阅读说明：本技术 一种耐刮擦聚丙烯注塑件的制备方法 (Preparation method of scratch-resistant polypropylene injection molding part ) 是由 张晓飞 马俊辉 周晓群 叶元明 于 2019-10-23 设计创作，主要内容包括：本发明公开了一种耐刮擦聚丙烯注塑件的制备方法,包括以下步骤：S1、将100份聚丙烯、0.01～3份β成核剂、0.1～3份极性添加剂混合,并充分搅拌均匀,得到混合料；S2、将混合料置于双螺杆挤出装置中进行熔融挤出,得到聚丙烯复合材料；S3、将聚丙烯复合材料进行冷却造粒,并将其放置在真空干燥箱中干燥4h；S4、将干燥过后的聚丙烯复合材料置于注塑机中进行注塑加工,得到聚丙烯胚件；S5、对聚丙烯胚件进行保压冷却操作,即可得到耐刮擦聚丙烯注塑件。(The invention discloses a preparation method of a scratch-resistant polypropylene injection molding piece, which comprises the following steps of S1, mixing 100 parts of polypropylene, 0.01-3 parts of β nucleating agent and 0.1-3 parts of polar additive, fully stirring uniformly to obtain a mixture, S2, placing the mixture in a double-screw extrusion device for melt extrusion to obtain a polypropylene composite material, S3, cooling and granulating the polypropylene composite material, placing the cooled and granulated polypropylene composite material in a vacuum drying box for drying for 4 hours, S4, placing the dried polypropylene composite material in an injection molding machine for injection molding to obtain a polypropylene blank, and S5, carrying out pressure-maintaining cooling operation on the polypropylene blank to obtain the scratch-resistant polypropylene injection molding piece.)

1. A preparation method of a scratch-resistant polypropylene injection molding part is characterized by comprising the following steps: the method comprises the following steps:

s1, mixing 100 parts of polypropylene, 0.01-3 parts of β nucleating agent and 0.1-3 parts of polar additive, and fully and uniformly stirring to obtain a mixture;

s2, placing the mixture in a double-screw extrusion device for melt extrusion to obtain a polypropylene composite material;

s3, cooling and granulating the polypropylene composite material, and placing the cooled and granulated polypropylene composite material in a vacuum drying oven for drying for 4 hours;

s4, placing the dried polypropylene composite material in an injection molding machine for injection molding processing to obtain a polypropylene blank;

and S5, performing pressure maintaining cooling operation on the polypropylene blank to obtain the scratch-resistant polypropylene injection molding piece.

2. The process for preparing the scratch-resistant polypropylene injection-molded part according to claim 1, wherein the polypropylene in the step S1 is one or more of homo-polypropylene, block co-polypropylene and random co-polypropylene, the β nucleating agent is one or more of aromatic compounds, rare earth compounds and organic acid compounds, and the polar additive is one or more of nitrogen-containing compounds and oxygen-containing compounds.

3. The process for producing a scratch-resistant polypropylene injection-molded article according to claim 2, characterized in that: the polar additive is one or a combination of more of ethanolamine, diethanolamine, triethanolamine, formamide, acetamide, dimethylacetamide, urea, ethylene glycol, glycerol, butanediol, pentaerythritol, benzoic acid, polyacrylate, polyethylene glycol and polyethylene oxide.

4. The process for producing a scratch-resistant polypropylene injection-molded article according to claim 1, characterized in that: in the step S2, the rotating speed of the double-screw extrusion device is 20-50 r/min, the temperature of the melting section of the double-screw extrusion device is 190-250 ℃, and the temperature of the die section of the double-screw extrusion device is 180-210 ℃.

5. The process for producing a scratch-resistant polypropylene injection-molded article according to claim 1, characterized in that: the temperature in the vacuum drying oven in the step S3 was 120 ℃.

6. The process for producing a scratch-resistant polypropylene injection-molded article according to claim 1, characterized in that: in the step S4, the melting temperature in the injection molding machine is 180-280 ℃, the injection pressure in the injection molding machine is 5-30MPa, and the injection speed of the injection molding machine is 20-80 mm/S.

Technical Field

The invention relates to the field of materials, in particular to a preparation method of a scratch-resistant polypropylene injection molding piece.

Background

The polypropylene material has excellent comprehensive performance and is widely applied to the fields of packaging engineering, automobile industry, electronic and electrical products and the like. Due to the poor scratch resistance of the surface of the polypropylene material, when the polypropylene material is scratched by a sharp object, scratches are easily formed, and the appearance of the product is further influenced.

The properties of a polymer are not only related to its chemical structure, but also depend on the processing shape and morphological structure. Therefore, a great deal of research is carried out in academia and industry at home and abroad for improving the polypropylene scraping performance, but the main focus is on improving the polypropylene scraping performance by adding an auxiliary agent, and a small amount of literature reports that the scraping performance is improved by adjusting a polypropylene annealing process. However, the above method is difficult to ensure that the mechanical properties of the polypropylene material are not affected. Therefore, a simple and practical preparation method of the scratch-resistant polypropylene injection molding is urgently needed in the market to improve the scratch resistance of the polypropylene injection molding.

