Silica gel mold glue for preparing carbon fiber protective shell, preparation method of silica gel mold glue and silica gel mold

Abstract

The invention discloses silica gel mold glue for preparing a carbon fiber protective shell, a preparation method of the silica gel mold glue and a silica gel mold, and relates to the technical field of silica gel materials. The silica gel mold glue for preparing the carbon fiber protective shell comprises the following components in parts by weight: 98-100 parts of polydimethylsiloxane, 2-5 parts of a cross-linking agent, 0.1-0.2 part of a catalyst, 1-3 parts of silane coupling agent modified calcium sulfate whiskers and 2-4 parts of modified organic montmorillonite. The organic montmorillonite and the calcium sulfate whiskers are added into the silica gel to form a composite material, and the mechanical property, the heat resistance and the dimensional stability of the silica gel can be remarkably improved through the synergistic effect, so that a high-heat and high-pressure preparation process of the carbon fiber protection shell is adapted, and the service life of a mold is prolonged.

Description

Technical Field

[0001] The invention relates to the field of silicone materials, and in particular to a silicone mold glue for preparing a carbon fiber protective shell, a preparation method thereof, and a silicone mold. Background Art

[0002] As the price of electronic products increases, consumers tend to buy protective cases to protect electronic products, making them more durable and increasing their service life. Existing protective cases are mostly made of plastic, but the texture of plastic is far inferior to the original surface texture of the mobile phone. While using such protective cases, they play a protective role, but reduce the design sense of the mobile phone's appearance. Therefore, in recent years, fiber-reinforced composite materials such as carbon fiber / Kevlar have been widely used in the protective case industry due to their light weight, good performance, and excellent texture.

[0003] However, high-performance carbon fiber materials require the use of metal molds and are made using processes such as molding and autoclaving. Long-term production and use of metal molds will result in scratches, which will affect the apparent quality of the product. In addition, a release agent must be used in each production, and the demolding efficiency is low, resulting in low production efficiency and low yield rate of the protective case. Summary of the invention

[0004] The present invention is made in view of the above-mentioned problems, and provides a silicone mold glue for preparing a carbon fiber protective case, a preparation method thereof, and a silicone mold, aiming to solve the problems of low production efficiency and low yield rate of the protective case caused by the mold.

[0005] The first aspect of the present invention provides a silicone mold glue for preparing a carbon fiber protective shell. The raw materials of the silicone mold glue include, by weight: 98 to 100 parts of polydimethylsiloxane, 2 to 5 parts of a cross-linking agent, 0.1 to 0.2 parts of a catalyst, 1 to 3 parts of silane coupling agent modified calcium sulfate whiskers, and 2 to 4 parts of modified organic montmorillonite.

[0006] In some embodiments of the present invention, the viscosity of the polydimethylsiloxane is 50000 cP to 100000 cP.

[0007] In some embodiments of the present invention, the average aspect ratio of the silane coupling agent modified calcium sulfate whiskers is 55-75.

[0008] In some embodiments of the present invention, the modifying agent for modifying the montmorillonite includes at least one of dodecylamine, sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide and tetraethyl orthosilicate.

[0009] In some embodiments of the present invention, the crosslinking agent includes at least one of methyl orthosilicate, butyl orthosilicate, ethyl orthosilicate, methyltriacetoxysilane, propyltriacetoxysilane, methyltrimethoxysilane, propyltrimethoxysilane, and tetrakis(methylisobutylketoxime)silane.

[0010] In some embodiments of the present invention, the catalyst includes dioctyltin diacetate or tributylbismuth oxide.

[0011] A second aspect of the present invention provides a method for preparing a silicone mold glue for preparing a carbon fiber protective shell, comprising the following steps:

[0012] a: adding calcium sulfate whisker powder to anhydrous ethanol for dispersion, adding silane coupling agent, deionized water and glacial acetic acid, heating and stirring to react, filtering and drying to obtain silane coupling agent modified calcium sulfate whisker;

[0013] b: dispersing the organic montmorillonite in the ethanol solution of the first modifier for reaction, then adding ethyl orthosilicate for reaction, filtering, vacuum drying, and calcining to obtain the modified organic montmorillonite;

[0014] c: Mix polydimethylsiloxane, silane coupling agent modified calcium sulfate whisker and modified organic montmorillonite, then add crosslinking agent and catalyst to react, remove bubbles, and obtain silicone mold glue.

