Preparation method of composite supporting rod

Abstract

The preparation method of the composite supporting rod comprises the following steps that S1, a ceramic core shaft and an HMSPP outer shaft are prepared in advance, and the ceramic core shaft and the HMSPP outer shaft are alternately cleaned with water and acetone and dried; s2, the surface of the ceramic mandrel is coated with a polyimide layer, and curing forming is carried out; and S3, an injection mold is preheated to 60 DEG C and vacuumized, then the supporting layer low-temperature curing material system is injected into the injection mold, curing is conducted according to the procedures of 60 DEG C / 4 h, 70 DEG C / 4 h, 80 DEG C / 4 h and 100 DEG C, and low-temperature curing is conducted between the polyimide layer and the HMSPP outer shaft to form the supporting layer. According to the invention, the advantage of light weight of the ceramic core shaft is combined with the excellent thermal stability, impact strength and environmental protection performance of the high-melt-strength polypropylene, and the thermal stability and low contractibility of the supporting layer are utilized, so that the requirements of low weight, high impact strength and high heat resistance of the marine sports equipment are met.

Description

Technical Field

[0001] The invention relates to a method for preparing a composite support rod. Background Art

[0002] There are many types of marine sports equipment, such as surfboards, lifebuoy core materials, floating lifesaving equipment and other products that use support rods. At present, ordinary support brackets are classified according to the material, mainly including metal rods, plastic rods, glass rods, etc. Metal rods are generally heavy and cannot meet the requirements of marine sports equipment for lightweight. Plastic rods and glass rods have low bearing capacity and cannot meet the requirements of marine sports equipment for high impact strength. At the same time, marine sports equipment will be exposed to high temperature environments for a long time, so the heat resistance of the product is required to be high.

[0003] Therefore, a method for preparing a composite support rod having light weight, strong impact strength and high heat resistance is urgently needed. Summary of the invention

[0004] In order to solve the defects in the prior art, the present invention provides a method for preparing a composite support rod.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: The present invention provides a method for preparing a composite support rod, wherein the composite support rod comprises a ceramic core shaft, a polyimide layer, a support layer and a HMSPP outer shaft, wherein the polyimide layer is coated on the surface of the ceramic core shaft, the support layer is coated on the surface of the polyimide layer, and the HMSPP outer shaft is coated on the surface of the support layer. The method for preparing the composite support rod comprises the following steps: S1. Prepare a ceramic mandrel and a HMSPP outer shaft in advance, wash and dry the ceramic mandrel and the HMSPP outer shaft alternately with water and acetone, and complete the last washing with acetone; S2, coating a polyimide layer on the surface of the ceramic mandrel and performing curing and molding, and after the curing is completed, placing the ceramic mandrel and the HMSPP outer shaft coaxially into the injection mold; S3. Preheat the injection mold to 60°C and evacuate it, then inject the support layer low-temperature curing material system into the injection mold, and cure it according to the program of 60°C / 4h, 70°C / 4h, 80°C / 4h, and 100°C, and perform low-temperature curing between the polyimide layer and the HMSPP outer shaft to form a support layer.

[0006] S31, select 60-80 parts by weight of cyanate resin and heat it to 70° C., add 6-8 parts by weight of polysilazane, stir and mix evenly, and carry out exothermic reaction. After the reaction is completed, keep 70° C.; S32, adding 18-25 parts by weight of benzoxazine resin, 2-6 parts by weight of auxiliary agent, and 5-10 parts by weight of modified resin to the material after the reaction in step S31, stirring and reacting, and maintaining 60° C. for standby use after the reaction is completed; S33, preheating the injection mold to 60°C, injecting the support layer material prepared in step S32 into the injection mold, and injecting it into between the polyimide layer and the HMSPP outer shaft, and then performing low-temperature curing.

[0007] Preferably, in step S2, the curing temperature of the polyimide layer is 300-350° C., and the curing time is 6-8 hours.

[0008] Preferably, the HMSPP outer shaft is made by HMSPP foaming.

[0009] Preferably, the preparation method of the support layer low temperature curing material system is as follows: S31, select 60-80 parts by weight of cyanate resin and heat it to 70°C, add 6-8 parts by weight of polysilazane and stir to mix evenly, and carry out exothermic reaction, the reaction temperature of the system is 80-100°C, and after the reaction is completed, keep 70°C; S32, adding 18 to 25 parts by weight of benzoxazine resin to the material after the reaction in step S31, stirring and performing an exothermic reaction, the system reaction temperature is 60-90° C., and after the reaction is completed, the temperature is maintained at 60° C. for standby use; S33, adding 2 to 6 parts by weight of auxiliary agent and 5 to 10 parts by weight of modified resin to the material after the reaction in step S32, and mixing them thoroughly at 30 to 40°C to obtain a support layer low-temperature curing material system.

