CN1631959B - High rigidity, high heat resistance and scratch resistance talcum powder filled polypropylene and preparation method thereof - Google Patents

Abstract

The invention relates to high molecular compound material, especially a polypropylene filled with talcum powder, with outstanding and resistance to heat and its preparing method. The invention is comprised of polypropylene and talcum powder with high crystal and the percentages of each component are: polypropylene 60-90, talcum powder 10-40, coupling agent 3-10, stabilizer 0.1-1.0, of talcum powder0.2-1.5 and ethylene bis stearamide 0.1-1. The preparing method is: mix each raw material in agitator, then place then into double screw extruder to form the particles. Keeping the same, it has low density, larger hardness of the surface, advanced strength to resist scratch, can satisfy the requirements of elements in kinds of auto, which can be applied in auto and electric field, such as pate of instrument, door, plate of auxiliary instrument, decorating stick and other ornament inside and outside automobile.

Description

High rigidity, high heat resistance and scratch resistance talcum powder filled polypropylene and preparation method thereof

technical field

The present invention relates to polymer composite materials, especially to a kind of high rigidity, high heat resistance and scratch resistance talcum powder filled polypropylene and its preparation method. This type of polymer composite material can be used in the fields of automobiles and home appliances, such as the dashboard of cars , Door panels, door guards, sub-dashboards, glove boxes, decorative pillars and other automotive interior and exterior trims. the

Background technique

Polypropylene has the advantages of excellent processing performance, high toughness, good gasoline and chemical resistance, light weight and low price. It is widely used in interior and exterior trim parts of automobiles, housings of electronics and household appliances, etc. However, polypropylene also has the disadvantages of poor heat resistance, low rigidity, scratch resistance, and poor low-temperature impact performance. the

The rigidity, strength and heat resistance of polypropylene materials are usually greatly improved by adding glass fibers, but there are disadvantages of poor molding performance and poor surface quality of products. The method of adding talcum powder is also used to improve the rigidity of polypropylene, but with the increase of talcum powder, the density of modified polypropylene increases and the weight of parts increases, which does not meet the current environmental protection requirements. In the case of rigidity requirements, further reducing the weight of the product is the common goal of many modified plastic manufacturers, and the most effective method is to improve the rigidity of polypropylene itself. the

Polypropylene is a crystalline polymer, its rigidity is mainly determined by the crystallinity of the material, and the degree of crystallinity is determined by the regularity of the material. In recent years, the polymerization technology of polypropylene has made great progress. The isotacticity of polypropylene has increased from 96% to more than 99%, and the crystallinity has been greatly improved, making the tensile strength of the material greater than 40MPa and the flexural modulus above 2000MPa. , At the same time, the scratch resistance of the material has also been significantly improved, basically meeting the rigidity requirements of the ABS material, but its density is smaller, and the resulting product is lighter in quality. Using this kind of material as the base material, supplemented by talcum powder filling, the rigidity and heat resistance of the modified polypropylene material will be greatly improved, that is to say, the performance of ordinary modified polypropylene can be achieved at a lower dosage. , so that the weight of the product can be reduced, which is conducive to reducing the weight of the vehicle. the

Contents of the invention

The object of the present invention is to develop a high rigidity, high heat resistance scratch-resistant talc powder filled polypropylene, that is, to provide a scratch-resistant talc with good appearance, good rigidity, easy processing, light weight and low price. Powder-filled polypropylene compositions and methods for their preparation. the

In order to achieve the above object, the technical solution of the present invention is to provide a scratch-resistant talcum powder filled polypropylene composition, with high crystallization polypropylene, which is made of the following raw materials in weight ratio:

A. High crystalline high isotactic polypropylene 60-90

B. Talc powder 10-40

C. Coupling agent 3-10

D. Stabilizer 0.1-1.0

E. Talc surface passivator 0.2-1.5

Wherein, A+B (the total weight of highly crystalline high-isotactic polypropylene and talcum powder) is 100 parts by weight, and the stabilizer is an acid absorber, a thermal oxygen stabilizer and a light stabilizer, wherein the thermal oxygen stabilizer is 1010 ("β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester) and Irganox PS 802 (distearyl thiodipropionate), the dosage is 0.1%-1.0 %, preferably 0.1%-0.5%; light stabilizer is 770 (bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate) and Chimassorb 944, the dosage is 0.1-1.0 Parts by weight; Acid absorbent is stearate, such as calcium stearate and zinc stearate, and its consumption is 0.05%-0.5%; Described talcum powder is the talcum powder of lamellar structure, and length/thickness ratio is 100 to 500, the particle size range is 1 to 10 microns; the talcum powder surface passivator is higher fatty acid or epoxy resin Araltide 7072; the coupling agent is maleic anhydride grafted polypropylene; Bisstearamide, the amount of which is 0.05 to 1.0 parts by weight; the crystallinity of the high-crystalline high-isotactic polypropylene is not less than 70%, and the isotacticity is greater than 99%.

