A high RTI value epoxy material composition and its preparation method

Abstract

This application relates to the field of epoxy materials, specifically providing an epoxy material composition with a high RTI value and its preparation method. The high RTI value epoxy material composition of this application comprises the following raw material components in parts by weight: 40-60 parts epoxy resin, 8-15 parts curing agent, 0.5-2 parts curing accelerator, 2-20 parts additives, and 3-10 parts silicone rubber microspheres. The silicone rubber microspheres are prepared as follows: a bi-amino-terminated silicone oil pre-emulsion is prepared; an epoxy-based silicone oil pre-emulsion is prepared; the epoxy-based silicone oil pre-emulsion is added dropwise to the bi-amino-terminated silicone oil pre-emulsion, and stirring is continued for 0.5-10 hours after the addition is complete; the mixture is then filtered, washed, and dried to obtain the silicone rubber microspheres. Adding the silicone rubber microspheres of this invention to epoxy materials can improve the RTI value and toughness of the epoxy materials.

Description

Technical Field

[0001] This application relates to the field of epoxy materials technology, and more specifically, to epoxy material compositions with high RTI values ​​and their preparation methods. Background Technology

[0002] With the miniaturization and increasing environmental demands of electronic products, higher requirements are being placed on their reliability in higher-temperature environments. This typically necessitates testing for the RTI (relative temperature index). RTI is a long-term operating temperature test performed on materials in UL certification; a higher RTI value indicates a higher temperature resistance rating. Epoxy resin is a widely used material in electronic products, but its heat resistance is not high. Therefore, improving the RTI value of electronic materials with epoxy resin as the main resin is of great significance for enabling electronic products to be used in higher-temperature environments.

[0003] Polysiloxanes are commonly used to improve the heat resistance and toughness of epoxy materials. The main methods include chemical modification—attaching polysiloxanes to the molecular structure of epoxy resins, and physical modification—adding modified polysiloxanes to epoxy material compositions.

[0004] However, the use of polysiloxanes still requires further research to further improve the performance of epoxy materials. Summary of the Invention

[0005] To address the problem of insufficient heat resistance of epoxy materials in the prior art, this application provides an epoxy material composition with a high RTI value and a preparation method thereof.

[0006] The technical solution adopted in this application is as follows:

[0007] A high RTI value epoxy material composition comprising the following raw material components in parts by weight: 40-60 parts epoxy resin, 8-15 parts curing agent, 0.5-2 parts curing accelerator, 2-20 parts additives and 3-10 parts silicone rubber microspheres;

[0008] The silicone rubber microspheres are prepared according to the following method.

[0009] S1. Mix the double-ended amino silicone oil, the first emulsifier and water at a weight ratio of 1-50:0.03-3:100 to obtain a double-ended amino silicone oil pre-emulsion.

[0010] S2. Mix epoxy silicone oil, second emulsifier and water at a weight ratio of 5-50:0.1-3:100 to obtain epoxy silicone oil pre-emulsion.

[0011] S3. Under stirring, the epoxy-based silicone oil preemulsion is added dropwise to the double-terminated amino silicone oil preemulsion. After the addition is complete, stirring is continued for 0.5-10 hours. The mixture is then filtered, washed, and dried to obtain the silicone rubber microspheres.

[0012] Preferably, the epoxy resin is selected from one or a combination of bisphenol A type epoxy resin, bisphenol F type epoxy resin and phenolic epoxy resin.

[0013] Preferably, the curing agent is selected from acid anhydride curing agents.

[0014] Preferably, the additives include one or a combination of leveling agents, defoamers, flame retardants, and antioxidants.

[0015] Preferably, the general structural formula of the double-terminated amino silicone oil in step S1 is R. 1 SiOMe2(SiOMe2) n (SiOR 2 Me) m SiMe2R 1 , where R 1 R is an organic group containing a primary amino group. 2 Selected from methyl, phenyl, 3,3,3-trifluoropropyl or propyl, where Me represents methyl, n>10, m≥0, the viscosity of the double-terminated amino silicone oil at 25°C is 200-5000 mPa·s.

[0016] Preferably, the general structural formula of the epoxy-based silicone oil in step S2 is R. 3 SiOMe2(SiOMe2) a (SiOR 4 Me) b (SiOMeR 5 ) c SiMe2R 3 , where R 3 Selected from hydroxyl, C1-C8 alkyl, or C1-C8 substituted alkyl, R 4 R is an organic group containing an epoxy group. 5 Selected from methyl, phenyl, 3,3,3-trifluoropropyl or propyl, where Me represents methyl, a>20, b≥3, c≥0, the epoxy-based silicone oil has a viscosity of 500-3000 mPa·s at 25°C.

[0017] Preferably, the first emulsifier in step S1 and the second emulsifier in step S2 are selected from one or more combinations of nonionic emulsifiers, anionic emulsifiers, cationic emulsifiers and zwitterionic emulsifiers.

