Hydrolysis-resistant reinforced PBT material and preparation method thereof

Abstract

The invention discloses a hydrolysis-resistant reinforced PBT (polybutylene terephthalate) material, which is prepared from the following components in percentage by mass: 65-75% of PBT; 20%-30% of glass fiber; 1%-6% of a toughening agent; 1%-3% of a hydrolysis-resistant auxiliary agent; and 1%-2% of a processing aid. The invention has the following advantages: the hydrolysis assistant and the hydrolysis stabilizer are added to consume carboxyl generated by hydrolysis and slow down the acidic hydrolysis speed of PBT polyester so as to improve the hydrolysis resistance of PBT polyester; the hydrolysis-resistant chemical additive can perform a targeted degradation protection reaction on the PBT polyester and prevent most of thermal degradation, thermal oxidative degradation and light degradation phenomena; the EBA and GMA terpolymer and the ethylene / GMA copolymerization can improve the impact strength of the PBT modified material. Meanwhile, the functional group GMA reacts with the terminal carboxyl group of PBT to seal the end, so that the concentration of the terminal carboxyl group is reduced. Initiation points of hydrolysis reaction can be reduced from the source, and the hydrolysis resistance of PBT is remarkably improved; special hydrolysis-resistant glass fibers are used; by using the flat glass fiber, the warping is reduced while the hydrolysis resistance is provided.

Description

Technical Field

[0001] The invention belongs to the field of modified polyester materials, and particularly relates to a hydrolysis-resistant reinforced PBT material and a preparation method thereof. Background Art

[0002] PBT is a crystalline linear saturated polyester made by polycondensation of terephthalic acid (PTA) or dimethyl terephthalate (DMT) and 1,4-butanediol (BDO). Its symmetrical molecular structure enables close stacking, has high crystallinity, and can crystallize quickly at low temperatures; it has the advantages of moisture resistance, wear resistance, oil resistance, and low creep. However, PBT also has defects such as easy combustion, easy warping of thin-walled parts, and poor hydrolysis resistance. In order to solve the above problems, our company has developed a material that is hydrolysis-resistant and has enhanced PBT's excellent performance.

[0003] Characteristics of hydrolysis-resistant reinforced PBT

[0004] 1. Excellent hydrolysis resistance: The specially treated hydrolysis-resistant reinforced PBT material can still maintain stable performance in high temperature and high humidity environment, and is not prone to hydrolysis reaction leading to a decrease in mechanical properties.

[0005] 2. Good mechanical strength and heat resistance: By adding reinforcing materials such as glass fiber, its mechanical strength and rigidity can be significantly improved, while its heat resistance can be improved. This enables the material to withstand various impacts and high temperature environments during vehicle driving, reducing the risk of failure.

[0006] 3. Easy to process and shape:

[0007] It has good processing performance and can quickly produce parts with complex shapes and high precision through processes such as injection molding.

[0008] 4. Wide range of applications:

[0009] Widely used in electronic and electrical equipment, automotive industry, aerospace field, industrial equipment and other fields Summary of the invention

[0010] The purpose of the present invention is to provide a hydrolysis-resistant reinforced PBT material and a preparation method thereof, which can increase the hydrolysis resistance of the material while maintaining the mechanical properties of the material, thereby broadening the application scope of the material.

[0011] The objective of the present invention is achieved through the following technical solutions:

[0012] A hydrolysis-resistant reinforced PBT material is made of the following components in mass fraction:

[0013]

[0014] In the above hydrolysis-resistant reinforced PBT material,

[0015] The viscosity of the PBT is between 1.0 and 1.2.

[0016] The glass fiber is one or more of hydrolysis-resistant glass fiber and flat glass fiber with a fiber diameter of 10-20 μm and a short cut length of 3-5 mm.

[0017] The toughening agent is one or more of ethylene / GMA copolymer, EBA and GMA terpolymer.

[0018] The anti-hydrolysis aid is one or more of acrylic epoxy compounds, EDTA (ethylenediaminetetraacetic acid), calcium zinc stabilizers, composite acid stabilizers, aluminum oxide stabilizers, organic tin stabilizers, organic germanium stabilizers, organic barium stabilizers and carbodiimide anti-hydrolysis agents.

[0019] The preparation method of the hydrolysis-resistant reinforced PBT material is as follows: PBT resin, glass fiber, hydrolysis-resistant additive, and processing additive are uniformly mixed, and then fed into a high-shear twin-screw extruder for melt extrusion and granulation. The glass fiber port of the twin-screw extruder is in the sixth zone, and the processing temperature from the feed section to the die is: the temperature of zones 1 to 4 is 230 to 245°C, the temperature of zones 5 to 9 is 200 to 230°C, and the die temperature is 240 to 250°C.

