阅读说明：本技术 一种高强度、轻量化、耐刮擦聚丙烯复合材料及其制备方法 (High-strength, light-weight and scratch-resistant polypropylene composite material and preparation method thereof ) 是由 冯杨 张锴 张千惠 蔡青 周文 于 2020-11-30 设计创作，主要内容包括：本发明公开了一种高强度、轻量化、耐刮擦聚丙烯复合材料及其制备方法。该种聚丙烯复合材料由以下重量百分比的原料组成：聚丙烯45-90％；聚合物型成核剂0.1-5％；纳米级无机填料0-15％；微米级无机填料5-20％；增韧剂5-20％；抗刮擦助剂0.5-3％；稳定剂0.1-2％；其他添加剂0-5％。聚合物型成核剂比无机填料诱导结晶能力更强,使聚丙烯结晶温度、力学强度更高,因此可以在保证材料高强度前提下减少无机填料用量,降低材料密度。纳米级无机填料替代部分常规微米级无机填料可以进一步降低无机填料总量,并同时保持材料尺寸稳定。无机填料的减少可以减弱材料受到刮擦后因无机填料外露导致的白色刮痕,而抗刮擦助剂的引入可以进一步提升材料耐刮擦能力,使材料成型后保持较好的表面外观。(The invention discloses a high-strength, light-weight and scratch-resistant polypropylene composite material and a preparation method thereof. The polypropylene composite material is composed of the following raw materials in percentage by weight: 45-90% of polypropylene; 0.1-5% of polymer type nucleating agent; 0-15% of nano inorganic filler; 5-20% of micron inorganic filler; 5-20% of a toughening agent; 0.5-3% of anti-scratch auxiliary agent; 0.1 to 2 percent of stabilizer; 0-5% of other additives. The polymer type nucleating agent has stronger induced crystallization capability than inorganic filler, so that the polypropylene has higher crystallization temperature and mechanical strength, and the dosage of the inorganic filler can be reduced and the material density can be reduced on the premise of ensuring the high strength of the material. The nanometer inorganic filler replaces part of the conventional micron inorganic filler, so that the total amount of the inorganic filler can be further reduced, and the size of the material is kept stable. The reduction of the inorganic filler can weaken white scratches of the material caused by the exposure of the inorganic filler after being scratched, and the introduction of the scratch-resistant auxiliary agent can further improve the scratch-resistant capability of the material, so that the material can keep better surface appearance after being molded.)

1. A high-strength, light-weight and scratch-resistant polypropylene composite material is characterized in that: the composite material consists of the following raw materials in percentage by weight: 45-90% of polypropylene; 0.1-5% of polymer type nucleating agent; 0-15% of nano inorganic filler; 5-20% of micron inorganic filler; 5-20% of a toughening agent; 0.5-3% of anti-scratch auxiliary agent; 0.1 to 2 percent of stabilizer; 0-5% of other additives.

2. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the polypropylene is homopolymerized or copolymerized polypropylene with melt flow rate of 30-90g/10min, the comonomer of the copolymerized polypropylene is ethylene, and the molar content of ethylene repeating units is 4-10%.

3. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the polymer type nucleating agent is polyvinyl cyclohexane or vinylidene fluoride or the combination of the two.

4. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the nano inorganic filler is any one or combination of several of nano talcum powder, nano calcium carbonate, nano montmorillonite, nano wollastonite and nano barite with the average size of not more than 0.1 mu m.

5. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the micron-sized inorganic filler is talcum powder with the average size of 1-10 mu m.

6. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the toughening agent is ethylene-octene copolymer or ethylene-butene copolymer or the combination of the two, and the density is 0.88-0.91g/cm³The melt flow rate is 0.5-10g/10 min.

7. A high strength, light weight, scratch resistant polypropylene composite and method of making the same as claimed in claim 1 wherein: the anti-scratch auxiliary agent is any one or a combination of more of erucamide, stearyl erucamide, oleamide, behenamide and silicone.

8. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the stabilizer is a main antioxidant and a secondary antioxidant which are considered to be required by a person skilled in the art, wherein the main antioxidant is a hindered phenol or thioester antioxidant, and the secondary antioxidant is a phosphite or lipid antioxidant.

9. A high strength, light weight, scratch resistant polypropylene composite as claimed in claim 1 wherein: the other additives are one or a combination of several of antioxidant, flame retardant, foaming agent, colorant, color master batch, antistatic auxiliary agent, surfactant, plasticizer, coupling agent and antimicrobial auxiliary agent which are considered to be needed by the people in the field.