[0018] Preferably, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the double-terminated amino silicone oil preemulsion is 2-20:1.

[0019] Preferably, the temperature of the reaction system during stirring in step S3 is 25-70°C.

[0020] A method for preparing a high RTI value epoxy material composition according to any of the above embodiments involves mixing the epoxy resin, the additives, and the silicone rubber microspheres, then adding the curing agent and the curing accelerator, mixing them evenly, and obtaining the epoxy material composition.

[0021] In summary, this application has the following beneficial effects:

[0022] 1. This application uses a mixture of double-amino-terminated silicone oil pre-emulsion and epoxy-based silicone oil pre-emulsion to obtain silicone rubber microspheres through a crosslinking reaction between the double-amino-terminated silicone oil and the epoxy-based silicone oil. Furthermore, by using an excess of epoxy groups in the epoxy-based silicone oil relative to the amino groups in the double-amino-terminated silicone oil, a large number of epoxy groups are distributed on the surface of the silicone rubber microspheres. The epoxy groups can not only improve the compatibility between the silicone rubber microspheres and epoxy resin, but also participate in the curing of epoxy materials, thereby enhancing the heat resistance and toughness of the silicone rubber microspheres.

[0023] 2. This application employs a crosslinking reaction between double-terminated amino silicone oil and epoxy silicone oil. The double-terminated amino silicone oil contains two amino groups, and the crosslinking density between the silicone oil and epoxy silicone oil is lower at both ends. The resulting silicone rubber microspheres have a lower crosslinking density and a looser structure compared to organosilicon resin microspheres obtained by hydrolyzing silane coupling agents. This loose structure facilitates the penetration of epoxy resin, curing agent, and curing accelerator into the silicone rubber microspheres. Therefore, when the silicone rubber microspheres of this application are added to the epoxy material composition, the crosslinking of the silicone rubber microspheres occurs not only on the surface of the microspheres but also inside them, improving the effectiveness of the silicone rubber microspheres and resulting in better performance in enhancing the heat resistance and toughness of the epoxy material.

[0024] 3. The crosslinking density of the silicone rubber microspheres in this application is relatively low, and the molecular chains between the crosslinking points are relatively long. After participating in the crosslinking and curing of epoxy materials, compared with the organosilicon resin microspheres obtained by hydrolysis of silane coupling agents (where the molecular chains between the crosslinking points are very short), they have better flexibility and can better alleviate the impact of external factors on epoxy materials, thereby improving the impact resistance of epoxy materials.

[0025] 4. If the density of the silicone rubber microspheres is too high, it hinders the penetration of epoxy resin, curing agent, and curing accelerator into the interior of the microspheres; if the density is too low, the microspheres become too soft, weakening their effect on improving the heat resistance and toughness of the epoxy material. In this application, by controlling the structure of the double-terminated amino silicone oil and the epoxy silicone oil, as well as the molar ratio of amino to epoxy groups, silicone rubber microspheres with a suitable crosslinking density were obtained. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below.

[0027] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0028] This application provides an epoxy material composition with a high RTI value, comprising the following raw material components in parts by weight: 40-60 parts epoxy resin, 8-15 parts curing agent, 0.5-2 parts curing accelerator, 2-20 parts additives, and 3-10 parts silicone rubber microspheres.

[0029] Silicone rubber microspheres are prepared according to the following method.

[0030] S1. Mix the double-ended amino silicone oil, the first emulsifier and water at a weight ratio of 1-50:0.03-3:100 to obtain a double-ended amino silicone oil pre-emulsion.

[0031] S2. Mix epoxy silicone oil, second emulsifier and water at a weight ratio of 5-50:0.1-3:100 to obtain epoxy silicone oil pre-emulsion.

[0032] S3. Under stirring, the epoxy-based silicone oil preemulsion is added dropwise to the double-terminated amino silicone oil preemulsion. After the addition is complete, stirring is continued for 0.5-10 hours. The mixture is then filtered, washed, and dried to obtain the silicone rubber microspheres.

[0033] In preferred embodiments of this application, the epoxy resin is selected from one or a combination of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenolic epoxy resin. In this application, either pure epoxy resin (i.e., unmodified epoxy resin) or modified epoxy resin can be used, such as polysiloxane-modified epoxy resin or flame-retardant modified epoxy resin. In this application, the epoxy resin can be in liquid or solid form; for example, for powdered epoxy materials, solid epoxy resin is used.

[0034] In a preferred embodiment of this application, the curing agent is selected from anhydride curing agents. In this application, anhydride curing agents are commonly used curing agents for epoxy resins, with a curing temperature generally of 100-150℃ or higher. They can be selected from phthalic anhydride, tetrahydrophthalic anhydride and its derivatives, hexahydrophthalic anhydride and its derivatives, methylnadic anhydride, trimellitic anhydride and its modified forms, aliphatic anhydrides (such as dodecyl succinic anhydride), aliphatic polyanhydrides (such as polyadipate anhydride, polyazelite anhydride), 3,3',4,4'-benzophenone tetracarboxylic dianhydride, etc. More preferably, this application uses anhydride curing agents that are in powder form at room temperature, such as trimellitic anhydride and its modified forms, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, etc.