[0010] Preferably, the cyanate resin is at least one of the monomers or prepolymers of bisphenol A cyanate, bisphenol E cyanate, bisphenol M cyanate, novolac cyanate, dicyclopentadiene cyanate, and bisphenol F cyanate; The polysilazane is at least one of polymethyl-hydrogensilazane, polydimethylsilazane, polymethyl-vinylsilazane, and polymethyl-ethylsilazane; The benzoxazine resin is a monofunctional or multifunctional bisphenol A type benzoxazine monomer or oligomer, a monofunctional or multifunctional bisphenol F type benzoxazine monomer or oligomer, a monofunctional or multifunctional dicyclopentadiene type benzoxazine monomer or oligomer, a monofunctional or multifunctional [-Si-O-] n - at least one of a benzoxazine monomer or polymer having a repeating unit; The auxiliary agent is at least one of monourea, diurea, imidazole, 2-ethyl-4-methylimidazole, and DMP-30; The modified resin is at least one of bisphenol A epoxy resin E-51, bisphenol A epoxy resin E-54, bisphenol A epoxy resin E-44, novolac epoxy resin F-51, novolac epoxy resin F-44, novolac epoxy resin F-46, bisphenol S epoxy resin, and silicone epoxy resin 665.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The ceramic core shaft of the present invention is light in weight, adopts a solid structure, and has a certain bearing capacity, which meets the requirements of floating marine sports equipment on water.

[0012] (2) The HMSPP outer shaft in the present invention is foamed by injection molding equipment. The high melt strength polypropylene has a melt strength that is more than 50% higher than that of ordinary PP, and the foaming ratio can reach more than 20 times. The HMSPP outer shaft is foamed using it and used as the outermost layer of the support rod. It is used in marine sports equipment and has good thermal stability and dimensional stability of the product at high temperatures. It also has high toughness, tensile strength and impact strength, a suitable and soft surface, as well as degradability and environmental adaptability, so that the product has good structural stability in a high temperature environment.

[0013] (3) In the present invention, the support layer selects a polysilazane catalyst and a cyanate ester to form an activated intermediate with a -NH-C≡N structure. The activated intermediate continues to react to generate a stable triazine ring resonance system and promotes the ring-opening polymerization of the benzoxazine resin. The synergistic effect of the two can promote the cyanate resin system to be rapidly cured at a temperature below 100°C, thereby avoiding the phenomenon of residual internal thermal stress caused by the high-temperature curing process, reducing the shrinkage rate, and improving the structural dimensional stability. The cured resin has good thermal stability.

[0014] (4) The composite support rod prepared by the present invention combines the lightweight advantages of the ceramic core shaft with the excellent thermal stability, impact strength and environmental protection performance of high melt strength polypropylene, and through the thermal stability and low shrinkage of the support layer, it meets the requirements of marine sports equipment for light weight, strong impact strength and high heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural cross-sectional view of the composite support rod of the present invention.

[0016] In the figure: 1. Ceramic core shaft; 2. Polyimide layer; 3. Support layer; 4. HMSPP outer shaft. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. Example 1

[0018] This embodiment provides a method for preparing a composite support rod, and the method for preparing a composite support rod comprises the following steps: S1. Prepare a ceramic core shaft 1 and an HMSPP outer shaft 4 in advance, wash and dry the ceramic core shaft 1 and the HMSPP outer shaft 4 alternately with water and acetone, and complete the last washing with acetone; wherein the HMSPP outer shaft is prepared by HMSPP foaming; S2, coating a polyimide layer 2 on the surface of the ceramic core shaft 1, and curing and molding, after the curing is completed, placing the ceramic core shaft 1 and the HMSPP outer shaft 4 coaxially into the injection mold; wherein the curing temperature is 300° C., and the curing time is 8 hours; S3. Preheat the injection mold to 60°C and evacuate it, then inject the support layer low-temperature curing material system into the injection mold, and cure it according to the program of 60°C / 4h, 70°C / 4h, 80°C / 4h, and 100°C, and perform low-temperature curing between the polyimide layer and the HMSPP outer shaft to form a support layer. The preparation method of the support layer low-temperature curing material system is as follows: S31, select 180g of cyanate resin and heat it to 70°C, add 18g of polymethyl-hydrogen silazane and stir to mix evenly, and carry out an exothermic reaction. The reaction temperature of the system is 80-100°C, and the reaction is maintained at 70°C after completion; S32, add 54g of benzoxazine resin to the material after the reaction in step S31, stir and carry out an exothermic reaction, the reaction temperature of the system is 60-90°C, and the reaction is maintained at 60°C for standby use after completion; S33, add 6g of 2-ethyl-4-methylimidazole and 30g of E-44 epoxy resin to the material after the reaction in step S32, and mix them thoroughly at 40°C to obtain the support layer low-temperature curing material system.

