阅读说明：本技术 一种具有长效耐热氧老化性能、低气味抗发粘聚丙烯复合材料及其制备方法 (Polypropylene composite material with long-acting thermal-oxidative-aging resistance, low odor and stickiness resistance and preparation method thereof ) 是由 付武昌 张锴 徐美玲 蔡青 周文 于 2020-12-15 设计创作，主要内容包括：本发明公开了一种具有长效耐热氧老化性能、低气味抗发粘聚丙烯复合材料及其制备方法,这种聚丙烯复合材料由以下重量百分比的原料组成：聚丙烯37～97,纳米无机填料0～30,环氧树脂0.5～5,八环氧基笼形聚倍半硅氧烷1～10,弹性体1～15,抗氧剂0.1～0.5,其他助剂0～2。本发明通过在纳米无机填料增强聚丙烯复合体系中引入环氧树脂和八环氧基笼形聚倍半硅氧烷,通过环氧基内部的键合作用,形成交联网络结构,能够与常规抗氧剂形成协同抗氧效应；同时八环氧基笼形聚倍半硅氧烷的小尺寸效应能够使得聚丙烯结晶尺寸更小,晶格更完善,结构更均匀,能够抑制氧气进入材料内部以及在材料内部扩散,从而显著提高聚丙烯复合材料的耐热氧老化性能。(The invention discloses a polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance and a preparation method thereof, wherein the polypropylene composite material is prepared from the following raw materials in percentage by weight: 37-97 parts of polypropylene, 0-30 parts of nano inorganic filler, 0.5-5 parts of epoxy resin, 1-10 parts of octa-epoxy cage polysilsesquioxane, 1-15 parts of elastomer, 0.1-0.5 part of antioxidant and 0-2 parts of other auxiliary agents. According to the invention, epoxy resin and octa-epoxy group cage polysilsesquioxane are introduced into a nano inorganic filler reinforced polypropylene composite system, and a cross-linked network structure is formed through the bonding effect inside an epoxy group, so that a synergistic antioxidant effect can be formed with a conventional antioxidant; meanwhile, due to the small size effect of the octa-epoxy cage polysilsesquioxane, the polypropylene crystal size is smaller, the crystal lattice is more perfect, the structure is more uniform, oxygen can be inhibited from entering the material and diffusing in the material, and the thermal oxygen aging resistance of the polypropylene composite material is obviously improved.)

1. A polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance is characterized in that: the raw materials by weight percentage are as follows:

2. the polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the melt flow rate of the polypropylene is 5-60 g/10min under the conditions of 230 ℃ and 2.16kg load.

3. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the polypropylene is homopolymerized propylene or block copolymerization propylene; the crystallinity of the homopolymerized propylene is more than 70 percent, and the isotacticity is more than 99 percent; the comonomer of the block copolymerization polypropylene is ethylene, and the molar content of the ethylene monomer repeating unit is 4-10%.

4. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the nano inorganic filler is one or a combination of several of nano talcum powder, nano calcium carbonate, nano silicon dioxide, nano wollastonite and the like, and the average particle size of the nano inorganic filler is 50-150 nm.

5. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the epoxy resin is bisphenol A type epoxy resin, and the epoxy equivalent is 550-650 g/eq.

6. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the octa-epoxy cage-shaped polysilsesquioxane is a novel organic-inorganic nano-structure hybrid system, and the particle size range of the octa-epoxy cage-shaped polysilsesquioxane is 10-50 nm.

7. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the elastomer is ethylene-octene linear copolymer or ethylene-butene linear copolymer or the combination of the two, and the density is 0.88-0.90 g/cm³The melt flow rate is 0.5-10 g/10 min.

8. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the antioxidant comprises a main antioxidant and an auxiliary antioxidant, wherein the main antioxidant is a hindered phenol antioxidant; the auxiliary antioxidant is phosphite ester or thioester antioxidant; the main antioxidant is one or two of 3114 and 1010; the secondary antioxidant is one or more of 618, 168 and DSTP.

9. The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and tack resistance as claimed in claim 1, wherein: the other additives are various color additives, light stabilizers, various esters or fatty acid lubricants.