[0015] In some embodiments of the present invention, in step a, the reaction temperature of the heated stirring reaction is 70°C to 80°C, the reaction time is 4h to 6h, the pH value is 2 to 3, the stirring speed is 500r / min to 600r / min, and the drying temperature is 85°C to 90°C.

[0016] In some embodiments of the present invention, in step b, the calcination temperature is 400° C. to 450° C. and the calcination time is 3 h to 6 h.

[0017] A third aspect of the present invention provides a silicone mold, which includes the above-mentioned silicone mold glue.

[0018] The beneficial effects that can be achieved by the present invention are:

[0019] The present invention provides a silicone mold glue for preparing a carbon fiber protective shell, wherein organic montmorillonite and calcium sulfate whiskers are added to the silicone to form a composite material, wherein the montmorillonite provides additional mechanical strength and thermal stability, while the calcium sulfate whiskers further enhance the dimensional stability and rigidity of the material. This synergistic effect can significantly improve the mechanical properties, heat resistance and dimensional stability of the silicone, thereby adapting to the high-temperature and high-pressure preparation process of the carbon fiber protective shell and extending the service life of the mold. At the same time, the present invention modifies the calcium sulfate whiskers and the organic montmorillonite, further increases the dispersion of the material, promotes the physical or chemical reaction between the organic functional groups on the surface of the montmorillonite and the calcium sulfate whiskers and the silicone molecular chains, enhances the interface interaction, and at high temperature, when the organic modifiers on the surface of the montmorillonite and the calcium sulfate whiskers are pyrolyzed, a stable carbon layer and an inorganic layer can be formed, thereby improving the thermal stability of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a silicone mold in use according to one embodiment of the present invention;

[0021] Figure 2 It is a schematic cross-sectional structure diagram of a silicone mold in use according to one embodiment of the present invention;

[0022] Figure 3 This is a scanning electron microscope image of a silane coupling agent modified calcium sulfate whisker according to an embodiment of the present invention. The scanning electron microscope model is JSM-5600LV, the high vacuum resolution is 3.5nm, the low vacuum resolution is 4.5nm, and the magnification range is 80-300000 times.

[0023] Description of reference numerals:

[0024] 1. Core mold; 2. Protective shell; 3. Silicone mold.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present invention, and are not intended to limit the subject matter described in the claims.

[0027] "Scope" disclosed in the present invention is defined in the form of lower limit and upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a particular range. The scope defined in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present invention, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0028] If not otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form a new technical solution.

[0029] Unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0030] If not otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0031] In recent years, fiber-reinforced composite materials such as carbon fiber and Kevlar have been widely used in the protective case industry due to their light weight, good performance and excellent texture. However, high-performance carbon fiber materials need to be made using metal molds and processes such as molding and autoclave. Long-term production and use of metal molds will cause scratches, affecting the apparent quality of the product. In addition, a release agent needs to be used for each production, and the demoulding efficiency is low, resulting in low production efficiency and low yield rate of protective cases.

[0032] In view of this, the present invention proposes a silicone mold glue for preparing a carbon fiber protective shell. The raw materials of the silicone mold glue include, by weight: 98 to 100 parts of polydimethylsiloxane, 2 to 5 parts of a cross-linking agent, 0.1 to 0.2 parts of a catalyst, 1 to 3 parts of silane coupling agent modified calcium sulfate whiskers, and 2 to 4 parts of modified organic montmorillonite.

[0033] The layered structure of montmorillonite and the needle-like structure of calcium sulfate whiskers can be used as reinforcements to improve the mechanical properties of silica gel. The interlayer space of montmorillonite can be intercalated by silica gel molecular chains to form an interlayer composite structure, thereby improving the strength and toughness of the material. The high aspect ratio and high modulus characteristics of calcium sulfate whiskers can significantly improve the tensile strength and elongation at break of silica gel.