[0019] Finally, a composite support rod (such as Figure 1 As shown), it includes a ceramic core shaft 1, a polyimide layer 2, a support layer 3 and a HMSPP outer shaft 4, the polyimide layer 2 is coated on the surface of the ceramic core shaft 1, the support layer 3 is coated on the surface of the polyimide layer 2, and the HMSPP outer shaft 4 is coated on the surface of the support layer 3. Example 2

[0020] This embodiment provides a method for preparing a composite support rod, and the method for preparing a composite support rod comprises the following steps: S1. Prepare a ceramic core shaft 1 and an HMSPP outer shaft 4 in advance, wash and dry the ceramic core shaft 1 and the HMSPP outer shaft 4 alternately with water and acetone, and complete the last washing with acetone; wherein the HMSPP outer shaft is prepared by HMSPP foaming; S2, coating a polyimide layer 2 on the surface of the ceramic core shaft 1, and curing and molding, after the curing is completed, placing the ceramic core shaft 1 and the HMSPP outer shaft 4 coaxially into the injection mold; wherein the curing temperature is 350° C., and the curing time is 8 hours; S3. Preheat the injection mold to 60°C and evacuate it, then inject the support layer low-temperature curing material system into the injection mold, and cure it according to the program of 60°C / 4h, 70°C / 4h, 80°C / 4h, and 100°C, and perform low-temperature curing between the polyimide layer and the HMSPP outer shaft to form a support layer. The preparation method of the support layer low-temperature curing material system is as follows: S31, select 240g of cyanate resin and heat it to 70°C, add 24g of polymethyl-vinylsilazane and stir to mix evenly, and carry out an exothermic reaction. The reaction temperature of the system is 80-100°C, and the reaction is maintained at 70°C after completion; S32, add 75g of benzoxazine resin to the material after the reaction in step S31, stir and carry out an exothermic reaction, the reaction temperature of the system is 60-90°C, and the reaction is maintained at 60°C for standby use after completion; S33, add 18g of 2-ethyl-4-methylimidazole and 15g of E-51 epoxy resin to the material after the reaction in step S32, and mix them thoroughly at 40°C to obtain the support layer low-temperature curing material system. Example 3

[0021] This embodiment provides a method for preparing a composite support rod, and the method for preparing a composite support rod comprises the following steps: S1. Prepare a ceramic core shaft 1 and an HMSPP outer shaft 4 in advance, wash and dry the ceramic core shaft 1 and the HMSPP outer shaft 4 alternately with water and acetone, and complete the last washing with acetone; wherein the HMSPP outer shaft is prepared by HMSPP foaming; S2, coating a polyimide layer 2 on the surface of the ceramic core shaft 1, and curing and molding, after the curing is completed, placing the ceramic core shaft 1 and the HMSPP outer shaft 4 coaxially into the injection mold; wherein the curing temperature is 320° C., and the curing time is 7 hours; S3. Preheat the injection mold to 60°C and evacuate it, then inject the support layer low-temperature curing material system into the injection mold, and cure it according to the program of 60°C / 4h, 70°C / 4h, 80°C / 4h, and 100°C, and perform low-temperature curing between the polyimide layer and the HMSPP outer shaft to form a support layer. The preparation method of the support layer low-temperature curing material system is as follows: S31, select 210g of cyanate resin and heat it to 70°C, add 20g of polydimethylsilazane and polymethyl-ethylsilazane mixture, stir and mix evenly, and carry out exothermic reaction. The reaction temperature of the system is 80-100°C, and the reaction is maintained at 70°C after completion; S32, add 60g of benzoxazine resin to the material after the reaction in step S31, stir and carry out exothermic reaction, the reaction temperature of the system is 60-90°C, and the reaction is maintained at 60°C for standby use after completion; S33, add 15g of 2-ethyl-4-methylimidazole and 20g of F-46 epoxy resin to the material after the reaction in step S32, and mix them thoroughly at 40°C to obtain the support layer low-temperature curing material system.

