Metal texture enhanced polypropylene material and preparation method thereof

Abstract

The invention relates to a metal texture reinforced polypropylene material and a preparation method thereof, and belongs to the technical field of polypropylene material preparation. The polypropylene material comprises the following raw materials in parts by weight: 100 parts of a PP base material, 15-25 parts of a texture additive, 15-30 parts of modified glass fibers, 0.1-0.5 part of an ultraviolet light absorber and 0.5-1.5 parts of a lubricant; the texture additive is metal powder modified by a double-bond silane coupling agent; the modified glass fiber is glass fiber modified by a crosslinking-promoting silane coupling agent; the cross-linking promoting silane coupling agent is prepared from an epoxy silane coupling agent, a 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-1-oxygen free radical and dibenzoyl peroxide through a reaction, and the cross-linking promoting silane coupling agent is prepared from the epoxy silane coupling agent, the 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-1-oxygen free radical and the dibenzoyl peroxide through a reaction. The obtained composite material has excellent metal texture, hardness, heat resistance and mechanical performance.

Description

Technical Field

[0001] The invention belongs to the technical field of polypropylene material preparation, and in particular relates to a polypropylene material with enhanced metallic texture and a preparation method thereof. Background Art

[0002] Competition in the automotive field is becoming increasingly fierce, and the pursuit of automotive interior decoration materials is becoming more and more quality-oriented, such as the requirement for metallic appearance. However, automotive interior decoration materials are generally made of polypropylene (hereinafter referred to as PP). Traditional automotive interior decoration materials are generally made of polypropylene and external fillers or reinforcing materials through melt mixing. Among them, the current automotive pedal material is to enhance the PP material by adding long fibers to the polypropylene system to meet the requirements of wear resistance and mechanical strength of the automotive pedal. However, the texture of the PP material reinforced by long fibers is still the appearance of general plastic parts, and cannot achieve metallic texture. In order to meet the requirements of metallic texture, the existing processing method is a secondary processing method, which gives the final obtained part a metallic texture by spraying paint on the parts of the long fiber reinforced PP material. This method has the disadvantages of extending the production line, the metal texture is not durable, and it is not environmentally friendly.

[0003] Therefore, it is necessary to develop a metal texture enhanced polypropylene material and a preparation method thereof. Summary of the invention

[0004] The object of the present invention is to provide a metal texture enhanced polypropylene material and a preparation method thereof.

[0005] One object of the present invention can be achieved by the following technical solutions:

[0006] A metal texture enhanced polypropylene material, comprising the following raw materials in parts by weight: 100 parts of PP base material, 15-25 parts of texture additive, 15-30 parts of modified glass fiber, 0.1-0.5 parts of ultraviolet light absorber, and 0.5-1.5 parts of lubricant;

[0007] The texture aid is a metal powder modified by a double-bond silane coupling agent;

[0008] The modified glass fiber is a glass fiber modified by a cross-linking-promoting silane coupling agent;

[0009] The cross-linking promoting silane coupling agent is prepared by reacting an epoxy silane coupling agent, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical and dibenzoyl peroxide.

[0010] When developing the invention of this technology, the inventor chose to introduce metal powder into the PP base material to give the texture of the obtained composite material. However, it was found that while the addition of metal powder improved the texture of the composite material, it would reduce the performance of the composite material in all aspects. At the same time, the metal powder was not easy to disperse and easy to agglomerate when mixed with other base materials. At the same time, the metal particles on the surface of the molding material were not corrosion-resistant, resulting in the metal texture of the obtained composite material not being durable. Based on the above-mentioned technical solution of directly introducing metal powder, improvements were made, and combined with the long fiber modification in the fiber-improved polypropylene technology, a metal powder modified by a double-bond silane coupling agent and a glass fiber modified by a cross-linking silane coupling agent were developed. Not only did the silane coupling agent solve the problem of the dispersion of metal powder and fiber in the base material, but also the two cooperated with each other. In the obtained composite material, an interpenetrating network with a three-dimensional structure of metal powder and fiber as the skeleton and a base material as the compacting material was formed, which not only gave the obtained composite material a metallic texture, but also greatly improved the hardness, heat resistance and mechanical properties of the obtained composite material.

[0011] Furthermore, the double bond silane coupling agent accounts for 6-13% of the mass of the metal powder.

[0012] Furthermore, the texture aid comprises the following steps:

[0013] The metal powder is added into the modified liquid, heated to the modification temperature under stirring, and kept warm for reaction until the reaction time is reached, and then the texture additive is obtained through post-treatment.

[0014] Furthermore, the modification temperature is 25-35° C., and the reaction time is 1-3 h.

