Polypropylene denim cotton spraying-free material and preparation method thereof

Abstract

The invention belongs to a material modification technology, and relates to modified polypropylene, in particular to a polypropylene denim cotton spraying-free material and a preparation method thereof. The polypropylene denim cotton spraying-free material is obtained by mixing polypropylene, a scratch-resistant agent, a filler, a flexibilizer, denim cotton, denim fluff and an auxiliary agent. According to the automobile interior decoration, an automobile is more attractive, meanwhile, the automobile is more practical, and in the automobile interior decoration, the natural texture imitating technology is widely applied. In the existing production, the automotive trim, such as a door post plate, with the appearance close to the effect of jeans is produced by mould pressing of wood chips imitating jean cotton cloth or film coating and injection molding in a low-pressure mould and then paint spraying treatment. According to the invention, polypropylene is used as a main material for the first time, the automotive interior plastic with the appearance close to the effect of jeans is prepared through formula design and conventional injection molding, the process is simple, the color requirement can be met without spraying, and particularly recycled jean cotton can be adopted.

Description

Technical Field

[0001] This invention pertains to material modification technology and relates to a modified polypropylene, specifically a polypropylene denim cotton coating-free material and its preparation method. Background Technology

[0002] Car interiors enhance both the aesthetics and practicality of vehicles, and the use of natural texture techniques is widespread. For interior materials requiring an appearance similar to denim jeans, the current industry process involves molding imitation denim cotton fabric from wood chips or using low-pressure in-mold coating, followed by painting. The drawbacks are: complex processing, low yield rate, and high cost. Summary of the Invention

[0003] Current production methods typically involve molding wood chips to resemble denim fabric or low-pressure in-mold coating, followed by painting to produce automotive interior trim, such as door pillars, that mimics the look of jeans. This invention, for the first time, uses polypropylene as the main material. Through formulation design, it achieves a conventional injection molding process for automotive interior plastics that closely resemble jeans. This not only simplifies the process but also eliminates the need for painting to achieve the desired color, and importantly, it allows the use of recycled denim.

[0004] The present invention adopts the following technical solution.

[0005] A polypropylene denim cotton coating-free material includes polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives.

[0006] In this invention, the mass ratio of polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives is (60-90): (3-6): (15-25): (2-6): (1-5): (1.5-2.5): (1-2).

[0007] Preferably, the mass ratio of polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives is (70-80): (4-6): (18-23): (3-6): (2-4): (1.6-2.2): (1-2).

[0008] In this invention, polypropylene includes copolymer polypropylene and homopolymer polypropylene; preferably, the mass ratio of copolymer polypropylene to homopolymer polypropylene is (1-2):1, such as 1.2:1, 1.5:1, 1.8:1 or any ratio within the range.

[0009] In this invention, the scratch-resistant agent is a wax-based scratch-resistant agent.

[0010] In this invention, the filler includes talc powder.

[0011] In this invention, the toughening agent includes a vinyl olefin copolymer.

[0012] In this invention, denim fleece includes black denim fleece, blue denim fleece, and red denim fleece; preferably, the mass ratio of black denim fleece, blue denim fleece, and red denim fleece is (0.5~1.5):(0.5~1.5):(0.5~1), and more preferably, the mass ratio of black denim fleece, blue denim fleece, and red denim fleece is (0.8~1.1):(0.9~1.0):(0.7~0.8).

[0013] In this invention, the additives include processing aids and pigments; preferably, the mass ratio of processing aids to pigments is (0.5-1.0):(0.5-0.9), and more preferably, the mass ratio of processing aids to pigments is (0.7-1.0):(0.6-0.9).

[0014] In this invention, the processing aids include antioxidants, weathering agents, and lubricants; preferably, the mass ratio of antioxidants, weathering agents, and lubricants is (0.1-0.5):(0.1-0.5):(0.1-0.5), and more preferably, the mass ratio of antioxidants, weathering agents, and lubricants is (0.1-0.3):(0.2-0.4):(0.2-0.4).

[0015] This invention discloses a method for preparing the aforementioned polypropylene denim cotton paint-free material, comprising the following steps: mixing polypropylene, a scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives to obtain the polypropylene denim cotton paint-free material. This invention, through material design, is the first to prepare a modified PP plastic with a denim cotton-like appearance, saving costs, simplifying the operation (one-time injection molding), and allowing the use of recycled denim cotton, making it low-carbon and environmentally friendly.

[0016] In this invention, the mixing method is a conventional technique, which can melt and mix polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives to obtain polypropylene denim cotton paint-free material.

[0017] The specific equipment, apparatus, and method for achieving melt mixing are conventional technologies, such as using an extruder to melt mix polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives to obtain polypropylene denim cotton paint-free material.

