A spray-free polypropylene material and a method for producing the same

Abstract

This invention discloses a paint-free polypropylene material and its preparation method. The paint-free polypropylene material comprises the following components by weight: 50-95 parts polypropylene resin, 0.1-5 parts metallic appearance filler, 0.1-10 parts magnetically attractable powder, and 1.25-35 parts functional additives. The magnetically attractable powder does not exert a magnetic attraction on the iron parts. This invention also discloses a method for preparing the paint-free polypropylene material. The paint-free polypropylene material provided by this invention has magnetic properties on its surface, eliminating the need for adhesives when placing decorative items and meeting the needs for personalized and rapid replacement.

Description

Technical Field

[0001] This invention belongs to the field of plastic materials technology, specifically relating to a paint-free polypropylene material and its preparation method. Background Technology

[0002] Polypropylene materials are used in many fields such as home appliances and automobiles. In some applications, such as exterior parts or interior components, users not only want them to have a good appearance, but also need to attach personalized stickers and fix personalized ornaments, such as placing air fresheners or pet toys on the car dashboard.

[0003] Currently, stickers and ornaments are mainly fixed by adhesives, but there are several problems with using adhesives: (1) The surface to be bonded needs to be clean to achieve a good fixing effect; (2) Because PP has low surface energy, it is a difficult material to bond, so it is easy to fall off after a long time; (3) The use of adhesives may cause air pollution in a small space and aggravate the unpleasant smell in the car; (4) The adhesive connection scheme is not easy to change, and it is easy to leave residual adhesive when changing, which has a great negative impact on the appearance. Summary of the Invention

[0004] To address the problem that polypropylene parts made of existing polypropylene materials are difficult to connect and fix to ornaments, this invention provides a paint-free polypropylene material and its preparation method.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] On one hand, embodiments of the present invention provide a paint-free polypropylene material, comprising the following weight components: 50-95 parts of polypropylene resin, 0.1-5 parts of metallic appearance filler, 0.1-10 parts of magnetically attractable powder, and 1.25-35 parts of functional additives, wherein the magnetically attractable powder has no magnetic attraction to the iron parts.

[0007] Optionally, the paint-free polypropylene material includes the following components by weight: 60-90 parts polypropylene resin, 0.1-5 parts metallic appearance filler, 1-10 parts magnetically adsorbable powder, and 1.3-30 parts functional additives.

[0008] Optionally, the melt flow rate of the polypropylene resin is 12-45 g / 10 min at 230°C and 2.16 kg.

[0009] Optionally, the magnetically adsorbable powder includes ferromagnetic particles and / or polymer-encapsulated ferromagnetic particles, wherein the ferromagnetic particles include one or more of metal powder, metal oxide, iron sulfide, and alloy.

[0010] Optionally, the metal powder includes one or more of Fe, Co, and Ni; the metal oxide includes one or both of Co3O4 and NiO; and the alloy includes one or more of Fe-Pt, Al-Ni, and Ni-C.

[0011] Optionally, the polymer includes one or more of polyethylene, polypropylene, polyacrylate, and polystyrene.

[0012] Optionally, the particle size range of the magnetically adsorbable powder is 0.01-100 μm.

[0013] Optionally, the metallic appearance filler includes one or more of the following: metal powder, pearlescent pigment, aluminum powder, water-based aluminum pigment, and mica pearlescent pigment.

[0014] Optionally, based on the weight of the paint-free polypropylene material, the functional additives include the following components by weight: 0-20 parts filler, 1-10 parts toughening agent, 0.1-0.5 parts coupling agent, 0.05-2 parts antioxidant, 0.05-2 parts light stabilizer, and 0.05-0.5 parts metal ion passivator.

[0015] Optionally, the filler includes one or more of talc, calcium carbonate, barium sulfate, wollastonite, and short glass fibers;

[0016] The toughening agent includes one or more of ethylene-octene copolymers and ethylene-butene copolymers;

[0017] The coupling agent includes one or more titanate coupling agents and silane coupling agents;

[0018] The antioxidants include one or more of amine antioxidants, phenolic antioxidants, phosphite antioxidants, and sulfur-containing antioxidants;

[0019] The light stabilizer includes one or more of hindered amine light stabilizers, salicylic acid light stabilizers, benzophenone light stabilizers, and benzotriazole light stabilizers;

[0020] The metal ion passivating agent includes one or more of bis(salicyl)diamine passivating agents and oxalamide passivating agents.