10. A method of preparing a high strength, light weight, scratch resistant polypropylene composite as claimed in any one of claims 1 to 9 wherein: the method comprises the following specific steps:

(1) dry-mixing the polymer nucleating agent, the nano-scale inorganic filler and part of polypropylene in a high-speed mixer for 8-15min according to the weight ratio to obtain a premix A;

(2) dry-mixing the rest polypropylene, the micron-sized inorganic filler, the toughening agent, the anti-scratch auxiliary agent, the stabilizing agent and other additives in a high-speed mixer for 8-15min according to the proportion to obtain a premix B;

(3) adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Technical Field

The invention relates to a high-strength, light-weight and scratch-resistant polypropylene composite material and a preparation method thereof.

Background

Polypropylene is a common thermoplastic polymer, and has the advantages of easy processing, low price, low density, recyclability and the like. As an important automotive material, high strength is a fundamental performance index that modified polypropylene must meet. The high strength of polypropylene composites is currently achieved mainly by the incorporation of inorganic mineral fillers, which cause a significant increase in the material density. At present, light weight is an important subject of great research of many vehicle enterprises, and part thinning and foaming injection molding are two important weight reduction means, but the two means mainly take the basic idea of reducing the material consumption of parts. To further reduce weight, weight reduction (density reduction) of the material itself is the central weight, and reducing the amount of inorganic mineral filler while ensuring high strength is the most direct and effective way. In addition, scratch resistance is an important practical indicator of appearance of the material, namely the material can cause the exposure of inorganic seasoning to generate white scratch after being scratched, so that the reduction of the use amount of the inorganic filler is also beneficial to the improvement of scratch resistance.

Although inorganic fillers are disadvantageous in terms of weight reduction and scratch resistance of the material, they can make the material more dimensionally stable, and thus cannot be completely removed from the material, and the amount can be reduced only within a reasonable range. Compared with inorganic mineral fillers, the polymer type nucleating agent is a more efficient polypropylene alpha crystal nucleating agent, the polymer type nucleating agent is more beneficial to improving the crystallization temperature and the mechanical strength of polypropylene at the same content, and in addition, the density is lower, so the total amount of the inorganic mineral fillers can be reduced by using the polymer type nucleating agent. Almost all studies and reports on polypropylene nucleating agents so far are directed to pure polypropylene systems, and the performance regulation of the nucleating agent used for a polypropylene composite material system (polypropylene/toughening agent/inorganic filler composite system) is rare. With the development of powder technology, nano inorganic fillers with particle size as low as 0.1 μm level have appeared, which provides a thought for further reducing the total amount of inorganic mineral fillers. Since the inorganic filler is exposed after the material is scratched, the reduction of the total amount of the inorganic mineral filler is also beneficial to improving the scratch resistance of the material, and in addition, the material can keep better appearance for a long time after being formed by being supplemented with a preferable scratch resistance auxiliary agent.

Disclosure of Invention

The invention aims to develop a high-strength, light-weight and scratch-resistant polypropylene composite material, and the obtained material can be used for injection molding of parts of automobiles and other products.

The invention also aims to provide a preparation method of the polypropylene composite material.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-strength, light-weight and scratch-resistant polypropylene composite material and a preparation method thereof are disclosed, which comprises the following raw materials by weight percent: 45-90% of polypropylene; 0.1-5% of polymer type nucleating agent; 0-15% of nano inorganic filler; 5-20% of micron inorganic filler; 5-20% of a toughening agent; 0.5-3% of anti-scratch auxiliary agent; 0.1 to 2 percent of stabilizer; 0-5% of other additives.

Wherein the content of the first and second substances,

the polypropylene is homopolymerized or copolymerized polypropylene with melt flow rate of 30-90g/10min, the comonomer of the copolymerized polypropylene is ethylene, and the molar content of ethylene repeating units is 4-10%.

The polymeric nucleating agent is Polyvinylcyclohexane (PVCH) or vinylidene fluoride (PVDF) or a combination of the two.

The nano inorganic filler is any one or combination of several of nano talcum powder, nano calcium carbonate, nano montmorillonite, nano wollastonite, nano barite and the like with the average size of not more than 0.1 mu m.

The micron-sized inorganic filler is talcum powder with the average size of 1-10 mu m.

The toughening agent is ethylene-octene copolymer or ethylene-butene copolymer or the combination of the two, and the density is 0.88-0.91g/cm³The melt flow rate is 0.5-10g/10 min.

The anti-scratch auxiliary agent is any one or a combination of more of erucamide, stearyl erucamide, oleamide, behenamide, silicone and the like.

The stabilizer is a main antioxidant and a secondary antioxidant which are considered to be required by a person skilled in the art, wherein the main antioxidant is a hindered phenol or thioester antioxidant, and the secondary antioxidant is a phosphite or lipid antioxidant.

The other additives are one or a combination of several of antioxidant, flame retardant, foaming agent, colorant, color master batch, antistatic auxiliary agent, surfactant, plasticizer, coupling agent and antimicrobial auxiliary agent which are considered to be needed by the people in the field.

