Conductive unsaturated polyester resin and preparation method thereof

Abstract

The invention discloses conductive unsaturated polyester resin and a preparation method thereof, and belongs to the technical field of polyester resin. The conductive unsaturated polyester resin comprises the following raw materials in parts by weight: 15-20 parts of butenedioic anhydride; 10 to 20 parts of phthalic anhydride; 20 to 30 parts of 1, 2-propylene glycol; 20 to 60 parts of styrene; 2-10 parts of bamboo fiber; 1-8 parts of modified carbon black; 0.1-5 parts of a curing agent; 0.1 to 5 parts of an accelerant; the modified carbon black is hyperbranched polysilane grafted carbon black, and hyperbranched polysilane is obtained by hydrolytic condensation of epoxy quaternary ammonium salt siloxane, flame-retardant siloxane and anti-aging siloxane. The conductive unsaturated polyester resin prepared by the invention has excellent conductivity and flame retardance, and the problem of poor flame retardance of unsaturated polyester resin in the prior art is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester resins, and in particular relates to a conductive unsaturated polyester resin and a preparation method thereof. Background Art

[0002] Unsaturated polyester resin is generally formed by condensation of unsaturated dibasic acid diols or saturated dibasic acid unsaturated diols. It is a linear polymer compound with ester bonds and unsaturated double bonds. As a thermosetting plastic that can be cured at room temperature or high temperature, unsaturated polyester resin has excellent molding processability, low cost and good comprehensive performance. It is the most widely used matrix resin in the resin-based fiber reinforced composite material industry to date.

[0003] Unsaturated polyester resin itself is an insulating material and does not have conductivity. By adding conductive fillers to unsaturated resin, the polymer can be made conductive, thereby expanding the application range of unsaturated resin. Carbon black is a kind of conductive filler. Carbon black itself has good conductivity and can effectively improve the conductivity of the polymer system. Carbon black, as a reinforcing agent, can enhance the physical properties of polymer materials such as mechanical strength, wear resistance and flexibility. This is of great significance for improving the service life and reliability of products. The patent with patent announcement number CN102675554B discloses a conductive unsaturated polyester resin composite material and a preparation method thereof. The conductive unsaturated polyester resin is prepared from butylated anhydride, phthalic anhydride, propylene glycol, styrene, bamboo fiber, carbon black, curing agent, and accelerator as raw materials. Carbon black provides short-range conductivity, and bamboo fiber plays a lap role to form a large number of carbon black particle aggregates with chain or grape-like structures, thereby forming a uniformly distributed spatial conductive network. At the same time, the addition of fiber material and carbon black reduces the shrinkage rate of the resin material, which is conducive to ensuring the external shape of the cured product and greatly improves the mechanical properties of the composite material. However, the conductive unsaturated polyester resin still has the problem of poor flame retardancy. In the fields of electronics and electrical engineering, conductive unsaturated polyester resin is often used as an insulating material or structural material. If the material is flammable, once a fire occurs, it will spread rapidly, threatening not only the safety of life, but also causing significant property losses. Therefore, it is necessary to improve the flame retardancy of the conductive unsaturated polyester resin. Summary of the invention

[0004] In order to solve the problem of poor flame retardancy of conductive unsaturated polyester resin in the prior art, the object of the present invention is to provide a conductive unsaturated polyester resin and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a conductive unsaturated polyester resin, comprising the following raw materials in parts by weight: 15-20 parts of maleic anhydride; 10-20 parts of phthalic anhydride; 20-30 parts of 1,2-propylene glycol; 20-60 parts of styrene; 2-10 parts of bamboo fiber; 1-8 parts of modified carbon black; 0.1-5 parts of curing agent; and 0.1-5 parts of accelerator; the modified carbon black is a hyperbranched polysilane grafted carbon black, and the hyperbranched polysilane is obtained by hydrolysis and condensation of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane.

[0006] Further, the modified carbon black is prepared by the following steps: Mix carbon black, acetic acid aqueous solution and anhydrous ethanol, and disperse them by ultrasonic for 1-1.5 hours. , add polysilane monomer, keep warm for 24 hours, filter, wash, 60-70 The modified carbon black was obtained by drying.

[0007] Among them, the dosage ratio of carbon black, acetic acid aqueous solution, anhydrous ethanol and polysilane monomer is 0.2g:1mL:6-8mL:2g; the mass fraction of acetic acid aqueous solution is 66.7%; the polysilane monomer is composed of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane in a mass ratio of 1:(0.3-0.7):(0.3-0.7).

