Polyimide-based regenerated powder flame retardant as well as preparation method and application thereof

Abstract

The invention relates to the field of flame-retardant substances, in particular to a polyimide-based regenerated powder flame retardant as well as a preparation method and application thereof. The preparation method comprises the following steps: mechanically grinding thermosetting polyimide wastes, cutting recycled polyimide leftover materials into fragments, and then crushing; in order to prevent degradation of polyimide, the raw material polyimide film can be soaked in liquid nitrogen and then crushed; cutting by using a splitting machine, dipping in liquid nitrogen for 1min, and crushing in an extrusion crusher; the obtained powder is observed by a scanning electron microscope to obtain particles which are planar, and the average particle size is 10-20 [mu] m. And creatively, the thermosetting polyimide can be utilized as a waste and is compounded again, so that an excellent flame-retardant effect is obtained.

Description

Technical Field

[0001] The invention relates to the field of flame retardant materials, in particular to a polyimide-based regenerated powder flame retardant and a preparation method and application thereof. Background Art

[0002] As an important special engineering material, polyimide has been widely used in aviation, aerospace, nanotechnology, liquid crystal, laser and other fields. However, in the production process of polyimide products, a large amount of polyimide waste is often generated. Since thermosetting polyimide cannot be melted and plasticized for a second time, it cannot be recycled at present.

[0003] On December 10, 2024, a search was conducted in the Chinese Patent Publication Database with "polyimide and regeneration and liquid nitrogen and flame retardant and phosphorus" as abstract keywords, and the option of allowing synonym expansion was checked, but no relevant literature was found.

[0004] On December 10, 2024, an abstract search for "polyimide and regeneration and liquid nitrogen and flame retardant and phosphorus" was conducted on China National Knowledge Infrastructure, and no relevant literature was found.

[0005] On December 10, 2024, a search was conducted on the website of the United States Patent and Trademark Office for "Polyimide with regeneration with liquid nitrogen with flame retardant with phosphorus", and no relevant literature was found; the search URL was https: / / ppubs.uspto.gov / pubwebapp / .

[0006] On December 10, 2024, a search was conducted on the Korean Patent Office for "Polyimideandregenerationandliquid nitrogenandflame retardantandphosphorus", and no relevant literature was found; the search URL was http: / / eng.kipris.or.kr / enghome / main.jsp.

[0007] On December 10, 2024, a search was conducted on WIPO's https: / / patentscope2.wipo.int / for "Polyimideandregenerationandliquid nitrogenandflame retardantandphosphorus", and no relevant literature was found.

[0008] On December 10, 2024, a search was conducted on the Japan Patent Office website https: / / www.j-platpat.inpit.go.jp / for "Polyimideandregenerationandliquid nitrogenandflame retardantandphosphorus", but no relevant literature was found.

[0009] Completely different from the concept of this patent. Summary of the invention

[0010] Purpose of the invention: To provide a better polyimide-based recycled powder flame retardant and its preparation method and use. The specific purpose can be seen in the multiple substantial technical effects in the specific implementation part.

[0011] In order to achieve the above purpose, the present invention adopts the following technical solutions: Use of the pulverized product obtained by cutting thermosetting polyimide waste into pieces and then crushing them as a flame retardant.

[0012] Thermosetting polyimide waste is immersed in liquid nitrogen for 1 minute and then crushed into powder, and used as a flame retardant.

[0013] The powder of the pulverized waste thermosetting polyimide and any one of ammonium polyphosphate, aluminum hypophosphite, diethyl aluminum hypophosphite or a concentrated mixture thereof are used as a flame retardant.

[0014] The invention discloses a recycled powder flame retardant based on polyimide, characterized in that the flame retardant is a pulverized product obtained by cutting thermosetting polyimide waste into pieces and then pulverizing them.

[0015] A further technical solution of the present invention is that the flame retardant is a thermosetting polyimide waste which is cut into pieces and then immersed in liquid nitrogen for 1 minute and then crushed.

[0016] The preparation method of the polyimide-based recycled powder flame retardant is characterized by comprising the following preparation steps: Thermosetting polyimide waste is mechanically ground, and the recycled polyimide scraps are cut into pieces and then crushed; in order to prevent polyimide degradation, the raw polyimide film can be immersed in liquid nitrogen and then crushed; After being cut by a slitting machine, the mixture is immersed in liquid nitrogen for 1 minute and then crushed in an extrusion mill. The obtained powder is observed by a scanning electron microscope to have planar particles with an average particle size of 10-20 μm.

[0017] A further technical solution of the present invention is to use the following pulverizers for pulverization: any one of an extrusion pulverizer, a turbine pulverizer, and an air flow pulverizer; or to use a plurality of different pulverizers in combination.

[0018] A further technical solution of the present invention is to compound the recycled powder of APP (ammonium polyphosphate) and polyimide in a mass ratio of 1:1-5:1, and add them to the polyolefin resin at a proportion of 20-30%, so as to achieve UL94 1.6mm-V0 flame retardancy.

