CN110343336B

CN110343336B - High-surface-quality polypropylene micro-foaming composite material and preparation method thereof

Info

Publication number: CN110343336B
Application number: CN201910459216.7A
Authority: CN
Inventors: 李胜男; 蒋团辉; 曾祥补; 沈超; 朱能贵; 王醴均; 何力; 龚维; 张纯
Original assignee: Guizhou Material Industrial Technology Research Institute
Current assignee: Kangmingyuan Guizhou Technology Development Co ltd
Priority date: 2019-05-29
Filing date: 2019-05-29
Publication date: 2021-08-31
Anticipated expiration: 2039-05-29
Also published as: CN110343336A

Abstract

The invention relates to a high-surface-quality polypropylene micro-foaming composite material which comprises the following components in parts by weight: 10-60 parts of copolymerized polypropylene resin, 10-50 parts of homopolymerized polypropylene resin, 0-30 parts of toughening agent, 0-30 parts of filler, 0.01-10 parts of gas adsorbent, 0.01-10 parts of gas blocking agent, 0.05-5 parts of foaming agent and 0-4 parts of nucleating agent, wherein the gas adsorbent and the gas blocking agent are used for regulating and controlling the dissolution, diffusion and migration of gas in a polymer melt, so that the migration and diffusion of the gas to the surface of the polymer are reduced, the problems of surface defects such as surface cavitation and silver lines of a polypropylene foamed product are solved while the physical property and the internal foaming amount of the composite material are ensured, and the surface quality of the product is greatly improved.

Description

High-surface-quality polypropylene micro-foaming composite material and preparation method thereof

Technical Field

The invention relates to the technical field of polypropylene micro-foaming, in particular to a high-surface-quality polypropylene micro-foaming composite material and a preparation method thereof.

Background

The polypropylene foaming material takes propylene as a main raw material, adopts a physical foaming technology to prepare foaming beads, and is mainly used for carrying out mould foaming and forming to various shapes and sizes for use in different occasions; the polypropylene foam material has the characteristics of light weight, environmental protection, good dimensional stability, heat and sound insulation, excellent mechanical property and the like, and is widely applied to the fields of automobiles, aerospace, household appliances, packaging and the like.

At present, in the process of filling a mold, gas is easy to migrate and diffuse to the surface of a polymer, so that the foaming quality of the polypropylene foaming material and the surface quality of a product are poor, and surface defects such as air pockets, silver lines and the like often occur, thereby limiting the expansion and application of the polypropylene foaming material.

Disclosure of Invention

Aiming at the problems that the existing polypropylene foaming material is easy to migrate and diffuse to the surface of a polymer in the process of filling a mold, so that the foaming quality of the polypropylene foaming material and the surface quality of a product are poor, and surface defects such as air pockets, silver lines and the like often occur, thereby limiting the expansion application of the polypropylene foaming material, the invention provides a high-surface-quality polypropylene micro-foaming composite material and a preparation method thereof

The technical scheme adopted by the invention is as follows:

the polypropylene micro-foaming composite material with high surface quality comprises the following components in parts by weight:

10-60 parts of copolymerized polypropylene resin, 10-50 parts of homopolymerized polypropylene resin, 0-30 parts of toughening agent, 0-30 parts of filler, 0.01-10 parts of gas adsorbent, 0.01-10 parts of gas blocking agent, 0.05-5 parts of foaming agent and 0-4 parts of nucleating agent.

Further, the anti-oxidant comprises 0.01-3 parts by weight of a main antioxidant and 0.01-3 parts by weight of an auxiliary antioxidant; the main antioxidant and the auxiliary antioxidant are any one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant TPL and antioxidant DSTP.

Further, 0.1-4 parts by weight of scratch-resistant agent is also included; the scratch resistant agent is any one or more of erucamide, polysiloxane, oleic acid or stearic acid.

Further, the paint also comprises 0.1-3 parts of a light stabilizer in parts by weight; the light stabilizer is any one or more of light stabilizer 622, light stabilizer 1084, light stabilizer 770, light stabilizer 901 or light stabilizer GW-540.

Further, the melt index of the copolymerized polypropylene resin is 1-150 g/10min under the test conditions of the temperature of 230 ℃ and the pressure weight of 2.16 Kg; the melt index of the homopolymerized polypropylene resin is 0.5-70 g/10min under the test conditions of the temperature of 230 ℃ and the pressure of 2.16 Kg.

