PBT alloy material, preparation method and application thereof

Abstract

The present application relates to a kind of PBT alloy material and its preparation method and application, PBT alloy material includes the following components and weight content: PBT resin 60-85 parts, ABS resin 10-20 parts, chopped glass fiber 5-10 parts, surface modifier 5-10 parts, other auxiliary agent 0.1-1 part.Preparation method is stirred uniformly in mixing barrel to each component, extrusion granulation is carried out by double screw extruder, obtains a kind of PBT alloy material for nano injection molding process.Compared with prior art, the material of the present application has strong bonding force with metal base material, is not easy to crack, can be applied to nano injection molding process, can be widely applied to smart phone back shell and other products, while low cost, has broad application prospect.

Description

Technical Field

[0001] This invention relates to the fields of polymer blending and polymer molding and processing technology, specifically to a PBT alloy material and its preparation method and application. Background Technology

[0002] PBT resin, or polybutylene terephthalate, possesses excellent high-temperature resistance and chemical corrosion resistance, and is commonly used in automotive interior and exterior trim, medical device housings, and other components. In mobile phone products, because metal casings can shield signal transmission, plastic components are typically required as signal transmission ports. Common plastics are bonded to the casing through methods such as inserts, adhesives, and nano-injection molding to form the phone's back cover. Among these processes, nano-injection molding, utilizing the riveting effect of nanopores, provides the strongest bonding force and best adhesion between plastic and metal materials, making it a primary direction for future application development. However, nano-injection molding requires good compatibility between the plastic material and the metal substrate, enabling the plastic material to penetrate into the nanopores of the metal component to achieve this riveting effect. Ordinary plastic materials, due to their low polarity, have a significant difference in polarity compared to the metal substrate, resulting in poor compatibility. When compatibility is poor, the plastic material cannot effectively enter the nanopores, significantly reducing the bonding strength between the two. Summary of the Invention

[0003] The purpose of this invention is to provide a PBT alloy material, its preparation method, and its application, which can be applied to nano-injection molding processes.

[0004] The objective of this invention can be achieved through the following technical solution: a PBT alloy material, comprising the following components and their weight percentages:

[0005]

[0006] Preferably, the PBT alloy material comprises the following components and their weight percentages:

[0007]

[0008] Preferably, the intrinsic viscosity η of the PBT resin at room temperature is 0.8-1.2.

[0009] Preferably, the relative molecular weight of the ABS resin is 80,000-150,000.

[0010] Preferably, the ABS resin contains 5-30 wt% rubber, 10-30 wt% acrylonitrile, and 40-70 wt% styrene.

[0011] Preferably, the length of the chopped glass fiber is 5 to 50 mm.

[0012] Preferably, the diameter of the chopped glass fiber is 10-15 nm.

[0013] Preferably, the surface modifier is AS-GMA, wherein the GMA content is not less than 0.5 wt%. When the GMA content is too low, the material has poor polarity and poor compatibility with the metal substrate.

[0014] Preferably, the surface modifier is AS-GMA, wherein the GMA content does not exceed 2 wt%. If the GMA content is too high, the material will cross-link, resulting in low impact strength.

[0015] Preferably, the surface modifier is AS-GMA, wherein the GMA content is 0.5-2 wt%.

[0016] In AS-GMA, AS represents the A and S components in ABS, which can also be written as SAN.

[0017] Preferably, the other additives include antioxidants, ultraviolet absorbers, and lubricants.

[0018] A method for preparing the above-mentioned PBT alloy material specifically includes the following steps:

[0019] (a) Prepare the ingredients according to the formula, premix each component in the mixing tank, and set aside for use after mixing evenly;

[0020] (b) The mixture obtained in step (a) is blended, melted, extruded and granulated using a twin-screw extruder to obtain PBT alloy material.

[0021] Preferably, the barrel temperature of the twin-screw extruder is 160-250℃, the screw speed is 200-600rpm, and the pressure is 1.5-2.5MPa.

[0022] An application of the above-mentioned PBT alloy material is to use the PBT alloy material in nano-injection molding.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. This invention reduces the overall linear expansion coefficient of the material by adding chopped glass fibers, ensuring that the shrinkage rates are similar when the material is bonded to the metal substrate, thus preventing cracking. Simultaneously, a surface modifier is added to increase the material's polarity, enhancing its compatibility and adhesion to the metal substrate. Because the polarity of the surface modifier differs significantly from that of PBT material, a second component, ABS, is added as a mixed substrate to improve the compatibility between the surface modifier and the substrate.

[0025] 2. The chopped glass fibers of this invention have a high aspect ratio, which effectively improves post-shrinkage of the material, while also exhibiting good compatibility with the substrate. The chopped glass fibers' excellent ability to prevent material shrinkage allows the post-shrinkage of the material to approach that of metallic materials, thereby improving the bonding strength between the material and the metallic material.

[0026] 3. After injection molding, the material shrinkage is small, which reduces the dimensional difference between the material and the metal.

[0027] 4. The material of this invention has strong adhesion to the metal substrate, is not easy to crack, can be applied to nano-injection molding process, and can be widely used in products such as smartphone back covers. At the same time, it is inexpensive and has broad application prospects. Detailed Implementation

[0028] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0029] The raw materials used in the following examples and comparative examples are as follows: PBT resin with a viscosity of 1.0, produced by Changchun Chemical; ABS resin using ABS8391, produced by Gaoqiao Petrochemical; chopped glass fibers with a length of 5-50 mm and a diameter of 13 nm, produced by Jushi Group; surface modifier using SAG001 with a GMA content of 1 wt%, produced by Rizhisheng Fine Chemicals; other additives include antioxidant B900 (Ciba Fine Chemicals), ultraviolet absorber Tinuvins UVP (Ciba), and lubricant barium stearate, with a weight ratio of 1:1:1 for each additive.

