A thin-walled polypropylene modified material for automotive interior and a preparation method thereof

Abstract

The present application relates to a kind of polypropylene modified material for thin-walled automotive interior and its preparation method, the polypropylene modified material for thin-walled automotive interior is prepared from the following mass percentage components: polypropylene 35%-85%, toughening agent 5%-15%, high mesh talc 5%-30%, anti-deformation aid 3%-10%, anti-tiger skin aid 1%-5%, antioxidant 0.2%-1%, weathering agent 0.1%-0.5%, colorant 0.7%-3.5%.The anti-tiger skin aid introduced in the present application migrates to the surface of the product during extrusion molding, which can solve the tiger skin defect of thin-walled products, at the same time, the introduction of high mesh new talc and anti-deformation aid can solve the shrinkage, deformation and poor dimensional stability defects caused by thin-walled parts, thereby solving the shrinkage, tiger skin, deformation, dimensional stability and other defects of modified polypropylene composite material during thin-walled molding, with excellent comprehensive performance and broad market prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer modified materials, and particularly relates to a polypropylene modified material for thin-wall automotive interior decoration and a preparation method thereof. BACKGROUND

[0002] Polypropylene (PP) is widely used in automotive interior and exterior decoration due to low price, easy processing, low density, chemical corrosion resistance and excellent physical and mechanical properties. However, due to the different structures of PP and the distribution and flow of modified components, some large thin-wall parts, such as some thin-wall column decoration parts, thin-wall door panel parts, thin-wall bumper parts and the like, have high requirements for dimensional stability and appearance. The traditional modified PP material is prone to tiger skin, shrinkage, deformation and poor dimensional stability during injection molding, which limits its application.

[0003] A Chinese patent with publication number CN105175881 discloses a high flowability reinforced polypropylene resin for thin-wall injection molding, which is made of the following components: polypropylene 35-80%, terpene resin 15-30%, metallocene-based polyolefin elastomer 20-30%, primary antioxidant 0.1-0.5%, secondary antioxidant 0.3-0.8%, complex nucleating agent 0.05-1.2%, which improves the tiger skin defect of the product by higher flowability, but the higher the flowability of the PP material, the smaller the molecular weight, the narrower the distribution, the more difficult the toughening, the worse the toughness of the PP material, the larger the post-shrinkage, and the worse the dimensional stability. A Chinese patent with publication number CN106674742 discloses a polypropylene composite material for thin-wall automobile bumpers and a preparation method thereof, which is made of the following components: polypropylene 50-80%, modified special talc powder 10-30%, elastomer 8-20%, antioxidant 0.1-1.0%, and other additives 0-3%, which reduces the shrinkage of the material and improves the dimensional stability of the product by modifying the special talc powder, but the silane modifier introduces a poor odor into the product, which cannot meet the odor requirements of interior parts, and at the same time, the surface of the product is prone to oil stains and the tiger skin problem of the thin-wall product is not solved. A Chinese patent with publication number CN106366454 discloses a modified polypropylene material for high-performance thin-wall automobile door panels and a preparation method thereof, which is made of the following components: homopolymer PP 5-10%, first copolymer PP 20-30%, second copolymer PP 15-25%, toughening agent 12-18%, compatibilizer 1-2%, antioxidant 0.4-0.6%, weathering agent 0.2-0.4%, melt index modifier 3-6%, mineral reinforcing agent 20-25%, scratch-resistant agent 1.5-3%, and other additives 1-2%, which improves the flowability of the modified PP material by using the melt index modifier, which is mostly peroxide, to oxidize and degrade the molecular chain length and improve the flowability of the material, and also brings the defects of worse toughness, larger post-shrinkage, and worse dimensional stability of the modified PP material. SUMMARY

[0004] Therefore, the present application provides a polypropylene modified material for thin-wall automobile interiors and a preparation method thereof, which can solve the defects of tiger skin, shrinkage, deformation, dimensional stability, and the like of the thin-wall material, can well meet the use requirements of the thin-wall automobile product, and has important practical significance.

[0005] To achieve the above object, the present application adopts the following technical scheme:

[0006] The polypropylene modified material for thin-wall automobile interior provided by the application is prepared from the following components with the mass percentage: 35-90% of polypropylene, 5-15% of toughening agent, 0-30% of high-mesh talcum powder, 3-10% of anti-deformation aid, 1-5% of anti-tiger skin aid, 0.2-1% of antioxidant, 0.1-0.5% of weathering agent and 0.7-3.5% of coloring agent.

