An ionic liquid flame-retardant plastic part and preparation and application thereof

Abstract

This invention belongs to the field of composite materials and discloses a flame-retardant plastic part, its preparation, and its application. The preparation of the flame-retardant plastic part includes the following steps: 1) twin-screw extrusion granulation to prepare plastic particles comprising the following components by weight percentage: resin 52%-98.5%; ionic liquid flame retardant 0.5%-5%; ionic liquid synergist 1-5%; glass fiber 0%-30%; antioxidant 0%-1%; release agent 0%-1%; toughening agent 0-6%; 2) processing the plastic particles into the desired part; 3) treating the plastic part at a temperature and DC voltage higher than the Tg of the plastic; 4) cooling to room temperature and removing the electric field to obtain the plastic part. The flame-retardant plastic part of this invention can achieve a high flame-retardant rating for plastic products with different wall thicknesses, even with minimal addition of flame retardant.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, and specifically relates to an ionic liquid flame-retardant plastic part, its preparation method, and its application. Background Technology

[0002] Flame-retardant plastic parts are an important class of plastic products, especially in the engineering plastics field, where flame-retardant products account for about half of the market application. With the gradual improvement of safety regulations in various countries, the requirements for flame retardancy levels in various application fields are becoming increasingly stringent. Conventional flame-retardant technologies mainly involve adding halogenated or phosphorus-based flame retardants. A major drawback is the large amount required, which can significantly affect the other comprehensive properties of the plastic product. At the same time, halogenated flame retardants are increasingly restricted in various fields due to their environmental unfriendliness. To reduce the amount of flame retardant used, one method is to use surface coating or spraying to enrich the flame retardant on the surface of the plastic product. However, this requires secondary processing, significantly increasing costs, and it is also difficult to guarantee the stability of the surface flame retardant. Currently, there is no mature technology for this.

[0003] Ionic liquid flame retardants are a relatively new type of flame retardant. Ionic liquids are organic compounds with good compatibility with plastics. By designing ionic liquids with different chemical structures, incorporating flame-retardant elements such as phosphorus, fluorine, and nitrogen, flame-retardant properties can be achieved. However, the main drawbacks of ionic liquid flame retardants are insufficient flame-retardant efficiency and high cost. If added in large quantities, they can act like plasticizers, reducing the mechanical properties of plastics and significantly increasing costs. The cations and anions in ionic liquids can move under an electric field. If the migration characteristics of ionic liquids in an electric field can be utilized to enrich the ionic liquid on the surface of plastic products, the flame-retardant efficiency can be significantly improved. Patent application CN202411364512.6 describes a method for achieving flame retardancy in plastic products using the migration characteristics of ionic liquids in an electric field. However, this method can only achieve flame retardancy in relatively thin plastic products; it does not achieve good flame-retardant effects when the wall thickness of the part is large. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a plastic part with ionic liquid flame retardancy. This plastic part uses ionic liquid as a flame retardant, requiring a small amount of flame retardant, resulting in low cost, while achieving a high flame retardancy rating across a wide range of wall thicknesses.

[0005] Another object of the present invention is to provide ionic liquid flame-retardant plastic parts prepared by the above method.

[0006] Another object of the present invention is to provide the application of the above-mentioned ionic liquid flame-retardant plastic parts.

[0007] The objective of this invention is achieved through the following solution:

[0008] A method for preparing an ionic liquid flame-retardant plastic part includes the following steps:

[0009] 1) Plastic particles comprising the following components by weight percentage were prepared by twin-screw extrusion granulation:

[0010]

[0011] 2) Process the plastic particles into the required parts;

[0012] 3) When plastic parts are treated at a temperature and DC voltage higher than the Tg of the plastic, the ionic liquid migrates to the area near the surface of the plastic parts and accumulates under the action of the electric field.

[0013] 4) After cooling to room temperature, remove the electric field to obtain the plastic part.

[0014] The resin mentioned in step (1) includes at least one of polycarbonate, polyamide, polybutylene terephthalate (PBT), and polyethylene terephthalate (PET).

[0015] The ionic liquid flame retardant mentioned in step (1) includes at least one of imidazole ionic liquids, pyrrolidine ionic liquids, quaternary ammonium salt ionic liquids, piperidine ionic liquids, and pyridine ionic liquids, preferably at least one of 1,3-dimethylimidazolium methanesulfonate ([C1MIm]MS), 1-ethylpyridine hexafluorophosphate ([C2Py]PF6), and 1-ethyl-1-methylpiperidine p-toluenesulfonate ([C2MPd]TS).

[0016] The ionic liquid synergist mentioned in step (1) includes one or a mixture of epoxidized linseed oil, N-butylbenzenesulfonamide.

[0017] When the resin mentioned in step (1) is mainly polybutylene terephthalate (PBT), especially when the resin is a single type of polybutylene terephthalate (PBT), the ionic liquid synergist is preferably epoxy linseed oil, and the weight percentage of epoxy linseed oil is 1-2%. Wherein, the resin being mainly polybutylene terephthalate (PBT) means that the resin contains at least polybutylene terephthalate (PBT), and the mass of polybutylene terephthalate (PBT) in the resin is the largest.

