Polypropylene composition as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composition as well as a preparation method and application thereof, and relates to the technical field of modified polypropylene materials. The polypropylene composition comprises PP resin, an organosilicon thermoplastic elastomer, a styrene flexibilizer and an optional silicate filler, and aims to solve the problem that automobile parts made of polypropylene materials in the prior art are difficult to realize good touch feeling, good scratch resistance, wear resistance, rigidity and toughness balance. The toughness and smoothness are improved by selecting the organic silicon thermoplastic elastomer with certain hardness, the balance of rigidity and toughness, friction resistance and soft touch are realized by selecting the styrene flexibilizer, and the good touch effect of the material is flexibly adjusted by selecting the optional silicate filler. The polypropylene composition is suitable for preparing automotive interior and exterior parts, and has the advantages of good touch feeling, good scratch resistance, wear resistance, and balanced rigidity and toughness.

Description

Technical Field

[0001] The present invention belongs to the technical field of modified polypropylene materials, and particularly relates to a polypropylene composition, a preparation method thereof, and an application thereof. Background Art

[0002] As more and more modified PP materials are applied to automotive parts, due to their high gloss and strong plastic feeling, the visual and user experience of vehicle occupants is reduced. Therefore, flocking or fabric wrapping is often used on door panels and pillars to reduce their plastic feeling. Thus, an invention introduced a fiber-like substance into the polypropylene composite material system. It has the characteristics of less dosage, easy addition, and no influence on the mechanical properties of the material. The addition of the fiber-like substance can reduce the plastic feeling and gloss on the surface of the polypropylene composite material, showing a certain matte and flocked-like effect. However, this flocked-like material is still essentially a polypropylene substrate. Visually, it shows a certain flocked-like effect, but there are still significant differences in hand feeling and during use compared with soft materials such as fabrics or wrapping materials, greatly affecting the driving experience of vehicle occupants. The prior art discloses a low-gloss, good-appearance, flocked-like gray glass fiber-reinforced polypropylene material. By using random copolymer polypropylene and fiber-like substances, not only the gloss and floating fibers of the product are reduced, but also the gray flocked-like effect of the material is increased. However, this patent is only applicable to gray or dark materials, and the proportion of glass fiber cannot be enlarged, limiting its scope of use.

[0003] The prior art discloses an interior material with a soft touch, using alkali-modified lignin and a toughening agent to modify polypropylene, where the toughening agent is at least one of ethylene-octene copolymer elastomer, ethylene-propylene copolymer elastomer, ethylene-butene copolymer, styrene-ethylene / butene-styrene, and ethylene propylene diene monomer. The softness of the material's touch is evaluated, but the smoothness of the material's touch is not evaluated, and the flexural modulus, impact strength, and scratch resistance of the material are relatively low, making it difficult to meet the requirements for making automotive parts with polypropylene.

[0004] Therefore, it is of great research significance and application value to develop a polypropylene composition with good touch, good scratch resistance, wear resistance, and a balance of stiffness and toughness. Summary of the Invention

[0005] To solve the technical problem in the prior art that it is difficult to achieve a balance of good touch, good scratch resistance, wear resistance, stiffness, and toughness when using polypropylene materials to make automotive parts, the primary object of the present invention is to provide a polypropylene composition. The polypropylene composition provided by the present invention uses an organosilicon thermoplastic elastomer, a styrene-based toughening agent, and a silicate filler to obtain a polypropylene composition with good touch, good scratch resistance, wear resistance, and a balance of stiffness and toughness.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned polypropylene composition.

[0007] Another object of the present invention is to provide the application of the above-mentioned polypropylene composition in the field of preparing automotive interior and exterior parts.

[0008] To achieve the above-mentioned invention objects, the present invention adopts the following technical solutions:

[0009] The present invention protects a polypropylene composition, which comprises the following components in parts by weight:

[0010] 39 - 86 parts of PP resin, 5 - 15 parts of silicone thermoplastic elastomer, 5 - 30 parts of styrenic toughening agent, 0 - 30 parts of silicate filler; the hardness of the silicone thermoplastic elastomer is 45 - 65A.

[0011] The present invention provides a polypropylene composition. By using the combination of silicone thermoplastic elastomer and styrenic toughening agent, the touch feeling, scratch resistance, toughness and wear resistance of the polypropylene composition are improved, so that the composition has a good touch feeling, good scratch resistance, wear resistance, and a balance of stiffness and toughness. By selecting the silicone thermoplastic elastomer as the toughening agent, the toughness is improved, and at the same time, the slipperiness, scratch resistance and friction resistance of the polypropylene material are improved; by selecting the styrenic toughening agent with good compatibility with the silicone thermoplastic elastomer, both soft segments and hard segments are imparted to the material, taking into account both rigidity and toughness and improving the soft touch effect of the polypropylene material; by optionally using the silicate filler, a good touch feeling effect under different filler ratios can be achieved. Compared with other fillers, the silicate filler has relatively high stiffness and slipperiness, so the good touch feeling effect of the material can be flexibly adjusted.