[0034] In this scheme, organic montmorillonite and calcium sulfate whiskers are added to silica gel to form a composite material. Montmorillonite provides additional mechanical strength and thermal stability, while calcium sulfate whiskers further enhance the dimensional stability and rigidity of the material. This synergistic effect can significantly improve the mechanical properties, heat resistance and dimensional stability of silica gel, thereby adapting to the high-temperature and high-pressure preparation process of the carbon fiber protective shell and extending the service life of the mold. At the same time, this scheme modifies the calcium sulfate whiskers and organic montmorillonite to further increase the dispersion of the material, promote physical or chemical reactions between the organic functional groups on the surface of montmorillonite and calcium sulfate whiskers and the silica gel molecular chains, enhance interfacial interactions, and at high temperatures, when the organic modifiers on the surface of montmorillonite and calcium sulfate whiskers are pyrolyzed, stable carbon layers and inorganic layers can be formed, thereby improving the thermal stability of the material.

[0035] In some embodiments, the viscosity of the polydimethylsiloxane is 50000 cP to 100000 cP. Within this viscosity range, the modified montmorillonite and calcium sulfate whiskers of the present solution are uniformly dispersed. Preferably, the viscosity is 70000 cP to 100000 cP.

[0036] In some embodiments, the average aspect ratio of the silane coupling agent modified calcium sulfate whiskers is 55 to 75. In this embodiment, if the aspect ratio is less than the range value, it will lead to agglomeration, the whisker needles will become rods, and the dispersibility will deteriorate, so as to obtain the best wetting value and dispersibility.

[0037] In some embodiments, the modifying agent for modifying montmorillonite includes at least one of dodecylamine, sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide and ethyl orthosilicate.

[0038] As a cationic surfactant, dodecylamine can be inserted into the interlayer of montmorillonite through ion exchange and replace the interlayer cations. This replacement increases the degree of organicization of montmorillonite and improves its adsorption capacity for organic pollutants. The long carbon chain of dodecylamine also helps to increase the hydrophobicity of montmorillonite, thereby improving its dispersibility in non-polar solvents.

[0039] As an anionic surfactant, sodium dodecylbenzenesulfonate (SDBS) usually does not insert into the interlayer of montmorillonite alone because it repels the negative charge between the interlayers of montmorillonite. However, when compounded with a cationic surfactant such as CTAB, the positive charge environment formed by the cationic surfactant in the interlayer of montmorillonite can promote the insertion of SDBS, thereby increasing the interlayer distance of montmorillonite and improving the adsorption performance.

[0040] Cetyltrimethylammonium bromide (CTAB) can effectively insert into the interlayer of montmorillonite, replace the interlayer cations, increase the degree of organicization and interlayer spacing of montmorillonite. The insertion of CTAB also increases the lipophilicity of montmorillonite and improves its dispersibility in silica gel.

[0041] Tetraethoxysilane (TEOS) can be used for inorganic modification of montmorillonite. It forms a Si-O-Si network on the surface of montmorillonite through hydrolysis and condensation reactions, increasing the interlayer spacing of montmorillonite and improving its thermal stability and mechanical properties. In addition, silane coupling agents can also improve the compatibility between montmorillonite and polymers and improve the performance of composite materials.

[0042] In summary, dodecylamine and CTAB increase the degree of organicization and lipophilicity through ion exchange, SDBS increases the interlayer spacing by compounding with cationic surfactants, and TEOS improves thermal stability and mechanical properties by forming a Si-O-Si network. In this scheme, these modification methods can be used alone or in combination.

[0043] In some embodiments, the crosslinking agent includes at least one of methyl orthosilicate, butyl orthosilicate, ethyl orthosilicate, methyltriacetoxysilane, propyltriacetoxysilane, methyltrimethoxysilane, propyltrimethoxysilane, and tetrakis(methylisobutylketoxime)silane.