[0007] The anti-tiger skin aid introduced in the application can migrate to the surface of the product in the extrusion process, and can solve the tiger skin defect of the thin-wall product, and the introduction of the high-mesh talcum powder and the anti-deformation aid can solve the defects of the product, such as shrinkage, deformation and poor dimensional stability caused by the thin wall, so that the defects, such as shrinkage, tiger skin, deformation and dimensional stability of the modified polypropylene composite material in the thin-wall forming process are solved, the comprehensive performance is excellent, and the market prospect is wide.

[0008] As a further improvement of the above-mentioned scheme of the application, the anti-tiger skin aid is at least one of perfluoro propylene vinyl ether (PFA), perfluoro methyl vinyl ether (MFA) and fluorinated ethylene propylene copolymer (FEP). The anti-tiger skin aid selected in the application can reduce the friction coefficient with the surface of the mold, improve the flow stability in the melt filling process, and optimize or even avoid the jumping phenomenon of the melt in the filling flow process; on the other hand, it can migrate to the surface and has a certain shielding effect on the surface defects after cooling and solidification.

[0009] As a further improvement of the above-mentioned scheme of the application, the anti-deformation aid is hollow glass beads. The glass beads can fill the product to a certain extent, and the shrinkage anisotropy of the product along the flow direction and the vertical direction is inconsistent, and the deformation of the product is mainly caused by the crystalline orientation caused by the filling stress, leading to the inconsistency of the shrinkage in each direction.

[0010] As a further improvement of the above-mentioned scheme of the application, the bulk density of the hollow glass beads is 0.01-1 g / cm 3 The hollow glass beads with the bulk density can better disperse and maintain the integrity of the filling powder during the preparation process, fully exert the ability of improving the deformation, and balance the mechanical properties of the material, and the influence on the mechanical properties is minimum in the bulk density range.

[0011] As a further improvement of the above-mentioned scheme of the application, the diameter-thickness ratio of the high-mesh talcum powder is 13-19:1, and the average particle size is 5000-10000 mesh. When the thin-wall product is formed, high modulus is needed to compensate for the performance decline caused by the reduction of the wall thickness, and the talcum powder with high mesh and high static thickness ratio can improve the bending strength and bending modulus of the product, and is beneficial to the control of the shrinkage rate in each direction.

[0012] As a further improvement of the above-mentioned scheme of the present application, the polypropylene is a copolymerized polypropylene and / or a homopolymerized polypropylene; the polypropylene of the present application can be selected according to different formula design requirements, and the copolymerized and / or homopolymerized polypropylene can be selected, wherein the homopolymerization can provide better original strength performance, and the copolymerized polypropylene can make the material system more easily toughened. The melt flow rate of the polypropylene has an influence on the injection molding of the thin-walled part; if the polypropylene with too high fluidity is used, the molecular weight is small, and it is difficult to adjust the impact performance in the formula, that is, it is difficult to toughen; if the polypropylene with too low fluidity is used, the overall material fluidity is also low, which is not conducive to the injection molding of the thin-walled part; therefore, the melt flow rate of the polypropylene of the present application is 10-60 g / 10 min at 230 ℃ and 2.16 Kg.

[0013] As a further improvement of the above-mentioned scheme of the present application, the toughening agent is at least one of ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-butene copolymer and ethylene-octene copolymer. The selected toughening agent of the present application has good compatibility with polyolefin, and the toughening effect is more prominent.

[0014] As a further improvement of the above-mentioned scheme of the present application, the antioxidant includes a primary antioxidant and a secondary antioxidant, the primary antioxidant is selected from at least one of hindered phenolic antioxidants, and the secondary antioxidant is selected from one or a mixture of several of phosphite antioxidants.

[0015] As a further improvement of the above-mentioned scheme of the present application, the weathering agent is selected from hindered amine weathering agents or ultraviolet absorbers.

[0016] And / or, the colorant is an organic pigment or an inorganic pigment.