[0018] When the resin in step (1) is mainly polycarbonate, especially when the resin is a single type of polycarbonate, the ionic liquid synergist is preferably epoxidized linseed oil, and the weight percentage of epoxidized linseed oil is 3-5%. Wherein, the resin is mainly polycarbonate, it means that the resin contains at least polycarbonate, and the mass of polycarbonate in the resin is the largest.

[0019] When the resin mentioned in step (1) is mainly polyamide, especially when the resin is a single type of polyamide, the ionic liquid synergist is preferably N-butylbenzenesulfonamide, and the weight percentage of N-butylbenzenesulfonamide is 1-3%. Wherein, the resin is mainly polyamide means that the resin contains at least polyamide, and the mass of polyamide in the resin is the largest.

[0020] The antioxidant mentioned in step (1) is at least one of hindered phenolic antioxidants, hindered amine antioxidants, and phosphite antioxidants;

[0021] The release agent mentioned in step (1) is at least one of fatty acid salts and fatty acid esters, preferably pentaerythritol stearate PETS;

[0022] The toughening agent mentioned in step (1) is at least one of polyolefin, polyacrylate copolymer, and polybutadiene copolymer, preferably the toughening agent MBS.

[0023] The processing and molding described in step (2) is preferably carried out by injection molding or extrusion molding, and the ionic liquid flame retardant will be evenly dispersed in the plastic part.

[0024] The plastic part mentioned in step (2) is a flat part with a thickness of 0.2-2mm; preferably 1-2mm.

[0025] The DC voltage mentioned in step (3) is 10-200V; the processing time is 1min-60min; the positive and negative poles of the DC voltage are both electrode plates, which are in direct contact with the two sides of the plastic part, and the contact surface covers the entire surface of the part, thereby ensuring that all ionic liquids in the plastic part can move under the action of the electric field.

[0026] When the resin in step (1) is a crystalline polymer, the temperature in step (3) is preferably higher than the Tg of the plastic and lower than the Tm of the resin; when the resin in step (1) is an amorphous polymer, the temperature in step (3) is preferably higher than the Tg of the plastic and lower than the Tf of the resin.

[0027] In step (4), as the temperature drops below the Tg of the plastic, the ionic liquid will be fixed near the surface of the plastic part, achieving a higher flame retardant efficiency than uniform distribution.

[0028] A flame-retardant plastic part made of ionic liquid prepared by the above method.

[0029] The above-mentioned ionic liquid flame-retardant plastic parts are used in automobiles, electronic appliances, or consumer electronics products.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] The flame-retardant plastic parts of this invention can achieve high flame-retardant ratings for plastic products with varying wall thicknesses, even with minimal addition of flame retardant. Furthermore, the preparation method of this invention is simple and easy to implement, making it suitable for large-scale production. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of electrochemical treatment of plastic parts. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0034] The technical solution of this application is described in detail below using examples. All raw materials used in the examples are commercially available, specifically: PBT is Changchun Chemical 1100-211S, polycarbonate PC is SABIC Lexan 141R, polyamide 66 is BASF Ultramid A3L, ionic liquids 1,3-dimethylimidazolium methanesulfonate ([C1MIm]MS), 1-ethylpyridine hexafluorophosphate ([C2Py]PF6), and 1-ethyl-1-methylpiperidine p-toluenesulfonate ([C2MPd]TS) were purchased from Merck, epoxidized linseed oil was purchased from Zhejiang Xingbang Polymer Materials Co., Ltd., and N-butylbenzenesulfonamide was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd. Flame retardancy testing was performed according to UL94 standard. Tensile strength testing was performed according to ISO527, and impact strength testing was performed according to ISO179.

[0035] Examples 1-5

[0036] Flame-retardant plastic parts are prepared using the following steps:

[0037] (1) Plastic particles comprising the following components by weight percentage were prepared by twin-screw extrusion at a processing temperature of 230-260℃:

[0038] Table 1. Raw materials and weight percentage of each raw material for flame-retardant plastic parts in Comparative Example 1 and Examples 1-5

[0039] Weight percentage (%) Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 PBT 94.7 93.7 92.7 91.7 90.7 89.7 [C1MIm]MS 5 5 5 5 5 5 1010 0.1 0.1 0.1 0.1 0.1 0.1 PETS 0.2 0.2 0.2 0.2 0.2 0.2 Epoxy linseed oil 1 2 3 4 5

[0040] 2) The obtained plastic particles were processed into UL94 flame retardant test strips with thicknesses of 0.8mm, 1.2mm, 1.6mm, 2.0mm and 4mm by injection molding at an injection temperature of 260℃ and a mold temperature of 50℃.

[0041] 3) Process the workpiece for 5 minutes at 120℃ and 30V DC voltage.

[0042] 4) After the sample has cooled to room temperature naturally, remove the electric field. Test the flame retardancy rating, tensile strength, and notched impact strength of the sample.