[0035] In this application, the curing accelerator is selected from imidazoles. Imidazole curing accelerators can promote faster curing and obtain cured products with good heat resistance, as well as superior mechanical properties. Imidazole curing accelerators can be selected from 2-ethyl-4-methylimidazole, 2-ethylimidazole, 2-methylimidazole, 2,4-dimethylimidazole, etc.

[0036] In a preferred embodiment of this application, the additives include one or a combination of leveling agents, defoamers, flame retardants, and antioxidants.

[0037] In this application, the leveling agent can be selected from polyether silicone oil leveling agents or acrylic leveling agents; the defoamer can be selected from dimethyl silicone oil defoamer or acrylic defoamer; the flame retardant can be a filler-type flame retardant, such as halides, phosphides, hydrated alumina, calcium aluminate, ammonium polyphosphate, etc.; the antioxidant can be selected from antioxidants 1010, 1076, etc. The leveling agent, defoamer, flame retardant, and antioxidant in this application can all be purchased from existing commercially available products.

[0038] In a preferred embodiment of this application, the general structural formula of the double-terminated amino silicone oil in step S1 is R. 1 SiOMe2(SiOMe2) n (SiOR 2 Me) m SiMe2R 1 , where R 1 R is an organic group containing a primary amino group. 2 Selected from methyl, phenyl, 3,3,3-trifluoropropyl, or propyl, where Me represents methyl, n > 10, m ≥ 0, the double-terminated amino silicone oil has a viscosity of 200-5000 mPa·s at 25°C. Generally, with similar molecular chain lengths, fewer cross-linkable groups in the molecular structure result in lower cross-linking density. However, if the number of cross-linking groups is below a certain threshold, a cross-linked structure cannot be formed. To obtain silicone rubber microspheres with a looser cross-linking structure, R is more preferably... 1This refers to an organic group containing only one primary amino group, such as 3-aminopropyl, N-β-aminoethyl-γ-aminopropyl, 4-aminobutyl, etc. Furthermore, from a preparation perspective, to reduce costs and simplify preparation steps, m can be 0 or R. 2 The methyl group, i.e., the repeating unit of the double-terminated amino silicone oil, contains only SiOMe2 units. If the goal is to increase the refractive index of the silicone rubber microspheres, R... 2 It can be selected from phenyl. More preferably, the viscosity of the double-terminated amino silicone oil at 25°C is 500-3000 mPa·s, and even more preferably, the viscosity of the double-terminated amino silicone oil at 25°C is 1000-2000 mPa·s.

[0039] In this application, the double-terminated amino silicone oil can be either commercially available or prepared using the following method: employing R... 1 Me2Si(OR 6 ) or 1,3-bis(aminopropane)tetramethyldisil as the end-capping agent, with octamethylcyclotetrasiloxane (D 4 ) and other cyclosiloxane monomers (such as D3) F (e.g., tetramethyltetraphenylcyclotetrasiloxane) are reacted at a certain weight ratio with tetramethylammonium hydroxide (or tetramethylammonium hydroxide silanolate or tetramethylammonium hydroxide siloxane alkoxide) as a catalyst at 110-120℃ for 1-2 hours. The temperature is then raised to above 135℃ to destroy the catalyst, and the temperature is further raised to 150-160℃ under negative pressure to remove low-boiling substances, thus obtaining a double-terminated amino silicone oil. Among them, R... 1 As mentioned above, R and Me 6 It is methoxy or ethoxy.

[0040] In a preferred embodiment of this application, the general structural formula of the epoxy-based silicone oil in step S2 is R. 3 SiOMe2(SiOMe2) a (SiOR 4 Me) b (SiOMeR 5 ) c SiMe2R 3 , where R 3 Selected from hydroxyl, C1-C8 alkyl, or C1-C8 substituted alkyl, R 4 R is an organic group containing an epoxy group. 5The epoxy-based silicone oil is selected from methyl, phenyl, 3,3,3-trifluoropropyl, or propyl, where Me represents methyl, a > 20, b ≥ 3, and c ≥ 0. The viscosity of the epoxy-based silicone oil at 25°C is 500-3000 mPa·s. Generally, the distribution density of epoxy groups in the epoxy-based silicone oil affects the crosslinking density of the silicone rubber microspheres. With a given dual-terminated amino silicone oil, a higher distribution density of epoxy groups in the epoxy-based silicone oil results in a greater crosslinking density of the silicone rubber microspheres, and vice versa. The distribution density of epoxy groups is mainly determined by the molecular weight and number of epoxy groups in the epoxy-based silicone oil; a larger molecular weight or a smaller number of epoxy groups results in a lower distribution density. In this application, more preferably, b is no more than 10. When the viscosity of the epoxy-based silicone oil at 25°C is 500-1000 mPa·s, more preferably, 3 ≤ b ≤ 5; when the viscosity of the epoxy-based silicone oil at 25°C is 1000-2000 mPa·s, more preferably, 5 ≤ b ≤ 7; when the viscosity of the epoxy-based silicone oil at 25°C is 2000-3000 mPa·s, more preferably, 7 ≤ b ≤ 10. By screening the molecular weight (expressed as viscosity) and the number of epoxy groups of the epoxy-based silicone oil, silicone rubber microspheres with a suitable crosslinking density can be obtained.