[0008] Carbon black, as a conductive filler, can improve the conductivity of unsaturated polyester resin, but carbon black is prone to agglomeration, which limits the improvement of the conductivity of unsaturated polyester resin. In the above steps, hyperbranched polysilane is grafted on the surface of carbon black. The branched structure of hyperbranched polysilane forms a protective layer on the surface of carbon black, which increases the steric hindrance between carbon black particles, helps to prevent carbon black particles from approaching and agglomerating each other in the resin matrix, thereby improving the dispersibility of carbon black, improving the conductivity and mechanical properties of unsaturated polyester resin, and hyperbranched polymers have high heat resistance, which can improve the flame retardant properties of unsaturated polyester resin. The specific mechanism of hyperbranched polysilane grafting carbon black is: the surface of carbon black carries a large number of hydroxyl groups, the methoxyl groups of polysilane monomers undergo hydrolysis reaction to generate silanols, which then bond with the hydroxyl groups of carbon black through hydrogen bonds, and finally dehydrate and condense, and the remaining hydroxyl groups on the silanols dehydrate and condense with the silanols generated by the hydrolysis of the polysilane monomers, and the dehydration and condensation reaction is repeated to finally form a hyperbranched structure.

[0009] Furthermore, the preparation method of the epoxy quaternary ammonium salt siloxane is: Step A1: Mix γ-chloropropylmethyldimethoxysilane and diethylamine, and heat to 110 After reacting for 20 hours, the heating was stopped, the mixture was cooled to room temperature, dried, and filtered to obtain N,N-diethylaminopropylmethyldimethoxysilane; Wherein, the molar ratio of γ-chloropropylmethyldimethoxysilane to diethylamine is 1:4.

[0010] The chlorine on γ-chloropropylmethyldimethoxysilane combines with the hydrogen on diethylamine to form a siloxane containing a tertiary amine group, namely N,N-diethylaminopropylmethyldimethoxysilane.

[0011] Step A2: Under nitrogen protection, add N,N-diethylaminopropylmethyldimethoxysilane and anhydrous methanol into a flask and heat to 55 , add a mixture of epichlorohydrin and anhydrous ethanol dropwise, keep warm for 6 hours, remove the solvent by rotary evaporation, wash with anhydrous ether 3-4 times, and vacuum dry for 4-5 hours to obtain epoxy quaternary ammonium siloxane.

[0012] The tertiary amine of N,N-diethylaminopropylmethyldimethoxysilane reacts with the halogen in epichlorohydrin to form epoxy quaternary ammonium siloxane.

[0013] Among them, the mass ratio of N,N-diethylaminopropylmethyldimethoxysilane, anhydrous methanol, epichlorohydrin and anhydrous ethanol is 9:15:4.2:8.

[0014] Furthermore, the preparation method of the flame retardant siloxane is: Under nitrogen protection, at -40 In a low-temperature tank, γ-aminopropyltriethoxysilane, triethylamine and toluene were mixed, and diphenylphosphine chloride was added dropwise after stirring for 10 minutes. The mixture was added dropwise within 30 minutes. After stirring for 15 minutes, the mixture was removed from the low-temperature tank, stirred at room temperature for 2.5 hours, filtered, washed, and the filtrate was combined and rotary evaporated to obtain flame-retardant siloxane.

[0015] Among them, the volume ratio of γ-aminopropyltriethoxysilane, triethylamine, toluene and diphenylphosphine chloride is 3.5:4.6:(60-70):5.6.

[0016] The amino group of γ-aminopropyltriethoxysilane reacts with diphenylphosphine chloride, and triethylamine is used as an acid-binding agent to obtain flame-retardant siloxane, which contains nitrogen, phosphorus and silicon flame-retardant elements.

[0017] Furthermore, the preparation method of the anti-aging siloxane is: Step A1: Add 2,4-dihydroxybenzophenone and 3-chloro-1-propanethiol to N,N-dimethylformamide, and then add potassium carbonate. , 300-500r / min stirring reaction 2-3h, at 6Pa, 55 Dry for 7 hours to obtain 2-hydroxy-4-(3-mercaptopropoxy)benzophenone; Among them, the usage ratio of 2,4-dihydroxybenzophenone, 3-chloro-1-propanethiol, N,N-dimethylformamide and potassium carbonate is 2.1g:1.1g:21-25mL:0.06g.