[0022] The following are the performance test results of the composite support rods prepared in Examples 1-3.

[0023] Example 4

[0024] The gel test results of the support layer low temperature curing material system obtained in Example 1 are shown in the following table: Example 5

[0025] The support layer low-temperature curing material system obtained in Example 1 was poured into a preheated mold, vacuumed at 60°C for 1 h, and then cured according to the procedure of 60°C / 4h, 70°C / 4h, 80°C / 4h, and 100°C / 4h to obtain a dense and hard yellow translucent cured sample.

[0026] The performance of the cured sample obtained in Example 5 was analyzed, and the results shown in the following table were obtained.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a composite support rod, characterized in that: The composite support rod comprises a ceramic core shaft (1), a polyimide layer (2), a support layer (3) and a HMSPP outer shaft (4), wherein the polyimide layer (2) is coated on the surface of the ceramic core shaft (1), the support layer (3) is coated on the surface of the polyimide layer (2), and the HMSPP outer shaft (4) is coated on the surface of the support layer (3). The preparation method of the composite support rod comprises the following steps: S1. Prepare a ceramic mandrel and a HMSPP outer shaft in advance, wash and dry the ceramic mandrel and the HMSPP outer shaft alternately with water and acetone, and complete the last washing with acetone; S2, coating a polyimide layer on the surface of the ceramic mandrel and performing curing and molding, and after the curing is completed, placing the ceramic mandrel and the HMSPP outer shaft coaxially into the injection mold; S3. Preheat the injection mold to 60°C and evacuate it, then inject the support layer low-temperature curing material system into the injection mold, and cure it according to the program of 60°C / 4h, 70°C / 4h, 80°C / 4h, and 100°C, and perform low-temperature curing between the polyimide layer and the HMSPP outer shaft to form a support layer.

2. The method for preparing a composite support rod according to claim 1, characterized in that: In the step S2, the curing temperature of the polyimide layer is 300-350° C., and the curing time is 6-8 hours.

3. The method for preparing a composite support rod according to claim 1, characterized in that: The HMSPP outer shaft is prepared by HMSPP foaming.

4. The method for preparing a composite support rod according to claim 1, characterized in that: The preparation method of the support layer low temperature curing material system is as follows: S31, select 60-80 parts by weight of cyanate resin and heat it to 70°C, add 6-8 parts by weight of polysilazane and stir to mix evenly, and carry out exothermic reaction, the reaction temperature of the system is 80-100°C, and after the reaction is completed, keep 70°C; S32, adding 18 to 25 parts by weight of benzoxazine resin to the material after the reaction in step S31, stirring and performing an exothermic reaction, the system reaction temperature is 60-90° C., and after the reaction is completed, the temperature is maintained at 60° C. for standby use; S33, adding 2 to 6 parts by weight of auxiliary agent and 5 to 10 parts by weight of modified resin to the material after the reaction in step S32, and mixing them thoroughly at 30 to 40°C to obtain a support layer low-temperature curing material system.

5. The method for preparing a composite support rod according to claim 1, characterized in that: The cyanate resin is at least one of the monomers or prepolymers of bisphenol A cyanate, bisphenol E cyanate, bisphenol M cyanate, novolac cyanate, dicyclopentadiene cyanate, and bisphenol F cyanate; The polysilazane is at least one of polymethyl-hydrogensilazane, polydimethylsilazane, polymethyl-vinylsilazane, and polymethyl-ethylsilazane; The benzoxazine resin is a monofunctional or multifunctional bisphenol A type benzoxazine monomer or oligomer, a monofunctional or multifunctional bisphenol F type benzoxazine monomer or oligomer, a monofunctional or multifunctional dicyclopentadiene type benzoxazine monomer or oligomer, a monofunctional or multifunctional [-Si-O-] n - at least one of a benzoxazine monomer or polymer having a repeating unit; The auxiliary agent is at least one of monourea, diurea, imidazole, 2-ethyl-4-methylimidazole, and DMP-30; The modified resin is at least one of bisphenol A epoxy resin E-51, bisphenol A epoxy resin E-54, bisphenol A epoxy resin E-44, novolac epoxy resin F-51, novolac epoxy resin F-44, novolac epoxy resin F-46, bisphenol S epoxy resin, and silicone epoxy resin 665.

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