[0021] On the other hand, the present invention also provides a method for preparing the spray-free polypropylene material as described above, wherein the functional additives include fillers, toughening agents, coupling agents, antioxidants, light stabilizers, and metal ion passivators, and includes the following steps:

[0022] A mixture of filler, metallic appearance filler, magnetically absorbable powder and coupling agent is obtained to obtain a mixed magnetically absorbable pigment filler.

[0023] The magnetically absorbable pigment filler is mixed with a portion of the polypropylene resin and then extruded and granulated using a twin-screw extruder to obtain magnetically absorbable masterbatch.

[0024] The magnetically absorbable masterbatch is mixed with the remaining polypropylene resin, toughening agent, antioxidant, light stabilizer, and metal ion passivator, and then extruded and granulated using a twin-screw extruder to obtain a paint-free polypropylene material.

[0025] Optionally, the extrusion granulation conditions are: the temperature in zone T1 is 70-120℃, the temperature from T2 to the die head is 160-210℃, and the screw speed is 400-800 r / min.

[0026] In this invention, the paint-free polypropylene material achieves a good appearance without spraying, reducing painting processes and improving the product's environmental friendliness and recyclability. Furthermore, the paint-free polypropylene material gives the prepared parts a magnetic surface, allowing users to attach or place personalized ornaments or decals on polypropylene products without the need for adhesives, enabling quick application and removal, and meeting the need for personalized and rapid replacement. Compared to traditional polypropylene composite materials, the paint-free polypropylene material of this invention uses magnetically adsorbable powder, and since there is no magnetic attraction between the magnetically adsorbable powder and the iron parts, it prevents the magnetically adsorbable powder from migrating to the surface of the parts, giving the parts both aesthetic appeal and functionality, and meeting more of the user's needs for finished products. Detailed Implementation

[0027] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the invention.

[0028] One embodiment of the present invention discloses a paint-free polypropylene material, comprising 50-95 parts of polypropylene resin, 0.1-5 parts of metallic appearance filler, 0.1-10 parts of magnetically attractable powder, and 1.25-35 parts of functional additives, wherein the magnetically attractable powder has no magnetic attraction to the iron parts.

[0029] In this embodiment, the paint-free polypropylene material achieves a good appearance without a painting process, reducing the painting steps and improving the product's environmental friendliness and recyclability. Furthermore, the paint-free polypropylene material gives the prepared parts a magnetic surface, allowing users to attach or place personalized ornaments or decals on polypropylene products without the need for adhesives, enabling quick application and removal, and meeting the need for personalized and rapid replacement. Compared to traditional polypropylene composite materials, the paint-free polypropylene material of this invention uses magnetically adsorbable powder, and since there is no magnetic attraction between the magnetically adsorbable powder and the iron parts, it prevents the magnetically adsorbable powder from migrating to the surface of the parts, giving the parts both aesthetic appeal and functionality, and meeting more of the user's needs for finished products.

[0030] In a preferred embodiment, the paint-free polypropylene material comprises the following components by weight: 60-90 parts polypropylene resin, 0.1-5 parts metallic appearance filler, 1-10 parts magnetically adsorbable powder, and 1.3-30 parts functional additives.

[0031] In some embodiments, the melt flow rate of the polypropylene resin is 12-45 g / 10 min at 230°C and 2.16 kg. A melt flow rate of 12-45 g / 10 min is beneficial for filler dispersion and improves appearance quality; within this range, the filler is more easily dispersed as the melt flow rate increases. However, when the melt flow rate exceeds 45 g / 10 min, the mechanical properties of products prepared from the non-sprayed polypropylene material are poor. Conversely, when the melt flow rate is less than 12 g / 10 min, the filler is difficult to disperse, affecting the appearance quality of the parts. Specifically, the melt flow rate can be 14 g / 10 min, 18 g / 10 min, 22 g / 10 min, 25 g / 10 min, 28 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, etc.

[0032] In some embodiments, the magnetically attractable powder comprises ferromagnetic particles and / or polymer-encapsulated ferromagnetic particles, wherein the ferromagnetic particles comprise one or more of metal powder, metal oxide, iron sulfide, and alloy. Specifically, the ferromagnetic particles are micron- or nano-sized particles.

[0033] In some embodiments, the metal powder includes one or more of Fe, Co, and Ni; the metal oxide includes one or both of Co3O4 and NiO; and the alloy includes one or more of Fe-Pt, Al-Ni, and Ni-C.