[0041] In this application, R 4 It can be selected from γ-glycidoxypropyl or β-(3,4-epoxycyclohexyl)ethyl. Epoxy silicone oils can be purchased from commercially available products or prepared as follows: using the general structural formula R... 3 SiOMe2(SiOMe2) a (SiOMeH) b (SiOMeR 5 ) c SiMe2R 3 Hydrogen-containing silicone oil (which can be prepared according to existing technology, by ring-opening reaction of a corresponding end-capping agent and siloxane cyclic compound under an acidic catalyst) is obtained by hydrosilylation reaction with a corresponding epoxy-containing unsaturated compound (such as allyl glycidyl ether or 4-vinylepoxycyclohexane), wherein R 3 Me, R 5 The meanings of a, b, and c are as shown above.

[0042] The emulsification of bi-amino-terminated silicone oils and epoxy-terminated silicone oils has been extensively reported in existing technologies. Specifically, bi-amino-terminated silicone oils or epoxy-terminated silicone oils are mixed with emulsifiers and water, and then emulsified under high-speed shearing (e.g., homogenization, high-speed stirring) to form an O / W type emulsion. The emulsifiers used can be commercially available products or selected and combined from existing emulsifier products. In the preferred embodiment of this application, the first emulsifier in step S1 and the second emulsifier in step S2 are respectively selected from one or more combinations of nonionic emulsifiers, anionic emulsifiers, cationic emulsifiers, and zwitterionic emulsifiers. More preferably, the first and second emulsifiers in this application can be composed of a nonionic emulsifier and an anionic emulsifier, respectively. The nonionic emulsifier can be selected from AEO-9, isomeric tridecyl alcohol polyoxyethylene ether 1305 or 1307, OP-4, OP-10, Span series emulsifiers, Tween series emulsifiers, etc., and the anionic emulsifier can be selected from sodium dodecylbenzenesulfonate, sodium dodecyl carboxylate, sodium dodecyl sulfonate, sodium bis(dodecylphenyl) ether disulfonate, etc. Furthermore, the weight ratio of the nonionic emulsifier to the anionic emulsifier can be 10:1 to 1:1. The combination of the nonionic emulsifier and the anionic emulsifier can combine the steric hindrance effect of the nonionic emulsifier and the electrostatic repulsion effect of the anionic emulsifier to improve the stability of the pre-emulsion.

[0043] In this invention, the dual-terminated amino silicone oil preemulsion and the epoxy silicone oil preemulsion can also be purchased directly from existing commercially available emulsion products.

[0044] In a preferred embodiment of this application, the ratio of the molar number of epoxy groups in the epoxy-based silicone oil pre-emulsion to the molar number of primary amino groups in the bi-amino-terminated silicone oil pre-emulsion is 2-20:1. In this application, to achieve an epoxy-based surface for the silicone rubber microspheres, the molar number of epoxy groups in the epoxy-based silicone oil emulsion needs to exceed the molar number of amino groups in the bi-amino-terminated silicone oil emulsion. To ensure a higher number of epoxy groups on the surface of the silicone rubber microspheres and better compatibility with epoxy resin, more preferably, the ratio of the molar number of epoxy groups in the epoxy-based silicone oil pre-emulsion to the molar number of primary amino groups in the bi-amino-terminated silicone oil pre-emulsion is 3-15, and even more preferably, it is 5-10, specifically 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10.

[0045] In a preferred embodiment of this application, the temperature of the reaction system during stirring in step S3 is 25-70°C. For the reaction between epoxy groups and amino groups, the higher the reaction temperature, the faster the reaction rate. In step S3 above, the epoxy-based silicone oil pre-emulsion is added dropwise to the bi-amino-terminated silicone oil pre-emulsion. The tiny droplets of the two pre-emulsions merge to form a single tiny droplet. The bi-amino-terminated silicone oil and epoxy-based silicone oil undergo a cross-linking reaction within the tiny droplet to form emulsified silicone rubber microspheres. After filtration and washing to remove the emulsifier (e.g., using anhydrous ethanol or deionized water), and drying, silicone rubber microspheres are obtained. Drying can be carried out in a forced-air drying oven at 60-80°C for 6-24 hours. The higher the temperature, the shorter the drying time.