[0044] They form chemical bonds between polymer chains to achieve cross-linking, and are used to improve the mechanical strength, heat resistance, wear resistance, and other properties of polymer materials. In some embodiments of this solution, methyl orthosilicate and methyl triacetoxysilane can react with hydroxyl groups on the surface of the material at room temperature to form silicon-oxygen bonds, thereby enhancing the bonding strength.

[0045] In some embodiments, the catalyst includes dioctyltin diacetate or tributylbismuth oxide. The above catalysts can promote the reaction between reactants by providing active centers. In this embodiment, the preferred catalyst is tributylbismuth oxide.

[0046] A second aspect of the present invention provides a method for preparing a silicone mold glue for preparing a carbon fiber protective shell, comprising the following steps:

[0047] a: adding calcium sulfate whisker powder to anhydrous ethanol for dispersion, adding silane coupling agent, deionized water and glacial acetic acid, heating and stirring to react, filtering and drying to obtain silane coupling agent modified calcium sulfate whisker;

[0048] b: dispersing the organic montmorillonite in the ethanol solution of the first modifier for reaction, then adding ethyl orthosilicate for reaction, filtering, vacuum drying, and calcining to obtain the modified organic montmorillonite;

[0049] c: Mix polydimethylsiloxane, silane coupling agent modified calcium sulfate whisker and modified organic montmorillonite, then add crosslinking agent and catalyst to react, remove bubbles, and obtain silicone mold glue.

[0050] It should be noted that the raw material proportions of the silicone mold glue in the preparation method are calculated by weight and include: 98-100 parts of polydimethylsiloxane, 2-5 parts of cross-linking agent, 0.1-0.2 parts of catalyst, 1-3 parts of silane coupling agent modified calcium sulfate whiskers, and 2-4 parts of modified organic montmorillonite.

[0051] In some embodiments, the silane coupling agent is an aqueous solution of KH560 with a concentration of 3% to 5%.

[0052] In some embodiments, in step a, the reaction temperature of the heated stirring reaction is 70°C to 80°C, the reaction time is 4h to 6h, the pH value is 2 to 3, the stirring speed is 500r / min to 600r / min, and the drying temperature is 85°C to 90°C.

[0053] The amount of modifier and the modification temperature will directly affect the solubility and retention rate of the whiskers. The modified pH value has a significant effect on the modification effect of the whiskers. The pH value will affect the surface charge and solubility of the whiskers. This scheme sets the modification parameters within the above range to obtain the best modification effect.

[0054] In some embodiments, in step b, the calcination temperature is 400° C. to 450° C. and the calcination time is 3 h to 6 h.

[0055] In some embodiments, the organic montmorillonite is dispersed in a dodecylamine ethanol solution, and the quaternary ammonium salt can be used as a cation exchanger, and its long chain structure helps to intercalate into the interlayer of the montmorillonite. The dodecylamine reacts with the cations between the montmorillonite layers to form an ammonium salt of the organic montmorillonite, thereby changing the surface properties of the montmorillonite. Tetraethyl orthosilicate (TEOS) is added to the reaction system at 40°C, and the tetraethyl orthosilicate is hydrolyzed and condensed to form silanols, which can further react with silanols or organic amines between the montmorillonite layers to form siloxane bonds, thereby achieving the modification of the montmorillonite.

[0056] In some embodiments, the dried solid is calcined at 400° C. to 450° C. for 3 to 6 hours. The purpose of calcination is to remove the organic amine and promote the formation of siloxane bonds, thereby finally obtaining a modified organic montmorillonite.

[0057] The third aspect of the present invention provides a silicone mold, wherein the silicone mold comprises the above-mentioned silicone mold glue. Figure 1 and Figure 2 The protective shell molds are respectively a core mold 1 and a silicone sleeve 3, wherein the core mold 1 is a solid inner core made of aluminum alloy, and the molding surface is coated with a layer of 0.3mm-0.5mm silicone mold glue 3, which has the advantages of easy demoulding and can ensure the precise size of the protective shell product. The product is molded in a way that the surface of the core mold is coated with a layer of silicone, without the use of a release agent, which is convenient for demoulding, uniform molding pressure, good surface quality, and no post-processing is required.