10. A method for preparing a low-odor and anti-sticking polypropylene composite material with long-acting thermal-oxidative aging resistance according to any one of claims 1 to 9, which is characterized in that: the method comprises the following specific steps:

(1) weighing the raw materials according to the weight ratio;

(2) placing the raw materials in a high-speed mixer to mix for 3-5 minutes;

(3) the mixed raw materials are placed in a double screw machine, and are subjected to melt extrusion and granulation, and the process comprises the following steps: 190-200 ℃ in the first area, 200-210 ℃ in the second area, 210-220 ℃ in the third area and 205-215 ℃ in the fourth area; the residence time of the whole extrusion process is 1-2 minutes, the pressure is 12-18 MPa, and the exhaust vacuum degree reaches 5-20 kPa.

Technical Field

The invention relates to a polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance and a preparation method thereof, which is a polypropylene composite material with simple process, low cost and good comprehensive performance, is mainly applied to household appliances, automotive interior and exterior decorations and the like, and belongs to the technical field of polymer modification and processing.

Background

The polypropylene has good processing performance, excellent mechanical, physical and chemical properties, light weight and low price, is widely applied to the industries of automobile interior and exterior decoration, household appliances, electronics and the like, and is the universal thermoplastic plastic with the highest growth speed at present. In recent years, with the rapid development of household appliances and automobile industry, the application range of thermoplastic plastic products, especially polypropylene materials, is wider and wider, and the requirements on the performance of the thermoplastic plastic products are higher and higher. For example, during the long-term use of polypropylene products, the products are easily embrittled and even pulverized, and the service life of the plastic products is seriously influenced. Meanwhile, when the polypropylene material is used as an automobile interior part, the enclosed environment and the higher internal temperature of an automobile provide higher challenges for the thermal oxidation aging resistance and the odor of the polypropylene material, and in recent years, consumers have increasingly complained about the odor in the automobile. Therefore, how to improve the thermo-oxidative aging resistance of the polypropylene composite material and have better odor effect becomes a problem which is urgently needed to be solved for developing the material.

At present, the thermal oxidation aging resistance of the polypropylene composite material is improved by the most conventional means of improving the content of the antioxidant, but the excessive antioxidant causes the problem that the antioxidant is separated out and sticky on the surface of the material in the using process. The existing patents improve the thermo-oxidative aging resistance of the polypropylene composite material by adding other kinds of auxiliary agents or increasing the content of antioxidant, but fail to mention the problem of tacky precipitation on the surface of the product. For example, CN101065432A patent adds primary antioxidant and secondary antioxidant into composite material to increase the stability of composite system, thereby achieving the long-term anti-thermo-oxidative aging performance, but higher content of antioxidant can cause the problem of antioxidant precipitation and stickiness. Patent CN102827422A improves the thermo-oxidative aging resistance of the composite material by adding beta nucleating agent and grafting aid, but does not relate to the anti-sticking property and odor condition of the material. Patent CN103044776A improves the odor and thermo-oxidative aging performance of polypropylene composite material by adding specific odor-removing agent and antioxidant, but does not relate to the problem of precipitation stickiness which may be brought about.

Disclosure of Invention

The invention aims to provide a polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance and a preparation method thereof, so as to solve the problems in the prior art.

In order to improve the thermal oxidation aging resistance of the polypropylene composite material, improve the odor problem of a complex system in the forming processing and using processes and solve the problem of easy sticky precipitation in the long-term use process, the technical scheme of the invention is that epoxy resin and octa-epoxy group cage polysilsesquioxane are added into the basic formula of the polypropylene composite material filled with the nano inorganic filler, and a cross-linked network structure is formed through the bonding effect inside an epoxy group in the extrusion blending process, so that the cross-linked network structure can form a synergistic antioxidant effect with a conventional antioxidant; meanwhile, due to the small size effect of the octa-epoxy cage polysilsesquioxane, the polypropylene crystal size is smaller, the crystal lattice is more complete, the structure is more uniform, oxygen can be inhibited from entering the material and diffusing in the material, and the thermal oxygen aging resistance of the polypropylene composite material is obviously improved; meanwhile, the cage structure of the octa-epoxy cage polysilsesquioxane and the coating effect of the epoxy resin on the nano particles are utilized, so that small molecular substances generated in the molding and processing process of the composite material can be captured, and the composite material is endowed with a good odor effect; the obtained composite material achieves long-acting and durable antioxidant effect under the condition of adding a very small amount of antioxidant, and can avoid the phenomenon of sticky precipitation in the long-term use process.

The polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance is prepared from the following raw materials in percentage by weight:

in the polypropylene composite material system applicable to the invention,

the melt flow rate of the polypropylene is 5-60 g/10min under the conditions of 230 ℃ and 2.16kg load.

The polypropylene is homopolymerized propylene or block copolymerization propylene; the crystallinity of the homopolymerized propylene is more than 70 percent, and the isotacticity is more than 99 percent; the comonomer of the block copolymerization polypropylene is ethylene, and the molar content of the ethylene monomer repeating unit is 4-10%.

The nano inorganic filler is one or a combination of several of nano talcum powder, nano calcium carbonate, nano silicon dioxide, nano wollastonite and the like, and the average particle size of the nano inorganic filler is 50-150 nm.

The epoxy resin is bisphenol A type epoxy resin, and the epoxy equivalent is 550-650 g/eq.

The octa-epoxy cage-shaped polysilsesquioxane is a novel organic-inorganic nano-structure hybrid system, and the particle size range of the octa-epoxy cage-shaped polysilsesquioxane is 10-50 nm.

The elastomer is ethylene-octene linear copolymer or ethylene-butene linear copolymer or the combination of the two, and the density is 0.88-0.90 g/cm³The melt flow rate is 0.5-10 g/10 min.

The antioxidant comprises a main antioxidant and an auxiliary antioxidant, wherein the main antioxidant is a hindered phenol antioxidant; the auxiliary antioxidant is phosphite ester or thioester antioxidant. The main antioxidant is one or two of 3114 and 1010; the secondary antioxidant is one or more of 618, 168 and DSTP.

The other additives are various color additives, light stabilizers, various esters or fatty acid lubricants and the like.

The preparation method of the polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance comprises the following specific steps:

(1) weighing the raw materials according to the weight ratio;

(2) placing the raw materials in a high-speed mixer to mix for 3-5 minutes;

(3) the mixed raw materials are placed in a double screw machine, and are subjected to melt extrusion and granulation, and the process comprises the following steps: 190-200 ℃ in the first area, 200-210 ℃ in the second area, 210-220 ℃ in the third area and 205-215 ℃ in the fourth area; the residence time of the whole extrusion process is 1-2 minutes, the pressure is 12-18 MPa, and the exhaust vacuum degree reaches 5-20 kPa.

The invention has the advantages that:

1. according to the invention, epoxy resin and octa-epoxy group cage polysilsesquioxane are introduced into a nano inorganic filler filled and reinforced polypropylene composite system, and a cross-linked network structure is formed through the bonding effect inside epoxy groups, so that a synergistic antioxidant effect can be formed with a conventional antioxidant;

2. according to the invention, by utilizing the small-size effect of the octa-epoxy cage-shaped polysilsesquioxane, the polypropylene crystal size is smaller, the crystal lattice is more complete, the structure is more uniform, and oxygen can be inhibited from entering the material and diffusing in the material, so that the thermal-oxidative aging resistance of the polypropylene composite material is improved;

3. according to the invention, the cage-shaped hollow structure of the octa-epoxy group cage-shaped polysilsesquioxane and the good coating effect of the epoxy resin on the nano particles are utilized, so that small molecular substances generated in the molding and processing process of the composite material can be captured, and the composite material is endowed with a good odor effect;

4. the invention can achieve the long-acting and durable anti-thermal-oxidative aging effect under the condition of adding a very small amount of antioxidant, and can avoid the phenomenon of sticky precipitation in the long-time use process;

5. the polypropylene composite material with long-acting thermal-oxidative aging resistance, low odor and stickiness resistance provided by the invention has a simple preparation process and can realize industrial production.

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.