[0034] The magnetic permeability of the above-mentioned magnetically adsorbable powders is relatively low, resulting in no magnetic attraction between them and iron parts. Since injection molding or extrusion equipment for paint-free polypropylene materials is primarily made of iron, excessively high magnetic permeability may cause the magnetically adsorbable powder to migrate to the surface of the part due to the attraction of the iron equipment. This can lead to filler concentration on the surface, causing a significant difference in the coefficients of thermal expansion between the surface and inner layers, resulting in warping and deformation of the part and increasing the difficulty of process control. Simultaneously, the magnetically adsorbable powder is prone to adhering to the inner wall of the screw or barrel, reducing equipment lifespan. Furthermore, the magnetically adsorbable powder itself usually has a certain color. If the magnetically adsorbable powder is too concentrated on the surface of the part, its own color may excessively interfere with the appearance of the part, obscuring the color development effect of the pigment and affecting the paint-free finish. Therefore, selecting magnetically adsorbable powders with relatively low magnetic permeability avoids the migration of magnetically adsorbable powder to the surface of the part during injection molding of paint-free polypropylene materials.

[0035] In some embodiments, the polymer includes one or more of polyethylene, polypropylene, polyacrylate, and polystyrene.

[0036] In some embodiments, the particle size of the magnetically attractable powder ranges from 0.01 to 100 μm. By controlling the particle size of the magnetically attractable powder, the adverse effects of excessively large particle size on the appearance of the part can be avoided. Specifically, the particle size of the magnetically attractable powder can be 0.01 μm, 5 μm, 10 μm, 25 μm, 30 μm, 50 μm, 60 μm, 70 μm, 100 μm, etc.

[0037] In some embodiments, the metallic appearance filler includes one or more of the following: metal powder, pearlescent pigment, aluminum powder, water-based aluminum pigment, and mica pearlescent pigment.

[0038] In some embodiments, based on the weight of the paint-free polypropylene material, the functional additives include the following components by weight: 0-20 parts filler, 1-10 parts toughening agent, 0.1-0.5 parts coupling agent, 0.05-2 parts antioxidant, 0.05-2 parts light stabilizer, and 0.05-0.5 parts metal ion passivator.

[0039] In a preferred embodiment, based on the weight of the paint-free polypropylene material, the functional additives comprise the following components by weight: 0-15 parts filler, 1-10 parts toughening agent, 0.1-0.5 parts coupling agent, 0.05-2 parts antioxidant, 0.05-2 parts light stabilizer, and 0.1-0.5 parts metal ion passivator. Metal ions catalyze the photodegradation of polypropylene materials. By adding a metal ion passivator, the adverse effects of metal ions introduced by magnetically adsorbable powder on the weather resistance of polypropylene can be eliminated.

[0040] In some embodiments, the filler includes one or more of talc, calcium carbonate, barium sulfate, wollastonite, and short glass fibers.

[0041] The toughening agent includes one or more of ethylene-octene copolymers and ethylene-butene copolymers.

[0042] The coupling agent includes one or more of titanate coupling agents and silane coupling agents.

[0043] The antioxidants include one or more of amine antioxidants, phenolic antioxidants, phosphite antioxidants, and sulfur-containing antioxidants.

[0044] The light stabilizer includes one or more of hindered amine light stabilizers, salicylic acid light stabilizers, benzophenone light stabilizers, and benzotriazole light stabilizers.

[0045] The metal ion passivating agent includes one or more of bis(salicyl)diamine passivating agents and oxalamide passivating agents.

[0046] On the other hand, an embodiment of the present invention also provides a method for preparing the spray-free polypropylene material as described above, comprising the following steps:

[0047] A mixture of filler, metallic appearance filler, magnetically attractable powder, and coupling agent is obtained to obtain a mixed magnetically attractable pigment filler.

[0048] The magnetically absorbable pigment filler is mixed with a portion of the polypropylene resin and then extruded and granulated using a twin-screw extruder to obtain magnetically absorbable masterbatch.

[0049] The magnetically absorbable masterbatch is mixed with the remaining polypropylene resin, toughening agent, antioxidant, light stabilizer, and metal ion passivator, and then extruded and granulated using a twin-screw extruder to obtain a paint-free polypropylene material.

[0050] In some embodiments, the extrusion granulation conditions are as follows: the temperature in zone T1 is 70-120°C, the temperature from T2 to the die head is 160-210°C, and the screw speed is 400-800 r / min.