Further, the toughening agent is one or two of rubber and thermoplastic elastomer.

Further, the gas adsorbent is any one or more of silicone oil, polyvinyl acetate and melamine-based microporous organic polymer.

Further, the gas barrier agent is any one or more of ethylene-vinyl alcohol copolymer, nano hydrotalcite, poly terephthalic acid plastic, polyvinylidene chloride and nylon.

Further, the foaming agent is any one or more of azo compounds, nitroso compounds, sulfonyl hydrazine compounds, carbonates, bicarbonates, nitrites, citric acid or hydrides; the foaming agent is usually selected from granules.

Further, the nucleating agent is any one or more of montmorillonite, silica, sorbitol, organic phosphate, sodium benzoate or rosin nucleating agent.

Further, the filler is any one or more of talcum powder, calcium carbonate, fiber, white carbon black, wollastonite powder or phosphogypsum.

Based on the formula of the polypropylene micro-foaming composite material, the technical scheme also provides a method for preparing the high-surface-quality polypropylene micro-foaming composite material.

The preparation method specifically comprises the following steps:

(1) weighing the raw material components according to the formula proportion, and uniformly mixing the weighed raw material components except the foaming agent to obtain a mixture;

(2) extruding and granulating the mixture at the extrusion temperature of 160-210 ℃ to obtain a modified polypropylene composite material;

(3) uniformly mixing 95-99.95 parts by weight of the modified polypropylene composite material and 0.05-5 parts by weight of a foaming agent (the total weight of the two is 100 parts) to obtain a foaming mixture;

(4) and performing injection molding on the foamed mixture at the injection molding temperature of 170-210 ℃ to obtain the polypropylene micro-foamed composite material.

In summary, compared with the prior art, the invention has the following beneficial effects:

(1) in the invention, the dissolution, diffusion and migration of gas in the polymer melt are regulated and controlled by the gas adsorbent and the gas barrier agent; the gas adsorbent can increase the solubility and diffusion coefficient of gas in the polymer and slow down the desorption speed of the gas, so that the polymer retains higher gas content, and meanwhile, the gas blocking agent can generate a labyrinth in the polymer matrix, so that the path of the gas penetrating through the matrix is more tortuous, and the process of gas molecule passing is blocked to a certain extent; due to the synergistic effect of the two components, the migration and diffusion of gas to the surface of the polymer can be reduced, the problem of surface defects such as air pockets and silver streaks on the surface of a polypropylene foaming product is solved while the foaming amount in the composite material is ensured, and the surface quality of the product is greatly improved;

(2) according to the invention, the provided composite material formula system can ensure that the surface quality is better than that of the prior art, and simultaneously can also ensure good physical properties, so that the requirements of practical application can be met;

(3) in the invention, the comprehensive tolerance performance of the obtained composite material can be improved by adding an antioxidant, a scratch-resistant agent and a light stabilizer into the micro-foaming composite material; the addition does not affect the surface quality of the obtained product under the system, thereby further improving the performance quality of the composite material, expanding the applicable range and prolonging the service life of the composite material while ensuring the surface quality of the composite material;

(4) in the invention, the preparation method provided by the formula of the polypropylene micro-foaming composite material selects the process parameter conditions suitable for the function exertion of each component, thereby further improving the molding surface quality of the prepared composite material.

Drawings

FIG. 1 is a surface comparison plot of a comparative sample and a sample of example 2;

FIG. 2 is a cross-sectional comparison of a comparative example and example 2.

Wherein, in fig. 1 and 2, the pictures illustrating the comparative example are both on the left, and the pictures illustrating the example 2 are both on the right; all pictures are amplified images, and the amplification times are 15 times; all pictures are on a 1000:1 scale.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following detailed description of the present invention is provided with reference to specific examples. Meanwhile, the illustrated embodiments of the present invention are only for illustration and do not limit the scope of the present invention.

It should be noted that in the composite formulations of the examples and comparative examples, the polypropylene copolymer used was supplied from Yanshan petrochemical under the trade designation K7100. The homopolymerized polypropylene is provided by a raisin, and the commodity brand is F401. The toughener POE was supplied by SK chemistry, korea, under the trade designation Solumer 8730. The inorganic filler is selected from pulvis Talci with particle size of 1250 mesh, and is provided by Asfeng powder. The gas adsorbent is polyvinyl acetate. The gas barrier agent is selected from ethylene-vinyl alcohol copolymer. The nucleating agent is sorbitol nucleating agent. Primary antioxidant 1010, secondary antioxidant 168 and light stabilizer 622 were supplied by BASF. The scratch-resistant agent is selected from erucamide. It should be understood that the selected brands and types of components are not limited to those described above, and that other materials having equivalent or similar properties may be used as the material of choice for the components in the illustrated embodiment.