[0046] The epoxy material composition of this application may further include 0-30 parts of filler and 0-5 parts of colorant. There are no specific limitations on the filler; it can be selected from organic or inorganic fillers. Organic fillers can be selected from polytetrafluoroethylene micropowder, polyethylene micropowder, etc., while inorganic fillers can be selected from wollastonite, talc, nano-calcium carbonate, precipitated silica, mica powder, alumina, aluminum hydroxide, etc. There are no specific limitations on the colorant; it can be titanium dioxide, phthalocyanine blue, phthalocyanine green, iron oxide red, carbon black, etc.

[0047] The raw material composition of this application may also include a dispersant, the weight of which is 1-5% of the weight of the filler, or the dispersant is added according to the weight of the color powder, the weight of which is 1-40% of the weight of the color powder.

[0048] Another aspect of this application proposes a method for preparing an epoxy material composition with a high RTI value as described in any of the above embodiments, wherein the epoxy resin, the additives and the silicone rubber microspheres are mixed and homogenized, and then the curing agent and the curing accelerator are added and mixed evenly to obtain the epoxy material composition.

[0049] If the raw material composition also includes fillers, color powders, dispersants, etc., after adding epoxy resin, additives and silicone rubber microspheres, and before adding curing agent and curing accelerator, add fillers, color powders and dispersants, and disperse them evenly.

[0050] In this application, to obtain a powdered epoxy material composition, the raw material components can be mixed evenly, then kneaded and extruded at 80-110℃, pulverized into flakes, and then ground, graded, and the epoxy material composition with the desired particle size can be collected. The epoxy material composition of this application can collect different particle size ranges as needed, such as 40 mesh, 50 mesh, 60 mesh, 70 mesh, etc.

[0051] The present application will now be described in further detail with reference to embodiments, comparative examples, and experimental data. Unless otherwise specified, all parts in the following embodiments and comparative examples are parts by weight.

[0052] Preparation Example 1

[0053] Double-ended amino silicone oil: R 1 SiOMe2(SiOMe2) n SiMe2R 1 , R 1 It is 3-aminopropyl, Me is methyl, and the viscosity (25℃) is 1260 mPa·s;

[0054] Epoxy silicone oil: Me3SiO(SiOMe2) a (SiOR 4 Me) 4.1 SiMe3,R 4 It is γ-glycidyl etheroxypropyl, Me is methyl, and the viscosity (25℃) is 730 mPa·s;

[0055] 20 parts of double-terminated amino silicone oil, 0.8 parts of AEO-9 and 0.4 parts of sodium dodecylbenzenesulfonate were added to 100 parts of deionized water and homogenized in a homogenizer to obtain a double-terminated amino silicone oil preemulsion.

[0056] 30 parts of epoxy-based silicone oil, 1 part of AEO-9 and 0.2 parts of sodium dodecylbenzenesulfonate were added to 100 parts of deionized water and homogenized in a homogenizer to obtain an epoxy-based silicone oil preemulsion.

[0057] The ratio of the number of epoxy groups in the epoxy-based silicone oil preemulsion to the number of primary amino groups in the bi-amino-terminated silicone oil preemulsion was 6. The epoxy-based silicone oil preemulsion was added dropwise to the bi-amino-terminated silicone oil preemulsion at 30°C. After the addition was complete, the mixture was stirred for 8 hours, filtered, washed twice with deionized water, washed once with anhydrous ethanol, and dried overnight in an oven at 60°C to obtain silicone rubber microspheres.

[0058] Preparation Example 2

[0059] Double-ended amino silicone oil: R 1 SiOMe2(SiOMe2) n SiMe2R 1 , R 1 It is 3-aminopropyl, Me is methyl, and the viscosity (25℃) is 1070 mPa·s;

[0060] Epoxy silicone oil: Me3SiO(SiOMe2) a (SiOR 4 Me) 8.9 SiMe3,R 4 It is β-(3,4-epoxycyclohexyl)ethyl, Me is methyl, and the viscosity (25℃) is 2760 mPa·s;

[0061] Ten parts of double-terminated amino silicone oil, 0.5 parts of isomeric tridecyl alcohol polyoxyethylene ether 1307 and 0.1 parts of sodium dodecylbenzene sulfonate were added to 100 parts of deionized water and transferred to a homogenizer for homogenization to obtain a double-terminated amino silicone oil preemulsion.

[0062] 25 parts of epoxy-based silicone oil, 1 part of isomeric tridecyl alcohol polyoxyethylene ether 1305 and 0.3 parts of sodium dodecylbenzene sulfonate were added to 100 parts of deionized water and transferred to a homogenizer for homogenization to obtain epoxy-based silicone oil preemulsion.

