Purification method of electronic-grade biphenyl novolac epoxy resin

Abstract

The invention discloses a method for purifying electronic-grade biphenyl phenolic epoxy resin, and relates to the technical field of epoxy resin preparation, and the method is characterized by comprising the following steps: adding biphenyl phenolic into epichlorohydrin, stirring and dissolving, adding alkali liquor, and carrying out etherification reaction to obtain a product; alkali liquor is continuously added for a ring-closure reaction, generated salt is removed through water washing and filtered, then distillation treatment is carried out, and a crude product is obtained; and dissolving the biphenyl novolac epoxy resin, continuously adding alkali liquor for refining reaction, pickling and filtering, and carrying out distillation treatment to obtain the final biphenyl novolac epoxy resin. In the synthesis process, a low-boiling-point nontoxic solvent is adopted, the actual yield of the biphenyl novolac epoxy resin is high, the epoxy equivalent is low, and the biphenyl novolac epoxy resin is easy to separate by controlling the alkali liquor amount and the reaction temperature in the ring opening and ring closing stages, and meanwhile through a molecular sieve, a microporous filter membrane and a further refining reaction, the yield of the biphenyl novolac epoxy resin is improved. The generation of aged resin is effectively reduced, so that the contents of hydrolyzed chlorine, inorganic chlorine and organic chlorine are all at a lower level.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy resin preparation, and more specifically, it relates to a purification method for electronic grade bisphenol A phenolic epoxy resin. Background Art

[0002] Due to its excellent electrical properties, low viscosity, good heat resistance, low water absorption and other characteristics, bisphenol A phenolic epoxy resin has broad application prospects in the fields of plastic packaging materials and ink printing for electronic appliances.

[0003] With the rapid development of the microelectronics and semiconductor industries, the performance requirements for electronic packaging materials are also constantly increasing, especially the control of chlorine content has become more stringent. In order to purify epoxy resin, currently two main methods are adopted: one is to improve the synthetic process route, and the other is to improve the purity and performance of the product through post-treatment refinement.

[0004] However, the existing methods usually include adding phase transfer catalysts or co-solvents, etc. For example, Chinese Patent CN103923301A discloses a preparation method for electronic grade brominated epoxy resin with low bromine content, and Chinese Patent CN118791934A discloses an electronic epoxy resin material and its preparation method. Although these methods can improve the catalytic effect to a certain extent, there are still the following problems: there are many side reactions, resulting in difficult separation of products, the phase transfer catalyst is difficult to completely remove, leading to excessive impurities, and the co-solvents used are volatile and toxic, such as solvents like benzene, toluene and xylene.

[0005] Therefore, the present invention aims to provide a purification method for electronic grade bisphenol A phenolic epoxy resin to improve the quality of epoxy resin without increasing side reactions. Summary of the Invention

[0006] The object of the present invention is to provide a purification method for electronic grade bisphenol A phenolic epoxy resin. In the synthesis process of the present invention, a low-boiling-point non-toxic solvent is adopted and no phase transfer catalyst is used. The obtained bisphenol A phenolic epoxy resin is easy to separate. At the same time, the amount of alkali solution and reaction temperature are reasonably controlled in the ring-opening and ring-closing stages. The obtained bisphenol A phenolic epoxy resin has a low epoxy equivalent and a high actual yield. Subsequently, through the adsorption and filtration of impurity ions by molecular sieves and microporous filtration membranes and further refining reactions, the generation of aged resin is effectively reduced, and the contents of hydrolyzed chlorine, inorganic chlorine and organic chlorine are all at a low level.

