Recycled polyamide composition for steel replacement and process for the preparation thereof

Abstract

This invention discloses a recycled polyamide composition for replacing steel with plastic and its preparation method. The composition is prepared from the following components in parts by weight: 21.2-23.1 parts recycled polyamide resin, 75 parts reinforcing agent, 0.2-0.3 parts antioxidant, 0.5-1 part lubricant, 1-2 parts organic black masterbatch, and 0.2-0.5 parts flowability improver. The polyamide composition of this invention uses recycled polyamide resin as the main raw material, which is modified with a flowability improver and an organic black masterbatch, and reinforced with glass fiber. The addition of the flowability improver and organic black masterbatch lowers the crystallization temperature of the polyamide material, improves the material's flowability, and solves the problems of appearance and flowability of highly glass fiber reinforced recycled polyamide materials.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic recycled polyamide compositions, specifically a recycled polyamide composition for replacing steel with plastic and its preparation method. Background Technology

[0002] "Replacing steel with plastics" refers to using plastic materials to replace traditional steel in manufacturing. This trend is becoming increasingly common in many industries, especially in the automotive, electronics, smart home, and photovoltaic sectors. Polyamide compositions, as a high-performance plastic material, play an important role in "replacing steel with plastics" products due to their excellent mechanical properties, durability, corrosion resistance, and heat resistance.

[0003] In plastic products that replace steel with plastics, reinforcing agents are usually used to significantly improve the mechanical properties of polyamide products by increasing the rigidity and strength of the material. However, the poor compatibility between reinforcing agents and the matrix can lead to appearance problems such as increased roughness, reduced gloss, deformation, and warping of the products. How to optimize the formulation and process of polyamide compositions to improve their appearance is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present invention provides a recycled polyamide composition for steel substitution and a method for preparing the same, in order to solve the problems mentioned in the background art. By using an organic black masterbatch and a flowability improver, the flowability of the material is improved, the crystallinity is reduced, and the material has a better appearance.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] On one hand, this invention discloses a recycled polyamide composition for replacing steel with plastic, which is prepared from the following components in parts by weight:

[0007]

[0008] 0.2-0.5 parts of flowability improver.

[0009] As a further aspect of the present invention: the polyamide recycled resin is polyhexamethylene adipate recycled resin.

[0010] As a further aspect of the present invention, the reinforcing agent is chopped glass fiber.

[0011] As a further aspect of the present invention: the antioxidant is 4,4'-bis(α.α-dimethylbenzyl)diphenylamine.

[0012] As a further aspect of the present invention: the lubricant is at least one of pentaerythritol stearate and acidified polyethylene wax.

[0013] As a further aspect of the present invention: the organic black masterbatch is an aniline black masterbatch with PA6 resin as a carrier, wherein the aniline black content is 40w.

[0014] As a further aspect of the present invention: the flowability improver is a hydroxyl-terminated polyester.

[0015] On the other hand, the present invention discloses a method for preparing the above-mentioned polyamide composition for replacing steel with plastic, comprising the following steps:

[0016] S1. Mix polyamide recycled resin, antioxidant, lubricant, flow improver and organic black masterbatch evenly to obtain a mixture;

[0017] S2. The mixture is added to the main feed hopper of a twin-screw extruder, and a reinforcing agent is added to the side feed. The mixture is then melted, extruded, and pelletized to obtain a polyamide composition.

[0018] As a further aspect of the present invention: the temperature of each zone of the twin-screw extruder is 230-280℃, the main engine speed is 300-500 rpm, and the vacuum degree is ≤-0.06MPa.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] The polyamide composition of this invention uses recycled polyamide resin as the main raw material, which is modified by flowability improver and organic black masterbatch, and reinforced by glass fiber as a reinforcing agent. The addition of flowability improver and organic black masterbatch reduces the crystallization temperature of polyamide material, improves material flowability, and solves the problems of appearance and flowability of high glass fiber reinforced recycled polyamide material. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0022] 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 this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0023] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0024] Polyhexamethylene adipate regenerated resin (PA66) has a relative viscosity of 3.2.

[0025] Short-cut glass fibers, with a diameter of 10μm and a chopped length of 3mm, were purchased from Chongqing International Composite Materials Co., Ltd.

[0026] The lubricant is stearate, purchased from Struktol GmbH, Germany, with the trade name TR044.

[0027] The antioxidant was 1098, purchased from BASF, Germany.

[0028] Organic black mother-of-pearl N54 / 1033, purchased from Gore-Likes, UK;

[0029] C100, a flowability improver, was purchased from Zhuhai Chenyuan Polymer.

[0030] It is understood that the above-mentioned raw materials and reagents are merely examples of some specific embodiments of the present invention, making the technical solution of the present invention clearer, and do not mean that the present invention can only use the above-mentioned reagents. The specific scope shall be determined by the claims. In addition, unless otherwise specified, "parts" in the examples and comparative examples refer to parts by weight.

[0031] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0032] Example 1

[0033] S1, add 23.1 parts of PA66 recycled resin, 0.2 parts of antioxidant, 0.5 parts of lubricant, 0.2 parts of flow improver and 1 part of organic black masterbatch to a drum mixer and premix for 10 minutes to obtain a mixture;

[0034] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. After melting, extrusion and pelletizing, a recycled polyamide composition with good appearance for plastic substitution for steel is obtained.

