Synthetic method and application of flexible double-bond hybrid epoxy resin

Abstract

The invention provides a synthesis method and application of flexible double-bond hybrid epoxy resin, and relates to the technical field of epoxy resin materials. The synthesis method of the flexible double-bond hybrid epoxy resin comprises the step of carrying out nucleophilic substitution reaction on 2, 2-tetradecenylheptyl bisphenol A and epoxy chloropropane to obtain the flexible double-bond hybrid epoxy resin simultaneously containing a flexible long carbon chain structure and a double-bond structure. By adopting the technical scheme, a long carbon chain and a double-bond structure are introduced into the epoxy resin to obtain the flexible double-bond hybrid epoxy resin, and due to the existence of the flexible carbon chain, the defect that the toughness of the cured epoxy resin is insufficient can be effectively improved; moreover, the flexible double-bond hybrid epoxy resin also contains a double-bond structure, so that when the flexible double-bond hybrid epoxy resin is subjected to toughening modification and is preferentially reacted with double bonds in nitrile rubber, the compatibility between the epoxy resin and a toughening agent is improved, carbon-carbon double bonds in nitrile rubber can be eliminated, and the heat-resistant stability and cohesive strength of an epoxy resin adhesive film are improved.

Description

Technical Field

[0001] The invention relates to the technical field of high molecular polymer materials, and in particular to a synthesis method and application of a flexible double-bond hybrid epoxy resin. Background Art

[0002] Epoxy resin (EP) is a thermosetting resin with an organic compound as the skeleton. It forms a three-dimensional network structure polymer through cross-linking reaction between thermosetting polymer and curing agent. Epoxy resin has excellent physical and mechanical properties, electrical insulation properties, heat resistance and bonding properties, making it widely used in the semiconductor industry. With the development of high integration and thinness of semiconductor technology, the requirements for epoxy resin adhesives as semiconductor packaging materials are getting higher and higher. Semiconductor packaging materials are composed of epoxy resin, curing agent and other additives, and epoxy resin is one of the important raw materials that determine packaging materials. However, as a general epoxy resin material, due to the high cross-linking density and internal stress of the resin, there are a large number of hydroxyl groups in the cross-linked network structure, which makes its stability poor and can no longer meet the special use requirements of epoxy resin cross-linking agents in the development of semiconductors in recent years; in addition, due to the high cross-linking density of pure epoxy resin cured products, the cross-linking network skeleton is rigid, which makes it difficult for molecular chains to slide relative to each other, so there are shortcomings such as brittleness, poor fatigue resistance, heat resistance, and impact toughness, which limits its application to a certain extent.

[0003] At present, the existing technology usually improves the toughness of epoxy resin by adding toughening agents, but the compatibility of toughening agents with epoxy resins is generally poor. For example, nitrile rubber is a commonly used epoxy resin toughening agent. In particular, the double bonds contained in nitrile rubber cause the epoxy resin to have higher activity, resulting in thermal stability of the film.

[0004] In order to solve the above technical problems, the present invention provides a hybrid epoxy resin with a flexible long carbon chain and a double bond structure, which has both flexibility and activity. When cross-linking with nitrile rubber, the double bond structure of the hybrid epoxy resin and the double bond structure of the nitrile rubber are preferentially cross-linked, thereby eliminating the double bond structure of the nitrile rubber, so that the obtained modified epoxy resin has a more stable structure, and at the same time has stronger toughness after being modified with nitrile rubber. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a synthesis method and application of a flexible double-bond hybrid epoxy resin, by introducing double bonds and flexible long-chain structures into the epoxy resin structure, and cross-linking with nitrile rubber to obtain a modified epoxy resin with both thermal stability and toughness.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for synthesizing a flexible double-bond hybrid epoxy resin comprises the steps of subjecting 2,2-tetradecylheptylbisphenol A and epichlorohydrin to a nucleophilic substitution reaction to obtain a flexible double-bond hybrid epoxy resin having both a flexible long carbon chain structure and a double bond structure.