[0058] Figure 1 and Figure 2 The figure is only an embodiment of a mobile phone protective case. The specific shapes of the core mold 1, the protective case 2, and the silicone mold 3 of this scheme are not limited, and can be used to protect electronic products such as mobile phones, tablet computers, e-readers, medical equipment, and headphone charging boxes.

[0059] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0060] Example 1

[0061] 1. Preparation of silicone mold glue materials

[0062] 1 kg of calcium sulfate whisker powder was added to anhydrous ethanol and ultrasonically dispersed for 15 minutes; then, silane coupling agent KH560 and deionized water were placed in a beaker and allowed to stand for 10 minutes to prepare a 4% solution, and the pH value was adjusted to 3 with glacial acetic acid solution; then, the KH560 solution was poured into the calcium sulfate whisker slurry and mixed, and the mass ratio of calcium sulfate whisker to KH560 coupling agent was 100:4, and the temperature was raised to about 80°C, and stirred at a constant temperature of 600r / min for 4 hours; the reaction was stopped, filtered, and the filter cake was extracted and washed with ethanol, and the filter cake was dried in an oven at 85°C for 12 hours, and then ground and bagged for use, and silane coupling agent modified calcium sulfate whiskers were obtained, and the average aspect ratio was 70;

[0063] The organic montmorillonite was dispersed in a dodecylamine ethanol solution, and then added with tetraethyl orthosilicate after reacting for 30 minutes. The mass ratio of the organic montmorillonite, dodecylamine and tetraethyl orthosilicate was 1:4:9. After reacting at 40°C for 5 hours, the solid was separated and dried in vacuum at 40°C. After drying, the solid was calcined at 400-450°C for 5 hours to obtain the modified organic montmorillonite.

[0064] 98 parts of polydimethylsiloxane, 2 parts of silane coupling agent modified calcium sulfate whiskers, and 2 parts of modified organic montmorillonite were added and mixed. The viscosity of polydimethylsiloxane was 70000 cP. After high-speed stirring for 10 minutes, 3 parts of butyl orthosilicate and 0.2 parts of tributyl bismuth oxide were added and stirred for 5 minutes. After vacuuming to remove bubbles, a silicone mold glue was obtained.

[0065] 2. Preparation of silicone mold

[0066] Lay two layers of 3K twill carbon fiber prepreg on the core mold, then put the silicone mold on the laid prepreg, use a vacuum bag to draw a vacuum, keep it at 140℃ in an autoclave for 20 minutes, take out the mold after cooling to room temperature, open the vacuum bag, remove the silicone mold, use a CNC machine to cut off the reserved edging of the product, and you can get a carbon fiber mobile phone protective case.

[0067] Example 2

[0068] 1. Preparation of silicone mold glue materials

[0069] 1 kg of calcium sulfate whisker powder was added to anhydrous ethanol and ultrasonically dispersed for 15 minutes; then, silane coupling agent KH560 and deionized water were placed in a beaker and allowed to stand for 10 minutes to prepare a 4% solution, and the pH value was adjusted to 3 with glacial acetic acid solution; then, the KH560 solution was poured into the calcium sulfate whisker slurry and mixed, and the mass ratio of calcium sulfate whisker to KH560 coupling agent was 100:4, and the temperature was raised to about 80°C, and stirred at a constant temperature of 600r / min for 4 hours; the reaction was stopped, filtered, and the filter cake was extracted and washed with ethanol, and the filter cake was dried in an oven at 85°C for 12 hours, and then ground and bagged for use, and silane coupling agent modified calcium sulfate whiskers were obtained, with an average aspect ratio of 55;

[0070] The organic montmorillonite was dispersed in a hexadecyltrimethylammonium bromide ethanol solution, and then added with tetraethyl orthosilicate after reacting for 30 minutes. The mass ratio of the organic montmorillonite, hexadecyltrimethylammonium bromide and tetraethyl orthosilicate was 1:4:9. After reacting at 40°C for 5 hours, the solid was separated and dried in vacuum at 40°C. After drying, the solid was calcined at 400-450°C for 5 hours to obtain the modified organic montmorillonite.