[0018] The hydroxyl group of 2,4-dihydroxybenzophenone reacts with the chlorine atom of 3-chloro-1-propanethiol via nucleophilic substitution reaction, and potassium carbonate is used as a base to promote the reaction, thereby obtaining 2-hydroxy-4-(3-mercaptopropoxy)benzophenone.

[0019] Step A2: Add 2-hydroxy-4-(3-mercaptopropoxy)benzophenone to a flask containing methanol and deionized water, and stir to obtain a mixed solution a. The control system is 70 , add a mixed solution b consisting of allyltrimethoxysilane, methanol and azobisisobutyronitrile to the flask. After the addition is completed, keep warm for 5-6 hours. After the reaction is completed, cool to room temperature, filter, wash, and vacuum dry to obtain anti-aging siloxane.

[0020] Among them, the mass ratio of 2-hydroxy-4-(3-mercaptopropoxy)benzophenone, methanol and deionized water in the mixed solution a is 2.9:40:4; the mass ratio of methanol, allyltrimethoxysilane and azobisisobutyronitrile in the mixed solution b is (15-17):1.6:0.2.

[0021] The mercapto group in 2-hydroxy-4-(3-mercaptopropoxy)benzophenone and the carbon-carbon double bond in allylsiloxane undergo a thiol-double bond click addition reaction to obtain anti-aging siloxane.

[0022] Furthermore, the length of the bamboo fiber is 5-10 mm.

[0023] Furthermore, the curing agent is any one of cyclohexanone peroxide, methyl ethyl ketone peroxide, and benzoyl peroxide.

[0024] Furthermore, the accelerator is any one of cobalt epoxyate, cobalt isooctanoate, dimethylaniline and diethylaniline.

[0025] In a second aspect, the present invention provides a method for preparing a conductive unsaturated polyester resin, comprising the following steps: Step C1: Add maleic anhydride, phthalic anhydride, 1,2-propylene glycol, and modified carbon black into the reaction vessel, pass nitrogen gas for protection, and heat to 80°C within 30 minutes. , stir thoroughly for 1.5h and then heat to 160 After 30 minutes of reaction, take a sample to measure the acid value; gradually increase the temperature and maintain it at 200 , the acid value was measured every 30 minutes, and when the acid value reached 50±2 mgKOH / g, heating was stopped, hydroquinone was added to terminate the reaction, and the mixture was cooled to room temperature to obtain modified carbon black / unsaturated polyester; Step C2: Add styrene, bamboo fiber and accelerator to the modified carbon black / unsaturated polyester at room temperature, mix, add curing agent, stir, and heat to 60 , and cured for 3 hours to obtain a conductive unsaturated polyester resin.

[0026] Beneficial effects of the present invention: 1. In the process of preparing conductive unsaturated polyester resin, the present invention significantly improves the conductivity, flame retardant properties and mechanical properties of unsaturated polyester resin by adding carbon black grafted with hyperbranched polysilane. Hyperbranched polysilane is formed by hydrolysis and condensation of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane; epoxy quaternary ammonium salt siloxane can make the carbon black surface carry epoxy groups, and these epoxy groups further react with the hydroxyl groups on the surface of bamboo fiber, thereby improving the dispersibility of modified carbon black, so that a tighter network structure can be formed between bamboo fiber and modified carbon black, further enhancing the conductive properties of unsaturated polyester resin. In addition, the addition of bamboo fiber not only improves the mechanical properties of the resin material, but also gives it antibacterial properties. The epoxy group reacts with the hydroxyl groups on the surface of bamboo fiber, so that the bamboo fiber is more evenly dispersed in the matrix, thereby further improving the mechanical properties and antibacterial properties of the resin material.