[0008] As a preferred embodiment, the synthesis method of the flexible double-bond hybrid epoxy resin comprises the following specific steps: after uniformly mixing 2,2-tetradecylheptylbisphenol A and epichlorohydrin under normal pressure, first heating to 80-90°C, stirring and reacting for 1-2 hours; then cooling to 50-70°C and uniformly adding solid sodium hydroxide within 5-8 hours, reacting at 50-60°C for 7-10 hours, thereby obtaining the double-bond hybrid flexible epoxy resin.

[0009] Preferably, the mass ratio of 2,2-tetradecylheptylbisphenol A to epichlorohydrin is 1:(3-4).

[0010] Preferably, the mass ratio of solid sodium hydroxide to 2,2-tetradecylheptylbisphenol A is 0.5:(1-1.5).

[0011] As a preferred embodiment, the preparation method of 2,2-tetradecylheptylbisphenol A includes: under N2 protection, bisphenol A and tetradecylheptyl ether are reacted under acidic conditions to prepare 2,2-tetradecylheptylbisphenol A.

[0012] As a preferred embodiment, the preparation method of 2,2-tetradecylheptylbisphenol A includes: stirring and uniformly mixing tetradecylheptyl ether, bisphenol A and water at normal temperature and pressure, then adding hydrochloric acid solution within 20 minutes to react, and finally distilling at normal pressure to obtain 2,2-tetradecylheptylbisphenol A.

[0013] Preferably, the molar ratio of tetradecyl heptyl ether to bisphenol A is 1:1.

[0014] Preferably, the reaction is carried out at 40-60° C. for 1-3 h.

[0015] Preferably, the mass fraction of the hydrochloric acid solution is 20%.

[0016] As one of the purposes of the invention, the present invention also provides a flexible double-bond hybrid epoxy resin, which is prepared by the above-mentioned method for synthesizing the flexible double-bond hybrid epoxy resin.

[0017] As one of the purposes of the invention, the present invention also provides a modified epoxy resin prepared by cross-linking the above-mentioned flexible double-bond hybrid epoxy resin with nitrile rubber.

[0018] As one of the purposes of the invention, the present invention also provides a method for preparing a modified epoxy resin, comprising the following steps:

[0019] Dissolving the flexible double-bond hybrid epoxy resin in ethyl acetate to form a flexible double-bond hybrid epoxy resin solution;

[0020] dissolving the nitrile rubber in butanone to form a nitrile rubber solution;

[0021] After the flexible double-bond hybrid epoxy resin solution and the nitrile rubber solution are uniformly mixed, an initiator is added, and the mixture is heated to carry out a cross-linking reaction to obtain the modified epoxy resin.

[0022] Preferably, the cross-linking reaction is carried out at 60-80° C. for 3-8 hours.

[0023] Preferably, the initiator is a peroxide initiator; preferably, the initiator is any one of BPO, DTBP, MEKP and CHP.

[0024] As one of the purposes of the invention, the present invention also provides an epoxy adhesive film, wherein the base material is the aforementioned modified epoxy resin.

[0025] The beneficial technical effect obtained by the present invention is as follows: by adopting the technical scheme of the present invention, a long carbon chain and a double bond structure are introduced into the epoxy resin to obtain a flexible double-bond hybrid epoxy resin. On the one hand, due to the presence of the flexible carbon chain in the epoxy resin, the disadvantage of insufficient toughness of the epoxy resin after curing can be effectively improved; on the other hand, the flexible double-bond hybrid epoxy resin also contains a double bond structure. When it is toughened and modified, it preferentially reacts with the double bonds in the nitrile rubber, thereby improving the compatibility between the epoxy resin and the toughening agent. Moreover, it can also eliminate the carbon-carbon double bonds in the nitrile rubber, thereby improving the heat resistance stability and cohesive strength of the epoxy resin film. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments.

