High-heat-resistance epoxy resin and preparation method thereof

Abstract

The invention discloses a method for preparing high-heat-resistance epoxy resin, and belongs to the field of high polymer materials. According to the technical scheme, the method for preparing the high-heat-resistance epoxy resin comprises the following steps that 1, raw materials are weighed, the raw materials of epoxy resin and a modifier are weighed according to the weight ratio of (80-120): (1-15), and the modifier is an organic matter containing quinolyl and carbonyl at the same time; 2, mixing the raw materials, heating to 90-140 DEG C, and stirring for 3-6 hours; and 3, extracting the high-heat-resistance epoxy resin from the product obtained in the step S2. The method for preparing the high-heat-resistance epoxy resin has the beneficial effects that the curing temperature is low, the curing time is short, the follow-up curing process flow is fast, and the high-heat-resistance epoxy resin with high heat resistance, excellent mechanical performance and high light response speed can be prepared through the method.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a high-heat-resistant epoxy resin and a preparation method thereof. Background Art

[0002] Epoxy resin has a wide range of applications, but in recent years, as its application environment has become increasingly harsh, epoxy resin has also exposed many problems in performance, especially the insufficient heat resistance of epoxy resin, which has seriously affected the application of epoxy resin in cutting-edge fields such as aviation and aerospace, so it needs to be heat-resistant modified.

[0003] Quinoline compounds, with their rigid ring structure, easily modifiable ring plane, and good intra-ring electron mobility, are a class of organic semiconductor materials with excellent optoelectronic properties. The unique optoelectronic properties and excellent thermal stability exhibited by the π-conjugated system of quinoline compounds hold great promise for applications in optoelectronic devices, materials chemistry, and other fields. Due to the easily modifiable planar structure of quinoline molecules, its derivatives or modified structures are often combined with other reaction products to achieve desired effects.

[0004] Introducing rigid-structured quinoline compounds into resin molecules can increase the rigidity and chain stacking of the resin molecules and improve the glass transition temperature of the resin. However, this cannot be achieved by simple physical blending, and high-temperature resistant curing agents are usually required to cure epoxy resins. However, most high-temperature resistant curing agents, such as amine curing agents, are highly toxic, while anhydride curing agents have the advantages of low toxicity, long pot life, and good heat resistance. However, due to the low activity of anhydride curing agents, they often require higher temperatures and longer times to fully cure. Therefore, accelerators are usually added during use to improve the curing progress, and the improved heat resistance is still limited.

[0005] Furthermore, domestic and international researchers have conducted research on the introduction of quinoline compounds into resin molecules, focusing on the following areas: Chinese invention patent application number CN201510205503.7, "A High-Hardness, High-Gloss, Flame-Retardant, and Heat-Resistant ABS Plastic," discloses the addition of various organic compounds, including quinoline compounds, to a compound whose main component is ABS resin. The quinoline compounds, when combined with the other organic compounds, produce a synergistic effect, enhancing the flame retardancy and heat resistance of the resin. Chinese invention patent application number CN201610906169.2, "A High-Adhesion Composite Epoxy Antirust Powder Coating for Automobile Chassis and Its Preparation Method," discloses the addition of various organic compounds, including 8-hydroxyquinoline-aluminum tripolyphosphate / polymethyl methacrylate polymer microspheres, to a compound whose main component is epoxy resin E-20, to improve the coating's rust resistance and adhesion to metal substrates. No research has been conducted on the use of quinoline compounds alone as thermal modifiers to simultaneously improve curing efficiency. Summary of the Invention

[0006] In order to solve the problems in the above-mentioned prior art, the present invention provides a method for preparing a high-heat-resistant epoxy resin, which can reduce the curing temperature, shorten the curing time, and effectively accelerate the subsequent curing process. The method can also be used to prepare a high-heat-resistant epoxy resin with high heat resistance, excellent mechanical properties, and fast light response speed.

[0007] In order to achieve the above object of the invention, the present invention provides a method for preparing a high heat-resistant epoxy resin, comprising the following steps:

[0008] Step S1: weighing raw materials, and weighing raw epoxy resin and modifier according to a weight ratio of (80-120): (1-15), wherein the modifier is an organic compound containing both quinoline and carbonyl groups;

[0009] Step S2: After mixing the raw materials, heating to 90-140° C. and stirring for 3-6 hours, preferably, heating to 100-120° C. and magnetically stirring for 4-5 hours;

[0010] Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2.