[0017] The present application provides a method for preparing the thin-walled polypropylene modified material for automobile interior as described above, which comprises the following steps:

[0018] S1. The polypropylene, the toughening agent, the high-mesh talcum powder, the anti-tiger skin agent, the antioxidant, the weathering agent and the colorant are mixed uniformly according to the proportion to obtain a mixture; preferably, the mixing is carried out in a high-speed mixer for 3-8 minutes, and the rotating speed of the high-speed mixer is 500-800 rpm / min;

[0019] S2. The mixture is put into the main feeding bin of the screw extruder, and the anti-deformation agent is put into the side feeding port of the screw extruder according to the proportion, and then the thin-walled polypropylene modified material for automobile interior is obtained through melting, extrusion, cooling, granulation and drying. Preferably, the screw diameter of the screw extruder is 35-65 mm, the length-diameter ratio L / D is 40-48, the temperature of each partition of the main barrel from the feeding port to the head outlet is set to be 180-220 ℃, and the main machine rotating speed is 300-500 revolutions / minute.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] 1. The anti-tiger skin agent introduced in the present application can migrate to the surface of the product during the extrusion molding process, solving the tiger skin defect of the thin-walled product. At the same time, the introduction of high-mesh new talc and anti-deformation agent can solve the defects of shrinkage, deformation, and poor dimensional stability caused by thin walls, thereby solving the defects of shrinkage, tiger skin, deformation, dimensional stability, etc. of the modified polypropylene composite material during the thin-walled molding process, and the comprehensive performance is excellent, and the market prospect is broad.

[0022] 2. The anti-tiger skin agent introduced in the present application can migrate to the surface of the product during the extrusion molding process, effectively solving the tiger skin defect of the thin-walled product, avoiding the dependence on material flowability, and being beneficial to the realization of high toughness of the material.

[0023] 3. The anti-deformation agent of the present application selects hollow glass microbeads. During the injection molding pressure maintaining process, the spherical structure of the glass microbeads can guide the orientation of the talc, and the talc will arrange in a fan shape or an arc shape on the surface of the glass microbeads. During the cooling and crystallization process, the polypropylene will crystallize along the glass microbeads and the fan-shaped distributed talc, reducing the inconsistency of orientation and shrinkage, thereby improving the non-uniformity of the shrinkage of the polypropylene modified material and solving the shrinkage and deformation problem of the thin-walled product.

[0024] 4. The anti-tiger skin agent and the anti-deformation agent introduced in the present application can reduce the friction coefficient with the mold surface, improve the flow stability during the melt filling process, and optimize or even avoid the jumping phenomenon of the melt during the filling flow process. After migration to the surface and cooling and solidification, it has a certain shielding effect on surface defects. On the other hand, the glass microbeads in the melt can balance the melt, making the flow inside more stable, and the influence on orientation and crystallization will also weaken the appearance of tiger skin.

[0025] 5. The talc added in the present application can play a role of heterogeneous nucleation in polypropylene, promote the formation of fine and small spherulites in polypropylene, and prevent the formation of larger spherulites, thereby reducing the shrinkage rate of the composite material. The high-mesh lamellar structure talc has better effect on improving the crystallization size and morphology. By introducing high-mesh talc, depending on the higher aspect ratio, the product rigidity is improved while the post-crystallization of PP material is limited, the product dimensional stability is realized, and the shrinkage problem caused by post-shrinkage is also solved. DETAILED DESCRIPTION

[0026] For the purpose of facilitating the understanding of the present application, a more comprehensive description of the present application will be given below in connection with specific embodiments. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, it is intended to cover any and all modifications of the present application within the scope of the disclosure.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0028] The raw material information used in the following examples and comparative examples is specifically as follows:

[0029] (1) Polypropylene: obtained by mixing copolymerized polypropylene and homopolymerized polypropylene at a weight ratio of 1:4, having a melt flow rate of 10-60 g / 10 min at 230°C;

[0030] (2) Toughening agent: ethylene-butene copolymer elastomer;

[0031] (3) Antioxidant: obtained by mixing hindered phenolic antioxidant and phosphite antioxidant at a weight ratio of 1:1;

[0032] (4) Weathering agent: hindered amine;

[0033] (5) Colorant: inorganic color powder;

[0034] (6) High mesh talc: 7000 mesh, aspect ratio of 18:1;

[0035] (7) Anti-deformation aid: hollow glass microbeads;

[0036] (8) Anti-tiger skin aid A: perfluoro propyl vinyl ether (PFA);

[0037] (9) Anti-tiger skin aid B: perfluoro methyl vinyl ether (MFA);

[0038] (10) Anti-tiger skin aid C: fluorinated ethylene propylene copolymer (FEP);

[0039] (11) Ordinary talc: 3000 mesh, aspect ratio of 10:1.

[0040] The above raw materials are only for the purpose of illustrating the source and composition of the reagents used in the experiments of the present application, so as to fully disclose, and do not mean that other similar reagents or reagents provided by other suppliers cannot realize the present application.