Example 1

45.3 parts of copolymerized polypropylene resin, 20 parts of homopolymerized polypropylene resin, 12 parts of toughening agent, 20 parts of filler, 0.1 part of gas adsorbent, 0.1 part of gas blocking agent, 0.05 part of nucleating agent, 10100.7 parts of main antioxidant, 1680.7 parts of auxiliary antioxidant, 0.55 part of scratch-resistant agent and 0.5 part of light stabilizer are put into a high-speed mixer to be mixed for 3-5min, and after uniform mixing, the mixture is added into a double-screw extruder to be melted, blended and extruded for granulation. The extruder barrel temperature was set at 160-210 ℃.

And uniformly mixing 96 parts of the prepared modified polypropylene composite material and 4 parts of the chemical foaming agent master batch, adding the mixture into an injection molding machine, and obtaining the polypropylene micro-foaming composite material by adopting an injection molding process, wherein the injection molding temperature of the injection molding machine is set to be 170-210 ℃. The performance test results of the obtained polypropylene micro-foamed composite material are shown in the following table 1.

Example 2

45 parts of copolymerized polypropylene resin, 20 parts of homopolymerized polypropylene resin, 12 parts of toughening agent, 20 parts of filler, 0.2 part of gas adsorbent, 0.3 part of gas blocking agent, 0.05 part of nucleating agent, 10100.7 parts of main antioxidant, 1680.7 parts of auxiliary antioxidant, 0.55 part of scratch-resistant agent and 0.5 part of light stabilizer are put into a high-speed mixer to be mixed for 3-5min, and after the mixture is uniformly mixed, the mixture is added into a double-screw extruder to be melted, blended and extruded for granulation. The extruder barrel temperature was set at 160-210 ℃.

And uniformly mixing 96 parts of the prepared modified polypropylene composite material with 4 parts of chemical foaming agent master batches, adding the mixture into an injection molding machine, and obtaining the polypropylene micro-foaming composite material by adopting an injection molding process. The injection temperature of the injection molding machine is set to 170-210 ℃. The performance test results of the obtained polypropylene micro-foamed composite material are shown in the following table 1.

Example 3

44.5 parts of copolymerized polypropylene resin, 20 parts of homopolymerized polypropylene resin, 12 parts of toughening agent, 20 parts of filler, 0.4 part of gas adsorbent, 0.6 part of gas blocking agent, 0.05 part of nucleating agent, 10100.7 parts of main antioxidant, 1680.7 parts of auxiliary antioxidant, 0.55 part of scratch-resistant agent and 0.5 part of light stabilizer are put into a high-speed mixer to be mixed for 3-5min, and after uniform mixing, the mixture is added into a double-screw extruder to be melted, blended and extruded for granulation. The extruder barrel temperature was set at 160-210 ℃.

Example 4

44 parts of copolymerized polypropylene resin, 20 parts of homopolymerized polypropylene resin, 12 parts of toughening agent, 20 parts of filler, 0.5 part of gas adsorbent, 1 part of gas blocking agent, 0.05 part of nucleating agent, 10100.7 parts of main antioxidant, 1680.7 parts of auxiliary antioxidant, 0.55 part of scratch-resistant agent and 0.5 part of light stabilizer are put into a high-speed mixer to be mixed for 3-5min, and after the mixture is uniformly mixed, the mixture is added into a double-screw extruder to be melted, blended and extruded for granulation. The extruder barrel temperature was set at 160-210 ℃.

Example 5

43.5 parts of copolymerized polypropylene resin, 20 parts of homopolymerized polypropylene resin, 12 parts of toughening agent, 20 parts of filler, 0.8 part of gas adsorbent, 1.2 parts of gas blocking agent, 0.05 part of nucleating agent, 10100.7 parts of main antioxidant, 1680.7 parts of auxiliary antioxidant, 0.55 part of scratch-resistant agent and 0.5 part of light stabilizer are put into a high-speed mixer to be mixed for 3-5min, and after uniform mixing, the mixture is added into a double-screw extruder to be melted, blended and extruded for granulation. The extruder barrel temperature was set at 160-210 ℃.

