CN105037955B - Polypropene composition that a kind of low VOC, scratch-resistant, resistance to stress are turned white and preparation method thereof - Google Patents

Abstract

The present invention provides the polypropene composition that a kind of low VOC, scratch-resistant, resistance to stress are turned white, and is calculated in mass percent, composed of the following components：Polypropylene 40 80, talcum powder 1 30, toughener 5 15, low molecule amount polysiloxane 13, polypropylene grafted HMW polysiloxane 2 10, antioxidant 0.1 1, light stabilizer 0.1 1, other auxiliary agents 02, the mass percent sum of said components is 100.The preparation method of the polypropene composition turned white present invention also offers the low VOC, scratch-resistant, resistance to stress.The polypropene composition that the present invention is provided has low VOC characteristic, and scraping and wiping resistance performance, stress-whitening resistance can be preferable.

Description

A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition and its preparation method

Technical field:

The invention relates to a polypropylene composition, in particular to a polypropylene composition with low VOC, scratch resistance and stress whitening resistance and a preparation method thereof.

Background technique:

Polypropylene composite materials filled with inorganic mineral powder have been widely used in automotive interior parts in recent years, such as door trim panels, instrument panels, pillars, seat guards, etc., but due to the reaction of inorganic mineral powder fillers with resins and additives The generation of small molecule volatile organic compounds leads to higher VOC. In addition, the common polyorganosiloxane scratch-resistant agents commonly used in this system have poor compatibility with polypropylene, and the characteristics of polypropylene material itself , so it is easy to cause stress whitening. With the improvement of the requirements for automotive interior materials and the specification of the air quality requirements for passenger cars, there is more and more attention and demand for automotive interior materials with low VOC, scratch resistance, and stress whitening resistance.

The publication number is CN103214740B, the publication date is 2015.06.03, and the applicant is Great Wall Motor Co., Ltd. The Chinese patent application discloses "polypropylene composite material for automobile interior decoration and its preparation method and interior decoration parts". The composite material Contains: 40-60 parts by weight of polypropylene resin; 0-30 parts by weight of filler; 1-5 parts by weight of compatibilizer; 5-15 parts by weight of toughening agent; 1-5 parts by weight of anti-scratch agent; -5 parts by weight; 5-15 parts by weight of antistatic agent; 0.1-0.5 parts by weight of antioxidant; and 0.3-1 parts by weight of lubricant. The composite material also has the characteristics of low odor, excellent surface scratch resistance, low surface resistivity, and excellent mechanical properties. Although the invention reduces VOC by adding an odor adsorbent, it improves the scratch resistance by adding a scratch-resistant agent. , but the compatibility between the odor adsorbent, the scratch-resistant agent and the polypropylene resin matrix is not good, the dispersion is uneven, and it is easy to induce silver streaks or cracks under the action of external force, thus increasing the stress whitening of the composite material.

Invention content:

The technical problem to be solved by the present invention is to provide a polypropylene composition with low VOC, scratch resistance and stress whitening resistance.

In order to solve the problems of the technologies described above, the technical solution of the present invention is:

A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition, in mass percent, consisting of the following components:

The sum of the mass percentages of the above components is 100.

Preferably, the polypropylene in the present invention is one or a mixture of copolymerized polypropylene and homopolypropylene, the ethylene content in the copolymerized polypropylene is 4-10mol%, and the melt flow rate is 2-100g/ 10 minutes, the melt flow rate test condition is 230°C/2.16kg; the crystallinity of homopolypropylene is 60%-70%, and the isotacticity is 95%-98%.

Preferably, the particle size of the talc powder in the present invention is 1-12 microns.

Preferably, the toughening agent in the present invention is one or a mixture of ethylene-octene copolymer, ethylene-propylene-diene rubber/propylene-α-olefin copolymer, and propylene-α-olefin copolymer.

Preferably, the low-molecular-weight polyorganosiloxane of the present invention is a long-chain alkyl polyorganosiloxane with a carbon number of 8-30 and a molecular weight of 15,000-50,000.

Preferably, the molecular weight of the high-molecular-weight polyorganosiloxane in the polypropylene-grafted high-molecular-weight polyorganosiloxane of the present invention is 600,000-1,200,000, and the mass percentage of the high-molecular-weight polyorganosiloxane is 40%-50% .

Preferably, the antioxidant of the present invention is composed of a primary antioxidant and an auxiliary antioxidant, wherein the primary antioxidant is one or more of antioxidant 3114, antioxidant 1010, and antioxidant DSTP The auxiliary antioxidant is one or a mixture of antioxidant 618 and antioxidant 168.

Preferably, the light stabilizer in the present invention is one or a mixture of hindered amine light stabilizer 944 and hindered amine light stabilizer 770 .

Preferably, the other additives described in the present invention are color powder or color masterbatch.

Another technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned low-VOC, scratch-resistant, and stress-whitening-resistant polypropylene composition.