[0007] The above technical object of the present invention is achieved through the following technical solutions: A purification method for electronic grade bisphenol A phenolic epoxy resin, comprising the following steps:

[0008] S1. Add bisphenol phenol aldehyde to epichlorohydrin, then dissolve and stir under heating to obtain a mixture. Next, add an alkali solution to the mixture to promote the etherification reaction, thereby obtaining an etherification reaction product;

[0009] S2. Continue to add an alkali solution to the obtained etherification reaction product to carry out a ring-closure reaction. After the ring-closure reaction is completed, wash away the salts generated during the reaction by water washing, then filter once through a molecular sieve, and subsequently carry out vacuum distillation treatment using a rotary evaporator to obtain crude dicyclopentadiene-phenol epoxy resin;

[0010] S3. Dissolve the crude dicyclopentadiene-phenol epoxy resin in a solvent, continue to add an alkali solution to carry out a refining reaction. After the refining reaction ends, add acetic acid for pickling until the pickling solution is neutral, then filter 2 - 3 times through a microporous filter membrane, and finally carry out vacuum distillation treatment using a rotary evaporator again to obtain the final bisphenol phenol aldehyde epoxy resin.

[0011] The present invention is further configured as follows: In the step S1, the hydroxyl equivalent of the bisphenol phenol aldehyde is 190 g / eq, the softening point is 87 °C, the mass ratio of the bisphenol phenol aldehyde to epichlorohydrin is 1:5 - 7, the dissolution and stirring temperature is 50 - 70 °C, and the dissolution and stirring time is 10 - 30 min.

[0012] The present invention is further configured as follows: The alkali solution is NaOH, KOH or ammonia water, and the mass concentration of the alkali solution is 40% - 52%.

[0013] The present invention is further configured as follows: In the step S1, the mass ratio of the alkali solution to the bisphenol phenol aldehyde is 0.02 - 0.04:1, the reaction temperature of the etherification reaction is 45 - 80 °C, and the reaction time is 1 - 2.5 h.

[0014] The present invention is further configured as follows: In the step S2, the mass ratio of the alkali solution in the ring-closure reaction to the bisphenol phenol aldehyde in the step S1 is 0.7 - 0.85:1, the reaction temperature of the ring-closure reaction is 60 - 80 °C, and the reaction time is 1 - 4 h.

[0015] The present invention is further configured as follows: The molecular sieve in the step S2 is a layered molecular sieve, a zeolite molecular sieve or an ordered mesoporous molecular sieve.

[0016] The present invention is further configured as follows: The solvent in the step S3 is N,N-dimethylformamide, tetrahydrofuran, methyl isobutyl ketone, methyl tert-butyl ketone ether and / or dimethyl sulfoxide, and the mass ratio of the solvent to the bisphenol phenol aldehyde in the step S1 is 4 - 5:1.

[0017] The present invention is further configured such that: the mass ratio of the lye in step S3 to the biphenol formaldehyde in step S1 is 0.2 - 0.4:1; the reaction temperature of the refining reaction is 75 - 95°C, and the reaction time is 0.5 - 3 h.

[0018] The present invention is further configured such that: the microporous filtration membrane in step S3 is a polyethersulfone membrane, a cellulose acetate membrane, a mixed cellulose ester membrane, a nitrocellulose membrane, a polyvinylidene fluoride membrane, or a polypropylene membrane.

[0019] The present invention is further configured such that: the vacuum degree of the rotary evaporator is 0.08 - -0.01 MPa, and the temperature is 100°C.

[0020] In summary, the present invention has the following beneficial effects:

[0021] 1. During the synthesis process of the present invention, a phase transfer catalyst is not used, avoiding the impurity problem caused by the difficulty in completely removing the catalyst, simplifying the separation step, and making the product easier to separate;

[0022] 2. The present invention uses a low-boiling-point non-toxic solvent, reducing the use and emission of toxic substances, and reducing environmental pollution and harm to operators;

[0023] 3. By reasonably controlling the lye dosage and reaction temperature in the etherification and ring-closure stages, the present invention reduces the epoxy equivalent of the biphenol formaldehyde epoxy resin and improves the actual yield at the same time;

[0024] 4. Through steps such as molecular sieve adsorption, microporous filtration membrane filtration, and refining reaction, the present invention effectively reduces the generation of aged resin, keeping the contents of hydrolyzed chlorine, inorganic chlorine, and organic chlorine at relatively low levels;

[0025] 5. Through the combined application of molecular sieve and microporous filtration membrane, the present invention can deeply adsorb and filter impurity ions, further improving the purity of the product;

[0026] 6. By precisely controlling the reaction conditions and parameters of each step, the present invention ensures the stable performance of the product, meeting the requirements of high performance and consistency of materials for electronic applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a process flow diagram of a purification method for an electronic-grade biphenol formaldehyde epoxy resin in an embodiment of the present invention;

[0028] Figure 2 is a physical comparison diagram of the synthesized product and the standard product in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following combines with the attached Figure 1-2A further detailed description of the present invention is provided.