[0027] The present invention provides a flexible double-bond hybrid epoxy resin, in which a long carbon chain is introduced into the epoxy resin. Due to the presence of the flexible carbon chain, the disadvantage of insufficient toughness of the epoxy resin after curing can be effectively improved. At the same time, the flexible double-bond hybrid epoxy resin also contains a double bond structure. When the flexible double-bond hybrid epoxy resin is subjected to toughening modification, it reacts preferentially with the double bonds in the nitrile rubber, thereby improving the compatibility between the epoxy resin and the toughening agent, and can also eliminate the carbon-carbon double bonds in the nitrile rubber, thereby improving the heat resistance stability and cohesive strength of the epoxy resin film.

[0028] Specifically, the preparation method of the flexible double bond hybrid epoxy resin provided by the present invention comprises: synthesizing 2,2-tetradecylheptylbisphenol A from bisphenol A and tetradecylheptyl ether, and then synthesizing the flexible double bond hybrid epoxy resin from 2,2-tetradecylheptylbisphenol A and epichlorohydrin. The principle of the synthesis technology is as follows:

[0029] 1) Synthesis of 2,2-tetradecylheptylbisphenol A:

[0030]

[0031] The ether bond dissociates under acid catalysis to produce a tert-butyl cation which is more stable than the methyl cation. The tert-butyl cation attacks the ortho position of the phenolic hydroxyl group and undergoes a nucleophilic substitution reaction at the ortho position. However, the phenolic hydroxyl group does not participate in the reaction due to its poor nucleophilicity. Therefore, the synthetic product obtained is 2,2-tetradecylheptylbisphenol A.

[0032] 2) Synthesis of double bond hybrid flexible epoxy resin:

[0033]

[0034] 3) Cross-linking of epoxy / nitrile rubber:

[0035]

[0036] The obtained double-bond hybridized flexible epoxy resin has a long carbon chain, which can improve the shortcoming of insufficient toughness of epoxy resin after curing. Further, the above-mentioned flexible double-bond hybridized epoxy resin is reacted with nitrile rubber to generate a flexible epoxy / nitrile rubber crosslinked product (modified epoxy resin), and the double bonds in the epoxy resin and the double bonds in the nitrile rubber are preferentially cross-linked, which greatly improves the compatibility between the epoxy resin and the nitrile rubber, improves the toughening effect of the rubber, and reacts the double bonds in the rubber, and greatly improves the heat resistance stability and cohesive strength.

[0037] The technical solution of the present invention is described in detail below through specific embodiments.

[0038] Example 1

[0039] This embodiment provides a modified epoxy resin, which is prepared by cross-linking reaction between nitrile rubber as a toughening agent and a flexible double-bond hybrid epoxy resin. Specifically, the specific steps of preparation include:

[0040] (1) Synthesis of tetradecyl heptyl ether

[0041] The preparation method of tetradecyl heptyl ether comprises:

[0042] Under N2 protection, 880g of n-heptanol, 1050g of tetradecenol and 10g of cuprous chloride were added into a three-necked flask respectively, stirred at room temperature at 300R / min for 20min, then 15mL of concentrated sulfuric acid was added dropwise at a rate of 1mL / min, the temperature was slowly raised to 90°C, refluxed and separated during stirring, stirred for 8h, cooled to room temperature, neutralized to neutrality by adding 10% aqueous sodium hydroxide solution, then washed with water, dried and fractionated to obtain tetradecyl heptyl ether.

[0043] The infrared spectrum data of the reaction product are as follows: IR (KBr, cm -1 ):~3400cm -1 The characteristic peaks of -OH around 950cm -1 and 890cm -1 Two -COC- bending vibration absorption peaks appeared on the left and right, confirming that the prepared substance was tetradecylheptyl ether.

[0044] (2) Synthesis of 2,2-Tetradecylheptylbisphenol A

[0045] Under N2 protection, 71.5 g of tetradecyl heptyl ether, 57 g of bisphenol A and 100 g of water were added into a three-necked flask in sequence, stirred at 300 R / min for 30 min at room temperature, and after stirring evenly, a 20% aqueous hydrochloric acid solution was added within 20 min, and reacted at 50 °C for 2 h, and then distilled at atmospheric pressure to obtain 2,2-tetradecyl heptyl bisphenol A.