In order to solve the above technical problems, the technical solution is:

A method for preparing a low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition, the steps of which are as follows:

(1) take various raw materials by mass percentage;

(2) Mix polypropylene, toughener, low molecular weight polyorganosiloxane, polypropylene grafted high molecular weight polyorganosiloxane, antioxidant, light stabilizer and other additives in a high-speed mixer for 3 -5 minutes, add talcum powder and mix for 5-10 minutes;

(3) Put the mixed material in step (2) into a twin-screw extruder with an aspect ratio of 40:1-52:1 to melt, extrude and granulate. The temperature of each section of the extruder screw is as follows: feeding section 190- 200°C, conveying section 200-205°C, melting section 210-220°C, die head 210-215°C, the residence time of the entire extrusion process is 1-2 minutes, the die head pressure is 10-20MPa, the end of the extruder pumps Vacuum exhaust, the exhaust vacuum degree is -0.06MPa to -0.08MPa.

As can be seen from the above, compared with the prior art, the present invention has the following beneficial effects:

1) Low-molecular-weight long-chain alkyl polyorganosiloxane has good flexibility, talc powder particles are easily adsorbed on the soft silicone molecular chain, and low-molecular-weight long-chain alkyl polyorganosiloxane is coated on talc powder On the surface, the talc powder and the polypropylene resin matrix are separated, and at the same time, the long-chain alkyl group of the polyorganosiloxane has good compatibility with the polypropylene resin matrix, making it difficult to precipitate, reducing the talc powder and polypropylene resin matrix. The reaction between polypropylene resin and antioxidant can reduce the production of low molecular volatile organic compounds and achieve the effect of low VOC;

2) The molecular chain of polypropylene grafted high-molecular-weight polyorganosiloxane has excellent elastic recovery properties, and is a good scratch-resistant agent. When polypropylene and high-molecular-weight polyorganosiloxane are heated and mixed , the two have undergone free radical reaction and chemical combination, and through the grafting of long-chain alkyl groups in low molecular weight polyorganosiloxane and high molecular weight polyorganosiloxane and polypropylene, the relationship between silicone and polypropylene has been greatly improved. The compatibility between the resin matrices and the dispersion in the matrix are excellent, so while significantly improving the scratch resistance of the polypropylene composition, it also solves the problem of high stress whitening caused by the addition of polyorganosiloxane question.

detailed description:

The present invention will be described in detail below in conjunction with specific embodiments, where the exemplary embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

Each component was weighed according to the content percentage of the product components described in Table 1.

Table 1 Low VOC, scratch-resistant and anti-stress whitening automotive interior polypropylene composition formulation

In each embodiment and comparative example polypropylene composition material formulation, the polypropylene used is the copolymerized polypropylene of melt flow rate 20; The talcum powder mesh number used is 3000 meshes, and average particle diameter is 4.5 microns; The toughening agent used is POE; The low molecular weight long-chain alkyl polyorganosiloxane used is a product of Shaoxing Jiahua Polymer Materials Co., Ltd., the brand name A-WD1620 is a long-chain alkyl silicone with fourteen carbons in the alkyl chain, with a molecular weight of 30,000; the polypropylene-grafted high-molecular-weight polyorganosiloxane used is a product of Shaoxing Jiahua Polymer Materials Co., Ltd., the brand name HG-600, the high molecular weight polyorganosiloxane molecular weight is 800000, the content of high molecular polyorganosiloxane is 50%; the antioxidant used is antioxidant 1010, the chemical name is four [β-(3,5- Di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol; the light stabilizer used is light stabilizer 770, the chemical name is bis(2,2,6,6-tetramethyl-4-piperidinyl) Sebacate.

The preparation method is: put the above-mentioned components except talcum powder into a high-speed mixer and mix for 3 minutes, then add talcum powder and mix for 5 minutes; put the mixed raw materials in a twin-screw extruder with an aspect ratio of 48:1 Melting extrusion granulation in the extruder, the temperature of each section of the extruder screw is as follows: feeding section 190-200°C, conveying section 200-205°C, melting section 210-220°C, head 210-215°C, the whole extrusion process The residence time of the extruder is 1-2 minutes, the die head pressure is 10-20MPa, the end of the extruder is vacuumed and exhausted, and the exhaust vacuum degree is -0.08MPa.

Performance evaluation methods and implementation standards:

The polypropylene composition composition material prepared by the above method was placed in a blast oven at 105° C. to dry for 2 hours, and then the dried material was injected into a standard test sample bar on an injection molding machine.

Tensile strength and elongation at break were measured according to ASTM D-638 standard.

Flexural strength is measured according to ASTM D-790 standard.

Notched Izod impact strength was measured according to ASTM D-256 standard.

Organic compound emission measurement (TVOC) is measured according to Volkswagen PV3341.