[0011] Furthermore, the steps of extracting the high heat-resistant epoxy resin are:

[0012] Step S301: adding an organic solvent and water to the solution obtained in step S2, and desalting at 60-80° C., preferably, the organic solvent is toluene;

[0013] Step S302: adding an acidic substance for neutralization and washing with water until the upper layer of the solution becomes transparent. Preferably, the acidic substance is phosphoric acid;

[0014] Step S303: heating to 140-150° C. to remove the solvent and obtain the high heat-resistant epoxy resin.

[0015] In one preferred embodiment, the step of extracting the high heat-resistant epoxy resin is:

[0016] Step S311: adding an organic reagent to the solution obtained in step S2 to dilute the solution and filtering to obtain a filtrate. Preferably, the organic solvent is methyl isobutyl ketone;

[0017] Step S312: washing the filtrate with deionized water until it becomes neutral;

[0018] Step S313: removing the organic reagent and water, preferably, using a rotary evaporator to remove the organic reagent methyl isobutyl ketone and water;

[0019] Step S314: adding ethyl acetate, shaking, and then filtering to remove white particles;

[0020] Step S315: removing the ethyl acetate and drying to a constant weight to obtain the high heat-resistant epoxy resin.

[0021] Furthermore, the general formula of the modifier is:

[0022]

[0023] In the general formula, R is a carbonyl group or a group containing a carbonyl group.

[0024] Furthermore, R in the general formula is an aldehyde group or an acetal group, or a group containing an aldehyde group or an acetal group.

[0025] Furthermore, the modifier is one or more of 4-quinolinecarboxaldehyde, 3-quinolinecarboxaldehyde, 2-quinolinecarboxaldehyde, 2-carbonylquinoline, and 2-quinolineacetal.

[0026] Furthermore, the epoxy resin is bisphenol A epoxy resin.

[0027] Furthermore, the high-heat-resistant epoxy resin obtained in step S3 becomes solid after being left at room temperature for 1 minute to 3 hours. Since aldehydes themselves can act as curing agents, the extract of the high-heat-resistant epoxy resin obtained by the above method under specific conditions can become a solid high-heat-resistant epoxy resin after being left at room temperature for 1 minute to 3 hours, which can be used in high-end electrical equipment. Room temperature generally refers to 20-25°C.

[0028] Furthermore, the high heat-resistant epoxy resin obtained in step S3 is in liquid state, and a curing process in step S4 is added after step S3 to obtain the high heat-resistant epoxy resin in solid state.

[0029] Furthermore, the curing process comprises the following steps:

[0030] Step S401: preheating the mold at 120-140° C. for 2-2.5 hours; adding the liquid high-heat-resistant epoxy resin and the curing agent in an equivalent ratio of 1:(0.3-1.5) into the reactor, stirring and degassing at 90-135° C. in a vacuum state for 20-50 minutes to obtain a to-be-cured material, preferably, stirring and degassing at 110° C. for 30 minutes to obtain a to-be-cured material;

[0031] Step S402: pouring the object to be solidified into a preheated mold and degassing in a vacuum for 3-8 minutes, preferably 5 minutes;

[0032] Step S403: Curing the mold with the object to be cured. The curing conditions are: first heating to 100-130°C and keeping warm for 3-6 hours, then heating to 130-150°C and keeping warm for 18-30 hours. Preferably, first heating to 120°C and keeping warm for 4 hours, then heating to 140°C and keeping warm for 24 hours.

[0033] Furthermore, the curing agent is an acid anhydride curing agent.

[0034] Furthermore, the curing agent is methyltetrahydrophthalic anhydride.

[0035] The beneficial effects of the present invention are as follows: the present invention provides a method for preparing a high-heat-resistant epoxy resin with high heat resistance, excellent mechanical properties, and fast light response speed, and the high-heat-resistant epoxy resin prepared by this method can also reduce the curing temperature and shorten the curing time, especially for low-toxic acid anhydride curing agents, effectively accelerating the subsequent curing process. DETAILED DESCRIPTION

[0036] In order to clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods.

[0037] Example 1

[0038] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 4-quinoline formaldehyde according to a weight ratio of 100:1;

[0039] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 110° C., and magnetically stirring at a stirring rate of 200 r / min for a reaction time of 4.5 hours;

[0040] Step S3: extracting a liquid high-heat-resistant epoxy resin from the product obtained in step S2.