[0041] Example 1

[0042] The embodiment provides a polypropylene modified material for thin-wall automobile interior decoration, which comprises the following component raw materials in percentage by mass: 60% of polypropylene, 10% of a toughening agent, 23% of high-mesh talcum powder, 5% of an anti-deformation aid, 1% of an anti-tiger skin aid A, 0.2% of an antioxidant, 0.1% of a weathering agent and 0.7% of a coloring agent.

[0043] The preparation method of the polypropylene modified material for thin-wall automobile interior decoration in the embodiment is as follows: the polypropylene, the toughening agent, the high-mesh talcum powder, the anti-tiger skin aid A, the antioxidant, the weathering agent and the coloring agent are added into a high-speed mixer in proportion and mixed for 8 minutes, the rotating speed of the high-speed mixer is 600 rpm / min, and a mixture is obtained; the mixture is put into a main feeding bin of a meshing co-rotating twin-screw extruder, and then added into a cylinder of the meshing co-rotating twin-screw extruder through a feeding screw, the anti-deformation aid is added into the meshing co-rotating twin-screw extruder through a side feeding port, and then the polypropylene modified material for thin-wall automobile interior decoration is obtained through melting, extrusion, cooling, granulation and drying treatment. The screw diameter of the meshing co-rotating twin-screw extruder is 52 mm, the length-diameter ratio L / D is 48, the temperature of each partition of the main cylinder from the feeding port to the head outlet is set to be 190 ℃, 200 ℃, 210 ℃, 210 ℃, 210 ℃, 200 ℃, 200 ℃, 190 ℃, 190 ℃, 200 ℃, 200 ℃ and 230 ℃, and the rotating speed of the main machine is 400 r / min.

[0044] Embodiment 2

[0045] The embodiment and the embodiment 1 adopt the same implementation manner, and the difference between the embodiment and the embodiment 1 is that the component raw materials and the percentage by mass of the polypropylene modified material for thin-wall automobile interior decoration in the embodiment are as follows: 55% of polypropylene, 10% of a toughening agent, 30% of high-mesh talcum powder, 3% of an anti-deformation aid, 1% of an anti-tiger skin aid A, 0.2% of an antioxidant, 0.1% of a weathering agent and 0.7% of a coloring agent.

[0046] Embodiment 3

[0047] The embodiment provides a polypropylene modified material for thin-wall automobile interior decoration, which adopts the same implementation manner as the embodiment 1, and the difference between the embodiment and the embodiment 1 is that the component raw materials and the percentage by mass of the polypropylene modified material for thin-wall automobile interior decoration in the embodiment are as follows: 55% of polypropylene, 5% of a toughening agent, 24% of high-mesh talcum powder, 10% of an anti-deformation aid, 5% of an anti-tiger skin aid B, 0.2% of an antioxidant, 0.1% of a weathering agent and 0.7% of a coloring agent.

[0048] Embodiment 4

[0049] The embodiment proposes a polypropylene modified material for thin-wall automotive interior decoration, which adopts the same implementation manner as that of the embodiment 1, and differs from the embodiment 1 in that the polypropylene modified material for thin-wall automotive interior decoration of the embodiment has the following component raw materials and mass percentages: polypropylene 55%, toughening agent 15%, high-mesh talcum powder 15%, anti-deformation aid 9%, anti-tiger skin aid C 5%, antioxidant 0.2%, weathering agent 0.1%, coloring agent 0.7%.

[0050] Embodiment 5

[0051] The embodiment proposes a polypropylene modified material for thin-wall automotive interior decoration, which adopts the same implementation manner as that of the embodiment 1, and differs from the embodiment 1 in that the polypropylene modified material for thin-wall automotive interior decoration of the embodiment has the following component raw materials and mass percentages: polypropylene 55%, toughening agent 15%, high-mesh talcum powder 15%, anti-deformation aid 9%, anti-tiger skin aid C 5%, antioxidant 0.2%, weathering agent 0.1%, coloring agent 0.7%.

[0052] Comparative Example 1

[0053] The comparative example proposes a polypropylene material for thin-wall automotive interior decoration, which adopts the same implementation manner as that of the embodiment 1, and differs from the embodiment 1 in that the polypropylene material for thin-wall automotive interior decoration of the comparative example has the following component raw materials and mass percentages: polypropylene 60%, toughening agent 5%, high-mesh talcum powder 24%, antioxidant 0.2%, weathering agent 0.1%, coloring agent 0.7%.