[0046] (3) Synthesis of double bond hybrid flexible epoxy resin:

[0047] 200g of 2,2-tetradecylheptylbisphenol A and 600g of epichlorohydrin were placed in a three-necked flask, heated to 80°C at 300R / min under normal pressure, stirred for reaction for 1h, cooled to 50°C, and then 100g of solid NaOH was uniformly added within 6h. After reacting at 50°C for 9h, the excess epichlorohydrin was recovered under reduced pressure to obtain a double-bond hybrid flexible epoxy resin.

[0048] (4) Crosslinking of epoxy / nitrile rubber:

[0049] 50g of flexible double-bond hybrid epoxy resin and 50g of ethyl acetate solution are added to a three-necked flask, and then 20g of 20% nitrile rubber solution pre-dissolved in butanone is added, and the mixture is stirred at 300R / min under normal pressure and heated to 70°C, and 40g of 50% BPO solution pre-dissolved in ethyl acetate is quickly and slowly added dropwise within 3h, and then stirred and reacted at 70°C for 5h, and the flexible epoxy / nitrile rubber cross-linked product obtained by ethanol filtration is the modified epoxy resin.

[0050] The modified epoxy resin prepared by the above reaction was dissolved in ethyl ester to obtain 200 parts of a solution with a solid content of 40 wt%, and 10 parts of dicyandiamide as a curing agent, 20 parts of gas silica (QS-102) as a filler, 2 parts of a coupling agent KH-550, and 1 part of a leveling agent BYK-333 were added. After stirring evenly, it was coated on a release film and baked in an oven at 100°C for 2 minutes to obtain a 50 μm special flexible double-bond hybrid epoxy resin film.

[0051] Example 2

[0052] The difference between this embodiment and embodiment 1 is that, during the cross-linking process of epoxy / nitrile rubber, 10 g of a 20% nitrile rubber solution pre-dissolved in butanone is added, and the other steps are the same as those in embodiment 1.

[0053] Example 3

[0054] The difference between this embodiment and embodiment 1 is that, during the cross-linking process of epoxy / nitrile rubber, 30 g of a 20% nitrile rubber solution pre-dissolved in butanone is added, and the other steps are the same as those in embodiment 1.

[0055] Comparative Example 1

[0056] The only difference between this comparative example and Example 1 is that nitrile rubber is directly added to ordinary bisphenol A epoxy resin (E-44), and the other steps are the same as those of Example 1.

[0057] The performance of the films prepared in the examples and comparative examples of the present invention was tested.

[0058] The test method includes: attaching the film side of the film to the surface of the SUS test plate and pre-pressing it for 10 seconds at 60°C and 0.1MPa pressure, then tearing off the release film, attaching the SUS test plate to the other side, and then pressing it at 160°C for 60 seconds at a pressure of 0.3MPa, putting it in a 140-degree oven for 30 minutes, taking it out, and standing it at room temperature for 24 hours, using a high and low temperature electronic tensile machine (Instron 3400) to test the initial and double 85 test 1000 hours later at room temperature and 100°C shear force. The test results are shown in Table 1.

[0059] Table 1 Properties of the films prepared in the examples and comparative examples of the present invention

[0060]

[0061] From the results in Table 1, it can be seen that the flexible double-bond hybrid epoxy resin provided by the present invention has no significant change in dynamic shear force for 1000 h at room temperature and 100°C compared with ordinary bisphenol A epoxy resin, indicating that the epoxy resin film has excellent toughness, heat stability and cohesive strength.

[0062] Obviously, by adopting the technical scheme of the present invention, on the one hand, introducing a flexible carbon chain into the epoxy resin can effectively improve the disadvantage of insufficient toughness of the epoxy resin after curing; on the other hand, the flexible double-bond hybrid epoxy resin also contains a double bond structure. When it is toughened and modified, it preferentially reacts with the double bonds in the nitrile rubber, thereby improving the compatibility between the epoxy resin and the toughening agent, and can also eliminate the carbon-carbon double bonds in the nitrile rubber, thereby improving the heat resistance stability and cohesive strength of the epoxy resin film.