[0071] 98 parts of polydimethylsiloxane, 3 parts of silane coupling agent modified calcium sulfate whiskers, and 2 parts of modified organic montmorillonite were added. The viscosity of polydimethylsiloxane was 70000 cP. After high-speed stirring for 10 minutes, 5 parts of butyl orthosilicate and 0.2 parts of tributyl bismuth oxide were added, stirred for 5 minutes, and then vacuumed to remove bubbles to obtain a silicone mold glue.

[0072] 2. Prepare a silicone mold by referring to the steps of preparing a silicone mold in Example 1.

[0073] Example 3

[0074] 1. Preparation of silicone mold glue materials

[0075] 1 kg of calcium sulfate whisker powder was added to anhydrous ethanol and ultrasonically dispersed for 15 minutes; then, silane coupling agent KH560 and deionized water were placed in a beaker and allowed to stand for 10 minutes to prepare a 4% solution, and the pH value was adjusted to 3 with glacial acetic acid solution; then, the KH560 solution was poured into the calcium sulfate whisker slurry and mixed, and the mass ratio of calcium sulfate whisker to KH560 coupling agent was 100:4, and the temperature was raised to about 80°C, and stirred at a constant temperature of 600r / min for 4 hours; the reaction was stopped, filtered, and the filter cake was extracted and washed with ethanol, and the filter cake was dried in an oven at 85°C for 12 hours, and then ground and bagged for use, and silane coupling agent modified calcium sulfate whiskers were obtained, and the average aspect ratio was 60;

[0076] The organic montmorillonite was dispersed in a sodium dodecylbenzene sulfonate ethanol solution, and then added with tetraethyl orthosilicate after reacting for 30 minutes. The mass ratio of the organic montmorillonite, sodium dodecylbenzene sulfonate and tetraethyl orthosilicate was 1:4:9. After reacting at 40°C for 5 hours, the solid was separated and dried in vacuum at 40°C. After drying, the solid was calcined at 400-450°C for 5 hours to obtain the modified organic montmorillonite.

[0077] 98 parts of polydimethylsiloxane, 1 part of silane coupling agent modified calcium sulfate whisker, and 3 parts of modified organic montmorillonite were added. The viscosity of polydimethylsiloxane was 70000 cP. After high-speed stirring for 10 minutes, 3 parts of butyl orthosilicate and 0.2 parts of tributyl bismuth oxide were added, stirred for 5 minutes, and then vacuumed to remove bubbles to obtain a silicone mold glue.

[0078] 2. Prepare a silicone mold by referring to the steps of preparing a silicone mold in Example 1.

[0079] Comparative Example 1

[0080] The calcium sulfate whiskers in Comparative Example 1 were not modified, and the rest was referred to Example 1.

[0081] Comparative Example 2

[0082] The organic montmorillonite in Comparative Example 2 was not modified, and the rest was referred to Example 1.

[0083] Performance Test:

[0084] The tensile strength, tear strength and thermal expansion coefficient of the silicone mold glue obtained in the embodiment and the comparative example were measured, and the appearance of the prepared silicone mold after being used 500 times was observed and the results were recorded:

[0085] 1. Tensile strength

[0086] According to GB / T528-1998 standard, the tensile test was carried out using a TCS-2000 electronic system tensile testing machine with a tensile speed of 500 mm / min.

[0087] 2. Tear strength

[0088] According to GB / T529-91 standard, the tear test was carried out using a TCS-2000 electronic system tensile testing machine with a tensile speed of 500 mm / min.

[0089] 3. Thermal expansion coefficient

[0090] The thermal expansion coefficient of mold glue was tested using a TAS100 thermomechanical analyzer to study its linear expansion coefficient. The test conditions are: prepare a 10mm*10mm*2mm sample, increase the temperature from room temperature to 200℃ at a rate of 1℃ / min, and record the thermal expansion coefficient at 150℃.