[0041] Step S4: Curing the liquid high heat-resistant epoxy resin:

[0042] Step S401: After spraying the mold with a release agent, the mold is placed in a 130°C oven for preheating for 2 hours; liquid high-heat-resistant epoxy resin and curing agent methyltetrahydrophthalic anhydride are added to a reactor at an equivalent ratio of 1:0.8, and the mixture is stirred and degassed at 110°C in a vacuum state for 30 minutes to obtain a solidified product;

[0043] Step S402: pouring the material to be solidified into the preheated mold and placing it in a vacuum box for degassing for 5 minutes;

[0044] Step S403: placing the mold with the object to be cured into it into an oven for curing. The curing conditions are: first heating to 120° C. and keeping it for 4 hours, then heating to 140° C. and keeping it for 24 hours.

[0045] A solid high heat-resistant epoxy resin is obtained.

[0046] Example 2

[0047] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 4-quinoline formaldehyde according to a weight ratio of 115:14;

[0048] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 120°C, and magnetically stirring at a stirring rate of 200 r / min for 4 hours;

[0049] Step S3: extracting a liquid high-heat-resistant epoxy resin from the product obtained in step S2.

[0050] Step S4: Curing the liquid high heat-resistant epoxy resin:

[0051] Step S401: After spraying the mold with a release agent, the mold is placed in a 130°C oven for preheating for 2 hours; liquid high-heat-resistant epoxy resin and curing agent methyltetrahydrophthalic anhydride are added to a reactor at an equivalent ratio of 1:0.5, and the mixture is stirred and degassed at 120°C in a vacuum state for 20 minutes to obtain a solidified product;

[0052] Step S402: pouring the object to be solidified into the preheated mold and placing it in a vacuum box for degassing for 3 minutes;

[0053] Step S403: placing the mold with the object to be cured into it into an oven for curing. The curing conditions are: first heating to 100° C. and keeping it for 6 hours, then heating to 130° C. and keeping it for 30 hours.

[0054] A solid high heat-resistant epoxy resin is obtained.

[0055] Example 3

[0056] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 4-quinoline formaldehyde according to a weight ratio of 85:6;

[0057] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 140° C., and magnetically stirring at a stirring rate of 300 r / min for 5 hours;

[0058] Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2 and then placing it at room temperature for 1 hour to obtain a solid high heat-resistant epoxy resin.

[0059] Example 4

[0060] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 4-quinoline formaldehyde according to a weight ratio of 100:12;

[0061] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 140° C., and magnetically stirring at a stirring rate of 300 r / min for 5 hours;

[0062] Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2, and leaving it at room temperature for 15 minutes to obtain a solid high heat-resistant epoxy resin.

[0063] Example 5

[0064] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 3-quinoline formaldehyde according to a weight ratio of 80:1;

[0065] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 110° C., and magnetically stirring at a stirring rate of 200 r / min for a reaction time of 4.5 hours;

[0066] Step S3: extracting a liquid high-heat-resistant epoxy resin from the product obtained in step S2.

[0067] Step S4: Curing the liquid high heat-resistant epoxy resin:

[0068] Step S401: After spraying the mold with a release agent, the mold is placed in a 130°C oven for preheating for 2 hours; liquid high-heat-resistant epoxy resin and curing agent methyltetrahydrophthalic anhydride are added to a reactor at an equivalent ratio of 1:0.8, and the mixture is stirred and degassed at 110°C in a vacuum state for 30 minutes to obtain a solidified product;

[0069] Step S402: pouring the material to be solidified into the preheated mold and placing it in a vacuum box for degassing for 5 minutes;

[0070] Step S403: placing the mold with the object to be cured into it into an oven for curing. The curing conditions are: first heating to 120° C. and keeping it for 4 hours, then heating to 140° C. and keeping it for 24 hours.

[0071] A solid high heat-resistant epoxy resin is obtained.

[0072] Example 6

[0073] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 3-quinoline formaldehyde according to a weight ratio of 110:12;

[0074] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 120°C, and magnetically stirring at a stirring rate of 200 r / min for 4 hours;

[0075] Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2, and leaving it at room temperature for 30 minutes to obtain a solid high heat-resistant epoxy resin.

[0076] Example 7

[0077] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 3-quinoline formaldehyde according to a weight ratio of 100:9;

[0078] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 140° C., and magnetically stirring at a stirring rate of 300 r / min for 5 hours;

[0079] Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2, and leaving it at room temperature for 55 minutes to obtain a solid high heat-resistant epoxy resin.

[0080] Example 8

[0081] Step S1: weighing raw materials, and weighing raw material bisphenol A epoxy resin and modifier 2-carbonylquinoline according to a weight ratio of 100:10;

[0082] Step S2: adding the raw materials into a three-necked flask, mixing, heating to 140° C., and magnetically stirring at a stirring rate of 300 r / min for 5 hours;

[0083] Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2, and leaving it at room temperature for 1.5 hours to obtain a solid high heat-resistant epoxy resin.