[0015] Furthermore, the modified liquid is formed by a hydrolysis reaction of a double-bond silane coupling agent in a mixed solution of water and ethanol.

[0016] Furthermore, the dosage ratio of the double bond silane coupling agent to the mixed solution is 1 g:15-20 mL; and the volume ratio of water to ethanol in the mixed solution is 1:4-5.

[0017] Furthermore, the conditions of the hydrolysis reaction are: pH 4-5, reaction temperature is 20-40°C, and reaction time is 20-30min.

[0018] Furthermore, the cross-linking promoting silane coupling agent includes the following:

[0019] After the epoxy silane coupling agent, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical and tetrahydrofuran are uniformly mixed, the pH is adjusted to 10-11, heated to 60-70°C, and stirred for reaction for 2-5 hours, cooled to room temperature, a tetrahydrofuran solution containing dibenzoyl peroxide is added, and the reaction is stirred for 4-8 hours at room temperature under nitrogen protection. After post-treatment, a cross-linking silane coupling agent is obtained.

[0020] Furthermore, the molar ratio of the epoxy silane coupling agent, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical, and dibenzoyl peroxide is 1:1-1.2:1.1-1.3.

[0021] Furthermore, the modified glass fiber is prepared by the following steps:

[0022] The glass fiber is ultrasonically dispersed in a mixed solution of a cross-linking silane coupling agent, water and ethanol, heated to 50-70°C with stirring, kept stirring and reacted for 3-6 hours, the reaction is stopped, and the modified glass fiber is obtained through post-treatment.

[0023] Furthermore, the mass ratio of the glass fiber to the cross-linking-promoting silane coupling agent is 1:0.08-0.13.

[0024] Furthermore, the ultraviolet light absorber is a well-known ultraviolet light absorber in the technical field, such as ultraviolet light absorber UV-O, ultraviolet light absorber UV-9, ultraviolet light absorber UV-531, and ultraviolet light absorber UVP-327;

[0025] Preferably, the ultraviolet light absorber is ultraviolet light absorber UVP-327.

[0026] Furthermore, the lubricant is a processing lubricant well known in the technical field, and the present invention does not limit the specific type.

[0027] Another object of the present invention can be achieved by the following technical solutions:

[0028] A method for preparing a metal texture enhanced polypropylene material, characterized by comprising:

[0029] The PP base material, texture additive, modified glass fiber, ultraviolet light absorber and lubricant are mixed, extruded and formed by an extruder to obtain metal texture enhanced polypropylene.

[0030] Furthermore, the extrusion temperature range of the extruder is set to 195-240°C.

[0031] Beneficial effects of the present invention:

[0032] The present invention provides a metal texture enhanced polypropylene material and a preparation method thereof, wherein metal powder modified by a double bond silane coupling agent and modified glass fiber are introduced, wherein the metal powder modified by a double bond silane coupling agent is used as a texture aid to give the obtained composite material a metal texture, and remarkably, the metal powder modified by a double bond silane coupling agent and the modified glass fiber cooperate with each other, and in the obtained composite material, an interpenetrating network with a three-dimensional structure of metal powder and fiber as a skeleton and a base material as a compacting material is formed, which not only gives the obtained composite material a metal texture, but also greatly improves the hardness, heat resistance and mechanical properties of the obtained composite material, which is explained as follows:

[0033] The metal powder modified by the double bond silane coupling agent improves the dispersion performance of the metal powder in the base material and improves the interface performance between the metal powder and the base material. Most importantly, the double bonds of the silane chains on the surface of the metal powder can be cross-linked with the PP base material.

[0034] The modified glass fiber surface is grafted with nitrogen-oxygen bonds (obtained by the reaction of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxygen free radicals and benzoyl peroxide), which are easily broken under high temperature or light radiation to generate nitrogen-oxygen free radicals, and then high-temperature cross-linking occurs. The nitrogen-oxygen free radicals generated by the nitrogen-oxygen bonds can capture active free radicals generated by the cleavage of PP base materials or double bonds and PP cross-linking networks, thereby hindering the collapse of double bonds and PP cross-linking networks and improving the hardness, heat resistance and mechanical properties of the obtained composite material. DETAILED DESCRIPTION

[0035] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] Preparation of modified glass fiber:

[0038] A1. After uniformly mixing 0.1 mol epoxy silane coupling agent (exemplarily KH560), 0.1 mol 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical and 60 mL tetrahydrofuran, the pH value was adjusted to 10-11, heated to 60° C., stirred and reacted for 5 h, cooled to room temperature, 30 mL tetrahydrofuran solution containing 0.11 mol dibenzoyl oxide was added, stirred and reacted for 4 h at room temperature under nitrogen protection, separated, and separated by oil phase chromatography to obtain a cross-linking-promoting silane coupling agent;

[0039] A2. Ultrasonic disperse 100 g of glass fiber in a mixed solution of 8 g of a cross-linking silane coupling agent, 15 mL of water and 45 mL of ethanol, heat to 50°C with stirring, keep stirring and react for 6 hours, stop the reaction, centrifuge to obtain the precipitate, repeatedly wash and dry to obtain the modified glass fiber.