[0030] After drying the PBT alloy materials prepared in Examples 1-4 and Comparative Examples 1-3 at 80°C for 5 hours, their physical properties were tested using injection molding test strips according to ASTM standards. The metal bonding strength test method is as follows: 1) The metal part (aluminum insert) is pretreated by chemical etching to create nano- and micro-sized pores on the metal surface; 2) Within the effective treatment time frame, plastic is injection molded onto the pretreated aluminum insert; 3) The bonding strength is measured by recording the force when the molded part is pulled to the breaking point on a standard tensile testing machine.

[0031] 4) Calculate the bond strength by dividing the bonding force by the bond area, expressed in MPa. See Table 1 for specific test standards and conditions.

[0032] Table 1

[0033]

[0034]

[0035] Example 1

[0036] This embodiment provides a PBT alloy material for nano-injection molding and its preparation method, the specific steps of which are as follows:

[0037] (1) Weigh each component according to the weight ratio in Table 2;

[0038] (2) Prepare the ingredients according to the formula, premix each component in the mixing tank, mix evenly and set aside for use;

[0039] (3) The mixture obtained in step (2) is blended, melted and extruded into granules by a twin-screw extruder to obtain the product.

[0040] The above-mentioned well-mixed mixture is fed into the main feed of a twin-screw extruder, and after melt extrusion, cooling, drying, and pelletizing, a sample is obtained. The twin-screw extruder is a co-rotating twin-screw extruder with a screw length-to-diameter ratio of 40:1. The screw barrel is equipped with a vacuum extraction device and a temperature control device. The temperature of the feeding section of the twin-screw extruder is 160℃, the temperature of the plasticizing section is 220℃, the temperature of the homogenizing section is 250℃, the screw speed is 400 rpm, and the pressure is 2.5 MPa.

[0041] Example 2

[0042] This embodiment provides a PBT alloy material for nano-injection molding process and its preparation method. The weight ratio of raw materials is shown in Table 2, and the preparation method is the same as in Embodiment 1.

[0043] Example 3

[0044] This embodiment provides a PBT alloy material for nano-injection molding process and its preparation method. The weight ratio of raw materials is shown in Table 2, and the preparation method is the same as in Embodiment 1.

[0045] Example 4

[0046] This embodiment provides a PBT alloy material for nano-injection molding process and its preparation method. The weight ratio of raw materials is shown in Table 2, and the preparation method is the same as in Embodiment 1.

[0047] Comparative Example 1

[0048] This comparative example provides a PBT alloy material for nano-injection molding process and its preparation method. The weight ratio of raw materials is shown in Table 2, and the preparation method is the same as in Example 1.

[0049] Comparative Example 2

[0050] This comparative example provides a PBT alloy material for nano-injection molding process and its preparation method. The weight ratio of raw materials is shown in Table 2, and the preparation method is the same as in Example 1.

[0051] Comparative Example 3

[0052] This comparative example provides a PBT alloy material for nano-injection molding process and its preparation method. The weight ratio of raw materials is shown in Table 2, and the preparation method is the same as in Example 1.

[0053] Table 2

[0054]

[0055] The physical properties and metal bonding strength test results of the PBT alloy materials in Examples 1-4 and Comparative Examples 1-3 are shown in Table 3 below.

[0056] Table 3

[0057]

[0058] The test results of Examples 1-4 and Comparative Examples 1-3 in Table 3 show that the addition of chopped glass fibers reduces the linear expansion coefficient of the material, making the shrinkage rate similar when the material is bonded to the metal substrate, thus preventing cracking. Simultaneously, the addition of a surface modifier increases the material's polarity, enhancing its compatibility and bonding strength with the metal substrate. Because the polarity of the surface modifier differs significantly from that of PBT material, a second component, ABS, is added as a mixed substrate to improve the compatibility between the surface modifier and the substrate. The material of this invention exhibits strong bonding strength with the metal substrate, is not prone to cracking, and can be applied to nano-injection molding processes.

[0059] This invention has many specific applications, and the above description is only a preferred embodiment. It should be noted that the above embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention. For those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A PBT alloy material, characterized in that, Includes the following components and their weight percentages: 60-85 parts of PBT resin, 10-20 parts of ABS resin 5-10 chopped glass fibers 5-10 parts of surface modifier, Other adjuvants: 0.1-1 part; The ABS resin has a relative molecular weight of 80,000-150,000, and contains 5-30 wt% rubber, 10-30 wt% acrylonitrile, and 40-70 wt% styrene. The surface modifier is AS-GMA, wherein the GMA content is not less than 0.5 wt% and not more than 2 wt%.

2. The PBT alloy material according to claim 1, characterized in that, The intrinsic viscosity η of the PBT resin at room temperature is 0.8-1.

2.

3. The PBT alloy material according to claim 1, characterized in that, The length of the chopped glass fiber is 5 to 50 mm.

4. The PBT alloy material according to claim 1, characterized in that, The other additives include antioxidants, ultraviolet absorbers, and lubricants.

5. A method for preparing the PBT alloy material according to any one of claims 1 to 4, characterized in that, Specifically, the following steps are included: (a) Prepare the ingredients according to the formula, premix each component, mix them evenly and set aside for use; (b) The mixture obtained in step (a) is blended, melted, extruded and granulated using a twin-screw extruder to obtain PBT alloy material.

6. The method for preparing PBT alloy material according to claim 5, characterized in that, The twin-screw extruder has a barrel temperature of 160-250℃, a screw speed of 200-600rpm, and a pressure of 1.5-2.5 MPa.

7. The application of the PBT alloy material according to any one of claims 1 to 4, characterized in that, The PBT alloy material is used for nano-injection molding.

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