Comparative example

45.5 parts of copolymerized polypropylene resin, 20 parts of homopolymerized polypropylene resin, 12 parts of toughening agent, 20 parts of filler, 0.05 part of nucleating agent, 10100.7 parts of antioxidant, 1680.7 parts of antioxidant, 0.55 part of scratch-resistant agent and 0.5 part of light stabilizer are put into a high-speed mixer to be mixed for 3-5min, and after uniform mixing, the mixture is added into a double-screw extruder to be melted, blended and extruded for granulation. The extruder barrel temperature was set at 160-210 ℃.

The results of testing the physical properties of the products obtained in examples 1 to 5 and comparative example are shown in Table 1.

TABLE 1 Performance test results of the polypropylene micro-foamed composites prepared in examples 1-5 and comparative examples

Comparing examples 1-5 with the comparative example, it can be seen that the tensile strength and the bending strength of the polypropylene micro-foamed composite material are not greatly changed, and the notch impact toughness is improved after the gas adsorbent and the gas barrier agent are added. The defects of surface gas marks, silver lines and the like are less and less along with the addition of the gas adsorbent and the gas barrier agent, and the foam holes are more and more uniform and compact (see figure 1). Further, the addition of the gas adsorbent and the gas barrier can regulate and control the dissolution, diffusion and migration of gas in the polymer melt, and reduce the gas migration and diffusion to the surface of the polymer, thereby achieving the purpose of improving the surface quality of the foamed product. In addition, as can be seen from fig. 2, compared with the comparative example, the polypropylene micro-foamed composite material obtained in the example has more uniform inner cells and an increased number of cells, so that the foaming uniformity (the reason for the improved notch impact toughness) and the foaming rate (the weight reduction and other foaming related properties of the composite material) of the composite material can be further improved under the formula system of the technical scheme.

The above-mentioned embodiments only express the specific embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, without departing from the technical idea of the present application, several changes and modifications can be made, which are all within the protection scope of the present application.

Claims

1. The high-surface-quality polypropylene micro-foaming composite material is characterized by comprising the following components in parts by weight:

43.5-60 parts of copolymerized polypropylene resin, 20-50 parts of homopolymerized polypropylene resin, 12-30 parts of toughening agent, 20-30 parts of filler, 0.1-10 parts of polyvinyl acetate, 0.1-10 parts of ethylene-vinyl alcohol copolymer, 4-5 parts of foaming agent, 0.05-4 parts of nucleating agent, 0.7-3 parts of main antioxidant, 0.7-3 parts of auxiliary antioxidant, 0.1-0.55 part of scratch-resistant agent and 0.5-3 parts of light stabilizer, wherein the main antioxidant and the auxiliary antioxidant are any one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant TPL and antioxidant DSTP, the scratch-resistant agent is any one or more of erucamide, polysiloxane, oleic acid or stearic acid, and the light stabilizer is any one or more of light stabilizer 622, light stabilizer 1084, light stabilizer 770, light stabilizer 901 or GW-540.

2. The high surface quality polypropylene microfoamed composite material according to claim 1, wherein: the melt index of the copolymerized polypropylene resin is 1-150 g/10min under the test conditions of the temperature of 230 ℃ and the pressure weight of 2.16 Kg; the melt index of the homopolymerized polypropylene resin is 0.5-70 g/10min under the test conditions of the temperature of 230 ℃ and the pressure of 2.16 Kg.

3. The high surface quality polypropylene microfoamed composite material according to claim 1, wherein: the foaming agent is any one or more of azo compounds, nitroso compounds, sulfonyl hydrazine compounds, carbonates, bicarbonates, nitrites, citric acid or hydrides.

4. The high surface quality polypropylene microfoamed composite material according to claim 1, wherein: the nucleating agent is any one or more of montmorillonite, silicon dioxide, sorbitol, organic phosphate, sodium benzoate or rosin nucleating agent.

5. A method for preparing the high surface quality polypropylene micro-foamed composite material according to any one of claims 1 to 4, which comprises the following steps:

(3) uniformly mixing 95-96 parts by weight of the modified polypropylene composite material with 4-5 parts by weight of a foaming agent to obtain a foaming mixture;