[0018] This invention discloses the application of the above-mentioned polypropylene denim cotton paint-free material in the preparation of denim-like appearance materials.

[0019] This invention discloses the application of the above-mentioned polypropylene denim cotton paint-free material in the preparation of automotive parts.

[0020] This invention discloses the application of the above-mentioned polypropylene denim cotton paint-free material in the preparation of automotive materials that resemble denim jeans.

[0021] This invention discloses the application of the above-mentioned polypropylene denim cotton paint-free material in the preparation of automotive interior materials that resemble denim jeans.

[0022] This invention discloses an automotive component material, including the aforementioned polypropylene denim cotton paint-free material.

[0023] Specifically, automotive component materials are prepared using the aforementioned polypropylene denim cotton paint-free material or a substance including the aforementioned polypropylene denim cotton paint-free material as raw materials; preferably, the automotive component materials are automotive interior materials.

[0024] This invention is the first to combine denim cotton and denim fleece in a specific ratio with polypropylene as the main material, unexpectedly achieving an appearance similar to jeans, with a beautiful surface, no need for painting, and low cost. Attached Figure Description

[0025] Figure 1 This is the finished product of Example 2.

[0026] Figure 2 The photo shows a blackened surface. Detailed Implementation

[0027] Existing technologies using denim cotton as a material in automotive interior materials such as felt sheets, sound-absorbing felt, sound-absorbing cotton, and sound-insulating felt are all fiber products; there are no reports of using denim cotton in plastic products. Furthermore, existing automotive interior materials that resemble denim jeans are obtained by molding imitation denim cotton fabric from wood chips or through low-pressure in-mold injection molding, followed by painting. This invention overcomes the biases of existing technologies by designing a modified PP plastic with a denim cotton-like appearance for the first time. This saves costs, is simple to operate (one-time injection molding), can use recycled denim cotton, and is low-carbon and environmentally friendly.

[0028] This invention uses a conventional screw extruder to melt and mix polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives to obtain a polypropylene denim cotton coating-free material.

[0029] In this invention, the formula is as follows, by mass percentage: Copolymer PP: 40-50% Homopolymer PP: 25-35% Scratch-resistant agent: 3-6% Talc: 20-25% Denim cotton: 1-5% Toughening agent: 2-6% Black denim fleece: 0.5-1% Blue denim fleece: 0.5-1% Red denim fleece: 0.5-0.8% Processing aids: 0.5-1% Pigment: 0.4-1.0% The following specific experiments illustrate the technological advancements of this invention. The raw materials used are existing products, and the specific preparation operations and performance testing employ conventional techniques. Specifically: Copolymer PP: Melt flow rate (230℃, 2.16kg): 32g / 10min, EP229S; Homopolymer PP: Melt flow rate (230℃, 2.16kg): 17g / 10min, H870F; Scratch-resistant agent: Wax-based modifier, 4201; Talc powder: 2500 mesh; Denim Cotton 1: Jiangsu Sunshine Group, natural white (pure cotton); Denim Cotton 2: Guangdong Esquel Textile Co., Ltd., R-311F (Polyester Cotton); Toughening agent: Vinyl olefin copolymer, DF640; Black denim fleece: 2cm in length; Blue denim fleece: 2cm in length; Red denim fleece: 2cm in length; Other processing aids: polyhedral hindered phenolic antioxidant 1010, phosphite auxiliary antioxidant 168, both used in the same amount; light stabilizer weathering agent UV234; metal soap lubricant - calcium stearate (external lubricant), fatty acid - stearic acid (internal lubricant), both used in the same amount. Pigments: Metal salt pigment - ultramarine M83, carbon black powder - M46, both used in the same amount. Example

[0030] Table 1. Comparative and Example Formulations (Kg) and Performance Test Results

[0031] Table 1 shows the formulation of the comparative example. The processing method is conventional technology, which is briefly described as follows: In a twin-screw extruder, denim fleece, lubricant, and denim cotton are mixed evenly and fed in from the side feed; other raw materials are mixed evenly and fed in from the main feed. The speed is 200 rpm, and granulation is carried out at a granulation temperature of 150-190℃.

[0032] Table 1 shows the test results of the comparative examples. Some experiments were not fully tested; only key performance indicators were examined. The material testing methods were conventional techniques, which are briefly described below: Appearance requirements: Test samples will be injection molded using a high-gloss mold (injection temperature 200℃, mold temperature 60℃). The appearance should resemble denim jeans, with a smooth denim nap and no blackening. Samples will be prepared using a magnifying glass and a colorimeter in an injection molding machine with a high-gloss mold. The appearance grade will be determined visually. Grade I: Visually black in color, with denim fleece clumping together in black spots, unqualified; Grade II: The color is slightly blackish, and the denim fleece is clumped together in black spots, which is unacceptable. Grade III: Visually normal color, imitation denim effect, no clumping of denim fleece on the surface, natural and smooth, qualified.