[0030] Example 1: A purification method for electronic grade biphenol novolac epoxy resin

[0031] Weigh 150 g of biphenol novolac DSF-75 and 750 g of epichlorohydrin, and place them in a three-necked flask equipped with a stirring paddle. Heat up to 70 °C and dissolve for 20 min. After complete dissolution, use a pipette to dropwise add 4.5 g of 49% sodium hydroxide solution, and react for 2 h. After completion, an etherification reaction product is obtained.

[0032] After that, heat up to 75 °C, and slowly dropwise add 117.2 g of 49% sodium hydroxide solution to the etherification product within half an hour using a dropping funnel. Start calculating the reaction time from the start of dropping (do not cool down and let it boil) for 4 h. After the reaction is completed, wash with water to remove the upper layer of salts, and further adsorb the residual impurity ions with ordered mesoporous molecular sieves. Then, perform vacuum distillation treatment using a rotary evaporator at a vacuum degree of 0.08 MPa and a temperature of 110 °C to obtain a crude biphenol novolac epoxy resin.

[0033] Dissolve the obtained crude biphenol novolac epoxy resin in 600 g of methyl tert-butyl ketone ether, and then add 45 g of 49% NaOH solution by mass concentration and carry out a refining reaction at 90 °C for 2 h. After the reaction is completed, add acetic acid for pickling multiple times until the pH value of the washing solution is 6 - 8, and filter through a polypropylene filter membrane 2 - 3 times. Then, perform vacuum distillation treatment using a rotary evaporator at a vacuum degree of 0.08 MPa and a temperature of 100 °C to obtain biphenol novolac epoxy resin.

[0034] Example 2: A purification method for electronic grade biphenol novolac epoxy resin

[0035] Weigh 150 g of biphenol novolac DSF-90 and 750 g of epichlorohydrin, and place them in a three-necked flask equipped with a stirring paddle. Heat up to 70 °C and dissolve for 20 min. After complete dissolution, use a pipette to dropwise add 4.5 g of 49% sodium hydroxide solution, and react for 2 h. After completion, an etherification reaction product is obtained.

[0036] After that, heat up to 75 °C, and slowly dropwise add 110.3 g of 49% sodium hydroxide solution to the etherification product within half an hour using a dropping funnel. Start calculating the reaction time from the start of dropping (do not cool down and let it boil) for 4 h. After the reaction is completed, wash with water to remove the upper layer of salts, and further adsorb the residual impurity ions with layered molecular sieves. Then, perform vacuum distillation treatment using a rotary evaporator at a vacuum degree of 0.08 MPa and a temperature of 110 °C to obtain a crude biphenol novolac epoxy resin.

[0037] The obtained crude biphenol phenolic epoxy resin was dissolved in 600 g of N,N-dimethylformamide, and then 45 g of a NaOH solution with a mass concentration of 49% was added for a refining reaction at 90 °C for 2 h. After the reaction was completed, acetic acid was added multiple times for pickling until the pH value of the washing solution was 6 - 8, and it was filtered through a polyvinylidene fluoride membrane 2 - 3 times, and then subjected to vacuum distillation using a rotary evaporator at a vacuum degree of 0.08 MPa and a temperature of 120 °C to obtain biphenol phenolic epoxy resin.

[0038] Experimental data:

[0039] The epoxy equivalent, hydrolyzable chlorine, total chlorine, and softening point of the biphenol phenolic epoxy resin prepared in Examples 1 and 2 were tested, and the results are shown in Table 1:

[0040] Table 1 Test table of epoxy equivalent, hydrolyzable chlorine, total chlorine, and softening point of biphenol phenolic epoxy resin

[0041]

[0042] As can be seen from Table 1, the dicyclopentadiene-phenol epoxy resin obtained by the purification method according to the present invention has a low epoxy equivalent, a high yield, and low contents of total chlorine and hydrolyzable chlorine.

