High-temperature-resistant epoxy resin prepreg as well as preparation method and application thereof

Abstract

The invention relates to a high-temperature-resistant epoxy resin prepreg as well as a preparation method and application thereof. Comprising the following steps: preparation of a first compound, preparation of a second compound, preparation of an epoxy resin composite adhesive, coating and bonding. Different from the prior art, according to the technical scheme, the epoxy resin composite adhesive is produced by adopting a special formula and a special process, so that the produced epoxy resin composite adhesive can keep mechanical properties at a high temperature (190-220 DEG C) and also can realize good toughness, thereby improving the quality of the high-temperature-resistant epoxy resin prepreg and prolonging the service life of the high-temperature-resistant epoxy resin prepreg. Further, the requirements of high toughness and high temperature resistance of a carbon fiber composite material product are met.

Description

Technical Field

[0001] This application relates to the field of composite materials, and particularly to a high-temperature resistant epoxy prepreg, its preparation method, and uses. Background Art

[0002] Epoxy prepreg is a composite material composed of epoxy resin and reinforcing materials (such as carbon fiber, glass fiber, etc.). It has a wide range of applications in the fields of aerospace, automotive, wind power, etc., and is favored for its excellent mechanical properties, heat resistance, and chemical resistance.

[0003] In the field of bicycles, some models require V-brakes. When continuously braking downhill, the temperature of the wheel rim will instantaneously exceed 180°C. At this time, due to the low Tg point (usually lower than 180°C) of traditional carbon fiber prepreg, the wheel rim may deform or even break, endangering the safety of the rider. Summary of the Invention

[0004] In view of the above problems, this application provides an epoxy prepreg with Tg > 220°C. This product has good toughness while maintaining good mechanical properties at high temperatures (190 - 220°C), and is suitable for applications in the fields of carbon fiber sports goods and drones.

[0005] The first aspect of this application provides a preparation method for a high-temperature resistant epoxy prepreg, including the following steps:

[0006] Preparation of the first composite: Mix 10 - 30 parts by mass of bisphenol A phenolic epoxy resin, 12 - 30 parts by mass of tetrafunctional nitrogen-containing epoxy resin, 10 - 30 parts by mass of EPICLON HP-4710, and 3 - 10 parts by mass of polyvinyl formal PVF, melt them, and stir evenly under vacuum to obtain the first composite;

[0007] Preparation of the second composite: Mix 15 - 30 parts by mass of bisphenol A liquid epoxy resin, 5 - 9 parts by mass of dicyandiamide curing agent Dyhard100S, and 1 - 5 parts by mass of accelerator, stir the obtained mixture evenly, and then grind it with a three-roll mill to obtain the second composite;

[0008] Preparation of the epoxy resin composite adhesive: Mix the first composite and the second composite to obtain the epoxy resin composite adhesive;

[0009] Coating: Coat the epoxy resin composite adhesive on a double-sided release paper to obtain a resin film;

[0010] Bonding: Bond the resin film and the reinforcing material under pressure at 100 - 130°C, and wind it up after cooling to obtain the high-temperature resistant epoxy resin prepreg; in the high-temperature resistant epoxy resin prepreg, the epoxy resin composite adhesive accounts for 25 - 45 wt%, and the reinforcing material accounts for 55 - 75 wt%.

[0011] The applicant found in the research and development that: the combination of double-component A-type phenolic epoxy resin, tetra-functional nitrogen-containing epoxy resin and EPICLON HP-4710 will increase the Tg point of the epoxy resin, and the addition of polyvinyl formal PVF can improve the brittleness of the epoxy resin and the adhesion during pasting, and can bond better with the reinforcing material.

[0012] Different from the prior art, the epoxy resin composite adhesive produced by the special formula and process in this technical solution can maintain the mechanical properties at high temperature (in the range of 190 - 220°C) and achieve good toughness at the same time, thus improving the quality of the high-temperature resistant epoxy resin prepreg, and further meeting the high-toughness and high-temperature requirements of carbon fiber composite products.

[0013] In some embodiments, in the step of preparing the first composite, the melting temperature is 135 - 150°C, the stirring speed is 600 - 1000 revolutions per minute, and the stirring time is 60 - 90 minutes.

[0014] In some embodiments, in the step of preparing the second composite, the stirring speed is 100 - 300 revolutions per minute, and the stirring time is 30 - 60 minutes.