[0063] The above are only preferred embodiments of the present invention, which do not limit the protection scope of the present invention. For those skilled in the art, the present invention may have various modifications and changes. Within the spirit and principle of the present invention, changes, modifications, replacements, integrations and parameter changes to these embodiments by conventional substitutions or by being able to achieve the same functions without departing from the principles and spirit of the present invention all fall within the protection scope of the present invention.

Claims

1. A method for synthesizing a flexible double-bond hybrid epoxy resin, characterized in that: The invention relates to a flexible double bond hybrid epoxy resin containing both a flexible long carbon chain structure and a double bond structure, wherein 2,2-tetradecylheptylbisphenol A and epichlorohydrin are subjected to a nucleophilic substitution reaction.

2. The method for synthesizing the flexible double-bond hybrid epoxy resin according to claim 1, characterized in that: The specific steps include: after uniformly mixing 2,2-tetradecylheptylbisphenol A and epichlorohydrin under normal pressure, first heating to 80-90° C., stirring and reacting for 1-2 hours; then cooling to 50-70° C. and uniformly adding solid sodium hydroxide within 5-8 hours, reacting at 50-60° C. for 7-10 hours, so as to obtain the double-bond hybrid flexible epoxy resin.

3. The method for synthesizing the flexible double-bond hybrid epoxy resin according to claim 1, characterized in that: The mass ratio of 2,2-tetradecylheptylbisphenol A to epichlorohydrin is 1:(3-4); The mass ratio of solid sodium hydroxide to 2,2-tetradecylheptylbisphenol A is 0.5:(1-1.5).

4. The method for synthesizing the flexible double-bond hybrid epoxy resin according to claim 1, characterized in that: The preparation method of 2,2-entetradecylheptyl bisphenol A comprises: under the protection of N2, bisphenol A and entetradecylheptyl ether are reacted under acidic conditions to prepare 2,2-entetradecylheptyl bisphenol A.

5. The method for synthesizing the flexible double-bond hybrid epoxy resin according to claim 4, characterized in that: The preparation method of 2,2-tetradecylheptylbisphenol A specifically comprises: stirring and mixing tetradecylheptyl ether, bisphenol A and water at normal temperature and pressure, then adding hydrochloric acid solution within 20 minutes to react, and finally distilling at normal pressure to obtain 2,2-tetradecylheptylbisphenol A; Preferably, the molar ratio of tetradecyl heptyl ether to bisphenol A is 1:1; Preferably, the reaction is carried out at 40 to 60° C. for 1 to 3 hours; Preferably, the mass fraction of the hydrochloric acid solution is 20%.

6. A flexible double-bond hybrid epoxy resin prepared by the synthesis method according to any one of claims 1 to 5.

7. A modified epoxy resin, prepared by the flexible double-bond hybrid epoxy resin prepared by the synthesis method according to any one of claims 1 to 5, or prepared by cross-linking the flexible double-bond hybrid epoxy resin according to claim 6 with nitrile rubber.

8. A method for preparing a modified epoxy resin as claimed in claim 7, characterized in that: The following steps are involved: Dissolving the flexible double-bond hybrid epoxy resin in ethyl acetate to form a flexible double-bond hybrid epoxy resin solution; dissolving the nitrile rubber in butanone to form a nitrile rubber solution; After the flexible double-bond hybrid epoxy resin solution and the nitrile rubber solution are uniformly mixed, an initiator is added, and the mixture is heated to carry out a cross-linking reaction to obtain the modified epoxy resin.

9. The method for preparing the modified epoxy resin according to claim 8, characterized in that: The cross-linking reaction is carried out at 60 to 80° C. for 3 to 8 hours. The initiator is a peroxide initiator; preferably, the initiator is any one of BPO, DTBP, MEKP and CHP.

10. An epoxy film, wherein the matrix material is the modified epoxy resin according to claim 7.

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