[0019] A further technical solution of the present invention is to compound AHP, i.e. aluminum hypophosphite, and recycled powder of polyimide in a mass ratio of 1:1-3:1, and add them to TPE / TPU in a proportion of 25-30%, so as to achieve UL94 1.6mm-V0 flame retardancy.

[0020] A further technical solution of the present invention is to compound ADP (ie, diethyl aluminum hypophosphite) and recycled powder of polyimide in a mass ratio of 1:1-3:1, and add them to PA in a proportion of 15-25%, so as to achieve UL94 1.6mm-V0 flame retardancy.

[0021] The present invention adopting the above technical solution has the following beneficial effects compared with the prior art: it is innovatively capable of utilizing thermosetting polyimide as waste and re-compounding to obtain excellent flame retardant effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to further illustrate the present invention, the following is further described in conjunction with the accompanying drawings: Figure 1 A diagram of the steps of the invention. DETAILED DESCRIPTION

[0023] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top", "bottom", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0024] Thermosetting polyimide waste is mechanically ground, and the recycled polyimide scraps are cut into pieces and then crushed. Use the following crushers for crushing: extrusion crusher, turbine crusher, air flow crusher, etc. You can also use a combination of multiple different crushers. In order to prevent polyimide degradation, the raw polyimide film can be immersed in liquid nitrogen before crushing; After cutting with a slitter, it was immersed in liquid nitrogen for 1 minute and then crushed in an extrusion mill. The obtained powder was observed by scanning electron microscope to be flat particles with an average particle size of 10-20μm. APP (ammonium polyphosphate) and PI powder are compounded in a ratio of 1:1-5:1 and added to polyolefin resin at a percentage of 20-30 to achieve UL94 1.6mm-V0 flame retardancy. AHP (aluminum hypophosphite) and PI powder are compounded in a ratio of 1:1-3:1 and added to TPE / TPU at a percentage of 25-30 to achieve UL94 1.6mm-V0 flame retardancy. By compounding ADP (diethylaluminum hypophosphite) and PI powder in a ratio of 1:1-3:1 and adding 15-25% to PA, UL94 1.6mm-V0 flame retardancy can be achieved.

[0025] The innovative technology can utilize thermosetting polyimide as waste and re-compound it to obtain excellent flame retardant effect.

[0026] It should be noted that the multiple solutions provided by this patent include the basic solution itself, which are independent of each other and do not restrict each other, but they can also be combined with each other without conflict to achieve multiple effects together.

[0027] The basic principle, main features and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the protection required.

Claims

1. Use of the pulverized product obtained by cutting thermosetting polyimide waste into pieces and then crushing them as flame retardants.

2. Use of the powder obtained by immersing thermosetting polyimide waste in liquid nitrogen for 1 minute and then pulverizing it as a flame retardant.

3. Use of powder obtained by crushing waste thermosetting polyimide and any one of ammonium polyphosphate, aluminum hypophosphite, diethyl aluminum hypophosphite or a concentrated mixture thereof as a flame retardant.

4. A polyimide-based recycled powder flame retardant, characterized in that: The flame retardant is a pulverized product obtained by cutting thermosetting polyimide waste into pieces and then pulverizing them.

5. The polyimide-based recycled powder flame retardant according to claim 4, characterized in that: The flame retardant is a thermosetting polyimide waste which is cut into pieces, immersed in liquid nitrogen for 1 minute and then crushed.

6. A method for preparing a polyimide-based recycled powder flame retardant, characterized in that: The preparation steps include: Thermosetting polyimide waste is mechanically ground, and the recycled polyimide scraps are cut into pieces and then crushed; in order to prevent polyimide degradation, the raw polyimide film can be immersed in liquid nitrogen and then crushed; After being cut by a slitting machine, the mixture is immersed in liquid nitrogen for 1 minute and then crushed in an extrusion mill. The obtained powder is observed by a scanning electron microscope to have planar particles with an average particle size of 10-20 μm.

7. The method for preparing a polyimide-based regenerated powder flame retardant according to claim 6, characterized in that: The pulverization is performed using a pulverizer selected from the group consisting of an extrusion pulverizer, a turbine pulverizer, and an airflow pulverizer; or a combination of a plurality of different pulverizers.

8. The method for preparing a polyimide-based regenerated powder flame retardant according to claim 6, characterized in that: By compounding the recycled powder of APP (ammonium polyphosphate) and polyimide in a mass ratio of 1:1-5:1 and adding 20-30% of the mixture into polyolefin resin, UL94 1.6mm-V0 flame retardancy can be achieved.

9. The method for preparing a polyimide-based regenerated powder flame retardant according to claim 6, characterized in that: By compounding AHP, i.e. aluminum hypophosphite, and recycled powder of polyimide in a mass ratio of 1:1-3:1 and adding 25-30% to TPE / TPU, UL94 1.6mm-V0 flame retardancy can be achieved.

10. The method for preparing a polyimide-based regenerated powder flame retardant according to claim 6, characterized in that: By compounding ADP (diethyl aluminum hypophosphite) and recycled powder of polyimide in a mass ratio of 1:1-3:1 and adding it to PA at a ratio of 15-25%, UL94 1.6mm-V0 flame retardancy can be achieved.

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