[0015] In some embodiments, in the step of preparing the epoxy resin composite adhesive, the feeding temperature of the first composite is 85 - 95°C, and the feeding temperature of the second composite is 30 - 35°C.

[0016] In some embodiments, in the coating step, the coating temperature is 67 - 73°C.

[0017] In some embodiments, in the bonding step, the bonding temperature is 100 - 130°C.

[0018] In some embodiments, in the bonding step, the reinforcing fibers include carbon fibers, glass fibers, aramid fibers, and basalt fibers.

[0019] The second aspect of this application provides a high-temperature resistant epoxy resin prepreg, and the high-temperature resistant epoxy resin prepreg is prepared by using the preparation method described in the first aspect of this application.

[0020] Different from the prior art, the epoxy resin composite adhesive produced by using a special formula and process in this technical solution enables the produced epoxy resin composite adhesive to have mechanical properties at high temperatures (in the range of 190 - 220 °C) while achieving good toughness, thereby improving the quality of the high-temperature resistant epoxy resin prepreg, and further meeting the high-toughness and high-temperature resistant requirements of carbon fiber composite products.

[0021] In some embodiments, the glass transition temperature Tg of the high-temperature resistant epoxy resin prepreg is > 220 °C.

[0022] The third aspect of this application provides the use of the high-temperature resistant epoxy resin prepreg described in the second aspect of this application in the fields of carbon fiber sports goods, industrial carbon fibers, and drones.

[0023] Different from the prior art, the high-temperature resistant epoxy resin prepreg produced by using a special formula and process in this technical solution can further meet the requirements in the fields of carbon fiber sports goods and drones.

[0024] The above relevant descriptions of the invention content are only an overview of the technical solution of this application. In order to enable those of ordinary skill in the art to more clearly understand the technical solution of this application, and thus can be implemented according to the content recorded in the specification, and in order to make the above objects, other objects, features, and advantages of this application more easily understood, the following is described in conjunction with the specific implementation manners of this application. Detailed Description of the Invention

[0025] To describe in detail the technical content, structural features, achieved objectives, and effects of the technical solution, the following is described in detail with specific embodiments.

[0026] To describe in detail the possible application scenarios, technical principles, specific implementable solutions, achievable objectives, and effects of this application, the following is described in detail with the listed specific embodiments. The embodiments described herein are only used to more clearly illustrate the technical solution of this application, so they are only examples and cannot be used to limit the protection scope of this application.

[0027] Referring to "embodiments" in this article means that the specific features, structures, or characteristics described in combination with the embodiments can be included in at least one embodiment of this application. The term "embodiment" that appears in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0028] Unless otherwise defined, the technical terms used herein have the same meanings as those commonly understood by those skilled in the technical field to which this application belongs; the use of relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0029] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that there can be three relationships. For example, A and / or B means: there is A, there is B, and there is both A and B at the same time. In addition, the character " / " herein generally represents an "or" logical relationship between the associated objects before and after.

[0030] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary or sequential relationships between these entities or operations.

[0031] Without further limitation, in this application, the expressions such as "including", "comprising", "having" or other similar expressions used in a statement are intended to cover non-exclusive inclusion. These expressions do not exclude that there may be additional elements in the process, method or product including the said elements, so that a process, method or product including a series of elements may not only include those defined elements, but also include other elements not explicitly listed, or also include elements inherent to this process, method or product.

[0032] The same as the understanding in the "Examination Guidelines", in this application, expressions such as "greater than", "less than", "exceeding" are understood not to include the present number; expressions such as "above", "below", "within" are understood to include the present number. In addition, in the description of the embodiments of this application, the meaning of "a plurality of" is two or more (including two), and similar expressions related to "many" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise specifically defined.