[0012] Among them, the silicone thermoplastic elastomer is a silicone rubber dispersed as a dispersed phase in a thermoplastic plastic matrix continuous phase, and the thermoplastic plastic matrix can be at least one of nylon, thermoplastic polyurethane or polyolefin.

[0013] Preferably, the PP resin is one or a mixture of homopolypropylene and copolymerized polypropylene, and at 230 °C and a load of 2.16 kg, its melt flow rate is 1 - 100 g / 10 min.

[0014] The test standard for the melt flow rate is ISO1133 - 2022.

[0015] The mass percentage of the PP resin in the polypropylene composition is more than 40%.

[0016] Preferably, the hardness of the silicone thermoplastic elastomer is 45A - 55A.

[0017] More preferably, the hardness of the silicone thermoplastic elastomer is one or more of 45A, 52A or 55A.

[0018] The test method and standard for hardness refer to ASTM D2240, and the test time is 10 sec.

[0019] Preferably, the styrenic toughening agent is selected from one or more of styrene-butadiene rubber, styrene-butadiene-styrene block copolymer, styrene-ethylene / butylene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated styrene-isoprene block copolymer, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer or acrylonitrile-styrene-acrylate copolymer.

[0020] Preferably, the mass percentage of styrene in the styrenic toughening agent is 5-20%.

[0021] Preferably, the hardness of the styrene toughening agent is 40-75A.

[0022] Preferably, the silicate filler is one or more of talc, kaolin, montmorillonite, glass fiber, mica, quartz, feldspar, bentonite, zeolite or perlite.

[0023] Preferably, the median particle size D50 of the silicate filler is 2-10 μm.

[0024] Particle size test method: Laser diffraction method for particle size distribution in GB / T 19077-2016.

[0025] Preferably, the weight parts of the silicate filler are 15-30 parts

[0026] Preferably, the polypropylene composition further comprises 0.1-1 part of an anti-aging agent.

[0027] Specifically, the anti-aging agent includes one or more of an antioxidant or a light stabilizer.

[0028] Preferably, the antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants or thioester antioxidants.

[0029] More preferably, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, antioxidant 3114, antioxidant 168, antioxidant PEP-36 or antioxidant 412S.

[0030] More preferably, the antioxidant is selected from at least one of antioxidant 1010 or antioxidant 168, preferably a compound antioxidant of the two, and preferably the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0031] Preferably, the light stabilizer is a hindered amine light stabilizer, and further preferably one or more of UV-3808, LA-402XP or LA-402AF.

[0032] Preferably, the polypropylene composition further comprises a colorant. Common colorants for polypropylene in the art can be used in the present invention.

[0033] Preferably, the colorant is iron oxide red.

[0034] Preferably, the weight parts of the colorant are 0-2 parts.

[0035] Preferably, the weight parts of the colorant are 0.05-1 part.

[0036] The present invention also provides a preparation method of a polypropylene composition, comprising the following steps:

[0037] Mix the PP resin, optional silicate filler, silicone thermoplastic elastomer, and styrene-based toughening agent evenly and then add them into a twin-screw extruder for melt extrusion to obtain the polypropylene composition.

[0038] Preferably, the conditions for melt extrusion are: the melt extrusion temperature is 200-220°C, and the screw speed is 350-450 rpm.

[0039] The application of the above polypropylene composition in the field of manufacturing automotive interior and exterior parts is also within the protection scope of the present invention.

[0040] The present invention also protects a part made of the above polypropylene composition.

[0041] Preferably, the part includes an automotive instrument panel, door panel, pillar, sill, and wheel arch.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The polypropylene composition provided by the present invention selects a silicone thermoplastic elastomer to improve the toughness, slipperiness, and scratch resistance of the polypropylene material; selects a styrene-based toughening agent to achieve the balance of stiffness and toughness and a soft touch, and improve wear resistance; and an optional silicate filler to flexibly adjust the good touch effect of the material under different filler ratios. The obtained polypropylene composition has the advantages of good touch, good scratch resistance, wear resistance, and the balance of stiffness and toughness. Detailed embodiments

[0044] The present invention will be further described below in conjunction with embodiments. These embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. For the experimental methods without specific conditions in the following embodiments, they are generally carried out according to the conventional conditions in the art or according to the conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

[0045] The partial reagents selected for the embodiments and comparative examples of the present invention are described as follows:

[0046] PP resin 1#: PP EP548R, MFR g / 10min = 25 at 230 °C and 2.16 kg load, Zhenhai Refining & Chemical;

[0047] PP resin 2#: PP 5450XT, MFR g / 10min = 45 at 230 °C and 2.16 kg load, Ningbo Formosa Plastics;

[0048] Silicone thermoplastic elastomer 1#: Si-TPV 2150-55A, Shore A hardness 55, TPO polyolefin matrix, Chengdu Silik;

[0049] Silicone thermoplastic elastomer 2#: Si-TPV 2150-45A, Shore A hardness 45, TPO polyolefin matrix, Chengdu Silik;

[0050] Silicone thermoplastic elastomer 3#: Si-TPV 2150-65A, Shore A hardness 65, TPO polyolefin matrix, Chengdu Silik;

[0051] Silicone thermoplastic elastomer 4#: TPSIV 3340-55A, Shore A hardness 55, TPU thermoplastic polyurethane matrix, Dow Corning USA;

[0052] Silicone thermoplastic elastomer 5#: TPSiV TM 1180-50D, Shore D hardness 50, nylon matrix, Dow Corning USA;

[0053] Styrene-based toughening agent 1#: SEBS: SEBS 7554 / U, Huizhou Lee Chang Yung Rubber Co., Ltd., styrene content 31%, Shore A hardness 72;

[0054] Styrene-based toughening agent 2#: Hydrogenated styrene-isoprene block copolymer, ZL-D760, Zhongli Technology, styrene content 7%, Shore A hardness 44;

[0055] Other toughening agent 1# Vistamaxx6202, ethylene content 15%, Exxon;

[0056] Other toughening agent 2# EVA: DuPont EVA150 in the United States;

[0057] Silicate filler 1#: Talc powder: TYT-777A, Liaoning Tianyuan, median particle size D50 is 5.8 μm;

[0058] Silicate filler 2#: Glass fiber, ECS13-03-508A, Jushi Glass Fiber, chopped strand mat for reinforced thermoplastics, average fiber diameter 13 μm, average fiber length 4.5 mm;

[0059] Non-silicate filler: Calcium carbonate, AC-05N, Changxing Tianhe;

[0060] Auxiliaries (all obtained commercially):

[0061] Colorant: Iron oxide red, R206 from Lanxess;

[0062] Antioxidant: 1010 / 168 from Lionon;

[0063] Light stabilizer: UV-3808 from Lionon.

[0064] The polypropylene compositions of the examples and comparative examples of the present invention are prepared through the following process:

[0065] Mix the PP resin, filler, toughening agent, and other auxiliaries evenly and then add them into a twin-screw extruder for melt mixing. The melt mixing temperature is 200 - 220 °C, the screw speed is 350 - 450 r / min, and then pelletize to obtain the polypropylene composition.

[0066] The examples and comparative examples prepare the polypropylene composition according to the formula shown in Tables 2 - 4, and then inject the composition into a standard ISO mechanical spline and a SAIC Volkswagen K4T leather grain board of 100 mm × 100 mm × 3 mm.

[0067] The performance test methods and standards of the examples and comparative examples of the present invention are as follows:

[0068] Dry the particle materials prepared by the above method in a forced-air oven at 75 °C for 3 hours, and then make the dried particles into standard splines on an injection molding machine for testing.

[0069] (1) Touch feeling: Subjective judgment, the test standard refers to the following table:

[0070] Table 1 Touch feeling grading standard table

[0071]

[0072]

[0073] (2) Scratch resistance test: PV3952, test speed 1000 mm / min, load 10 N. The smaller the DL value, the stronger the scratch resistance ability.

[0074] (3) Rubbing fastness test: Test according to Q / BYDQA1901.402.3, dry rubbing 100 times, observe the staining grade and color change grade. The higher the grade, the stronger the wear resistance ability.

[0075] (4) Flexural modulus: Test according to the standard ISO 178 - 2010. Specimen size: 80×10×4. Test conditions: 23°C, bending speed 2 mm / min, unit MPa. The higher the strength, the better the rigidity of the material. If it is too low, it will affect the use of the material.

[0076] (5) Izod notched impact strength: Test according to the standard ISO 180 - 2019, V-notch, specimen size: 80×10×4. Test conditions: 23°C, pendulum energy 4 J, unit KJ / m 2 , the higher the strength, the better the toughness of the material. If it is too low, it will affect the use of the material.

[0077] Examples 1 - 15

[0078] This example provides a series of polypropylene compositions, and the weight parts of each component in the formula are shown in Table 2 and Table 3.