The preparation method of the high-strength, light-weight and scratch-resistant polypropylene composite material comprises the following specific steps:

(1) and dry-mixing the polymer type nucleating agent, the nanoscale inorganic filler and part of the polypropylene in a high-speed mixer for 8-15min according to the weight ratio to obtain the premix A.

(2) And dry-mixing the rest polypropylene, the micron-sized inorganic filler, the toughening agent, the anti-scratch auxiliary agent, the stabilizing agent and other additives in a high-speed mixer for 8-15min according to the proportion to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

The polypropylene composite material with high strength, light weight and scratch resistance is finally obtained through the combined action of the high-efficiency polymer nucleating agent and the nano-scale inorganic mineral filler and the matching of the high-efficiency polymer nucleating agent, the preferred polypropylene, the preferred toughening agent and the preferred scratch resistance auxiliary agent. The production process adopts the processes of premixing the nano-filler, the polymer type nucleating agent and part of polypropylene and sectional lateral feeding, greatly improves the dispersion effect of each component and ensures the stability of the material performance.

The invention has the advantages that:

1. by introducing the high-efficiency polymer nucleating agent, the crystallization inducing effect better than that of inorganic filler with the same content can be achieved, so that the crystallization temperature of polypropylene is higher, and the mechanical strength is higher. Therefore, the using amount of the inorganic filler can be reduced on the premise of ensuring the high strength of the product, and the material is light in weight.

2. By using the nanoscale inorganic filler to replace part of the conventional micron-sized inorganic filler, the total amount of the inorganic filler in the material can be further reduced, so that the density of the material is reduced, and the dimensional stability of the material is ensured.

3. The obtained material can realize weight reduction during conventional injection molding, and can also be used for thin-wall parts, so that higher weight reduction amplitude can be realized on the premise of not influencing the use of the parts.

4. The overall content of inorganic filler in the material is reduced, meaning that the exposed filler is also reduced after the material is scratched, and the whitening degree of the scratch is reduced accordingly. On the basis, by using the preferable scratch resistant auxiliary agent, the excellent scratch resistant effect of the material after processing and forming can be ensured.

Detailed Description

The present invention is further illustrated by the following examples and comparative examples, which are not intended to limit the scope of the invention.

In the composite formulations of the examples and comparative examples, the high flow polypropylene used was a block copolymer polypropylene with a melt flow rate of about 60g/10 min.

The polymeric nucleating agent used was PVDF from Solvay (melt flow rate about 2g/10 min).

The micron-sized inorganic filler is talcum powder, and the average grain size is 10 mu m.

The nano inorganic filler is nano talcum powder with average grain size of 0.1 μm.

The toughening agent used was ethylene-octene copolymer 8150 from DOW corporation.

The scratch-resistant aid used is silicone.

The stabilizers used were Negonox DSTP (chemical name: stearyl thiodipropionate) from ICE of the United kingdom, Irganox 1010 (chemical name: pentaerythritol tetrakis (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate) from Ciba, and Irgafos 168 (chemical name: tris (2, 4-di-tert-butylphenyl) phosphite) from Ciba.

Example 1

(1) Weighing 0.5 percent of polymer type nucleating agent and 10.0 percent of polypropylene according to the weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain the premix A.

(2) Weighing 56.5% of polypropylene, 16.5% of micron-sized talcum powder, 15.0% of flexibilizer, 0.3% of Negonox DSTP, 0.78% of Irganox 10100.1%, 1680.1% of Irgafos and 1.0% of toner according to weight percentage, and dry-mixing for 8min in a high-speed mixer to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Example 2

(1) Weighing 1.0 percent of polymer type nucleating agent and 10 percent of polypropylene according to the weight percentage, and dry mixing in a high-speed mixer for 8min to obtain the premix A.

(2) Weighing 56% of polypropylene, 16.5% of micron-sized talcum powder, 15.0% of toughening agent, 0.3% of Negonox DSTP, 0.78% of Irganox 10100.1%, 1680.1% of Irgafos and 1.0% of toner according to weight percentage, and dry-mixing for 8min in a high-speed mixer to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Example 3

(1) Weighing 1.0 percent of polymer type nucleating agent, 10.5 percent of nano-scale talcum powder and 25.0 percent of polypropylene according to the weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain the premix A.

(2) Weighing 41.0% of polypropylene, 6.0% of micron-sized talcum powder, 15.0% of flexibilizer, 0.3% of Negonox DSTP, 0.78% of Irganox 10100.1%, 1680.1% of Irgafos and 1.0% of toner according to weight percentage, and dry-mixing for 8min in a high-speed mixer to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Example 4

(1) Weighing 10.5 percent of nano-scale talcum powder and 25.0 percent of polypropylene according to the weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain the premix A.