Disclosure of Invention

The invention aims to solve the problems and provides a preparation method of a polypropylene injection molding part capable of improving scratch resistance.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of a scratch-resistant polypropylene injection molding piece comprises the following steps:

s1, mixing 100 parts of polypropylene, 0.01-3 parts of β nucleating agent and 0.1-3 parts of polar additive, and fully and uniformly stirring to obtain a mixture;

s2, placing the mixture in a double-screw extrusion device for melt extrusion to obtain a polypropylene composite material;

s3, cooling and granulating the polypropylene composite material, and placing the cooled and granulated polypropylene composite material in a vacuum drying oven for drying for 4 hours;

s4, placing the dried polypropylene composite material in an injection molding machine for injection molding processing to obtain a polypropylene blank;

and S5, performing pressure maintaining cooling operation on the polypropylene blank to obtain the scratch-resistant polypropylene injection molding piece.

Further, in the step S1, the polypropylene is one or a combination of more of homo-polypropylene, block co-polypropylene and random co-polypropylene, the β nucleating agent is one or a combination of more of aromatic compounds, rare earth compounds and organic acid compounds, and the polar additive is one or a combination of more of nitrogen-containing compounds and oxygen-containing compounds.

Further, the polar additive is one or a combination of more of ethanolamine, diethanolamine, triethanolamine, formamide, acetamide, dimethylacetamide, urea, ethylene glycol, glycerol, butanediol, pentaerythritol, benzoic acid, polyacrylate, polyethylene glycol and polyethylene oxide.

Further, in the step S2, the rotating speed of the double-screw extrusion device is 20-50 r/min, the temperature of the melting section of the double-screw extrusion device is 190-250 ℃, and the temperature of the die section of the double-screw extrusion device is 180-210 ℃.

Further, the temperature in the vacuum drying oven in the step S3 is 120 ℃.

Further, in the step S4, the melting temperature in the injection molding machine is 180-280 ℃, the injection pressure in the injection molding machine is 5-30MPa, and the injection speed of the injection molding machine is 20-80 mm/S.

Compared with the prior art, the invention has the advantages and positive effects that:

the β nucleating agent adopted by the invention is aromatic, rare earth, organic acid and salt compounds thereof, and is processed under specific process conditions in the injection molding process of a polypropylene part, so that the defect of high flexibility of a polypropylene material is solved, the surface hardness of the material is effectively improved, and a better scratch-resistant effect can be obtained by higher surface hardness of the material when the polypropylene part is scratched by external force, finally, the scratch-resistant performance of the polypropylene part is more stable by adding β nucleating agent, and the service life of the part can be effectively prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a graph of performance testing of example 1;

FIG. 2 is a graph showing the performance test of example 2;

FIG. 3 is a graph of the friction resistance versus the effect of the samples.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived from the embodiments of the present invention by a person skilled in the art without any creative effort, should be included in the protection scope of the present invention.

As shown in figures 1, 2 and 3, the preparation method of the scratch-resistant polypropylene part provided by the invention comprises the steps of fully mixing 100 parts of polypropylene, 0.01-3 parts of β nucleating agent and 0.1-3 parts of polar additive, then placing the mixture in a double-screw extrusion device, carrying out melt extrusion at the conditions of a melting section temperature of 190-.

Wherein β the nucleating agent is at least one of aromatic, rare earth, organic acid and salt compound thereof, and the polar additive is at least one of nitrogen-containing and oxygen-containing compounds.

The aromatic β nucleating agent is TMB series compound (developed by Shanxi chemical research institute), CHB-5 compound (produced by Guangzhou and Erxin chemical science and technology Limited), NU-100 compound (produced by Japan physicochemical Co., Ltd.) and NB-328 compound (produced by Luoyang chemical Co., Ltd.), the rare earth β nucleating agent is WBG series compound (produced by Guangdong Wei Linna functional material Co., Ltd.), and the organic acid β nucleating agent is DCHT compound (produced by Japan physicochemical Co., Ltd.), hydrazine isodiacid and suberic acid (produced by Shanghai Xiangrong chemical Co., Ltd.).

The polypropylene in the above products is at least one of homo-polypropylene, block co-polypropylene and random co-polypropylene. The polar additive in the above products is at least one of ethanolamine, diethanolamine, triethanolamine, formamide, acetamide, dimethylacetamide, urea, ethylene glycol, glycerol, butanediol, pentaerythritol, benzoic acid, polyacrylate, polyethylene glycol, and polyethylene oxide.

In addition, in the actual industrial production, other known processing aids such as antioxidants, stabilizers, plasticizers, and the like, and other fillers which contribute to further enhancing the properties of the product, such as glass fibers, and the like, can be added as needed, provided that the processing aids do not adversely affect the achievement of the object of the present invention and the achievement of the excellent effects of the present invention.