A process for the preparation of a low chlorine content dicyclopentadiene-phenol epoxy resin

Abstract

The application discloses a preparation method of a low-chlorine-content dicyclopentadiene-phenol epoxy resin, which comprises the following steps: adding epichlorohydrin to dicyclopentadiene-phenol, heating and stirring, then adding lye to the mixture to perform etherification reaction, obtaining an etherification reactant; adding lye to the etherification reactant to perform ring-closing reaction, after the reaction is completed, removing salt by water washing, then performing reduced-pressure distillation treatment, obtaining a dicyclopentadiene-phenol epoxy resin crude product; dissolving the dicyclopentadiene-phenol epoxy resin crude product in a good solvent, then adding lye to perform refining reaction, after the reaction is completed, adding deionized water to perform water washing until the water washing liquid is neutral, then performing reduced-pressure distillation treatment, obtaining the dicyclopentadiene-phenol epoxy resin. The preparation method is simple, no auxiliary solvent and phase transfer catalyst are used, the product is easy to separate, and the prepared dicyclopentadiene-phenol epoxy resin has the advantages of low epoxy equivalent weight, high yield and low chlorine content.

Description

Technical Field

[0001] This invention belongs to the field of epoxy resin preparation, and more specifically, this invention relates to a method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin. Background Technology

[0002] Dicyclopentadiene-phenol epoxy resin, due to its excellent electrical properties, low viscosity, good heat resistance, and low water absorption, can be used in encapsulation materials and ink printing for electronic appliances. With the rapid development of microelectronics and semiconductors, the performance requirements for materials in electronic packaging are becoming increasingly stringent, especially regarding chlorine content. Currently, methods to improve the quality of epoxy resins generally involve two approaches: improving the synthesis process and post-processing purification. Existing methods mainly improve catalytic effects by adding phase transfer catalysts and co-solvents, but these methods suffer from numerous side reactions and difficulties in separation. For example, in patent CN102898619A, a phase transfer catalyst is added to increase the contact between the aqueous phase of the alkaline solution and the organic phase of epichlorohydrin, improving the reaction process and resulting in a product with a light color and low chlorine content. However, in this method, the phase transfer catalyst is coated into the product and difficult to separate. In patent CN102838725A, a co-solvent is added to increase the compatibility between the catalyst and the raw materials, resulting in an epoxy resin with a low epoxy value. However, the solvents used, such as toluene and xylene, are highly volatile and toxic. Patent CN103613738A discloses a method to control the water content and reduce byproducts by vacuuming, resulting in a product with an epoxy equivalent of 250 g / eq and hydrolyzed chlorine up to 44 ppm. However, the total chlorine content is high at 801 ppm, and because the boiling points of epichlorohydrin and water are not significantly different, prolonged use of vacuum can lead to the extraction of epichlorohydrin. Therefore, how to synthesize a high-purity, low-chlorine-content dicyclopentadiene-phenol epoxy resin through a simple process route is a problem that needs to be solved. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0004] To achieve these objectives and other advantages of the present invention, a method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin is provided, comprising the following steps:

[0005] Step 1: Add epichlorohydrin to dicyclopentadiene-phenol, heat and stir, then add alkaline solution to carry out etherification reaction to obtain etherified product;

[0006] Step 2: Add alkaline solution to the etherification reactants to carry out the ring-closing reaction. After the reaction is completed, wash with water to remove the upper salt, and then perform vacuum distillation to obtain crude dicyclopentadiene-phenol epoxy resin.

[0007] Step 3: Dissolve the crude dicyclopentadiene-phenol epoxy resin in a good solvent, then add alkaline solution for purification reaction. After the reaction is completed, add deionized water for washing until the pH of the washing solution is 6-8, and then perform vacuum distillation to obtain dicyclopentadiene-phenol epoxy resin.

[0008] Preferably, in step one, the hydroxyl equivalent of dicyclopentadiene-phenol is 170 g / eq, the softening point is 87 °C, the mass ratio of dicyclopentadiene-phenol to epichlorohydrin is 1:3 to 6, the stirring temperature is 40 to 60 °C, and the stirring time is 10 to 30 min.

[0009] Preferably, in steps one, two and three, the alkaline solution is a NaOH or KOH solution with a mass concentration of 30-50%.