[0063] The ratio of the number of epoxy groups in the epoxy-based silicone oil preemulsion to the number of primary amino groups in the bi-amino-terminated silicone oil preemulsion was 12.2. At 35°C, the epoxy-based silicone oil preemulsion was added dropwise to the bi-amino-terminated silicone oil preemulsion. After the addition was complete, the mixture was stirred for 4.5 hours, filtered, washed twice with deionized water, washed once with anhydrous ethanol, and dried overnight in an oven at 60°C to obtain silicone rubber microspheres.

[0064] Preparation Example 3

[0065] Double-ended amino silicone oil: R 1 SiOMe2(SiOMe2) n SiMe2R 1 R 1 It is 3-aminopropyl, Me is methyl, and the viscosity (25℃) is 1630 mPa·s;

[0066] Epoxy silicone oil: Me3SiO(SiOMe2) a (SiOR 4 Me) 6.2 SiMe3,R 4 It is γ-glycidyl etheroxypropyl, Me is methyl, and the viscosity (25℃) is 1380 mPa·s;

[0067] 32 parts of double-terminated amino silicone oil, 1 part of isomeric tridecyl alcohol polyoxyethylene ether 1305 and 0.5 parts of sodium dodecylbenzene sulfonate were added to 100 parts of deionized water and transferred to a homogenizer for homogenization to obtain a double-terminated amino silicone oil preemulsion.

[0068] 15 parts of epoxy-based silicone oil, 0.7 parts of AEO-9 and 0.1 parts of sodium dodecylbenzenesulfonate were added to 100 parts of deionized water and homogenized in a homogenizer to obtain an epoxy-based silicone oil preemulsion.

[0069] The ratio of the number of epoxy groups in the epoxy-based silicone oil preemulsion to the number of primary amino groups in the bi-amino-terminated silicone oil preemulsion was 8.5. The epoxy-based silicone oil preemulsion was added dropwise to the bi-amino-terminated silicone oil preemulsion at 45°C. After the addition was complete, the mixture was stirred for 3 hours, filtered, washed twice with deionized water, washed once with anhydrous ethanol, and dried overnight in an oven at 60°C to obtain silicone rubber microspheres.

[0070] Preparation Example 4

[0071] In Preparation Example 3, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the bi-amino-terminated silicone oil preemulsion was adjusted from 8.5 to 3.2, while the other steps remained unchanged.

[0072] Preparation Example 5

[0073] In Preparation Example 3, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the bi-amino-terminated silicone oil preemulsion was adjusted from 8.5 to 5.7, while the other steps remained unchanged.

[0074] Preparation Example 6

[0075] In Preparation Example 3, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the bi-amino-terminated silicone oil preemulsion was adjusted from 8.5 to 12.3, while the other steps remained unchanged.

[0076] Preparation Example 7

[0077] In Preparation Example 3, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the bi-amino-terminated silicone oil preemulsion was adjusted from 8.5 to 14.5, while the other steps remained unchanged.

[0078] Preparation of Comparative Example 1

[0079] In Preparation Example 3, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the bi-amino-terminated silicone oil preemulsion was adjusted from 8.5 to 1.5, while the other steps remained unchanged.

[0080] Preparation of Comparative Example 2

[0081] In Preparation Example 3, the ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the bi-amino-terminated silicone oil preemulsion was adjusted from 8.5 to 22.7, while the other steps remained unchanged.

[0082] Example 1

[0083] The following raw materials were used: 50 parts of powdered epoxy resin NPES-602, 8.5 parts of trimellitic anhydride, 0.8 parts of 2-methylimidazole, 0.7 parts of acrylic leveling agent, 0.4 parts of dimethyl silicone defoamer, 8 parts of flame retardant Melapur MC-25, and 4 parts of silicone rubber microspheres from Preparation Example 1. The powdered epoxy resin NPES-602, flame retardant Melapur MC-25, dimethyl silicone defoamer, and silicone rubber microspheres were mixed and homogenized. The acrylic leveling agent was added and mixed evenly. Then trimellitic anhydride and 2-methylimidazole were added and mixed. The mixture was kneaded and extruded at 100°C for 5 minutes. The mixture was then pulverized, ground, and classified to obtain an epoxy material composition with a particle size of 50 mesh.

[0084] Example 2

[0085] The following raw materials were used to prepare Example 2: 60 parts of powdered epoxy resin NPES-602, 14 parts of trimellitic anhydride, 1 part of 2-methylimidazole, 1 part of acrylic leveling agent, 0.5 parts of dimethyl silicone oil defoamer, 8 parts of flame retardant Melapur MC-25 and 7 parts of silicone rubber microspheres.

[0086] Powdered epoxy resin NPES-602, flame retardant Melapur MC-25, dimethyl silicone oil defoamer, and silicone rubber microspheres were mixed and homogenized. An acrylic leveling agent was added and mixed evenly. Trimericic anhydride and 2-methylimidazole were then added. The mixture was kneaded and extruded at 100°C for 5 minutes. The mixture was then pulverized, ground, and classified to obtain an epoxy material composition with a particle size of 50 mesh.