On the basis of the above scheme, the polypropylene is high crystalline homopolypropylene and block copolymer polypropylene, wherein the comonomer of block copolymer polypropylene is ethylene, and its content is in the range of 4-10mol%. The bulk flow rate is 5-50g/10min at 230°C and 2.16kg load, more commonly 5-30g/10min. the

On the basis of the above scheme, the particle size range of the talcum powder is 0.5-10 microns, preferably 1-10 microns. the

On the basis of the above scheme, the crystallinity of the high crystallization and high isotacticity polypropylene is not less than 70%, and the isotacticity is greater than 99%. the

A kind of preparation method of high rigidity, high heat resistance scratch-resistant talcum powder filled polypropylene, its method is as follows:

(1) Take raw materials by weight ratio;

(2) Mix polypropylene, talcum powder, stabilizer, coupling agent and ethylene bis stearamide in a high-speed mixer for 10 to 20 minutes;

(3) Put the mixed raw materials into the twin-screw extruder. The residence time of the materials in the screw is 1-2 minutes. ～210℃, four zone 195～215℃; the speed of twin-screw extruder is 300-700 rpm;

(4) Discharge, melt and extrude in a twin-screw extruder, cool, dry and pelletize after extrusion to obtain the finished product. the

The advantages of the present invention are:

1. The present invention adopts the blending of highly crystalline polypropylene and talcum powder, which greatly improves the rigidity of polypropylene. the

2. Heat resistance, strength, hardness and scratch resistance can meet the material requirements of auto parts. the

3. Due to the use of high crystalline PP, under the same rigidity, the requirement can be met with a smaller amount of talcum powder, which is beneficial to reduce the density of the material, thereby reducing the weight of auto parts. the

4. The sources of various materials used in the present invention are wide and easy to get. the

Below in conjunction with embodiment, the present invention is described in further detail. the

Detailed ways

The polypropylene mentioned in the present invention is high isotacticity, high crystallinity homopolymerization or block copolymerization polypropylene, wherein the comonomer of block copolymerization polypropylene is ethylene, butene to 20 carbon olefins. A typical comonomer in the copolymerized propylene used in the present invention is ethylene in an amount not exceeding 15 mol%, more usually not exceeding 5 mol%. the

The polypropylene used in the present invention can be obtained by different polymerization methods, such as suspension polymerization and solution polymerization. The state of propylene monomer can be gas phase or slurry liquid state. The catalyst used is usually Ziegler-Natta type, and of course it also includes Any other catalyst can produce polypropylene with high regularity structure, and its isotacticity should be greater than 99%. the

The fluidity of polypropylene used in the present invention is usually expressed by melt flow rate (MFR), and its test piece is: 230 ℃, 2.16kg load conditions; melt flow rate is inversely proportional to the molecular weight of polypropylene, that is, the molecular weight of polypropylene The larger the value, the worse the fluidity and the smaller the MFR. When choosing the size of MFR, it is mainly necessary to consider the molding processability and the physical and mechanical properties of the material. If the MFR is too small, the fluidity is too poor, so it is not suitable for injection molding. If the MFR is too large, the toughness of polypropylene is too poor, and the material is too brittle. The MFR range of polypropylene is 0.5-100g/10min, and the more common MFR range is 0.5-50g/10min. the

The filler mentioned in the present invention is talcum powder, which is a typical sheet structure, with a length/thickness ratio (L/T) of 100-500 and a particle size range of 1-10 microns. In order to significantly improve the rigidity of polypropylene, the amount of talcum powder in modified polypropylene is generally not less than 10%, if it is too low, the rigidity of the material is too poor; but the amount of talc powder should not be too much, if it exceeds 40%, it will Significantly affect the processing performance of polypropylene, so the general amount of talc powder (wt%) is 10, 15, 20, 25, 30 and 35, etc., or any natural number between 10-35, more commonly 15-25wt %. the