[0051] The present invention will be further illustrated by the following examples.

[0052] Example 1

[0053] This embodiment illustrates the spray-free polypropylene material and its preparation method disclosed in this invention, including the following steps:

[0054] Ten parts of 1250-mesh talc powder (filler), two parts of water-based aluminum silver paste (Al 60%, average particle size 50 μm), three parts of carbonyl micron Fe powder (magnetically adsorbable powder), and 0.1 parts of titanate coupling agent were mixed and premixed in a high-speed mixer for 5 minutes at 1000 rpm to obtain a mixed magnetically adsorbable pigment filler. The average particle size of the carbonyl micron Fe powder was 10 μm.

[0055] The obtained mixed magnetically absorbable pigment filler was mixed with 40 parts of polypropylene resin and extruded and granulated using a twin-screw extruder to obtain magnetically absorbable masterbatch. The temperature in zone T1 was 100℃, from T2 to the die head was 180℃, and the screw speed was 600 r / min. The melt flow rate of the polypropylene resin was 12 g / 10 min at 230℃ and 2.16 kg.

[0056] The magnetically absorbable color masterbatch was mixed with 40 parts of polypropylene resin, 5 parts of ethylene-octene copolymer (toughening agent), 0.05 parts of a compound of phenolic antioxidant and phosphorous acid antioxidant, 0.05 parts of hindered amine light stabilizer, and 0.1 parts of BASF Irganox MD1024 (metal ion passivator). The mixture was then extruded and granulated using a twin-screw extruder to obtain a paint-free polypropylene material.

[0057] The temperature in zone T1 was 100℃, and from T2 to the die head it was 180℃, with a screw speed of 600 r / min. The melt flow rate of the toughening agent was 4.8 g / 10 min at 230℃ and 2.16 kg.

[0058] Example 2

[0059] In this embodiment, most of the operational steps are included in Example 1. The difference from Example 1 is that 75 parts of polypropylene resin are used, 5 parts of pearlescent powder are used instead of water-based aluminum silver paste, and 5 parts of Ni-C powder are used instead of carbonyl micronized Fe powder. The average particle size of the pearlescent powder is 180 μm, and the average particle size of the Ni-C powder is 50 μm.

[0060] Example 3

[0061] In this embodiment, most of the operational steps are included in Example 1. The difference from Example 1 is that 75 parts of polypropylene resin are used, 1 part of pearlescent powder is used instead of water-based aluminum silver paste, 4 parts of ethylene-octene copolymer are used, and 10 parts of carbonyl micronized Fe powder are used. The melt flow rate of the polypropylene resin at 230°C and 2.16 kg is 35 g / 10 min. The average particle size of the pearlescent powder is 180 μm.

[0062] Example 4

[0063] This embodiment includes most of the operating steps in Embodiment 1, but unlike Embodiment 1, it does not contain the metal ion passivating agent: BASF Irganox MD1024.

[0064] Example 5

[0065] In this embodiment, most of the operating steps in Example 1 are included. The difference from Example 1 is that the melt flow rate of polypropylene resin is 45 g / 10 min at 230°C and 2.16 kg.

[0066] Example 6

[0067] In this embodiment, most of the operating steps in Example 1 are included. The difference from Example 1 is that the melt flow rate of polypropylene resin is 25 g / 10 min at 230°C and 2.16 kg.

[0068] Comparative Example 1

[0069] In this comparative example, most of the operating steps are included in Example 2, except that 5 parts of Fe3O4 powder are used instead of Ni-C powder. The average particle size of the Fe3O4 powder is 50 μm.

[0070] Comparative Example 2

[0071] In this comparative example, most of the operating steps in Example 1 are included. The difference from Example 1 is that the melt flow rate of the polypropylene resin is 9 g / 10 min at 230°C and 2.16 kg.

[0072] Comparative Example 3

[0073] In this comparative example, most of the operating steps in Example 1 are included. The difference from Example 1 is that the melt flow rate of the polypropylene resin is 50 g / 10 min at 230°C and 2.16 kg.

[0074] Performance testing

[0075] The paint-free polypropylene materials obtained in Examples 1-6 and Comparative Examples 1-3 were injection molded into parts, and their performance was tested.

[0076] Tensile strength was tested according to GB / T 1040.2-2018, and notched impact strength of the cantilever beam was tested according to GB / T 1843-2008. The magnetic properties were evaluated by testing the vertical pull-out force using a commercially available neodymium boron magnet and a tensile testing machine. The appearance was visually assessed.