[0027] 2. The epoxy quaternary ammonium salt siloxane contains quaternary ammonium salt groups, which can improve the antibacterial property of the resin material; the flame retardant siloxane contains nitrogen-phosphorus-silicon flame retardant elements, which can give the resin material flame retardant properties; the anti-aging siloxane contains benzophenone groups and sulfur elements, and the benzophenone groups have the ability to absorb ultraviolet rays, which can improve the anti-aging properties of the resin material. The sulfur element is a flame retardant element, which can play a synergistic role with flame retardant elements such as nitrogen-phosphorus-silicon to jointly improve the flame retardant properties of the polyester material. And the flame retardant, antibacterial agent or ultraviolet absorber is easily precipitated when added to the substrate alone. The present invention effectively improves the flame retardant, antibacterial, anti-aging properties and timeliness of the resin material by introducing flame retardants, antibacterial agents and ultraviolet absorbers into hyperbranched polysilane, and solves the problem that small molecule additives are easily precipitated, resulting in poor effects. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] A conductive unsaturated polyester resin comprises the following raw materials in parts by weight: 15 parts of maleic anhydride; 10 parts of phthalic anhydride; 20 parts of 1,2-propylene glycol; 20 parts of styrene; 2 parts of bamboo fiber, the length of the bamboo fiber is 5-10 mm; 1 part of modified carbon black; 0.1 part of cyclohexanone peroxide; and 0.1 part of cobalt epoxylate.

[0031] Modified carbon black is made by the following steps: 0.2 g of carbon black, 1 mL of acetic acid solution and 7 mL of anhydrous ethanol were mixed and ultrasonically dispersed for 1.2 h. The temperature was controlled at 75 , add 2g polysilane monomer, keep warm for 24h, filter, wash, 65 The polysilane monomer is composed of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane in a mass ratio of 1:0.3:0.7.

[0032] The preparation method of epoxy quaternary ammonium salt siloxane is: Step A1: Mix 1.8 g of γ-chloropropylmethyldimethoxysilane and 2.9 g of diethylamine, and heat to 110 After reacting for 20 hours, the heating was stopped, the mixture was cooled to room temperature, dried, and filtered to obtain N,N-diethylaminopropylmethyldimethoxysilane; Step A2: Under nitrogen protection, add 9 g of N,N-diethylaminopropylmethyldimethoxysilane and 15 g of anhydrous methanol into a flask and heat to 55 , add dropwise a mixture of 4.2 g of epichlorohydrin and 8 g of anhydrous ethanol, keep warm for 6 h, remove the solvent by rotary evaporation, wash with anhydrous ether 4 times, and vacuum dry for 4.5 h to obtain epoxy quaternary ammonium siloxane.

[0033] The preparation method of flame retardant siloxane is: Under nitrogen protection, at -40 In a low-temperature tank, 3.5 mL of γ-aminopropyltriethoxysilane, 4.6 mL of triethylamine and 65 mL of toluene were mixed, and 5.6 mL of diphenylphosphine chloride was added dropwise after stirring for 10 min. The mixture was added within 30 min, and the mixture was stirred for 15 min before being removed from the low-temperature tank. The mixture was stirred at room temperature for 2.5 h, filtered, washed, and the filtrate was combined and rotary evaporated to obtain flame-retardant siloxane.

[0034] The preparation method of anti-aging siloxane is: Step A1: 2.1 g of 2,4-dihydroxybenzophenone and 1.1 g of 3-chloro-1-propanethiol were added to 23 mL of N,N-dimethylformamide, and then 0.06 g of potassium carbonate was added. , 400r / min stirring reaction for 2.5h, at 6Pa, 55 Dry for 7 hours to obtain 2-hydroxy-4-(3-mercaptopropoxy)benzophenone; Step A2: Add 2.9 g of 2-hydroxy-4-(3-mercaptopropoxy)benzophenone into a flask containing 40 g of methanol and 4 g of deionized water, and stir to obtain a mixed solution a. The control system is 70 , add a mixed solution b consisting of 1.6 g of allyltrimethoxysilane, 16 g of methanol and 0.2 g of azobisisobutyronitrile to the flask. After the addition is completed, keep warm and react for 5.5 hours. After the reaction is completed, cool to room temperature, filter, wash, and vacuum dry to obtain anti-aging siloxane.

[0035] The preparation method of the conductive unsaturated polyester resin comprises the following steps: Step C1: Add maleic anhydride, phthalic anhydride, 1,2-propylene glycol, and modified carbon black into the reaction vessel, pass nitrogen gas for protection, and heat to 80°C within 30 minutes. , stir thoroughly for 1.5h and then heat to 160 After 30 minutes of reaction, take a sample to measure the acid value; gradually increase the temperature and maintain it at 200 , the acid value was measured every 30 minutes, and when the acid value reached 50±2 mgKOH / g, heating was stopped, hydroquinone was added to terminate the reaction, and the mixture was cooled to room temperature to obtain modified carbon black / unsaturated polyester; Step C2: Add styrene, bamboo fiber and accelerator to the modified carbon black / unsaturated polyester at room temperature, mix, add curing agent, stir, and heat to 60 , and cured for 3 hours to obtain a conductive unsaturated polyester resin.