[0033] The first aspect of this application provides a method for preparing a high-temperature resistant epoxy resin prepreg, including the following steps:

[0034] Preparation of the first composite: Mix 10 - 30 parts by mass of bisphenol A phenolic epoxy resin, 12 - 30 parts by mass of tetrafunctional nitrogen-containing epoxy resin, 10 - 30 parts by mass of EPICLON HP-4710, and 3 - 10 parts by mass of polyvinyl formal PVF, then melt and stir evenly under vacuum to obtain the first composite;

[0035] Preparation of the second composite: Mix 15 - 30 parts by mass of bisphenol A liquid epoxy resin, 5 - 9 parts by mass of dicyandiamide curing agent Dyhard100S, and 1 - 5 parts by mass of accelerator, and stir the mixture evenly. Then, grind the obtained mixture with a three - roll mill to obtain the second composite;

[0036] Preparation of epoxy resin composite adhesive: Mix the first composite and the second composite to obtain the epoxy resin composite adhesive;

[0037] Coating: Coat the epoxy resin composite adhesive on a double - sided release paper to obtain a resin film;

[0038] Bonding: Press - bond the resin film and the reinforcing material, cool and then wind up to obtain the high - temperature - resistant epoxy resin prepreg; in the high - temperature - resistant epoxy resin prepreg, the epoxy resin composite adhesive accounts for 25 - 45 wt%, and the reinforcing material accounts for 55 - 75 wt%.

[0039] The applicant found in the research and development that: Combining bisphenol A phenolic epoxy resin and tetra - functional nitrogen - containing epoxy resin with EPICLON HP - 4710 will increase the Tg point of the epoxy resin, and the addition of polyvinyl formal (PVF) can improve the brittleness of the epoxy resin and the conformability during pasting, and can better bond with the reinforcing material.

[0040] Different from the prior art, the epoxy resin composite adhesive produced by the special formula and process in this technical solution has good mechanical properties at high temperatures (in the range of 190 - 220 °C) and good toughness at the same time, thus improving the quality of the high - temperature - resistant epoxy resin prepreg, and further meeting the high - toughness and high - temperature requirements of carbon fiber composite products.

[0041] In some embodiments, in the step of preparing the first composite, the melting temperature is 135 - 150 °C, the stirring speed is 600 - 1000 revolutions per minute, and the stirring time is 60 - 90 minutes.

[0042] In some embodiments, in the step of preparing the second composite, the stirring speed is 100 - 300 revolutions per minute, and the stirring time is 30 - 60 minutes.

[0043] In some embodiments, in the step of preparing the epoxy resin composite adhesive, the feeding temperature of the first composite is 85 - 95 °C, and the feeding temperature of the second composite is 30 - 35 °C.

[0044] In some embodiments, in the coating step, the coating temperature is 67 - 73 °C.

[0045] In some embodiments, in the bonding step, the bonding temperature is 100 - 130 °C.

[0046] In some embodiments, in the bonding step, the reinforcing fibers include carbon fibers, glass fibers, aramid fibers, and basalt fibers.

[0047] The second aspect of the present application provides a high-temperature resistant epoxy resin prepreg, and the high-temperature resistant epoxy resin prepreg is prepared by using the preparation method described in the first aspect of the present application.

[0048] Different from the prior art, the epoxy resin composite adhesive produced by using a special formula and process in the present technical solution enables the produced epoxy resin composite adhesive to have good mechanical properties at high temperatures (190 - 220 °C) while achieving good toughness, thereby improving the quality of the high-temperature resistant epoxy resin prepreg and further meeting the high-toughness and high-temperature resistant requirements of carbon fiber composite products.

[0049] In some embodiments, the glass transition temperature Tg of the high-temperature resistant epoxy resin prepreg > 220 °C.

[0050] The third aspect of the present application provides the use of the high-temperature resistant epoxy resin prepreg described in the second aspect of the present application in the fields of carbon fiber sports goods, industrial carbon fibers, and drones.

[0051] Different from the prior art, the high-temperature resistant (190 - 220 °C) epoxy resin prepreg produced by using a special formula and process in the present technical solution can further meet the requirements in the fields of carbon fiber sports goods and drones.

[0052] In this embodiment, the bisphenol A liquid epoxy resin is NPEL-128, the bisphenol A phenolic epoxy resin is BNE200, the tetrafunctional nitrogen-containing epoxy resin is AG-80 (CAS: 28768-32-3) from Shanghai Huayi, EPICLON HP-4710C is a product of DIC Corporation of Japan, the polyvinyl formal PVF is Vinylec-C from JNC CORPORATION of Japan, the dicyandiamide curing agent is Dyhard 100S (CAS: 461-58-5), and the accelerator is PN-23 from Ajinomoto of Japan.