[0035] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0036] Example 2

[0037] S1, add 22.1 parts of PA66 recycled resin, 0.2 parts of antioxidant, 0.5 parts of lubricant, 0.2 parts of flow improver and 2 parts of organic black masterbatch to a drum mixer and premix for 10 minutes to obtain a mixture;

[0038] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. After melting, extrusion and pelletizing, a recycled polyamide composition with good appearance for plastic substitution for steel is obtained.

[0039] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0040] Example 3

[0041] S1, add 23 parts of PA66 recycled resin, 0.2 parts of antioxidant, 0.5 parts of lubricant, 0.3 parts of flow improver and 1 part of organic black masterbatch to a drum mixer and premix for 10 minutes to obtain a mixture;

[0042] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. After melting, extrusion and pelletizing, a recycled polyamide composition with good appearance for plastic substitution for steel is obtained.

[0043] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0044] Example 4

[0045] S1, add 21.3 parts of PA66 recycled resin, 0.3 parts of antioxidant, 1 part of lubricant, 0.3 parts of flow improver and 2 parts of organic black masterbatch to a drum mixer and premix for 10 minutes to obtain a mixture;

[0046] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. After melting, extrusion and pelletizing, a recycled polyamide composition with good appearance for plastic substitution for steel is obtained.

[0047] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0048] Example 5

[0049] S1, add 21.7 parts of PA66 recycled resin, 0.3 parts of antioxidant, 0.5 parts of lubricant, 0.4 parts of flow improver and 2 parts of organic black masterbatch to a drum mixer and premix for 10 minutes to obtain a mixture;

[0050] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. After melting, extrusion and pelletizing, a recycled polyamide composition with good appearance for plastic substitution for steel is obtained.

[0051] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0052] Comparative Example 1

[0053] S1, add 23.1 parts of PA66 recycled resin, 0.2 parts of antioxidant, 0.5 parts of lubricant and 1.2 parts of organic black masterbatch to a drum mixer and premix for 10 minutes to obtain a mixture;

[0054] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. The mixture is then melted, extruded, and pelletized to obtain a recycled polyamide composition for plasticizing steel.

[0055] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0056] Comparative Example 2

[0057] S1, add 23.1 parts of PA66 recycled resin, 0.2 parts of antioxidant, 0.5 parts of lubricant, and 1.2 parts of flowability improver to a drum mixer and premix for 10 minutes to obtain a mixture.

[0058] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. The mixture is then melted, extruded, and pelletized to obtain a recycled polyamide composition for plasticizing steel.

[0059] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0060] Comparative Example 3

[0061] S1, add 24.3 parts of PA66 recycled resin, 0.2 parts of antioxidant, and 0.5 parts of lubricant to a drum mixer and premix for 10 minutes to obtain a mixture;

[0062] S2, the mixture is fed into a twin-screw extruder through the main feed hopper, and 75 parts of chopped glass fiber are added at the side feed point. The mixture is then melted, extruded, and pelletized to obtain a recycled polyamide composition for plasticizing steel.

[0063] The temperatures of each zone in the twin-screw extruder barrel are 230℃, 250℃, 260℃, 280℃, 275℃, 265℃, 265℃, 265℃, and 275℃, respectively. The main extruder speed is 400 rpm, and the vacuum degree is ≤-0.06MPa.

[0064] The recycled polyamide compositions obtained in the examples and comparative examples were subjected to performance tests. The test items and results are shown in Table 1. Among them, the appearance was evaluated by using an injection molding color swatch to assess the state of exposed floating fibers. The grades 0-5 represent the appearance grades of the products, with higher values ​​indicating less exposed floating fibers. The crystallization peak temperature was detected by differential scanning calorimetry (DSC).

[0065] Table 1

[0066]

[0067] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0068] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A recycled polyamide composition for replacing steel with plastic, characterized in that, It is prepared from the following components in parts by weight: 21.2-23.1 parts of recycled polyamide resin 75 parts of reinforcing agent Antioxidant 0.2-0.3 parts, Lubricant 0.5-1 part 1-2 parts organic black masterbatch 0.2-0.5 parts of flowability improver; The flowability improver is hydroxyl-terminated polyester C100; The recycled polyamide resin is recycled polyhexamethylene adipate resin; the reinforcing agent is chopped glass fiber. The organic black masterbatch is an aniline black masterbatch with PA6 resin as a carrier, wherein the aniline black content is 40w.

2. The recycled polyamide composition for replacing steel with plastic according to claim 1, characterized in that, The antioxidant is 4,4'-bis(α.α-dimethylbenzyl)diphenylamine.

3. The recycled polyamide composition for replacing steel with plastic according to claim 1, characterized in that, The lubricant is at least one of pentaerythritol stearate and acidified polyethylene wax.

4. A method for preparing a polyamide composition for replacing steel with plastic as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Mix polyamide recycled resin, antioxidant, lubricant, flow improver and organic black masterbatch evenly to obtain a mixture; S2. The mixture is added to the main feed hopper of a twin-screw extruder, and a reinforcing agent is added to the side feed. The mixture is then melted, extruded, and pelletized to obtain a polyamide composition.

5. The preparation method according to claim 4, characterized in that, The temperature of each zone of the twin-screw extruder is 230-280℃, the main engine speed is 300-500 rpm, and the vacuum degree is ≤-0.06MPa.

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