A PBT alloy and its preparation method and application

Abstract

The invention discloses a PBT alloy, which comprises the following components by weight: 100 parts of a PBT / ABS / PC mixed resin; 1-5 parts of a maleic anhydride-styrene block copolymer; 5-20 parts of a talcum powder and a styrene-butadiene block copolymer; wherein the weight ratio of PBT / ABS / PC is in the range of (1-4): (2-5): 1; and the weight ratio of talcum powder to styrene-butadiene block copolymer is in the range of (1.5-9): 1. The invention compoundes PBT / ABS / PC, adds a specific amount of maleic anhydride-styrene block copolymer as a compatibilizer, and a specific ratio of ultrafine talcum powder and styrene-butadiene block copolymer as a low-noise additive, so that the PBT alloy of the invention has the advantages of low noise and low linear thermal expansion coefficient.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a PBT alloy and a preparation method and application thereof. Background Art

[0002] PBT resin has been widely used in various fields, such as household appliances, electrical components, and the automotive industry, due to its good resistance to chemical reagents and good thermal stability. However, as a semi-crystalline polymer, it has the disadvantages of poor dimensional stability and poor low-temperature impact performance. ABS resin has become one of the most widely used general-purpose plastics due to its excellent low-temperature impact performance and good dimensional stability. PC resin is colorless and transparent, has excellent flame retardancy, heat resistance, high strength and environmental protection performance, and is dimensionally stable. It is a very widely used engineering plastic. Combining the advantages and disadvantages of the three, it has become a trend to prepare alloy materials with excellent comprehensive performance. At the same time, in the automotive industry, as more and more OEMs have higher and higher requirements for the comprehensive performance of interior and exterior materials, improving the noise resistance level of interior and exterior materials and reducing the coefficient of linear thermal expansion (CLTE) of materials will inevitably become an indispensable technical requirement for future automotive interior and exterior materials.

[0003] However, the compatibility issues of PBT / ABS / PC are serious, which will result in excessively high linear thermal expansion coefficient and easy generation of noise. Summary of the invention

[0004] The object of the present invention is to provide a PBT alloy having the advantages of low noise and low linear thermal expansion coefficient, and a preparation method and application thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] A PBT alloy, comprising the following components in parts by weight:

[0007] PBT / ABS / PC mixed resin 100 parts;

[0008] 1-5 parts of maleic anhydride-styrene block copolymer;

[0009] 5-20 parts of talc and styrene-butadiene block copolymer;

[0010] Among them, the weight ratio range of PBT / ABS / PC is (1-4): (2-5): 1;

[0011] The weight ratio of talc to styrene-butadiene block copolymer is in the range of (1.5-9):1.

[0012] Preferably, the weight ratio of PBT / ABS / PC is in the range of (2-3):(3-4):1.

[0013] Preferably, the weight ratio of talc to styrene-butadiene block copolymer is in the range of (3-6):1.

[0014] Starting from low noise, the rubber weight content of the ABS is 5-25wt%, preferably 10-20wt%. The NRM technology is used to test the rubber phase content of ABS. In the low-field nuclear magnetic method, the nuclear magnetic signal of the matrix decays very quickly, generally decaying to zero within ten microseconds. The nuclear magnetic signal of the rubber filler decays much slower, and the signal can usually last for tens or hundreds of milliseconds. Therefore, by properly sampling the NMR signal, only the nuclear magnetic signal of the rubber can be obtained, so as to perform quantitative measurement. In the ABS matrix, the rubber content directly affects the impact and MFR of the bulk material. The ABS with a high rubber phase content has a molecular chain that changes rapidly with temperature, so the CLTE is higher; and the high rubber phase content makes the molecular chain entanglement degree in the resin matrix higher, so that it can better absorb external energy in the alloy composite system and reduce noise.

[0015] The average particle size of the talcum powder is in the range of 1-30 microns.

[0016] Preferably, the average particle size of the talc powder is in the range of 5-15 microns. If the particle size of the talc powder is too small, the dispersion is better, but its microporous structure is also reduced, and the energy absorption of noise is reduced; if the particle size of the talc powder is too large, its dispersion effect in the system is poor, and the noise and CLTE are higher.

[0017] The viscosity range of the PBT is 0.5-2dL / g (test standard is GB / T 14190-2008); the melt index range of PC is 8-15g / 10min, the test conditions are 300°C, 1.2kg, and the test standard is ISO1133.