[0079] Table 2 Formulas of Examples 1 - 9 (parts)

[0080]

[0081]

[0082] Table 3 Formulas of Examples 10 - 15 (parts)

[0083]

[0084] Comparative Examples 1 - 8

[0085] This comparative example provides a series of polypropylene compositions, and each component in the formula is shown in Table 4.

[0086] Table 4 Formulas of Comparative Examples 1 - 8 (parts)

[0087]

[0088]

[0089] As can be seen from Table 2 and Table 3, the polypropylene compositions prepared in Examples 1 to 15 of the present invention have both good touch, good scratch resistance, wear resistance, and a balance of stiffness and toughness. Among them, Example 10 contains 0% filler, the touch grade is greater than or equal to 5.5, the flexural modulus in the mechanical property test of the injection-molded specimen is greater than 1000 MPa, and the Izod notched impact strength is greater than 60 KJ / m 2 , the scratch resistance DL of the K4T leather grain board of SAIC Volkswagen is ≤ 0.2; Example 1 contains 15% filler, the touch grade is greater than or equal to 5, the flexural modulus in the mechanical property test of the injection-molded specimen is greater than 1600 MPa, and the Izod notched impact strength is greater than 40 KJ / m 2 , the scratch resistance DL of the K4T leather grain board of SAIC Volkswagen is ≤ 0.3; Example 11 contains 30% filler, the touch grade is greater than or equal to 4.5, the flexural modulus in the mechanical property test of the injection-molded specimen is greater than 2200 MPa, and the Izod notched impact strength is greater than 40 KJ / m 2 , the scratch resistance DL of the K4T leather grain board of SAIC Volkswagen is < 0.5.

[0090] In Comparative Example 1, a silicone thermoplastic elastomer with high hardness is selected, the touch is relatively hard, and the Izod notched impact is reduced; in Comparative Example 2, other toughening agents (POE) are selected to replace the styrene-based toughening agent, and in Comparative Example 3, other toughening agents EVA are selected to replace the styrene-based toughening agent, making it difficult to balance rigidity and toughness, and the wear resistance performance decreases; in Comparative Example 4, the silicone thermoplastic elastomer is not added, the soft touch grade drops significantly, the scratch resistance performance decreases, and it is difficult to meet the requirements; in Comparative Example 5, the styrene-based toughening agent is not added, the rigidity and toughness cannot be balanced, and the wear resistance decreases; in Comparative Example 6, non-silicate filler calcium carbonate is used, and there is no high stiffness and touch effect; the substances in Comparative Examples 7 and 8 are not within the range, and the comprehensive performance decreases.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composition, characterized in that, Comprising the following components in parts by weight: 39 - 86 parts of PP resin, 5 - 15 parts of silicone thermoplastic elastomer, 5 - 30 parts of styrene toughening agent, 0 - 30 parts of silicate filler; Among them, the hardness of the silicone thermoplastic elastomer is 45 - 65A.

2. The polypropylene composition according to claim 1, characterized in that, The PP resin is one or a mixture of two of homopolypropylene and copolymerized polypropylene, and its melt flow rate is 1 - 100 g / 10 min at 230 °C under a load of 2.16 kg.

3. The polypropylene composition according to claim 1, wherein The hardness of the silicone thermoplastic elastomer is 45A - 55A.

4. The polypropylene composition according to claim 1, wherein The styrene toughening agent is selected from one or more of styrene - butadiene rubber, styrene - butadiene - styrene block copolymer, styrene - ethylene / butylene - styrene block copolymer, styrene - isoprene - styrene block copolymer, hydrogenated styrene - isoprene block copolymer, acrylonitrile - butadiene - styrene copolymer, methyl methacrylate - butadiene - styrene copolymer or acrylonitrile - styrene - acrylate copolymer.

5. The polypropylene composition according to claim 1, wherein The silicate filler is one or more of talc, kaolin, montmorillonite, glass fiber, mica, quartz, feldspar, bentonite, zeolite or perlite.

6. The polypropylene composition according to claim 1, wherein The polypropylene composition further comprises 0.1 - 1 part of antioxidant and / or 0 - 2 parts of colorant.

7. The polypropylene composition according to claim 1, characterized in that The weight parts of the silicate filler are 15 - 30 parts.

8. A method for preparing the polypropylene composition according to any one of claims 1 to 7, characterized in that, Comprising the following steps: Mix the PP resin, optional silicate filler, silicone thermoplastic elastomer and styrene toughening agent evenly and then add them into a twin - screw extruder for melt extrusion to obtain the polypropylene composition.

9. Use of the polypropylene composition according to any one of claims 1 - 7 in the field of preparing automotive interior and exterior parts.

10. A part made from the polypropylene composition according to any one of claims 1 - 7.

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