[0084] Comparative Example

[0085] Test the viscosity and glass transition temperature of raw epoxy resin;

[0086] The raw material epoxy resin is cured and the tensile and bending properties after curing are tested. The specific curing process is:

[0087] After spraying the mold with the release agent, place it in a 130°C oven for preheating for 2 hours; add epoxy resin and curing agent methyltetrahydrophthalic anhydride into the reactor at an equivalent ratio of 1:0.8, and stir and degas at 110°C in a vacuum state for 30 minutes to obtain a reaction product; pour the reaction product into the preheated mold, place it in a vacuum box for degassing for 5 minutes; place the mold in an oven for curing, and the curing conditions are: first heat to 120°C and keep warm for 4 hours, then heat to 140°C and keep warm for 24 hours.

[0088] In the above embodiments and comparative examples, the viscosity was tested using a rotational viscometer; the glass transition temperature was tested using a differential scanning calorimeter (DSC) with a heating range of 50°C to 250°C and a heating rate of 10°C / min; the tensile strength and flexural strength were tested in accordance with GB / T 2567-2008.

[0089] The test performance is shown in the following table:

[0090]

[0091] The epoxy group in epoxy resin organic compound molecules is highly reactive and can react with groups such as hydroxyl (-OH), carboxyl (-COOH), and aldehyde (-CHO) under specific conditions. 4-Quinolinecarboxaldehyde, 3-Quinolinecarboxaldehyde, and 2-Quinolinecarboxaldehyde, among others, all possess both an aldehyde structure and a rigid structure, capable of forming hydrogen bonds and easily forming a resin cross-linking network, which contributes to improving the thermal stability of the material. Modifying epoxy resins with 4-Quinolinecarboxaldehyde, 3-Quinolinecarboxaldehyde, and 2-Quinolinecarboxaldehyde as modifiers can yield modified epoxy resins with high heat resistance, known as high-heat-resistant epoxy resins.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a high heat-resistant epoxy resin, characterized in that: The following steps are involved: Step S1: weighing raw materials, and weighing raw epoxy resin and modifier according to a weight ratio of (80-120): (1-15), wherein the modifier is an organic compound containing both quinoline and carbonyl groups; Step S2: Mix the raw materials, heat to 90-140°C and stir for 3-6 hours; Step S3: extracting high heat-resistant epoxy resin from the product obtained in step S2.

2. The method according to claim 1, characterized in that The general formula of the modifier is: In the general formula, R is a carbonyl group or a group containing a carbonyl group.

3. The method according to claim 2, characterized in that In the general formula, R is an aldehyde group or an acetal group, or a group containing an aldehyde group or an acetal group.

4. The method according to any one of claims 1 to 3, characterized in that The modifier is one or more of 4-quinolinecarboxaldehyde, 3-quinolinecarboxaldehyde, 2-quinolinecarboxaldehyde, 2-carbonylquinoline, and 2-quinolineacetal.

5. The method according to any one of claims 1 to 4, characterized in that The epoxy resin is bisphenol A epoxy resin.

6. The method according to any one of claims 1 to 5, characterized in that The high heat-resistant epoxy resin obtained in step S3 is in a solid state after being left at room temperature for 1 minute to 3 hours.

7. The method according to any one of claims 1 to 5, characterized in that The high heat-resistant epoxy resin obtained in step S3 is in liquid state, and a curing process in step S4 is added after step S3 to obtain the high heat-resistant epoxy resin in solid state.

8. The method according to claim 7, characterized in that The curing process comprises the following steps: Step S401: preheating the mold at 120-140°C for 2-2.5 hours; adding the liquid high-heat-resistant epoxy resin and the curing agent in an equivalent ratio of 1:(0.3-1.5) into the reaction kettle, stirring and degassing at 90-135°C in a vacuum state for 20-50 minutes to obtain a to-be-cured material; Step S402: pouring the object to be solidified into a preheated mold and degassing in a vacuum for 3-8 minutes; Step S403: Curing the mold with the object to be cured. The curing conditions are: first heating to 100-130° C. and keeping it warm for 3-6 hours, then heating to 130-150° C. and keeping it warm for 18-30 hours.

9. The method according to claim 8, characterized in that The curing agent is an acid anhydride curing agent.

10. The method according to claim 9, characterized in that The curing agent is methyltetrahydrophthalic anhydride.

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