[0020] The advantages of the present invention are:

[0021] 1. Adding hydrolysis aids and hydrolysis stabilizers will consume the carboxyl groups produced by hydrolysis, slow down the acidic hydrolysis rate of PBT polyester, and thus improve its hydrolysis resistance; hydrolysis-resistant chemical additives can play a targeted degradation protection reaction on PBT polyester, preventing most thermal degradation, thermal oxidation degradation and photodegradation phenomena;

[0022] 2: The terpolymer of EBA and GMA (AX8750T) and ethylene / GMA copolymer (AX8850) can improve the impact strength of PBT modified materials. At the same time, its functional group GMA reacts with the terminal carboxyl group of PBT to cap the end and reduce the concentration of the terminal carboxyl group. It can reduce the initiation point of the hydrolysis reaction from the source and significantly improve the hydrolysis resistance of PBT;

[0023] 3: Use special hydrolysis-resistant glass fiber;

[0024] 4: Use flat glass fiber to provide hydrolysis resistance while reducing warping;

[0025] 5: The glass fiber port is set in the sixth zone of the twin-screw extruder to ensure the length and distribution of the glass fiber and improve the performance of the reinforced PBT material. DETAILED DESCRIPTION

[0026] Table 1 Weight parts of raw materials in Examples 1 to 6 and Comparative Examples 1-2

[0027]

[0028]

[0029] The method for preparing a hydrolysis-resistant reinforced PBT material of the present invention is characterized in that PBT resin, glass fiber, hydrolysis-resistant additive, and processing additive are mixed uniformly, and then fed into a high-shear twin-screw extruder for melt extrusion and granulation. The glass fiber port of the twin-screw extruder is in the sixth zone, and the processing temperature from the feed section to the die is: the temperature of zones 1 to 4 is 230 to 245°C, the temperature of zones 5 to 9 is 200 to 230°C, and the die temperature is 240 to 250°C. The weight portions of each raw material are shown in Table 1, and the product is prepared by an injection molding machine to prepare test specimens, and the test results are shown in Table 2.

[0030] The tensile strength is tested according to the method specified in ISO 527, with a test speed of 50 mm / min; the flexural strength is tested according to the method specified in ISO178, with a test speed of 2 mm / min; the notched impact is tested according to the method specified in ISO179-1eA simply supported beam, and the heat deformation temperature is tested according to the method specified in ISO 75.

[0031] Hydrolysis resistance test conditions: 85℃*1000h*85% humidity

[0032] The test data is shown in the following table:

[0033] Table 2 Performance test results of Examples 1 to 6 and Comparative Examples 1-2

[0034]

[0035] It can be seen from Examples 1-6 and Comparative Example 1 that the compounding of hydrolysis-resistant glass fiber, hydrolysis-resistant additive and toughening agent can greatly improve the retention rate of notched impact strength after hydrolysis resistance.

Claims

1. A hydrolysis-resistant reinforced PBT material, characterized in that: Made of the following components in percentage by mass:

2. The hydrolysis-resistant reinforced PBT material according to claim 1, characterized in that :The viscosity of the PBT is between 1.0-1.

2.

3. The hydrolysis-resistant reinforced PBT material according to claim 1, characterized in that The glass fiber is one or more of hydrolysis-resistant glass fiber and flat glass fiber with a fiber diameter of 10-20 μm and a short cut length of 3-5 mm.

4. The hydrolysis-resistant reinforced PBT material according to claim 1, characterized in that : The toughening agent is one or more of ethylene / GMA copolymer, EBA and GMA terpolymer.

5. The hydrolysis-resistant reinforced PBT material according to claim 1, characterized in that The anti-hydrolysis agent is one or more of acrylic epoxy compounds, EDTA (ethylenediaminetetraacetic acid), calcium zinc stabilizer, composite acid stabilizer, aluminum oxide stabilizer, organic tin stabilizer, organic germanium stabilizer, organic barium stabilizer and carbodiimide anti-hydrolysis agent.

6. The method for preparing the hydrolysis-resistant reinforced PBT material according to any one of claims 1 to 5, characterized in that: The PBT resin, glass fiber, hydrolysis-resistant additive, and processing aid are mixed evenly and then fed into a high-shear twin-screw extruder for melt extrusion and granulation. The glass fiber port of the twin-screw extruder is in the sixth zone, and the processing temperature from the feed section to the die is: the temperature of zones 1 to 4 is 230 to 245°C, the temperature of zones 5 to 9 is 200 to 230°C, and the die temperature is 240 to 250°C.

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