The scratch resistance performance is tested according to Volkswagen PV3952. Use ERICHSEN430P-1, the load is 10N, the diameter of the pen tip is 1mm, and the scratch test is carried out on the surface of the sample. The scratch interval is 2mm, and the vertical and horizontal strokes are 20. The 3600A color test system tests the color change of the cross-cut material, and records the ΔL value of the material. The smaller the ΔL value, the better the scratch resistance.

The anti-stress whitening performance is tested according to Volkswagen PV3966. A 500g heavy stainless steel ball is dropped from a height of 500mm to impact a 3mm thick sample. The Japanese Minolta CM-3600A color test system is used to test the color change of the sample before and after the ball is dropped, and the ΔL value of the material is recorded, ΔL Smaller values indicate better stress whitening resistance

The comprehensive performance of the polypropylene composite material is judged by the obtained tensile strength, elongation at break, flexural strength, IZOD notched impact strength, TVOC, scratch resistance and stress whitening resistance. The test results of Examples and Comparative Examples are as described in Table 2.

Table 2 embodiment comparative example material performance table

From the comparison of Examples 1-7 and Comparative Examples 1-3, it can be found that: with the addition of low-molecular-weight long-chain alkyl polyorganosiloxane, the TVOC of the material decreased significantly, and with the grafting of high-molecular-weight polyorganosiloxane to polypropylene The scratch resistance of the siloxane additive material is significantly increased, and the stress whitening situation does not change significantly, and it is significantly lower than the stress whitening (generally 1.15) when using ordinary silicone scratch-resistant agents. In addition, There is no significant difference in the mechanical properties between the examples and the comparative examples, so in the polypropylene/talcum powder composite material, low molecular weight long-chain alkyl polyorganosiloxane and polypropylene grafted high molecular weight polyorganosiloxane compound Use can significantly reduce TVOC, increase scratch resistance and stress whitening resistance.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (8)

1. A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition, characterized in that: by mass percent, it consists of the following components: The sum of the mass percentages of the above components is 100%; The molecular weight of the high molecular weight polyorganosiloxane in the polypropylene grafted high molecular weight polyorganosiloxane is 600,000-1,200,000, and the mass percentage of the high molecular weight polyorganosiloxane is 40%-50%; The antioxidant is composed of a main antioxidant and an auxiliary antioxidant, wherein the main antioxidant is one or a mixture of antioxidant 3114, antioxidant 1010, and antioxidant DSTP, and the auxiliary antioxidant The oxygen agent is one or a mixture of the antioxidant 618 and the antioxidant 168 . 2. A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition according to claim 1, characterized in that: the polypropylene is one of copolymerized polypropylene, homopolypropylene or Two mixtures, the ethylene content in the copolymerized polypropylene is 4-10mol%, the melt flow rate is 2-100g/10min, and the melt flow rate test condition is 230°C/2.16kg; the crystallinity of the homopolypropylene is 60%-70%, isotacticity is 95%-98%. 3. A low-VOC, scratch-resistant, and stress-whitening-resistant polypropylene composition according to claim 1, characterized in that: the particle diameter of the talcum powder is 1-12 microns. 4. A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition according to claim 1, characterized in that: the toughening agent is ethylene-octene copolymer, propylene-alpha olefin copolymer one or a mixture of several. 5. A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition according to claim 1, characterized in that: the low molecular weight polyorganosiloxane is a long-chain alkyl polyorganosilicon Oxane, carbon number is 8-30, molecular weight is 15000-50000. 6. A low-VOC, scratch-resistant, and stress-whitening-resistant polypropylene composition according to claim 1, wherein the light stabilizer is hindered amine light stabilizer 944, hindered amine light stabilizer One or a mixture of two stabilizers 770. 7. A low-VOC, scratch-resistant, stress-whitening-resistant polypropylene composition according to claim 1, characterized in that: said other additives are toner or color masterbatch. 8. A method for preparing a low-VOC, scratch-resistant, and stress-whitening-resistant polypropylene composition according to any one of claims 1 to 7, wherein the steps are as follows: (1) take various raw materials by mass percentage; (2) Mix polypropylene, toughener, low molecular weight polyorganosiloxane, polypropylene grafted high molecular weight polyorganosiloxane, antioxidant, light stabilizer and other additives in a high-speed mixer for 3 -5 minutes, add talcum powder and mix for 5-10 minutes; (3) Put the mixed material in step (2) into a twin-screw extruder with an aspect ratio of 40:1-52:1 to melt, extrude and granulate. The temperature of each section of the extruder screw is as follows: feeding section 190- 200°C, 200-205°C in the conveying section, 210-220°C in the melting section, 210-215°C in the head, the residence time of the entire extrusion process is 1-2 minutes, the pressure of the die head is 10-20MPa, the end of the extruder pumps Vacuum exhaust, the exhaust vacuum degree is -0.06MPa to -0.08MPa.