[0033] Impact strength: Under normal temperature conditions, according to standard ISO 179-1eA, the required value is ≥6 kJ / m. 2 ; Scratch resistance: According to Q / JLY J7110279 standard, method A, 10N load, scratch-resistant head diameter: 1mm, speed: 1000±50mm / min, evaluate the degree of whitening, requiring ΔL≤1.5.

[0034] Flexural modulus: At room temperature of 23±℃, the required value is ≥1800MPa according to standard ISO 178.

[0035] The embodiments of this invention are similar in appearance to jeans, with a blue base color, meeting production requirements. For example, the conventionally produced product of embodiment 2 is shown below. Figure 1 Two products were compared, one using a common type of denim material on the market; the other, comparison 3, was prepared using a high-gloss mold and blackened, see [reference needed]. Figure 2 .

[0036] Comparative Example 5 Based on Example 2, using zero (i.e., omitting denim fleece), one or two of the following: black denim fleece, blue denim fleece, and red denim fleece, with the rest remaining the same, the resulting particle injection molded part does not resemble the appearance of jeans and cannot replace the existing spray-painted injection molded part.

[0037] Comparative Example 6 Based on Example 1, the particles prepared using only 75 kg of copolymer polypropylene or only 75 kg of homopolymer polypropylene cannot meet the above mechanical property requirements.

[0038] It is generally believed that the addition of denim cotton and denim fleece will lead to a significant reduction in material properties, especially mechanical properties. This invention uses homopolymer PP combined with copolymer PP as the main resin, and adds talc powder and an appropriate amount of toughening agent. Its bending and impact properties are not reduced. Even with the addition of denim cotton and denim fleece, the impact and modulus are qualified, thus making this invention a basis for replacing the existing spray-painted injection molded parts.

[0039] Existing technologies use denim cotton as a material for automotive interior materials such as felt sheets, sound-absorbing felt, sound-absorbing cotton, and sound-insulating felt. These are all fiber products, and there are no reports of using denim cotton in plastic products. Furthermore, existing automotive interior materials that resemble denim jeans are obtained by molding imitation denim cotton fabric from wood chips or through low-pressure in-mold injection molding, followed by painting. This invention overcomes the biases of existing technologies by designing a modified PP plastic with a denim cotton-like appearance for the first time. This saves costs, is simple to operate (one-time injection molding), and can use recycled denim cotton, making it low-carbon and environmentally friendly. This invention unexpectedly produces automotive parts with a denim cotton-like appearance using plastic, especially low-cost and common polypropylene. This is a pioneering technology in this field, solving the technical problem that existing technologies can only obtain automotive interior materials with a denim cotton-like appearance through wood chips or low-pressure in-mold injection molding followed by painting. It has the significant advantages of advancing technology in this field and providing new technical ideas for the industry.

Claims

1. A polypropylene denim cotton coating-free material, comprising polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives.

2. The polypropylene denim cotton paint-free material according to claim 1, characterized in that, The mass ratio of polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives is (60-90): (3-6): (15-25): (2-6): (1-5): (1.5-2.5): (1-2).

3. The polypropylene denim cotton paint-free material according to claim 1, characterized in that, Polypropylene includes copolymer polypropylene and homopolymer polypropylene; fillers include talc; denim fleece includes black denim fleece, blue denim fleece, and red denim fleece; additives include processing aids and pigments.

4. The polypropylene denim cotton paint-free material according to claim 3, characterized in that, The mass ratio of black denim fleece, blue denim fleece, and red denim fleece is (0.5~1.5):(0.5~1.5):(0.5~1).

5. A method for preparing the polypropylene denim cotton paint-free material according to any one of claims 1 to 4, comprising the following steps: mixing polypropylene, scratch-resistant agent, filler, toughening agent, denim cotton, denim fleece, and additives to obtain the polypropylene denim cotton paint-free material.

6. The application of the polypropylene denim cotton paint-free material according to any one of claims 1 to 4 in the preparation of denim-like appearance materials.

7. The application of the polypropylene denim cotton paint-free material according to any one of claims 1 to 4 in the preparation of automotive parts.

8. The application of the polypropylene denim cotton paint-free material according to any one of claims 1 to 4 in the preparation of automotive materials that resemble denim jeans.

9. The application of the polypropylene denim cotton paint-free material according to any one of claims 1 to 4 in the preparation of automotive interior materials with a denim-like appearance.

10. An automotive component material, the raw materials for which are prepared include the polypropylene denim cotton paint-free material as described in any one of claims 1 to 4.

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