[0053] Example 1

[0054] Preparation of the first composite: Mix 10 - 30 parts by mass of bisphenol A phenolic epoxy resin, 12 - 30 parts by mass of tetrafunctional nitrogen-containing epoxy resin, 10 - 30 parts by mass of EPICLON HP-4710, and 3 - 10 parts by mass of polyvinyl formal PVF, then melt at 135 - 150 °C and stir evenly under vacuum. The stirring speed is 600 - 1000 revolutions per minute, and the stirring time is 60 - 90 minutes; obtain the first composite; after the stirring ends, cool down to 85 - 95 °C and set aside;

[0055] Preparation of the second composite: Mix 15 - 30 parts by mass of bisphenol A liquid epoxy resin, 5 - 9 parts by mass of dicyandiamide curing agent Dyhard100S, and 1 - 5 parts by mass of accelerator, and then stir at a stirring speed of 100 - 300 revolutions per minute for 30 - 60 minutes; After the mixture is stirred evenly, grind it with a three-roll grinder for 2 - 3 times to obtain the second composite; Keep the second composite at 30 - 35 °C for standby;

[0056] Preparation of epoxy resin composite adhesive: Mix the first composite at 85 - 95 °C and the second composite at 30 - 35 °C through a self-weight glue filling machine (there is a static mixer at the head of the glue filling machine) to obtain the epoxy resin composite adhesive;

[0057] Coating: The self-weight glue filling machine injects the epoxy resin composite adhesive into the coating machine, and the coating machine coats the epoxy resin composite adhesive on the double-sided release paper to obtain a resin film; The temperature of the coating machine is set at: 67 - 73 °C. Bonding: Wrap 70% of the carbon fiber reinforced material with 30 wt% of the resin film, press and bond at 100 - 130 °C, and wind it up after cooling to obtain the high-temperature resistant epoxy resin prepreg.

[0058] Example 2

[0059] Preparation of the first composite: Mix 20 parts by mass of bisphenol A novolac epoxy resin, 20 parts by mass of tetra-functional nitrogen-containing epoxy resin, 123 parts of EPICLON HP-4710, and 7 parts by mass of polyvinyl formal PVF, then melt at 135 - 150 °C and stir evenly under vacuum at a stirring speed of 600 - 1000 revolutions per minute for 60 - 90 minutes; Obtain the first composite; After the stirring is completed, cool down to 85 - 95 °C for standby;

[0060] Preparation of the second composite: Mix 20 parts by mass of bisphenol A liquid epoxy resin, 7 parts by mass of dicyandiamide curing agent Dyhard100S, and 3 parts by mass of accelerator, and then stir at a stirring speed of 100 - 300 revolutions per minute for 30 - 60 minutes; After the mixture is stirred evenly, grind it with a three-roll grinder for 2 - 3 times to obtain the second composite; Keep the second composite at 30 - 35 °C for standby;

[0061] Preparation of epoxy resin composite adhesive: Mix the first composite at 85 - 95 °C and the second composite at 30 - 35 °C through a self-weight glue filling machine (there is a static mixer at the head of the glue filling machine) to obtain the epoxy resin composite adhesive;

[0062] Coating: The self-weight glue filling machine injects the epoxy resin composite glue into the glue coating machine, and the glue coating machine coats the epoxy resin composite glue on the double-sided release paper to obtain a resin film; the temperature of the glue coating machine is set at: 67 - 73 °C. Bonding: Wrap 70% carbon fiber reinforced material with 30wt% resin film and press-bond at 100 - 130 °C, then wind up after cooling to obtain the high-temperature resistant epoxy resin prepreg.

[0063] Example 3

[0064] Preparation of the first composite: Mix 30 parts by mass of bisphenol A phenolic epoxy resin, 30 parts by mass of tetra-functional nitrogen-containing epoxy resin, 10 parts by mass of EPICLON HP-4710, and 10 parts by mass of polyvinyl formal PVF. After melting at 135 - 150 °C, stir evenly under vacuum. The stirring speed is 600 - 1000 revolutions per minute, and the stirring time is 60 - 90 minutes; obtain the first composite; after the stirring ends, cool down to 85 - 95 °C and set aside;

[0065] Preparation of the second composite: Mix 20 parts by mass of bisphenol A liquid epoxy resin, 5 parts by mass of dicyandiamide curing agent Dyhard100S, and 5 parts by mass of accelerator, and stir. The stirring speed is 100 - 300 revolutions per minute, and the stirring time is 30 - 60 minutes; after stirring evenly, grind the obtained mixture with a three-roll grinder for 2 - 3 times to obtain the second composite; keep the second composite at 30 - 35 °C and set aside;