In order to further enhance the interaction between talc powder and polypropylene surface, it is usually necessary to add a coupling agent. Coupling agents are some low-molecular or high-molecular compounds containing active functional groups. Common low-molecular coupling agents include silane coupling agents, titanate coupling agents, aluminate coupling agents, etc., while high-molecular coupling agents Usually some graft copolymers, typically maleic anhydride grafted polypropylene, maleic acid grafted polypropylene, maleic anhydride grafted polyethylene, maleic acid grafted polyethylene, etc. Relatively speaking, high Molecular coupling agent has better effect, so the present invention adopts maleic anhydride grafted polypropylene. the

There are many methods for grafting polypropylene, which can be divided into melt grafting, solution grafting, solid phase grafting, etc. from the reaction form. Melt grafting is widely used because the preparation method is simple and has no by-products. The present invention adopts melt grafting Maleic anhydride grafted polypropylene prepared by branching method. the

Due to the presence of tertiary carbon atoms in polypropylene molecules, it is more prone to aging than polyethylene, especially under the action of high temperature and ultraviolet light, polypropylene without stabilizers will become brittle in a short period of time and lose its use value. Incorporation is especially important for modified polypropylene. The general polypropylene stabilization system includes: phenolic primary antioxidants, phosphite or thioester synergistic antioxidants, acid absorbers, ultraviolet absorbers, hydroperoxide decomposers, etc. the

In the stable system of polypropylene, phenolic primary antioxidants are common, such as Irganox 1010 (tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid) ] Pentaerythritol ester) and Irganox 1076 (2,6-bis(1-phenyl)ethyl-4-nonylphenol), of which 1010 is more commonly used, the dosage is generally 0.1-1.0%, and the more commonly used is 0.1-0.5 %. the

Phosphite and thioester auxiliary antioxidants have a synergistic effect with the above-mentioned primary antioxidants. The common varieties are: Irgafos 168 (tri(2,4-di-tert-butylphenyl ) phosphite) and Irganox PS 802 (distearyl thiodipropionate), the latter being more commonly used due to the former's tendency to hydrolyze in talc-filled polypropylene. Its dosage is 0.1-1.0%, more commonly 0.1-0.5%. the

In the stable system of polypropylene, acid absorbers need to be added. The common varieties are stearates, which also act as internal lubricants, such as calcium stearate and zinc stearate. The dosage is 0.05-0.5%, more commonly 0.05-0.2%. the

In order to improve the weather resistance of modified polypropylene, it is often necessary to add light stabilizers. Commonly used light stabilizers are divided into: UV absorbers, quenchers, hydroperoxide decomposers and free radical scavengers according to the mechanism of action. Usually, the combination of several light stabilizers can greatly improve the weather resistance of materials. The ultraviolet absorbers in the composition include; benzophenones, acetanilides, benzotriazoles, and triazines, among which benzophenones and acetanilides are the most common in PP; The dosage of UV absorber is 0.1-1.0%, and the optimum dosage is 0.1-0.5%. The typical UV absorber products are Sanduvor PR-25 and Sanduvor VSU of Clariant Company in Switzerland. the

The free radical quenchers in the composition are: hindered amines and nickel chelates, the latter are rarely used due to environmental protection issues. Common hindered amine light stabilizers include 'rinuvin 770 (bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate) and Chimassorb 944 (a A high-molecular-weight hindered amine light stabilizer, which has good heat resistance, extraction resistance, lower volatility and migration, and has good compatibility with polypropylene), and its dosage is 0.1-2.0 (parts by mass), the optimum dosage is 0.1-1.0 (parts by mass). In the light stabilization system of polypropylene, usually a variety of light stabilizers are used together, and the total amount is not more than 2%. the

Generally, the specific surface area of the filler is relatively high, and it is easy to absorb various low-molecular additives added, especially antioxidants and anti-ultraviolet agents, so surface treatment must be carried out. In addition to some conventional surface treatment methods, such as the use of higher fatty acids, titanate coupling agents, aluminate coupling agents and silane coupling agents, it is also necessary to add some surface passivation agents such as some epoxy compounds, typical Epoxy resin is arranged, and present embodiment adopts the solid epoxy resin Araltide 7072 of Swiss Ciba Specialty Chemical Company, and its consumption is 0.2-1.5%, and optimum consumption is 0.5-1.0%. the

In order to improve the dispersion of talcum powder, it is usually necessary to add processing aids, such as stearate, fatty acid amide, fluorine-containing or silicon-containing compounds, the dosage is generally 0.1-1.0%, and the optimum dosage is 0.1-0.5%. , the more suitable dosage is 0.2-0.4%. the

Description of materials used:

The present invention compares a variety of high crystallization homopolymerization or copolymerization PP, among which the more typical ones are homopolymerization and block copolymerization polypropylene with a melt flow rate of about 10g/10min, and its isotacticity is 99.5%. The high isotactic homopolypropylene HJ700 produced by Star Company (melt flow rate is 10 under the condition of 230 ℃ and 2.16kg load) and the high isotactic block copolymer CB5108 produced by Korea Petrochemical Company (melt flow rate The rate is 8) under the conditions of 230° C. and 2.16 kg load. As a comparison, we use the homopolypropylene Y1600 produced by Shanghai Petrochemical Company, with an isotacticity of 95%, a melt flow rate of 16 at 230°C and a load of 2.16kg, and a general-purpose block produced by Korea Petrochemical Company. Copolypropylene SB9310 (melt flow rate 10 at 230°C, 2.16 kg load). the

The talcum powder used in the present invention is produced in Guangxi, China, its particle size is 1-10 microns, and its whiteness is above 95%. The glass fiber is ER-13 produced by Zhejiang Jushi Company in China, which is treated with silane coupling agent. the

In order to enhance the interaction between talc powder and polypropylene surface, a coupling agent needs to be added. The invention adopts maleic anhydride grafted polypropylene (GPP), and the grafting rate is 0.5% (obtained by infrared spectrum method). the

The various auxiliary agents used in the present invention are: the acid absorbing agent is calcium stearate; The company's Irganox 1010 ([β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester) and IrganoxPS 802 (distearyl thiodipropionate); the light stabilizer is Tinuvin770 (bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate) and Chimassorb 944 from Ciba Refined Chemical Company of Switzerland; the processing aid is ethylene bis stearamide. the

Performance Testing

(1) Scratch resistance performance test: The size of the injection molding sample is 150×100×3.2mm, and the scratch test is carried out on the surface of the sample with a hand-held hardness test pen with a load of 10N and a pen tip diameter of 0.75mm. The scratch interval is 2mm, and the longitudinal direction Draw 10-20 lines in the horizontal and horizontal directions, use the color test system produced by Minolta Japan to test the color change of the scratched material, and record the ΔL value of the material to identify the scratch resistance of the material. the

(2) Melt flow rate (MFR) measurement: according to the ISO 1183 standard, carried out on the melt index instrument of Shanghai Scientist Scientific Instrument Co., Ltd., the test temperature is 230 ° C, and the load is 2.16 kg;

(3) Determination of tensile properties: according to the ISO 527 standard, carried out on the Z010 universal material testing machine of the German Zwick company, the tensile rate is 50mm/min:

(4) Determination of bending performance: according to the ISO 178 standard, carried out on the Z010 universal material testing machine of Zwick Company in Germany, with a span of 64mm and a speed of 2mm/min, and the calculation of the bending modulus is carried out according to the tangent method:

(5) Impact performance measurement: according to the ISO 179 standard, it is carried out on the impact testing machine of Zwick Company in Germany. The spline is 80×10×4mm, V-shaped notch, and the bottom radius is 0.25mm. the

(6) Hardness test: According to the ISO 2039-1 standard, it is carried out on the hardness tester of Zwick Company in Germany, with a load of 358N and a reading of 30 seconds. the

(7) Heat distortion temperature: according to the ISO 75 standard, it is carried out on HDT 300 produced by Italy Ceast Company, the spline is 120×10×4, and the load is 0.45MPa

Table 1 and Table 2 respectively compare the effects of polypropylene varieties on the mechanical properties and scratch resistance of modified polypropylene materials. The basic formula in the experiment is as follows: the main material formula is shown in Table 1 and Table 2, and the additive formula is: 10100.1, PS 8020.3, EBS 0.2, calcium stearate 0.1, 7700.2, 9440.2. the

Concrete preparation method is as follows:

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

(2) Polypropylene, talcum powder, coupling agent GPP, stabilizer, talcum powder surface deactivator and processing aid were mixed in a high-speed mixer for 1.5 minutes;

(3) Put the mixed raw materials into a twin-screw extruder (diameter 34mm, aspect ratio 40/1, the residence time of the material in the screw is 1.5 minutes, and the temperature in the screw is: 190°C in the first zone, 205°C in the second zone , 210°C in the third zone, 210°C in the fourth zone; the speed of the twin-screw extruder is 300 rpm:

(4) Discharge, melt and extrude in a twin-screw extruder, cool, dry and pelletize after extrusion to obtain the finished product. the