[0036] Example 2

[0037] Compared with Example 1, this embodiment is different in that: A conductive unsaturated polyester resin comprises the following raw materials in parts by weight: 17 parts of maleic anhydride; 15 parts of phthalic anhydride; 25 parts of 1,2-propylene glycol; 40 parts of styrene; 6 parts of bamboo fiber, the length of the bamboo fiber is 5-10 mm; 4.5 parts of modified carbon black; 2.5 parts of methyl ethyl ketone peroxide; and 2.5 parts of cobalt isooctanoate.

[0038] The polysilane monomer is composed of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane in a mass ratio of 1:0.7:0.3.

[0039] The remaining materials and steps are the same as in Example 1.

[0040] Example 3

[0041] Compared with Example 1, this embodiment is different in that: A conductive unsaturated polyester resin comprises the following raw materials in parts by weight: 20 parts of maleic anhydride; 20 parts of phthalic anhydride; 30 parts of 1,2-propylene glycol; 60 parts of styrene; 10 parts of bamboo fiber, the length of the bamboo fiber is 5-10 mm; 8 parts of modified carbon black; 5 parts of benzoyl peroxide; and 5 parts of diethylaniline.

[0042] The polysilane monomer is composed of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane in a mass ratio of 1:0.5:0.5.

[0043] The remaining materials and steps are the same as in Example 1.

[0044] Example 4

[0045] Compared with Example 1, this embodiment is different in that: The amount of modified carbon black added is 0.5 parts, and the other raw materials and steps are the same as Example 1.

[0046] Example 5

[0047] Compared with Example 3, this embodiment is different in that: The amount of modified carbon black added is 8.5 parts, and the other raw materials and steps are the same as Example 3.

[0048] Comparative Example 1

[0049] This comparative example is compared with Example 1, except that:

[0050] The polysilane monomer is composed of epoxy quaternary ammonium salt siloxane and flame retardant siloxane in a mass ratio of 1:1.

[0051] The remaining materials and steps are the same as in Example 1.

[0052] Comparative Example 2

[0053] This comparative example is compared with Example 1, except that:

[0054] The polysilane monomer is composed of epoxy quaternary ammonium salt siloxane and anti-aging siloxane in a mass ratio of 1:1.

[0055] The remaining materials and steps are the same as in Example 1.

[0056] Comparative Example 3

[0057] This comparative example is compared with Example 1, except that:

[0058] The polysilane monomer is KH560, and the other raw materials and steps are the same as in Example 1.

[0059] Comparative Example 4

[0060] This comparative example is compared with Example 1, except that:

[0061] Modified carbon black is made by the following steps: 0.2 g of carbon black, 1 mL of acetic acid solution and 7 mL of anhydrous ethanol were mixed and ultrasonically dispersed for 1.2 h. The temperature was controlled at 75 , add 0.02g KH560, keep warm for 24h, filter, wash, 65 The modified carbon black was obtained by drying.

[0062] The remaining materials and steps are the same as in Example 1.

[0063] Comparative Example 5

[0064] This comparative example is compared with Example 1, except that:

[0065] The carbon black was not modified, and the other raw materials and steps were the same as in Example 1.

[0066] The performance of the conductive unsaturated polyester resins prepared in Examples 1 to 5 and Comparative Examples 1 to 5 was tested. The results are shown in Table 1.

[0067] Among them, the volume resistivity is carried out in accordance with GB / T 15738-2008 standard.

[0068] The test method for antibacterial performance is as follows: the unsaturated polyester resin obtained in each embodiment and comparative example is tested according to the test method of GB / T21866-2008, and 200 μL of a concentration of 1×10 -7 A drop of Escherichia coli liquid with 100 CFU / mL was placed on the surface of the sample after UV sterilization, and the sample was incubated for 1 hour before being rinsed. 20 μL of the eluate was taken and incubated in the culture medium for 48 hours before recording the colony number N. The colony number of the blank group was M, and the sterilization rate was calculated as (M–N) / M×100%.