[0054] Comparative Example 2

[0055] The comparative example proposes a polypropylene material for thin-wall automotive interior decoration, which adopts the same implementation manner as that of the embodiment 1, and differs from the embodiment 1 in that the polypropylene material for thin-wall automotive interior decoration of the comparative example has the following component raw materials and mass percentages: polypropylene 65%, toughening agent 5%, high-mesh talcum powder 24%, anti-tiger skin aid A 5%, antioxidant 0.2%, weathering agent 0.1%, coloring agent 0.7%.

[0056] Comparative Example 3

[0057] The comparative example proposes a polypropylene material for thin-wall automotive interior decoration, which adopts the same implementation manner as that of the embodiment 1, and differs from the embodiment 1 in that the polypropylene material for thin-wall automotive interior decoration of the comparative example has the following component raw materials and mass percentages: polypropylene 64%, toughening agent 5%, ordinary talcum powder 30%, antioxidant 0.2%, weathering agent 0.1%, coloring agent 0.7%.

[0058] The component raw material usage of the above embodiments and comparative examples is shown in Table 1.

[0059] Table 1 raw material usage (mass percentage) of components of examples and comparative examples

[0060]

[0061]

[0062] Test example

[0063] The materials prepared in the above examples and comparative examples were dried in a material drying tank and then injection molded, and the appearance of the molded samples of the comparative materials was observed, and the results are shown in Table 2.

[0064] Table 2 appearance of molded samples

[0065]

[0066] From the results in Table 2, it can be seen that the molded samples of Examples 1 to 5 did not have tiger stripes or warping deformation, while the molded samples of Comparative Examples 1-3 had slight or obvious tiger stripes and shrinkage deformation, which shows that the present application can effectively solve the defects of tiger stripes and shrinkage deformation of thin-walled automotive interior trim, and the developed polypropylene modified material can be applied to thin-walled interior and exterior trim.

[0067] The technical features of the above-described examples can be combined in any way, and to make the description concise, not all possible combinations of the technical features in the above examples are described, however, as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present disclosure.

[0068] The above-described examples only express several embodiments of the present application, and the description is more specific and detailed, but it should not be construed as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present patent should be subject to the appended claims.

Claims

1. A thin-walled polypropylene modified material for automotive interior trim, characterized in that, It is prepared from the following components by mass percentage: 35%-85% polypropylene, 5%-15% toughening agent, 5%-30% high-mesh talc, 3%-10% anti-deformation agent, 1%-5% anti-stripping agent, 0.2%-1% antioxidant, 0.1%-0.5% weathering agent, and 0.7%-3.5% colorant; the anti-stripping agent is at least one of perfluoropropylene vinyl ether, perfluoromethyl vinyl ether, and fluorinated ethylene propylene copolymer; the anti-deformation agent is hollow glass microspheres; the high-mesh talc has an aspect ratio of 13-19:1 and an average particle size of 5000-10000 mesh.

2. The thin-walled polypropylene modified material for automotive interiors according to claim 1, characterized in that, The bulk density of the hollow glass microspheres is 0.01-1 g / cm³. 3 .

3. The thin-walled polypropylene modified material for automotive interiors according to claim 1, characterized in that, The polypropylene is copolymer polypropylene and / or homopolymer polypropylene, and the melt flow rate of the polypropylene at 230℃ is 10-60 g / 10 min for 2.16 kg.

4. The thin-walled polypropylene modified material for automotive interiors according to claim 1, characterized in that, The toughening agent is at least one of ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-butene copolymer, and ethylene-octene copolymer.

5. The thin-walled polypropylene modified material for automotive interiors according to claim 1, characterized in that, The antioxidant includes a primary antioxidant and a secondary antioxidant. The primary antioxidant is selected from at least one of hindered phenolic antioxidants, and the secondary antioxidant is selected from one or a mixture of several phosphite antioxidants.

6. The thin-walled polypropylene modified material for automotive interior trim according to claim 1, characterized in that, The weathering agent is selected from hindered amine weathering agents or ultraviolet absorbers; And / or, the colorant is an organic pigment or an inorganic pigment.

7. A method for preparing a thin-walled polypropylene modified material for automotive interior trim as described in any one of claims 1-6, characterized in that, It includes the following steps: S1. Mix polypropylene, toughening agent, high-mesh talc powder, anti-tiger-skin texture additive, antioxidant, weathering agent, and colorant in a certain proportion to obtain a mixture; S2. The mixture is fed into the main feed hopper of the screw extruder, and the anti-deformation agent is added into the side feed port of the screw extruder in proportion. After melting, extrusion, cooling, granulation and drying, a thin-walled modified polypropylene material for automotive interior is obtained.

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