[0077] The results of each test are shown in Table 1.

[0078] Table 1

[0079]

[0080]

[0081] The test results of Examples 1-6 and Comparative Examples 2-3 show that changing the melt flow rate of polypropylene can affect the appearance quality and mechanical properties of paint-free polypropylene products. The test results of Examples 1-3 and Comparative Example 1 show that although using magnetically adsorbed powder with high magnetic permeability results in a higher vertical pull-out force on the part, the color of the magnetically adsorbed powder itself significantly affects the appearance due to its migration to the surface of the part, leading to a poor paint-free appearance.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A paint-free polypropylene material, characterized in that, It comprises the following components by weight: 50-95 parts of polypropylene resin, 0.1-5 parts of metallic appearance filler, 0.1-10 parts of magnetically attractable powder, and 1.25-35 parts of functional additives, wherein the magnetically attractable powder has no magnetic attraction to the iron parts; The magnetically adsorbable powder includes ferromagnetic particles and / or polymer-encapsulated ferromagnetic particles, wherein the ferromagnetic particles include one or more of metal powder, metal oxide, iron sulfide, and alloy. The metal powder includes one or more of Co and Ni; the metal oxide includes one or both of Co3O4 and NiO; the alloy includes one or more of Fe-Pt, Al-Ni and Ni-C.

2. The paint-free polypropylene material according to claim 1, characterized in that, The paint-free polypropylene material comprises the following components by weight: 60-90 parts polypropylene resin, 0.1-5 parts metallic appearance filler, 1-10 parts magnetically adsorbable powder, and 1.3-30 parts functional additives.

3. The paint-free polypropylene material according to claim 1, characterized in that, The melt flow rate of the polypropylene resin is 12-45 g / 10 min at 230°C and 2.16 kg.

4. The paint-free polypropylene material according to claim 1, characterized in that, The polymer includes one or more of polyethylene, polypropylene, polyacrylate, and polystyrene.

5. The paint-free polypropylene material according to claim 1, characterized in that, The particle size range of the magnetically adsorbable powder is 0.01-100μm.

6. The paint-free polypropylene material according to claim 1, characterized in that, The metallic appearance filler includes one or more of the following: metal powder, pearlescent pigment, and water-based aluminum pigment.

7. The paint-free polypropylene material according to claim 1, characterized in that, Based on the weight of the paint-free polypropylene material, the functional additives include the following components by weight: 0-20 parts filler, 1-10 parts toughening agent, 0.1-0.5 parts coupling agent, 0.05-2 parts antioxidant, 0.05-2 parts light stabilizer, and 0.05-0.5 parts metal ion passivator.

8. The paint-free polypropylene material according to claim 7, characterized in that, The filler includes one or more of talc, calcium carbonate, barium sulfate, wollastonite, and short glass fibers; The toughening agent includes one or more of ethylene-octene copolymers and ethylene-butene copolymers; The coupling agent includes one or more titanate coupling agents and silane coupling agents; The antioxidants include one or more of amine antioxidants, phenolic antioxidants, phosphite antioxidants, and sulfur-containing antioxidants; The light stabilizer includes one or more of hindered amine light stabilizers, salicylic acid light stabilizers, benzophenone light stabilizers, and benzotriazole light stabilizers; The metal ion passivating agent includes one or more of bis(salicyl)diamine passivating agents and oxalamide passivating agents.

9. A method for preparing a paint-free polypropylene material as described in any one of claims 1-8, characterized in that, The functional additives include fillers, toughening agents, coupling agents, antioxidants, light stabilizers, and metal ion passivating agents. The preparation method includes the following steps: A mixture of filler, metallic appearance filler, magnetically absorbable powder and coupling agent is obtained to obtain a mixed magnetically absorbable pigment filler. The magnetically absorbable pigment filler is mixed with a portion of the polypropylene resin and then extruded and granulated using a twin-screw extruder to obtain magnetically absorbable masterbatch. The magnetically absorbable masterbatch is mixed with the remaining polypropylene resin, toughening agent, antioxidant, light stabilizer, and metal ion passivator, and then extruded and granulated using a twin-screw extruder to obtain a paint-free polypropylene material.

10. The preparation method according to claim 9, characterized in that, The extrusion granulation conditions are as follows: the temperature in zone T1 is 70-120℃, the temperature from T2 to the die head is 160-210℃, and the screw speed is 400-800 r / min.

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