[0040] Example 2

[0041] Preparation of modified glass fiber:

[0042] A1. After uniformly mixing 0.1 mol epoxy silane coupling agent (exemplarily KH560), 0.12 mol 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical and 60 mL tetrahydrofuran, the pH value was adjusted to 10-11, heated to 70° C., stirred and reacted for 2 h, cooled to room temperature, 30 mL tetrahydrofuran solution containing 0.14 mol dibenzoyl oxide was added, stirred and reacted for 8 h at room temperature under nitrogen protection, separated, and separated by oil phase chromatography to obtain a cross-linking silane coupling agent;

[0043] A2. Ultrasonic disperse 100 g of glass fiber in a mixed solution of 13 g of a cross-linking silane coupling agent, 20 mL of water and 50 mL of ethanol, heat to 70°C with stirring, keep stirring and react for 3 hours, stop the reaction, centrifuge to obtain the precipitate, repeatedly wash and dry to obtain the modified glass fiber.

[0044] Example 3

[0045] Preparation of texture additives:

[0046] B1, 6 g of double bond silane coupling agent (exemplarily KH570), 15 mL of water and 75 mL of ethanol were mixed evenly, the pH was adjusted to 4-5, the mixture was heated to 20° C. with stirring, and the mixture was stirred and reacted for 30 min. The stirring and heating were stopped, and the mixture was cooled to room temperature to obtain a modified solution;

[0047] B2. Add 100g of metal powder (nano-aluminum flake powder, particle size 200-300nm) to the modified solution, heat to 25°C with stirring, and keep the reaction warm for 3h. Stop heating, centrifuge, take the precipitate, wash repeatedly, and dry to obtain a texture additive.

[0048] Example 4

[0049] Preparation of texture additives:

[0050] B1, 13g of double bond silane coupling agent (exemplarily KH570), 52mL of water and 208mL of ethanol were mixed evenly, pH was adjusted to 4-5, stirred and heated to 40°C, and stirred and reacted for 20min, stirring and heating were stopped, and the mixture was cooled to room temperature to obtain a modified solution,

[0051] B2. Add 100g of metal powder (nano-aluminum flake powder, particle size 200-300nm) into the modified solution, heat to 35°C with stirring, and keep the reaction warm for 1h. Stop heating, centrifuge, take the precipitate, wash repeatedly, and dry to obtain a texture additive.

[0052] Example 5

[0053] Preparation of polypropylene material:

[0054] The first step is to prepare the following raw materials in parts by weight: 100 parts of PP base material, 15 parts of the texture additive prepared in Example 3, 30 parts of the modified glass fiber prepared in Example 1, 0.1 parts of ultraviolet light absorber (ultraviolet light absorber UVP-327), and 0.5 parts of lubricant (polypropylene wax);

[0055] In the second step, the PP base material, texture additive, modified glass fiber, ultraviolet light absorber and lubricant are mixed, extruded through an extruder, and then irradiated to obtain metallic texture enhanced polypropylene, wherein the extrusion temperature range of the extruder is set to 195-240°C.

[0056] Example 6

[0057] Preparation of polypropylene material:

[0058] The first step is to prepare the following raw materials in parts by weight: 100 parts of PP base material, 20 parts of the texture additive prepared in Example 3, 20 parts of the modified glass fiber prepared in Example 1, 0.3 parts of ultraviolet light absorber (ultraviolet light absorber UVP-327), and 1 part of lubricant (polypropylene wax);

[0059] In the second step, the PP base material, texture additive, modified glass fiber, ultraviolet light absorber and lubricant are mixed, extruded through an extruder, and then irradiated to obtain metallic texture enhanced polypropylene, wherein the extrusion temperature range of the extruder is set to 195-240°C.

[0060] Example 7

[0061] Preparation of polypropylene material:

[0062] The first step is to prepare the following raw materials in parts by weight: 100 parts of PP base material, 25 parts of the texture additive prepared in Example 3, 15 parts of the modified glass fiber prepared in Example 1, 0.5 parts of ultraviolet light absorber (ultraviolet light absorber UVP-327), and 1.5 parts of lubricant (polypropylene wax);

[0063] In the second step, the PP base material, texture additive, modified glass fiber, ultraviolet light absorber and lubricant are mixed, extruded through an extruder, and then irradiated to obtain metallic texture enhanced polypropylene, wherein the extrusion temperature range of the extruder is set to 195-240°C.