Example 1

The polypropylene composite material mainly comprises 69.6% of polypropylene, 20% of nano talcum powder, 1% of epoxy resin, 2% of octa-epoxy cage polysilsesquioxane, 5% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Example 2

The polypropylene composite material mainly comprises 68.6% of polypropylene, 20% of nano talcum powder, 2% of epoxy resin, 2% of octa-epoxy cage polysilsesquioxane, 5% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Example 3

The polypropylene composite material mainly comprises 67.6% of polypropylene, 20% of nano talcum powder, 2% of epoxy resin, 3% of octa-epoxy cage polysilsesquioxane, 5% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Example 4

The polypropylene composite material mainly comprises 64.6 percent of polypropylene, 20 percent of nano talcum powder, 3 percent of epoxy resin, 5 percent of octa-epoxy cage polysilsesquioxane, 5 percent of elastomer, 0.1 percent of antioxidant 1010, 0.1 percent of auxiliary antioxidant DSTP, 0.2 percent of auxiliary antioxidant 168 and 2 percent of other auxiliary agents.

Example 5

The polypropylene composite material mainly comprises 51.6% of polypropylene, 30% of nano talcum powder, 3% of epoxy resin, 5% of octa-epoxy cage polysilsesquioxane, 8% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Example 6

The polypropylene composite material mainly comprises 50.6% of polypropylene, 30% of nano talcum powder, 4% of epoxy resin, 5% of octa-epoxy cage polysilsesquioxane, 8% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Example 7

The polypropylene composite material mainly comprises 47.6% of polypropylene, 30% of nano talcum powder, 4% of epoxy resin, 8% of octa-epoxy cage polysilsesquioxane, 8% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Comparative example 1

The polypropylene composite material mainly comprises 72.6% of polypropylene, 20% of nano talcum powder, 5% of elastomer, 0.1% of antioxidant 1010, 0.1% of auxiliary antioxidant DSTP, 0.2% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Comparative example 2

The polypropylene composite material mainly comprises 71.6 percent of polypropylene, 20 percent of nano talcum powder, 1 percent of epoxy resin, 5 percent of elastomer, 0.1 percent of antioxidant 1010, 0.1 percent of auxiliary antioxidant DSTP, 0.2 percent of auxiliary antioxidant 168 and 2 percent of other auxiliary agents.

Comparative example 3

The polypropylene composite material mainly comprises 70.6 percent of polypropylene, 20 percent of nano talcum powder, 2 percent of octa-epoxy cage polysilsesquioxane, 5 percent of elastomer, 0.1 percent of antioxidant 1010, 0.1 percent of auxiliary antioxidant DSTP, 0.2 percent of auxiliary antioxidant 168 and 2 percent of other auxiliary agents.

Comparative example 4

The polypropylene composite material mainly comprises 70% of polypropylene, 20% of nano talcum powder, 1% of epoxy resin, 2% of octa-epoxy cage polysilsesquioxane, 5% of elastomer and 2% of other auxiliary agents.

Comparative example 5

The polypropylene composite material mainly comprises 72.3% of polypropylene, 20% of nano talcum powder, 5% of elastomer, 0.2% of antioxidant 1010, 0.2% of auxiliary antioxidant DSTP, 0.3% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

Comparative example 6

The polypropylene composite material mainly comprises 58.9% of polypropylene, 30% of nano talcum powder, 8% of elastomer, 0.3% of antioxidant 1010, 0.3% of auxiliary antioxidant DSTP, 0.5% of auxiliary antioxidant 168 and 2% of other auxiliary agents.

The mass percentages of the main components of the examples and comparative examples are shown in Table 1.

TABLE 1 materials formulation tables for examples 1-7 and comparative examples 1-6 (% by weight)

In the above examples and comparative example composite formulations, the polypropylene was made from a commercially available polypropylene obtained from Shanghai petrochemical industry under the trade designation M2600R and having a melt flow rate of 30g/10min (test conditions: 230 ℃ C. times.2.16 kg). The talcum powder is 10000 meshes, the average grain diameter is 100nm, and the talcum powder is commercially available. The epoxy resin is KD-213 produced by national chemical industry. The octa-epoxy group cage-shaped polysilsesquioxane is self-made, wherein the average particle size is 20nm, and the molecular weight is 40000-80000. The elastomer used was an ethylene-octene copolymer from DOW under the trade name Engage8150, having a density of 0.868g/cm3 and a melt index of 0.5g/10min (test conditions: 190 ℃ C.. times.2.16 kg). The main antioxidant is 1010 produced by BASF company and has a chemical name of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, the auxiliary antioxidant is DSTP produced by British ICE company and has a chemical name of octadecyl thiodipropionate, and 168 produced by BASF company and has a chemical name of tris (2, 4-di-tert-butylphenyl) phosphite ester. The other auxiliary agents comprise various color additives, light stabilizers, various ester or fatty acid lubricants and the like.