[0087] Example 3

[0088] Prepare the silicone rubber microspheres of Example 3 according to the following raw material composition: 42 parts of powdered epoxy resin NPES-602, 9 parts of trimellitic anhydride, 0.6 parts of 2-methylimidazole, 0.6 parts of acrylic leveling agent, 0.3 parts of dimethyl silicone oil defoamer, 8 parts of flame retardant Melapur MC-25 and 10 parts of raw material composition.

[0089] Powdered epoxy resin NPES-602, flame retardant Melapur MC-25, dimethyl silicone oil defoamer, and silicone rubber microspheres were mixed and homogenized. An acrylic leveling agent was added and mixed evenly. Trimericic anhydride and 2-methylimidazole were then added. The mixture was kneaded and extruded at 100°C for 5 minutes. The mixture was then pulverized, ground, and classified to obtain an epoxy material composition with a particle size of 50 mesh.

[0090] Example 4

[0091] Prepare the silicone rubber microspheres of Example 3 according to the following raw material composition: 55 parts of powdered epoxy resin NPES-605, 14 parts of 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 0.7 parts of 2-ethylimidazole, 1 part of acrylic leveling agent, 0.6 parts of dimethyl silicone oil defoamer, 8 parts of flame retardant Melapur MC-25 and 8 parts of silicone rubber microspheres.

[0092] Powdered epoxy resin NPES-605, flame retardant Melapur MC-25, dimethyl silicone oil defoamer, and silicone rubber microspheres were mixed and homogenized. An acrylic leveling agent was added and mixed evenly. Then, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and 2-ethylimidazole were added. The mixture was kneaded and extruded at 100°C for 5 minutes, pulverized, ground, and classified to obtain an epoxy material composition with a particle size of 60 mesh.

[0093] Example 5

[0094] In Example 4, the silicone rubber microspheres were replaced with an equal weight of the silicone rubber microspheres used in Preparation Example 4, while the remaining steps remained unchanged.

[0095] Example 6

[0096] The silicone rubber microspheres in Example 4 were replaced with an equal weight of the silicone rubber microspheres in Preparation Example 5, while the remaining steps remained unchanged.

[0097] Example 7

[0098] In Example 4, the silicone rubber microspheres were replaced with an equal weight of the silicone rubber microspheres in Preparation Example 6, while the remaining steps remained unchanged.

[0099] Example 8

[0100] In Example 4, the silicone rubber microspheres were replaced with an equal weight of the silicone rubber microspheres in Preparation Example 7, while the remaining steps remained unchanged.

[0101] Example 9

[0102] The following raw materials were used: 55 parts of powdered epoxy resin NPES-605, 16 parts of 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 0.6 parts of 2-ethylimidazolium, 1.1 parts of acrylic leveling agent, 0.5 parts of dimethyl silicone defoamer, 8 parts of flame retardant Melapur MC-25, 20 parts of talc, 2 parts of polyacrylic acid superdispersant, and 5 parts of silicone rubber microspheres prepared in Example 2;

[0103] Powdered epoxy resin NPES-605, flame retardant Melapur MC-25, dimethyl silicone defoamer, and silicone rubber microspheres were mixed and homogenized. An acrylic leveling agent was added and mixed evenly. Talc and polyacrylic acid superdispersant were then added and dispersed evenly. 3,3',4,4'-benzophenone tetracarboxylic dianhydride and 2-ethylimidazole were added. The mixture was kneaded and extruded at 100°C for 5 minutes. The mixture was then pulverized, ground, and classified to obtain an epoxy material composition with a particle size of 60 mesh.

[0104] Example 10

[0105] In Example 9, the amount of silicone rubber microspheres was changed from 5 parts to 8 parts, while the remaining steps remained unchanged.

[0106] Comparative Example 1

[0107] In Example 4, the silicone rubber microspheres were replaced with an equal weight of the silicone rubber microspheres used in Comparative Example 1, while the remaining steps remained unchanged.

[0108] Comparative Example 2

[0109] In Example 4, the silicone rubber microspheres were replaced with an equal weight of the silicone rubber microspheres used in Comparative Example 2, while the remaining steps remained unchanged.

[0110] Comparative Example 3

[0111] In Example 4, the silicone rubber microspheres were replaced with an equal weight of commercially available silicone resin microspheres with a D50 of 2 μm, while the remaining steps remained unchanged.

[0112] Comparative Example 4

[0113] In Example 4, the silicone rubber microspheres were replaced with an equal weight of the epoxy-based silicone oil used in Preparation Example 3, while the remaining steps remained unchanged.

[0114] Curing test method: The epoxy material compositions of Examples 1-3 were cured at 150°C for 30 minutes, and then allowed to cool naturally to room temperature for 24 hours; the epoxy material compositions of Examples 4-10 and Comparative Examples 1-4 were cured at 150°C for 30 minutes, and then allowed to cool naturally to room temperature for 24 hours.