(2) Weighing 42.0% of polypropylene, 6.0% of micron-sized talcum powder, 15.0% of flexibilizer, 0.3% of Negonox DSTP, 0.78% of Irganox 10100.1%, 1680.1% of Irgafos and 1.0% of toner according to weight percentage, and dry-mixing for 8min in a high-speed mixer to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Example 5

(1) Weighing 1.0 percent of polymer type nucleating agent, 8.5 percent of nano-scale talcum powder and 25.0 percent of polypropylene according to the weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain the premix A.

(2) Weighing 44.0 percent of polypropylene, 5.0 percent of micron-sized talcum powder, 15.0 percent of flexibilizer, 0.3 percent of Negonox DSTP, Irganox 10100.1 percent, Irgafos 1680.1 percent and 1.0 percent of toner according to weight percentage, and dry-mixing for 8min in a high-speed mixer to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Example 6

(1) Weighing 61.5% of polypropylene, 20.0% of micron-sized talcum powder, 15.0% of flexibilizer, 2.0% of scratch-resistant auxiliary agent, 0.3% of Negonox DSTP, Irganox 10100.1%, Irgafos 1680.1% and 1.0% of toner according to weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain the premix.

(2) Adding the premix into a double-screw extruder from a main screw feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Example 7

(1) Weighing 1.0 percent of polymer type nucleating agent, 8.5 percent of nano-scale talcum powder and 25.0 percent of polypropylene according to the weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain the premix A.

(2) Weighing 42.0% of polypropylene, 5.0% of micron-sized talcum powder, 15.0% of toughening agent, 2.0% of scratch-resistant auxiliary agent, 0.3% of Negonox DSTP, 0.78% of Irganox 10100.1%, 1680.1% of Irgafos and 1.0% of toner according to weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain a premix B.

(3) Adding the premix B into a double-screw extruder from a main screw feeding port, adding the premix A into the double-screw extruder from the middle side of a screw to the feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Comparative example 1

(1) Weighing 63.5% of polypropylene, 20.0% of micron-sized talcum powder, 15.0% of flexibilizer, 0.3% of Negonox DSTP, Irganox 10100.1%, Irgafos 1680.1% and 1.0% of toner according to weight percentage, and dry-mixing in a high-speed mixer for 8min to obtain a premix.

(2) Adding the premix into a double-screw extruder from a main screw feeding port, performing melt extrusion, cooling and granulating, wherein the process comprises the following steps: the first zone 190-; the retention time is 1-2min, and the pressure is 12-18 MPa.

Performance evaluation method:

the sample density was performed according to ISO 1183-1 standard; the melt flow rate is carried out according to ISO 1133-1; the tensile property test is carried out according to the ISO 527-2 standard, and the size of a test sample is 170mm multiplied by 10mm multiplied by 4 mm; the bending performance test is carried out according to ISO 178 standard, the size of a test sample is 80mm multiplied by 10mm multiplied by 4mm, the bending speed is 2mm/min, and the span is 64 mm; the impact test of the simple beam notch is carried out according to the ISO 179-1 standard, the size of a sample is 80mm multiplied by 10mm multiplied by 4mm, and the depth of the notch is one third of the thickness of the sample; the scratch resistance was evaluated by measuring the Δ L (change in gloss) value of the surface of the scratch specimen, which is measured under a load of 10N in accordance with PV3952, and a smaller Δ L value indicates a better scratch resistance of the material.

The weight percentages of the main components of each example and comparative example are shown in table 1, and the corresponding performance test results are shown in table 2.

TABLE 1 EXAMPLES 1-7 AND COMPARATIVE EXAMPLE 1 Material compositions (in weight percent)

TABLE 2 results of testing the Properties of the materials of examples 1-7 and comparative example 1

As can be seen from the performance test results of the materials of the comparative example 1 and the examples 1 and 2, the introduction of the polymeric nucleating agent in the composite material can reduce the dosage of the talcum powder while keeping the original strength level, thereby reducing the density and improving the scratch resistance. The results of comparative examples 2, 3 and 4 show that the existence of the polymeric nucleating agent and the nano inorganic filler can ensure that the strength and the scratch resistance of the material are improved as much as possible under a certain weight reduction range. It can be seen from the test results of examples 3 and 5 that although the reduced amount of micro-and nano-talc results in a reduction in the strength of the material, the performance of example 5 is still comparable to that of comparative example 1, and in exchange for a lower density. As can be seen from the test results of comparative example 6 and comparative example 1, the introduction of the scratch resistance assistant can effectively improve the scratch resistance of the material, so that the best combination of the performances of example 7 obtained after the scratch resistance assistant is introduced on the basis of example 5 is achieved.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.