[0010] Preferably, in step one, the mass ratio of alkali solution to dicyclopentadiene-phenol is 0.01 to 0.05:1.

[0011] Preferably, in step one, the etherification reaction temperature is 40–60°C and the reaction time is 1–2 hours.

[0012] Preferably, in step two, the mass ratio of the alkali solution to the dicyclopentadiene-phenol in step one is 0.60 to 0.85:1.

[0013] Preferably, in step two, the closed-loop reaction temperature is 50–70°C and the reaction time is 1–4 hours.

[0014] Preferably, in step three, the good solvent is at least one of methyl isobutyl ketone and butanone; the mass ratio of the good solvent to dicyclopentadiene-phenol in step one is 3 to 5:1.

[0015] Preferably, in step three, the mass ratio of the alkali solution to the dicyclopentadiene-phenol in step one is 0.2 to 0.5:1; the purification reaction temperature is 70 to 90°C; and the reaction time is 0.5 to 3 hours.

[0016] Preferably, in steps two and three, the vacuum degree of the reduced pressure distillation is 10 to 30 mbar.

[0017] This invention offers at least the following advantages: It discloses a method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin. The process is simple, does not use co-solvents or phase transfer catalysts, and the product is easily separated. By rationally controlling the amount of alkali solution and the reaction temperature, this invention yields a dicyclopentadiene-phenol epoxy resin with low epoxy equivalent and high yield. Through purification, this invention effectively reduces the generation of aged resin, and both hydrolyzed chlorine and total chlorine are at low levels. The dicyclopentadiene-phenol epoxy resin obtained by this invention has hydrolyzed chlorine <200 ppm, total chlorine <1000 ppm, and an epoxy equivalent of 240–250 g / eq.

[0018] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0019] Figure 1 The image shows the GPC diagrams of the dicyclopentadiene-phenol epoxy resin and dicyclopentadiene-phenol prepared in Example 3. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0021] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0022] Example 1

[0023] A method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin includes the following steps:

[0024] Step 1: Add 450g of epichlorohydrin to 150g of dicyclopentadiene-phenol, heat to 40℃, stir for 10min, then add 3.5g of 35% NaOH solution and carry out etherification reaction at 40℃ for 2h to obtain the etherified product.

[0025] Step 2: Add 100g of 35% NaOH solution to the obtained etherified reactant and carry out the ring-closing reaction at 60℃ for 2h. After the reaction is completed, wash with water to remove the upper salt, and then perform vacuum distillation at 20mbar to obtain crude dicyclopentadiene-phenol epoxy resin.

[0026] Step 3: Dissolve the crude dicyclopentadiene-phenol epoxy resin in 450g of methyl isobutyl ketone, then add 30g of 35% NaOH solution and carry out a purification reaction at 80℃ for 2h. After the reaction is completed, add deionized water for washing until the pH of the washing solution is 6-8. Then, perform vacuum distillation at 20mbar to obtain dicyclopentadiene-phenol epoxy resin.

[0027] Example 2

[0028] A method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin includes the following steps:

[0029] Step 1: Add 850g of epichlorohydrin to 150g of dicyclopentadiene-phenol, heat to 50℃, stir for 15min, then add 5.1g of 45% NaOH solution and carry out etherification reaction at 50℃ for 1h to obtain the etherified product.

[0030] Step 2: Add 115g of 45% NaOH solution to the obtained etherified reactant and carry out the ring-closing reaction at 70℃ for 3h. After the reaction is completed, wash with water to remove the upper salt, and then perform vacuum distillation at 20mbar to obtain crude dicyclopentadiene-phenol epoxy resin.

[0031] Step 3: Dissolve the crude dicyclopentadiene-phenol epoxy resin in 500g of methyl isobutyl ketone, then add 37g of 45% NaOH solution and carry out a purification reaction at 80℃ for 2h. After the reaction is completed, add deionized water for washing until the pH of the washing solution is 6-8. Then, perform vacuum distillation at 20mbar to obtain dicyclopentadiene-phenol epoxy resin.

[0032] Example 3

[0033] A method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin includes the following steps:

[0034] Step 1: Add 900g of epichlorohydrin to 150g of dicyclopentadiene-phenol, heat to 50℃, stir for 30min, then add 4.7g of 50% KOH solution and carry out etherification reaction at 50℃ for 1h to obtain the etherified product.