(5) Prepare samples from the extruded pellets on a 100-ton Haitian injection molding machine. The temperature of the injection molding machine was set at 200°C, 220°C, and 230°C, the melt temperature was 230°C, and the molding processing time was 60 seconds. the

It can be seen from Table 1 that under the same amount of talc powder, the ball indentation hardness and flexural modulus of highly crystalline modified polypropylene are significantly higher than those of general homopolypropylene, indicating that the rigidity of the material has been significantly improved. The heat distortion temperature, especially under high load conditions (1.82MPa), is also more than 20 degrees higher for high crystalline polypropylene, indicating that the heat resistance of the material has also been significantly improved. In addition, due to the increased surface hardness of the material, the scratch resistance performance is also improved to a certain extent. Comparing E1 with C3, glass fiber reinforced polypropylene has higher flexural strength and flexural modulus, hardness and heat denaturation resistance, but the scratch resistance of the material is relatively poor, which is mainly related to the exposed glass fiber, and the product The appearance quality is also significantly deteriorated. the

Table 2 compares the properties of talc-filled high crystalline copolymer polypropylene and talc-filled general-purpose copolymer polypropylene. It can be seen that under the same amount of talcum powder, the rigidity of high crystalline polypropylene is better. Compared with the general-purpose filled homopolypropylene in Table 1, the rigidity of the high-crystalline co-polypropylene is equivalent to that of the general-purpose homopolypropylene, but the notched impact strength is higher and the toughness of the material is better. the

Table 1 embodiment 1-3 and comparative example 1-3

Table 2 embodiment 4-7 and comparative example 4-5

Claims (4)

1. a high rigidity, high heat-resisting mar-proof talc powder filled polypropylene is characterized in that, are major ingredient with the polypropylene of high degree of isotacticity, high-crystallinity, and its each component weight part is:

High crystallization high isotatic polypropylene 60-90

Talcum powder 10-40

Coupling agent 3-10

Stablizer 0.1-1.0

Talcum powder surface passivation agent 0.2-1.5

Wherein, high crystallization high isotatic polypropylene and talcum powder gross weight are 100 weight parts, described stablizer is acid absorber, thermal oxidation stabilizer and photostabilizer, wherein, thermal oxidation stabilizer is [β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester and thio-2 acid 2 stearyl ester, consumption is respectively 0.1%-1.0%; Photostabilizer is two (2,2,6,6-tetramethyl--4-piperidyl) sebate and Chimassorb 944, and consumption is 0.1～1.0 weight part; Acid absorber is a stearate, and its consumption is 0.05%-0.5%;

Described talcum powder is the talcum powder of sheet structure, and length/thickness rate is 100～500, and particle size range is 1～10 micron;

Described talcum powder surface passivation agent is higher fatty acid or Resins, epoxy Araltide 7072;

Described coupling agent is a maleic anhydride inoculated polypropylene;

Also comprise ethylene bis stearamide, its consumption is 0.05～1.0 weight part;

Degree of crystallinity is not less than 70% in the described high crystallization high isotatic polypropylene, and degree of isotacticity is greater than 99%.

2. a kind of high rigidity according to claim 1, high heat-resisting mar-proof talc powder filled polypropylene, it is characterized in that: described polypropylene is high crystallization homo-polypropylene and block copolymerization propylene, wherein the comonomer of block copolymerization propylene is an ethene, its content is in the scope of 4-10mol%, and polyacrylic melt flow rate (MFR) is 5-50g/10min under 230 ℃, 2.16kg loading condiction.

3. a kind of high rigidity according to claim 1, high heat-resisting mar-proof talc powder filled polypropylene, it is characterized in that: the consumption of described [β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester and thio-2 acid 2 stearyl ester is respectively 0.1%-0.5%.

4. the preparation method of a kind of high rigidity according to claim 1, high heat-resisting mar-proof talc powder filled polypropylene, its method is as follows:

(1) takes by weighing raw material by weight ratio;

(2) polypropylene, talcum powder, stablizer, coupling agent, talcum powder surface passivation agent and ethylene bis stearamide were mixed in homogenizer 10～20 minutes;

(3) mixed raw material is put into twin screw extruder, material residence time in screw rod is 1～2 minute, and temperature is in the screw rod: 185～195 ℃ in a district, 190～210 ℃ in two districts, 190～210 ℃ in three districts, 195～215 ℃ in four districts; The twin screw extruder rotating speed is 300～700 rev/mins;

(4) discharging, compound melt extrudes from twin screw extruder, extrudes postcooling, drying, pelletizing and gets product.