[0069] The flame retardant performance test is carried out in accordance with GB / T 2406.3-2022 standard, the tensile strength test is carried out in accordance with ISO 527-4:2021 standard, and the yellowness index test is carried out in accordance with ASTM D6290-2019 standard.

[0070] Table 1

[0071] It can be seen from Table 1 that the comprehensive performance of the unsaturated polyester resins prepared in Examples 1 to 5 is better than the comprehensive performance of the unsaturated polyester resins prepared in Comparative Examples 1 to 5.

[0072] Compared with Example 1 and Example 3, Example 4 and Example 5 are different in that the amount of modified carbon black added in Example 4 is less, and the amount of modified carbon black added in Example 5 is more. The comprehensive performance of both is lower than that of Example 1 and Example 3, indicating that adding too much or too little modified carbon black is not conducive to improving the performance of unsaturated polyester resin, and the amount of modified carbon black added in the present invention is the optimal amount.

[0073] Compared with Example 1, Comparative Example 1 is different in that Comparative Example 1 does not contain anti-aging siloxane, so its yellowness index is higher than that of Example 1, indicating that the benzophenone group has the ability to absorb ultraviolet rays and can improve the aging resistance of the resin material; The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 does not contain flame retardant siloxane, so its limiting oxygen index is lower than that of Example 1, indicating that the flame retardant siloxane contains nitrogen, phosphorus and silicon flame retardant elements, which can give the resin material flame retardant properties. The unsaturated polyester resin prepared in Comparative Example 2 still has certain flame retardant properties, indicating that sulfur is a flame retardant element that can improve the flame retardant properties of the material.

[0074] Compared with Example 1, Comparative Example 3 differs in that there is no flame retardant siloxane and anti-aging siloxane, its antibacterial rate and limiting oxygen index are lower than those of Example 1, and its yellowness index is higher than that of Example 1, but its tensile strength is similar to that of Example 1, indicating that the epoxy group can further react with the hydroxyl group on the surface of the bamboo fiber, thereby further improving the dispersibility of the modified carbon black, and the bamboo fiber can improve the mechanical properties of the resin material. The reaction of the epoxy group with the hydroxyl group on the surface of the bamboo fiber can make the bamboo fiber more evenly dispersed in the matrix, thereby further improving the mechanical properties of the resin material.

[0075] Compared with Example 1, Comparative Example 4 does not contain a hyperbranched structure, and the carbon black is only modified by a silane coupling agent. The dispersibility of the carbon black is lower than that of Example 1, and its comprehensive performance is reduced compared with that of Example 1.

[0076] Compared with Example 1, in Comparative Example 5, no modifier is added, the carbon black is easy to agglomerate, and its comprehensive performance is the worst.

[0077] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0078] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A conductive unsaturated polyester resin, characterized in that: The invention comprises the following raw materials in parts by weight: 15-20 parts of maleic anhydride; 10-20 parts of phthalic anhydride; 20-30 parts of 1,2-propylene glycol; 20-60 parts of styrene; 2-10 parts of bamboo fiber; 1-8 parts of modified carbon black; 0.1-5 parts of curing agent; and 0.1-5 parts of accelerator. The modified carbon black is a hyperbranched polysilane grafted carbon black, and the hyperbranched polysilane is obtained by hydrolysis and condensation of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane.

2. A conductive unsaturated polyester resin according to claim 1, characterized in that: The modified carbon black is prepared by the following steps: Mix carbon black, acetic acid aqueous solution and anhydrous ethanol, and disperse them by ultrasonic for 1-1.5 hours. , add polysilane monomer, keep warm for 24 hours, filter, wash, 60-70 The modified carbon black was obtained by drying.

3. A conductive unsaturated polyester resin according to claim 2, characterized in that: The dosage ratio of carbon black, acetic acid aqueous solution, anhydrous ethanol and polysilane monomer is 0.2g:1mL:6-8mL:2g; the mass fraction of acetic acid aqueous solution is 66.7%; the polysilane monomer is composed of epoxy quaternary ammonium salt siloxane, flame retardant siloxane and anti-aging siloxane in a mass ratio of 1:(0.3-0.7):(0.3-0.7).