[0043] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A purification method for electronic grade phenolic epoxy resin, characterized in that: It includes the following steps: S1. Add bisphenol phenol aldehyde into epichlorohydrin, then dissolve and stir under heating conditions to obtain a mixture. Then add an alkali solution to the mixture to promote the occurrence of the etherification reaction, thereby obtaining an etherification reaction product; S2. Continue to add an alkali solution to the obtained etherification reaction product to carry out a ring-closing reaction. After the ring-closing reaction is completed, wash away the salts generated during the reaction by water washing, then filter once through a molecular sieve, and then carry out vacuum distillation treatment with a rotary evaporator to obtain a crude dicyclopentadiene-phenol epoxy resin; S3. Dissolve the crude dicyclopentadiene-phenol epoxy resin in a solvent, continue to add an alkali solution to carry out a refining reaction. After the refining reaction ends, add acetic acid for pickling until the pickling solution is neutral, then filter 2-3 times through a microporous filtration membrane, and finally carry out vacuum distillation treatment with a rotary evaporator again to obtain the final bisphenol phenol aldehyde epoxy resin.

2. The purification method of an electronic grade cascade phenol aldehyde epoxy resin according to claim 1, characterized in that: In step S1, the hydroxyl equivalent of bisphenol phenol aldehyde is 190 g / eq, the softening point is 87 °C, the mass ratio of bisphenol phenol aldehyde to epichlorohydrin is 1:5-7, the dissolution and stirring temperature is 50-70 °C, and the dissolution and stirring time is 10-30 min.

3. A purification method for an electronic grade phenol-aldehyde epoxy resin according to claim 1, characterized in that: The alkali solution is NaOH, KOH or ammonia water, and the mass concentration of the alkali solution is 40%-52%.

4. A purification method for an electronic grade cascaded phenol aldehyde epoxy resin according to claim 1, characterized in that: In step S1, the mass ratio of the alkali solution to bisphenol phenol aldehyde is 0.02-0.04:1, the reaction temperature of the etherification reaction is 45-80 °C, and the reaction time is 1-2.5 h.

5. The purification method of an electronic grade cascade phenol aldehyde epoxy resin according to claim 1, characterized in that: In step S2, the mass ratio of the alkali solution in the ring-closing reaction to bisphenol phenol aldehyde in step S1 is 0.7-0.85:1, the reaction temperature of the ring-closing reaction is 60-80 °C, and the reaction time is 1-4 h.

6. A purification method for an electronic grade cascade phenolic aldehyde epoxy resin according to claim 1, characterized in that: The molecular sieve in step S2 is a layered molecular sieve, a zeolite molecular sieve or an ordered mesoporous molecular sieve.

7. The purification method of an electronic grade cascaded phenol aldehyde epoxy resin according to claim 1, characterized in that: The solvent in step S3 is N,N-dimethylformamide, tetrahydrofuran, methyl isobutyl ketone, methyl tert-butyl ketone ether and / or dimethyl sulfoxide, and the mass ratio of the solvent to bisphenol phenol aldehyde in step S1 is 4-5:

1.

8. A purification method for an electronic grade cascade phenol aldehyde epoxy resin according to claim 1, characterized in that: In step S3, the mass ratio of the alkali solution to bisphenol phenol aldehyde in step S1 is 0.2-0.4:1; the reaction temperature of the refining reaction is 75-95 °C, and the reaction time is 0.5-3 h.

9. The purification method of an electronic grade cascade phenol aldehyde epoxy resin according to claim 1, characterized in that: The microporous filtration membrane in step S3 is a polyethersulfone membrane, a cellulose acetate membrane, a mixed cellulose ester membrane, a nitrocellulose membrane, a polyvinylidene fluoride membrane or a polypropylene membrane.

10. A purification method for an electronic-grade cascade phenolic aldehyde epoxy resin according to claim 1, characterized in that: The vacuum degree of the rotary evaporator is 0.08- -0.01 MPa, and the temperature is 100 °C.

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