[0066] Preparation of the epoxy resin composite glue: Mix the first composite at 85 - 95 °C and the second composite at 30 - 35 °C through a self-weight glue filling machine (there is a static mixer at the head of the glue filling machine) to obtain the epoxy resin composite glue;

[0067] Coating: The self-weight glue filling machine injects the epoxy resin composite glue into the glue coating machine, and the glue coating machine coats the epoxy resin composite glue on the double-sided release paper to obtain a resin film; the temperature of the glue coating machine is set at: 67 - 73 °C. Bonding: Wrap 70% carbon fiber reinforced material with 30wt% resin film and press-bond at 100 - 130 °C, then wind up after cooling to obtain the high-temperature resistant epoxy resin prepreg.

[0068] Test the epoxy resin composite glue prepared in Examples 1 - 3, and the results are as described in the following table

[0069]

[0070] As can be seen from the above table, the epoxy resin composite has excellent high-temperature performance below 220 °C. In addition to high temperature resistance, it also has excellent flexibility.

[0071] Finally, it should be noted that although the above embodiments have been described in the text of the specification of this application, the patent protection scope of this application cannot be limited thereby. Any technical solutions resulting from equivalent structural or equivalent process substitutions or modifications made based on the essential concept of this application and using the content recorded in the text of the specification of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of this application.

Claims

1. A method for preparing a high temperature resistant epoxy resin prepreg, characterized in that: The following steps are involved: Preparation of the first composite: 10-30 parts by weight of bisphenol A novolac epoxy resin, 12-30 parts by weight of tetrafunctional nitrogen-containing epoxy resin, 10-30 parts by weight of EPICLON HP-4710, and 3-10 parts by weight of polyvinyl formal PVF are mixed, melted, and vacuum stirred to obtain the first composite; Preparation of the second composite: 15-30 parts by weight of bisphenol A liquid epoxy resin, 5-9 parts by weight of dicyandiamide curing agent Dyhard 100S, and 1-5 parts by weight of accelerator are mixed and stirred evenly, and the obtained mixture is ground with a three-roll grinder to obtain the second composite; Preparation of epoxy resin composite adhesive: mixing the first composite material with the second composite material to obtain the epoxy resin composite adhesive; Coating: coating the epoxy resin composite adhesive on double-sided release paper to obtain a resin film; Bonding: Wrap the resin film with the reinforcing material and bond them under pressure, and roll them up after cooling to obtain the high temperature resistant epoxy resin prepreg; the high temperature resistant epoxy resin prepreg contains 25-45wt% epoxy resin composite adhesive and 55-75wt% reinforcing material.

2. The preparation method according to claim 1, characterized in that: In the first composite preparation step, the melting temperature is 135-150° C., the stirring speed is 600-1000 rpm, and the stirring time is 60-90 minutes.

3. The preparation method according to claim 1, characterized in that: In the second composite preparation step, the stirring speed is 100-300 rpm and the stirring time is 30-60 minutes.

4. The preparation method according to claim 1, characterized in that: In the step of preparing the epoxy resin composite adhesive, the feeding temperature of the first composite material is 85-95°C, and the feeding temperature of the second composite material is 30-35°C.

5. The preparation method according to claim 1, characterized in that: In the coating step, the coating temperature is 67-73°C.

6. The preparation method according to claim 1, characterized in that: In the bonding step, the bonding temperature is 100-130°C.

7. The preparation method according to claim 1, characterized in that: In the bonding step, the reinforcing fibers include carbon fibers, glass fibers, aramid fibers, and basalt fibers.

8. A high temperature resistant epoxy resin prepreg, characterized in that: The high temperature resistant epoxy resin prepreg is prepared by the preparation method described in any one of claims 1 to 7.

9. The high temperature resistant epoxy resin prepreg according to claim 8, characterized in that: The glass transition temperature Tg of the high temperature resistant epoxy resin prepreg is greater than 220°C.

10. Use of the high temperature resistant epoxy resin prepreg according to claim 8 or 9 in the fields of carbon fiber sports goods, industrial carbon fiber and unmanned aerial vehicles.

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