4. A conductive unsaturated polyester resin according to claim 2, characterized in that: The preparation method of the epoxy quaternary ammonium salt siloxane is: Step A1: Mix γ-chloropropylmethyldimethoxysilane and diethylamine, and heat to 110 After reacting for 20 hours, the heating was stopped, the mixture was cooled to room temperature, dried, and filtered to obtain N,N-diethylaminopropylmethyldimethoxysilane; Wherein, the molar ratio of γ-chloropropylmethyldimethoxysilane to diethylamine is 1:4; Step A2: Under nitrogen protection, add N,N-diethylaminopropylmethyldimethoxysilane and anhydrous methanol into a flask and heat to 55 , dropwise add a mixture of epichlorohydrin and anhydrous ethanol, keep warm for 6 hours, rotary evaporate, wash, and vacuum dry for 4-5 hours to obtain epoxy quaternary ammonium salt siloxane; Among them, the mass ratio of N,N-diethylaminopropylmethyldimethoxysilane, anhydrous methanol, epichlorohydrin and anhydrous ethanol is 9:15:4.2:

8.

5. A conductive unsaturated polyester resin according to claim 2, characterized in that: The preparation method of the flame retardant siloxane is: Under nitrogen protection, at -40 In a low temperature tank, γ-aminopropyltriethoxysilane, triethylamine and toluene were mixed, stirred for 10 minutes, and then diphenylphosphine chloride was added dropwise, and the mixture was added within 30 minutes. After stirring for 15 minutes, the mixture was removed from the low temperature tank, stirred at room temperature for 2.5 hours, filtered, washed, and the filtrate was combined and rotary evaporated to obtain flame retardant siloxane; Among them, the volume ratio of γ-aminopropyltriethoxysilane, triethylamine, toluene and diphenylphosphine chloride is 3.5:4.6:(60-70):5.

6.

6. A conductive unsaturated polyester resin according to claim 2, characterized in that: The preparation method of the anti-aging siloxane is: Step A1: Add 2,4-dihydroxybenzophenone and 3-chloro-1-propanethiol to N,N-dimethylformamide, and then add potassium carbonate. , 300-500r / min stirring reaction 2-3h, at 6Pa, 55 Dry for 7 hours to obtain 2-hydroxy-4-(3-mercaptopropoxy)benzophenone; Among them, the usage ratio of 2,4-dihydroxybenzophenone, 3-chloro-1-propanethiol, N,N-dimethylformamide and potassium carbonate is 2.1g:1.1g:21-25mL:0.06g; Step A2: Add 2-hydroxy-4-(3-mercaptopropoxy)benzophenone to a flask containing methanol and deionized water, and stir to obtain a mixed solution a. The control system is 70 , dropwise add a mixed solution b consisting of allyltrimethoxysilane, methanol and azobisisobutyronitrile into the flask, and after the dropwise addition is completed, heat-retain and react for 5-6 hours. After the reaction is completed, cool to room temperature, filter, wash, and vacuum dry to obtain anti-aging siloxane; Among them, the mass ratio of 2-hydroxy-4-(3-mercaptopropoxy)benzophenone, methanol and deionized water in the mixed solution a is 2.9:40:4; the mass ratio of methanol, allyltrimethoxysilane and azobisisobutyronitrile in the mixed solution b is (15-17):1.6:0.

2.

7. A conductive unsaturated polyester resin according to claim 1, characterized in that: The length of the bamboo fiber is 5-10 mm.

8. A conductive unsaturated polyester resin according to claim 1, characterized in that: The curing agent is any one of cyclohexanone peroxide, methyl ethyl ketone peroxide and benzoyl peroxide.

9. The conductive unsaturated polyester resin according to claim 1, characterized in that: The accelerator is any one of cobalt epoxyate, cobalt isooctanoate, dimethylaniline and diethylaniline.

10. The method for preparing a conductive unsaturated polyester resin according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step C1: Add maleic anhydride, phthalic anhydride, 1,2-propylene glycol, and modified carbon black into the reaction vessel, pass nitrogen gas for protection, and heat to 80°C within 30 minutes. , stir thoroughly for 1.5h and then heat to 160 After 30 minutes of reaction, take a sample to measure the acid value; gradually increase the temperature and maintain it at 200 , the acid value was measured every 30 minutes, and when the acid value reached 50±2 mgKOH / g, heating was stopped, hydroquinone was added to terminate the reaction, and the mixture was cooled to room temperature to obtain modified carbon black / unsaturated polyester; Step C2: Add styrene, bamboo fiber and accelerator to the modified carbon black / unsaturated polyester at room temperature, mix, add curing agent, stir, and heat to 60 , and cured for 3 hours to obtain a conductive unsaturated polyester resin.

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