[0043] Table 2. Performance data of Comparative Example 1 and Examples 1-5

[0044]

[0045] Examples 6-11

[0046] Flame-retardant plastic parts are prepared using the following steps:

[0047] (1) Plastic particles comprising the following components by weight percentage were prepared by twin-screw extrusion at a processing temperature of 250-290℃:

[0048] Table 3. Raw materials and weight percentage of each raw material for the flame-retardant plastic parts in Comparative Example 2 and Examples 6-11

[0049]

[0050] 2) The obtained plastic particles were injection molded into UL94 flame retardant test strips with thicknesses of 0.4mm, 0.8mm, 1.2mm, 2.0mm and 4mm. The injection temperature was 300℃ and the mold temperature was 80℃.

[0051] 3) Process the workpiece for 2 minutes at 170℃ and 100V DC voltage.

[0052] 4) After allowing the sample to cool naturally to room temperature, remove the electric field. Test the flame retardancy rating and tensile strength of the sample.

[0053] Table 4 Performance data for Comparative Example 2 and Examples 6-11

[0054]

[0055] Examples 12-16

[0056] Flame-retardant plastic parts are prepared using the following steps:

[0057] 1) Plastic particles comprising the following components by weight percentage were prepared by twin-screw extrusion at a processing temperature of 250-280℃:

[0058] Table 5. Raw materials and weight percentage of each raw material for the flame-retardant plastic parts in Comparative Example 3 and Examples 12-16

[0059]

[0060] 2) The obtained plastic particles were injection molded into UL94 flame retardant test strips with thicknesses of 0.8mm, 1.2mm, 1.6mm, 2.0mm and 4mm. The injection temperature was 280℃ and the mold temperature was 60℃.

[0061] 3) Process the workpiece for 5 minutes at 140℃ and 50V DC voltage.

[0062] 4) After allowing the sample to cool naturally to room temperature, remove the electric field. Test the flame retardancy rating and tensile strength of the sample.

[0063] Table 6. Performance data of Comparative Example 3 and Examples 12-16

[0064]

[0065] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an ionic liquid flame-retardant plastic part, characterized in that... Includes the following steps: 1) Plastic particles comprising the following components by weight percentage were prepared by twin-screw extrusion granulation: Resin content: 52%-95.7%; Ionic liquid flame retardant 0.5%-5%; 3-5% ionic liquid synergist; Fiberglass 0%-30%; Antioxidant 0%-1%; Release agent 0%-1%; Toughening agent 0-6%; 2) Process the plastic particles into the required parts; 3) When plastic parts are treated at a temperature and DC voltage higher than the Tg of the plastic, the ionic liquid migrates to the area near the surface of the plastic parts and accumulates under the action of the electric field. 4) After cooling to room temperature, remove the electric field to obtain the plastic part; The resin mentioned in step (1) includes at least one of polycarbonate, polyamide, and polybutylene terephthalate; When the resin mentioned in step (1) is polycarbonate or polybutylene terephthalate, the ionic liquid synergist mentioned in step (1) is epoxy linseed oil. When the resin mentioned in step (1) is polyamide, the ionic liquid synergist mentioned in step (1) is N-butylbenzenesulfonamide; The ionic liquid flame retardant mentioned in step (1) is at least one of 1,3-dimethylimidazolium methanesulfonate, 1-ethylpyridine hexafluorophosphate, and 1-ethyl-1-methylpiperidine p-toluenesulfonate; The plastic part mentioned in step (2) is a flat part with a thickness of 1.6-2mm.

2. The method for preparing ionic liquid flame-retardant plastic parts according to claim 1, characterized in that: The antioxidant mentioned in step (1) is at least one of hindered phenolic antioxidants, hindered amine antioxidants, and phosphite antioxidants; The release agent mentioned in step (1) is at least one of fatty acid salts and fatty acid esters; The toughening agent mentioned in step (1) is at least one of polyolefin, polyacrylate copolymer, and polybutadiene copolymer.

3. The method for preparing ionic liquid flame-retardant plastic parts according to claim 2, characterized in that: The release agent mentioned in step (1) is pentaerythritol stearate PETS.

4. The method for preparing ionic liquid flame-retardant plastic parts according to claim 2, characterized in that: The toughening agent mentioned in step (1) is toughening agent MBS.

5. The method for preparing ionic liquid flame-retardant plastic parts according to claim 1, characterized in that: The DC voltage mentioned in step (3) refers to 10-200V; the processing time is 1min-60min.

6. The method for preparing ionic liquid flame-retardant plastic parts according to claim 1, characterized in that: When the resin in step (1) is a crystalline polymer, the temperature in step (3) is higher than the Tg of the plastic and lower than the Tm of the resin; when the resin in step (1) is an amorphous polymer, the temperature in step (3) is higher than the Tg of the plastic and lower than the Tf of the resin.

7. A flame-retardant plastic part made of an ionic liquid prepared by the method according to any one of claims 1-6.

8. The application of the ionic liquid flame-retardant plastic parts according to claim 7 in automobiles, electronic appliances, and consumer electronics products.

Images