[0035] Step 2: Add 110g of 50% KOH solution to the obtained etherified reactant and carry out the ring-closing reaction at 70℃ for 3h. After the reaction is completed, wash with water to remove the upper salt, and then carry out vacuum distillation at 20mbar to obtain crude dicyclopentadiene-phenol epoxy resin.

[0036] Step 3: Dissolve the crude dicyclopentadiene-phenol epoxy resin in 750g of methyl isobutyl ketone, then add 45g of 50% KOH solution and carry out a purification reaction at 85℃ for 2h. After the reaction is completed, add deionized water for washing until the pH of the washing solution is 6-8. Then, perform vacuum distillation at 20mbar to obtain dicyclopentadiene-phenol epoxy resin.

[0037] The epoxy equivalent, hydrolytic chlorine, total chlorine, yield, and softening point of the dicyclopentadiene-phenol epoxy resins prepared in Examples 1-3 were tested, and the results are shown in Table 1. It can be seen that the dicyclopentadiene-phenol epoxy resin of the present invention has a low epoxy equivalent, high yield, and low total chlorine and hydrolytic chlorine content. In addition, the weight ratio of dicyclopentadiene phenol to epichlorohydrin affects the epoxy equivalent of the product. Increasing the amount of epichlorohydrin is beneficial to obtaining a product with a low epoxy equivalent. The amount of refined alkali also has a certain effect on the chlorine content. Increasing the amount of refined alkali is beneficial to reducing the chlorine content of the product.

[0038] Table 1

[0039]

[0040]

[0041] Figure 1 The GPC chromatograms of the dicyclopentadiene-phenol epoxy resin and dicyclopentadiene-phenol prepared in Example 3 show that both dicyclopentadiene-phenol and dicyclopentadiene-phenol epoxy resins exhibited peaks with similar areas at the corresponding retention times, indicating that the dicyclopentadiene-phenol epoxy resin was successfully synthesized.

[0042] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin, characterized in that, Includes the following steps: Step 1: Add epichlorohydrin to dicyclopentadiene-phenol, heat and stir, then add alkali solution to carry out etherification reaction to obtain the etherified product; wherein, the hydroxyl equivalent of dicyclopentadiene-phenol is 170 g / eq, and the softening point is 87ºC; the mass ratio of dicyclopentadiene-phenol to epichlorohydrin is 1:3~6; the stirring temperature is 40~60ºC, and the stirring time is 10~30 min; the mass ratio of alkali solution to dicyclopentadiene-phenol is 0.35~0.51:15; the etherification reaction temperature is 40~50ºC, and the reaction time is 1~2 h; Step 2: Add alkali solution to the etherification reactants to carry out the ring-closing reaction. After the reaction is completed, wash with water to remove the upper salt layer, and then perform vacuum distillation to obtain crude dicyclopentadiene-phenol epoxy resin. The mass ratio of alkali solution to dicyclopentadiene-phenol in Step 1 is 0.60~0.85:

1. The ring-closing reaction temperature is 60~70ºC and the reaction time is 2~3h. Step 3: Dissolve the crude dicyclopentadiene-phenol epoxy resin in a good solvent, then add alkali solution for purification reaction. After the reaction is completed, add deionized water for washing until the pH of the washing solution is 6-8, and then perform vacuum distillation to obtain dicyclopentadiene-phenol epoxy resin. The mass ratio of alkali solution to dicyclopentadiene-phenol in Step 1 is 0.2-0.5:

1. The purification reaction temperature is 70-90℃ and the reaction time is 0.5-3h.

2. The method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin as described in claim 1, characterized in that, In steps one, two, and three, the alkaline solution is a NaOH or KOH solution with a mass concentration of 30-50%.

3. The method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin as described in claim 1, characterized in that, In step three, the good solvent is at least one of methyl isobutyl ketone and butanone; the mass ratio of the good solvent to dicyclopentadiene-phenol in step one is 3~5:

1.

4. The method for preparing a low-chlorine-content dicyclopentadiene-phenol epoxy resin as described in claim 1, characterized in that, In steps two and three, the vacuum degree of the reduced pressure distillation is 10~30 mbar.

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