[0115] RTI value: The temperature at which the tensile strength drops to half of its initial value was determined according to the UL746B Medium and Long-Term Aging Test Protocol (LTTA). The results are shown in Table 1 (rounded to the nearest whole number).

[0116] Impact strength: Tested according to GB / T 2571-1995. The results are shown in Table 1 (rounded to one decimal place).

[0117] Table 1

[0118] Sample to be tested RTI value Impact strength / KJ / m2 Example 1 115 25.4 Example 2 122 31.2 Example 3 130 30.1 Example 4 127 50.2 Example 5 116 42.9 Example 6 125 48.5 Example 7 121 45.8 Example 8 118 43.1 Example 9 122 48.4 Example 10 128 52.2 Comparative Example 1 110 33.5 Comparative Example 2 113 37.4 Comparative Example 3 121 35.1 Comparative Example 4 112 42.7

[0119] As shown in Table 1, the use of silicone rubber microspheres prepared in this application in the epoxy material composition can not only improve the RTI value of the epoxy material, but also improve the toughness of the epoxy material.

[0120] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high RTI (Residual Tolerance) epoxy material composition, characterized in that: It contains the following raw material components in parts by weight: 40-60 parts epoxy resin, 8-15 parts curing agent, 0.5-2 parts curing accelerator, 2-20 parts additives and 3-10 parts silicone rubber microspheres; The silicone rubber microspheres are prepared according to the following method. S1. Mix the double-ended amino silicone oil, the first emulsifier and water at a weight ratio of 1-50:0.03-3:100 to obtain a double-ended amino silicone oil pre-emulsion. S2. Mix epoxy-based silicone oil, the second emulsifier, and water in a weight ratio of 5-50: Mix 0.1-3:100 thoroughly to obtain an epoxy-based silicone oil preemulsion; S3. Under stirring, the epoxy-based silicone oil preemulsion is added dropwise to the double-terminated amino silicone oil preemulsion. After the addition is complete, stirring is continued for 0.5-10 hours. The mixture is then filtered, washed, and dried to obtain the silicone rubber microspheres. The general structural formula of the double-terminated amino silicone oil in step S1 is R. 1 SiOMe2(SiOMe2) n (SiOR 2 Me) m SiMe2R 1 , where R 1 It is 3-aminopropyl or 4-aminobutyl, R 2 Selected from methyl, phenyl, 3,3,3-trifluoropropyl or propyl, Me represents methyl, n>10, m≥0, the viscosity of the double-terminated amino silicone oil at 25°C is 200-5000 mPa·s; The general structural formula of the epoxy-based silicone oil in step S2 is R. 3 SiOMe2(SiOMe2) a (SiOR 4 Me) b (SiOMeR 5 ) c SiMe2R 3 , where R 3 Selected from hydroxyl, C1-C8 alkyl, or C1-C8 substituted alkyl, R 4 Selected from γ-glycidoxypropyl or β-(3,4-epoxycyclohexyl)ethyl, R 5 Selected from methyl, phenyl, 3,3,3-trifluoropropyl or propyl, Me represents methyl, a>20, 3≤b≤10 and c≥0, the epoxy silicone oil has a viscosity of 500-3000 mPa·s at 25°C; When the viscosity of epoxy-based silicone oil at 25℃ is 500-1000 mPa·s, 3≤b≤5; when the viscosity of epoxy-based silicone oil at 25℃ is 1000-2000 mPa·s, 5≤b≤7; when the viscosity of epoxy-based silicone oil at 25℃ is 2000-3000 mPa·s, 7≤b≤10. The ratio of the number of moles of epoxy groups in the epoxy-based silicone oil preemulsion to the number of moles of primary amino groups in the double-terminated amino silicone oil preemulsion is 5-10:

1.

2. The epoxy material composition with high RTI value according to claim 1, characterized in that: The epoxy resin is selected from one or a combination of bisphenol A type epoxy resin, bisphenol F type epoxy resin and phenolic epoxy resin.

3. The epoxy material composition with high RTI value according to claim 1, characterized in that: The curing agent is selected from acid anhydride curing agents.

4. The epoxy material composition with high RTI value according to claim 1, characterized in that: The additives include one or a combination of leveling agents, defoamers, flame retardants, and antioxidants.

5. The epoxy material composition with high RTI value according to claim 1, characterized in that: The first emulsifier mentioned in step S1 and the second emulsifier mentioned in step S2 are respectively selected from one or a combination of nonionic emulsifiers, anionic emulsifiers, cationic emulsifiers and zwitterionic emulsifiers.

6. The epoxy material composition with high RTI value according to claim 1, characterized in that: The temperature of the reaction system during stirring in step S3 is 25-70℃.

7. A method for preparing an epoxy material composition with a high RTI value according to any one of claims 1-6, characterized in that: The epoxy resin, the additives, and the silicone rubber microspheres are mixed and homogenized, and then the curing agent and the curing accelerator are added and mixed evenly to obtain the epoxy material composition.