoxy resin.

[0029] Example 2 It is basically the same as Example 1, except that the reaction temperature in step (3) is 70°C.

[0030] Example 3 The process is basically the same as in Example 1, except that in step (3), the toluene solution of the epoxy resin is pumped into the raw material mixing device through the mixing channel at a flow rate of 107.8 mL / min using a horizontal flow pump, and the ethanol solution of potassium tert-butoxide is pumped into the raw material mixing device through the mixing channel at a flow rate of 12.2 mL / min using a horizontal flow pump. After being mixed evenly by collision, the mixture enters the microchannel reactor and reacts for 30 seconds.

[0031] Example 4 (1) Take 800g of epoxy resin and put it into a 3000mL four-necked bottle. Add 1600g of toluene to prepare a toluene solution of epoxy resin. Preheat to 50℃ and wait for use. (2) Prepare a 10% potassium tert-butoxide ethanol solution by mixing 24.78g of potassium tert-butoxide with anhydrous ethanol solution, and preheat it to 50°C for later use. (3) The microchannel reactor is heated to the reaction temperature of 80°C using an externally installed heat exchanger. During the heating process, the microchannel reactor is purged with nitrogen. When the temperature reaches the preset reaction temperature, the toluene solution of the epoxy resin is pumped into the mixing device through the feed channel at a flow rate of 53.4 mL / min using a horizontal flow pump. At the same time, the ethanol solution of potassium tert-butoxide with a mass concentration of 10% is pumped into the mixing device through the feed channel at a flow rate of 6.6 mL / min using a horizontal flow pump. After being mixed evenly by collision, the mixture is introduced into the microchannel reactor and reacted for 60 seconds. The mass ratio of the toluene solution of the epoxy resin to the ethanol solution of potassium tert-butoxide with a mass concentration of 10% is 9.7:1. (4) After the reaction is discharged, the liquid is collected into a four-necked flask with 300g of water added beforehand, stirred for 30min, poured into a separatory funnel and allowed to stand for separation; after the aqueous phase is separated, the oil phase is heated at room temperature and atmospheric pressure to desolvate, and when the desolvation temperature reaches 105℃, the temperature is lowered to 80℃, the system is slowly evacuated to -0.1MPa, and the desolvation is continued under negative pressure until the temperature of the vessel reaches 150℃. At this time, there is basically no material feeding. The temperature is kept at this temperature and evacuated for 20min, then cooled, and the obtained product is separated by molecular distillation at 145℃ to separate the macromolecular impurities and residual trace amounts of inorganic chlorine, thus obtaining the low total chlorine epoxy resin.

[0032] Comparative Example 1 Steps (1) and (2) are the same as in Example 1; The reaction process in step (3) is carried out in a conventional four-necked flask. The toluene solution of epoxy resin is added to the four-necked flask and the temperature is raised to 80°C. The ethanol solution of potassium tert-butoxide is added dropwise to the four-necked flask for 0.5 hours. After the addition is completed, the reaction is kept at the temperature for 3 hours. Step (4) is the same as in Example 1.

[0033] Comparative Example 2 It is basically the same as Comparative Example 1, except that the reaction is kept at a constant temperature for 5 hours.

[0034] Test case The epoxy equivalent, chlorine content and color of the low total chlorine epoxy resin products obtained in Examples 1-4 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0035] Table 1. Detection data of low total chlorine epoxy resins obtained in Examples 1-4 and Comparative Examples 1-2

[0036] As shown in Table 1, the low total chlorine liquid epoxy resins obtained in Examples 1-4 have an epoxy equivalent of 170-172 g / eq, an inorganic chlorine content of ≤1 ppm, a hydrolyzed chlorine content of ≤100 ppm, a total chlorine content of ≤300 ppm, and a color of ≤5 APHA; the chlorine content is lower than that of the epoxy resins in Comparative Examples 1-2.

[0037] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a low-total-chlorine epoxy resin, comprising the following steps: An epoxy resin organic solution and a dechlorinating agent organic solution are mixed in a microchannel reactor to carry out a substitution reaction, thereby obtaining the low total chlorine epoxy resin.

2. The preparation method according to claim 1, characterized in that, The temperature of the substitution reaction is 50~100℃, and the residence time of the substitution reaction is 10~200s.

3. The preparation method according to claim 1, characterized in that, The dechlorinating agent in the dechlorinating organic solution includes an alkali metal salt; the organic solvent in the epoxy resin organic solution includes one or more of toluene, xylene, cyclohexane, n-hexane, tetrahydrofuran, acetone, and butanone; the organic solvent in the dechlorinating agent organic solution includes one or more of ethanol, toluene, n-hexane, tetrahydrofuran, and acetone.

4. The preparation method according to claim 1 or 3, characterized in that, The epoxy resin organic solution has a mass ratio of epoxy resin to organic solvent of 1:0.5~10, and the dechlorinating agent organic solution has a mass concentration of 0.1~15%; the epoxy resin organic solution to dechlorinating agent organic solution has a mass ratio of 5~15:

1.

5. The preparation method according to claim 4, characterized in that, The feed rate of the epoxy resin organic solution is 30~240mL / min, and the feed rate of the dechlorinating agent organic solution is 3~50mL / min.

6. The preparation method according to claim 1, characterized in that, After the reaction is completed, the process further includes mixing the obtained liquid with water, allowing it to stand and separate into layers, separating and removing the aqueous phase, and sequentially subjecting the oil phase to atmospheric pressure desolvation and negative pressure desolvation to obtain a crude product; the crude product is then subjected to molecular distillation to obtain the low total chlorine epoxy resin.

7. The preparation method according to claim 6, characterized in that, The atmospheric pressure desolvation temperature is 100~150℃; the negative pressure desolvation temperature is 120~170℃, and the vacuum degree is -0.1MPa; the molecular distillation temperature is 140~150℃.

8. The low total chlorine epoxy resin prepared by the preparation method according to any one of claims 1 to 7, wherein the total chlorine content of the low total chlorine epoxy resin is less than or equal to 300 ppm.

9. The low total chlorine epoxy resin according to claim 8, characterized in that, The low total chlorine epoxy resin has an inorganic chlorine content of less than or equal to 1 ppm, a hydrolyzed chlorine content of less than or equal to 100 ppm, an epoxy equivalent of 170~172 g / eq, and a color of less than or equal to 5 APHA.

10. The use of the low total chlorine epoxy resin of claim 8 or 9 in electronic packaging raw materials.

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