[0091] Table 1: Test results of Examples 1 to 3 and Comparative Examples 1 to 2

[0092]

[0093] As can be seen from Table 1, a silicone mold glue for preparing a carbon fiber protective shell is provided, and organic montmorillonite and calcium sulfate whiskers are added to the silicone to form a composite material, wherein the montmorillonite provides additional mechanical strength and thermal stability, while the calcium sulfate whiskers further enhance the dimensional stability and rigidity of the material. This synergistic effect can significantly improve the mechanical properties, heat resistance and dimensional stability of the silicone, thereby adapting to the high-temperature and high-pressure preparation process of the carbon fiber protective shell and extending the service life of the mold. At the same time, the present invention modifies the calcium sulfate whiskers and the organic montmorillonite, further increases the dispersion of the material, promotes the physical or chemical reaction between the organic functional groups on the surface of the montmorillonite and the calcium sulfate whiskers and the silicone molecular chains, enhances the interface interaction, and at high temperatures, when the organic modifiers on the surface of the montmorillonite and the calcium sulfate whiskers are pyrolyzed, a stable carbon layer and an inorganic layer can be formed, thereby improving the thermal stability of the material.

[0094] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the main purpose of the present invention, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A silicone mold glue for preparing a carbon fiber protective shell, characterized in that: In parts by weight, the raw materials of the silicone mold glue include: 98-100 parts of polydimethylsiloxane, 2 to 5 parts of cross-linking agent, 0.1-0.2 parts of catalyst, Silane coupling agent modified calcium sulfate whisker 1-3 parts, 2 to 4 parts of modified organic montmorillonite.

2. The silicone mold glue for preparing a carbon fiber protective shell according to claim 1, characterized in that: The viscosity of the polydimethylsiloxane is 50000 cP to 100000 cP.

3. The silicone mold glue for preparing a carbon fiber protective shell according to claim 1, characterized in that: The average aspect ratio of the silane coupling agent modified calcium sulfate whisker is 55-75.

4. The silicone mold glue for preparing a carbon fiber protective shell according to claim 1, characterized in that: The modified montmorillonite modification agent comprises at least one of dodecylamine, sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide and ethyl orthosilicate.

5. The silicone mold glue for preparing a carbon fiber protective shell according to claim 1, characterized in that: The crosslinking agent includes at least one of methyl orthosilicate, butyl orthosilicate, ethyl orthosilicate, methyl triacetoxysilane, propyl triacetoxysilane, methyl trimethoxysilane, propyl trimethoxysilane, and tetrakis (methyl isobutyl ketoxime) silane.

6. The silicone mold glue for preparing a carbon fiber protective shell according to claim 1, characterized in that: The catalyst includes dioctyltin diacetate or tributylbismuth oxide.

7. A method for preparing the silicone mold glue according to any one of claims 1 to 6, characterized in that: The following steps are involved: a: adding calcium sulfate whisker powder to anhydrous ethanol for dispersion, adding silane coupling agent, deionized water and glacial acetic acid, heating and stirring to react, filtering and drying to obtain silane coupling agent modified calcium sulfate whisker; b: dispersing the organic montmorillonite in the ethanol solution of the first modifier for reaction, then adding ethyl orthosilicate for reaction, filtering, vacuum drying, and calcining to obtain the modified organic montmorillonite; c: Mix polydimethylsiloxane, silane coupling agent modified calcium sulfate whisker and modified organic montmorillonite, then add crosslinking agent and catalyst to react, remove bubbles, and obtain silicone mold glue.

8. The method for preparing the silicone mold adhesive according to claim 7, characterized in that: In step a, the reaction temperature of the heating and stirring reaction is 70°C to 80°C, the reaction time is 4h to 6h, the pH value is 2 to 3, the stirring speed is 500r / min to 600r / min, and the drying temperature is 85°C to 90°C.

9. The method for preparing the silicone mold adhesive according to claim 7, characterized in that: In step b, the calcination temperature is 400° C. to 450° C. and the calcination time is 3 h to 6 h.

10. A silicone mold, characterized in that: The silicone mold comprises the silicone mold glue as described in any one of claims 1 to 6.

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