[0064] Comparative Example 1

[0065] Preparation of polypropylene material:

[0066] Compared with Example 5, an equal amount of modified glass fiber is replaced by glass fiber, and the rest is the same.

[0067] Comparative Example 2

[0068] Preparation of polypropylene material:

[0069] Compared with Example 5, an equal amount of modified glass fiber is replaced with glass fiber modified by KH560, and the rest is the same, wherein the steps for obtaining the glass fiber modified by KH560 are as follows:

[0070] 100 g of glass fiber was ultrasonically dispersed in a mixed solution of 8 g of KH56, 15 mL of water and 45 mL of ethanol, heated to 50°C with stirring, kept stirring and reacted for 6 hours, the reaction was stopped, the precipitate was centrifuged, repeatedly washed and dried to obtain KH560 modified glass fiber.

[0071] Comparative Example 3

[0072] Compared with Example 5, an equal amount of the texture aid was replaced with metal powder, and the rest was the same.

[0073] Comparative Example 4

[0074] Compared with Example 5, the texture aid was deleted, and the rest was the same.

[0075] The polypropylene materials obtained in Examples 5-7 and Comparative Examples 1-4 were tested for physical properties, and the results are shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] It can be seen from the data in Table 1 that the composite materials obtained in Examples 5-7 of the present invention have excellent glossiness, mechanical properties and heat resistance.

[0080] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0081] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A metal texture enhanced polypropylene material, characterized in that: It includes the following raw materials in parts by weight: 100 parts of PP base material, 15-25 parts of texture additive, 15-30 parts of modified glass fiber, 0.1-0.5 parts of ultraviolet light absorber, and 0.5-1.5 parts of lubricant; The texture aid is a metal powder modified by a double-bond silane coupling agent; The modified glass fiber is a glass fiber modified by a cross-linking-promoting silane coupling agent; The cross-linking-promoting silane coupling agent is prepared by reacting an epoxy silane coupling agent, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical and dibenzoyl peroxide.

2. The metal texture enhanced polypropylene material according to claim 1, characterized in that: The double bond silane coupling agent accounts for 6-13% of the mass of the metal powder.

3. The metal texture enhanced polypropylene material according to claim 1, characterized in that: The texture aid comprises the following steps: The metal powder is added into the modified liquid, heated to the modification temperature under stirring, and kept warm for reaction until the reaction time is reached, and then the texture additive is obtained through post-treatment.

4. The metal texture enhanced polypropylene material according to claim 3, characterized in that: The modification temperature is 25-35° C., and the reaction time is 1-3 h.

5. The metal texture enhanced polypropylene material according to claim 4, characterized in that: The modified liquid is formed by hydrolyzing a double-bond silane coupling agent in a mixed solution of water and ethanol.

6. The metal texture enhanced polypropylene material according to claim 4, characterized in that: The dosage ratio of the double-bond silane coupling agent to the mixed solution is 1 g:15-20 mL; the volume ratio of water to ethanol in the mixed solution is 1:4-5.

7. The metal texture enhanced polypropylene material according to claim 4, characterized in that: The conditions of the hydrolysis reaction are: pH 4-5, reaction temperature 20-40° C., and reaction time 20-30 min.

8. The metal texture enhanced polypropylene material according to claim 1, characterized in that: The cross-linking promoting silane coupling agent comprises the following: After the epoxy silane coupling agent, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical and tetrahydrofuran are uniformly mixed, the pH is adjusted to 10-11, the mixture is heated to 60-70°C, stirred and reacted for 2-5 hours, cooled to room temperature, a tetrahydrofuran solution containing dibenzoyl peroxide is added, stirred and reacted at room temperature for 4-8 hours, and post-treated to obtain a cross-linking silane coupling agent; The molar ratio of the epoxy silane coupling agent, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl free radical and dibenzoyl peroxide is 1:1-1.2:1.1-1.

3.

9. The metal texture enhanced polypropylene material according to claim 1, characterized in that: The modified glass fiber comprises the following steps: The glass fiber is ultrasonically dispersed in a mixed solution of a cross-linking silane coupling agent, water and ethanol, heated to 50-70°C with stirring, kept stirring and reacted for 3-6 hours, the reaction is stopped, and the modified glass fiber is obtained through post-treatment.

10. The method for preparing a polypropylene material with enhanced metallic texture according to claim 1, characterized in that: include: The PP base material, texture additive, modified glass fiber, ultraviolet light absorber and lubricant are mixed, extruded and formed by an extruder to obtain metal texture enhanced polypropylene.

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