In the above examples and comparative examples, the resins and additives were dry-mixed in a high-speed mixer for 3-5 minutes, and then melt-extruded and pelletized in a twin-screw extruder, and the process was: 190-200 ℃ in the first area, 200-210 ℃ in the second area, 210-220 ℃ in the third area and 205-215 ℃ in the fourth area; the residence time of the whole extrusion process is 1-2 minutes, the pressure is 12-18 MPa, and the exhaust vacuum degree reaches 5-20 kPa.

And (3) drying the particle material prepared by the method in a blowing oven at 90-100 ℃ for 2-3 hours, then carrying out injection molding sample preparation on the dried particle material on an injection molding machine, and carrying out performance test.

And (3) testing tensile property: according to ISO 527-2 standard, the sample size is 170 multiplied by 10 multiplied by 4mm, and the stretching speed is 50 mm/min;

and (3) testing the bending property: according to ISO 178 standard, the size of the sample is 80 multiplied by 10 multiplied by 4mm, the bending speed is 2mm/min, and the span is 64 mm;

notched impact strength test: the method is carried out according to ISO 179-1 standard, the size of a sample is 80 multiplied by 10 multiplied by 4mm, and the depth of a notch is one third of the thickness of the sample;

and (3) testing thermal oxidation aging resistance: referring to DIN 53497 standard, injection molding 1mm and 3mm sample plates, and storing in a forced convection oven at 150 deg.C until the sample plate has embrittlement as evaluation standard;

tack property test: the tests were performed according to the general standard PV1306 and the samples were evaluated according to the scale described in table 2 below:

TABLE 2 surface tackiness rating and evaluation results

Grade	Evaluation results	Grade	Evaluation results
				1	OK	5	Is very sticky
2	Slightly tacky	H	Resinification of
				3	Stickiness	W	Smooth surface, waxy
4	Is relatively viscous	X	The sample was cracked and could not be evaluated

And (3) odor test: performed according to popular PV3900 standard, using a 50g template, 1L odor bottle. Placing the sample in a smell bottle, placing the smell bottle in an oven at 80 +/-2 ℃ for 2h +/-10 min, cooling the smell bottle to 60 +/-5 ℃, and judging according to the grades (a half grade and other intermediate grades) described in the following table 3;

TABLE 3 odor rating and evaluation results

Grade	Evaluation results	Grade	Evaluation results
				Level 1	Can not feel	4 stage	Disturbing the human body
Stage 2	Can be felt without disturbing the human body	Grade 5	Strong aversion to cold
				Grade 3	Can be obviously sensed, but is not disturbing	Grade 6	Are difficult to tolerate

The performance test results of the polypropylene composite materials of examples 1-7 and comparative examples 1-6 of the invention are shown in Table 4.

TABLE 4 tables of Properties of the materials of examples 1-7 and comparative examples 1-6

As can be seen from the comparison of examples 1 to 7 and the comparison of examples 1 to 4 with comparative examples 1 to 4, the simultaneous addition of the epoxy resin and the octaepoxy group cage-shaped polysilsesquioxane can obviously improve the thermal oxidative aging resistance of the polypropylene composite material, and the thermal oxidative aging resistance of the composite material is further improved along with the increase of the contents of the epoxy resin and the octaepoxy group cage-shaped polysilsesquioxane; meanwhile, compared with the system which does not contain or only contains one of epoxy resin and octa-epoxy group cage-shaped polysilsesquioxane, the odor of the composite system can be obviously improved under the condition that the epoxy resin and the octa-epoxy group cage-shaped polysilsesquioxane exist at the same time, and even the more ideal odor level of grade 3 can be reached. From the comparison between example 1 and comparative example 5, and between example 5 and comparative example 6, it can be seen that higher thermal-oxidative aging resistance can be achieved by adding higher content of antioxidant, but the problem of sticky precipitation exists on the surface after the material is subjected to the sticky resistance test, so that the long-term use effect of the product is influenced; in the presence of epoxy resin and octa-epoxy cage polysilsesquioxane, the long-acting thermo-oxidative aging resistance can be achieved under the condition of adding a lower content of antioxidant, and meanwhile, the material has good comprehensive mechanical properties.