[0018] By weight, 0-1 part of lubricant is also included.

[0019] The lubricant may be a stearic acid lubricant.

[0020] The preparation method of PBT alloy is characterized in that the components are mixed uniformly according to the ratio, and the PBT alloy is obtained by extruding and granulating through a twin-screw extruder, with the screw temperature ranging from 240 to 260° C. and the screw speed ranging from 200 to 400 rpm.

[0021] PBT alloy is used to prepare automotive interior parts, such as seat handles, switch panels, door handles, central control panels, reading lights, etc.

[0022] The present invention has the following beneficial effects

[0023] The present invention compounds PBT / ABS / PC, adds a specific amount of maleic anhydride-styrene block copolymer as a compatibilizer, and a specific ratio of ultrafine talcum powder and styrene-butadiene block copolymer as a low-noise additive (talcum powder plays the role of a porous material in the system and is dispersed in the matrix, which is beneficial to the adsorption of noise and small molecules; at the same time, the addition of talcum powder can greatly reduce the CLTE of the material; styrene-butadiene block copolymer allows the molecular chains of the complex ternary system to be cross-linked and interlaced with each other to form a network structure, absorb external energy, and reduce noise), so that the PBT alloy of the present invention has the advantages of low noise and low linear thermal expansion coefficient. Implementation

[0024] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0025] The sources of raw materials used in the present invention are as follows:

[0026] PBT: viscosity 0.95dL / g, Yizheng Chemical Fiber, PBT GX121;

[0027] PC: Mitsubishi Chemical, PC S-2000F, melt index range is 8-12g / 10min, test conditions are 300℃, 1.2kg;

[0028] ABS-1: rubber weight content is 9.8wt%, Takahashi Petrochemical, ABS 275;

[0029] ABS-2: rubber weight content is 11.7wt%, Takahashi Petrochemical, ABS 8434;

[0030] ABS-3: rubber weight content is 18.5wt%, Guoqiao Petrochemical, ABS D-670;

[0031] ABS-4: rubber content is 25wt%, Guoqiao Petrochemical, ABS D-100;

[0032] Talc was purchased from Liaoning Tianyuan Chemical Company, and the raw materials with corresponding average particle size were obtained by screening.

[0033] Talc A: average particle size 1.25 microns;

[0034] Talc B: average particle size 5.03 μm;

[0035] Talc C: average particle size 15.00 μm;

[0036] Talc D: average particle size 28.39 μm;

[0037] Talc E: average particle size 36.77 microns.

[0038] Maleic anhydride-styrene block copolymer A: Polyscope, SZ23110;

[0039] Maleic anhydride-styrene block copolymer B: Jiaxing Huawen, SMA-725K;

[0040] Styrene-butadiene block copolymer A: Li Changrong Chemical, SBS 3546;

[0041] Styrene-butadiene block copolymer B: South Korea Kumho, SBS KTR-101.

[0042] Preparation method of PBT alloy in the embodiment and comparative example: according to the ratio, the components are mixed uniformly, and extruded into granules by a twin-screw extruder, and the screw temperature range is 140°C in the first zone, 240°C in the second zone, 260°C in the third zone, 250°C in the fourth zone, 250°C in the fifth zone, 240°C in the sixth zone, 240°C in the seventh zone, 240°C in the eighth zone, 250°C in the ninth zone, and 260°C in the tenth zone. The screw speed range is 300-350rpm to obtain PBT alloy.

[0043] Various test methods:

[0044] (1) CLTE effect evaluation: The coefficient of linear thermal expansion (CLTE) of the test material is tested according to the test standard ISO11359-2-1999, and the CLTE data in the flow direction of -30℃-80℃ is obtained. The smaller the CLTE value, the better.

[0045] (2) Noise test (RPN): Adopt the German Automotive Industry Association VDA 230-206 stick-slip test standard (RPN value), RPN 1-3, low risk; 4-5 is medium risk; 6-10 is high risk. A low RPN value means a low noise risk.

[0046] Table 1: Content of each component (parts by weight) and test results of PBT alloys in Examples 1-8

[0047] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 PBT 14.3 25 57.1 40 33.3 28.6 42.9 37.5 ABS-1 71.4 50 28.6 50 50 57.1 42.9 50 PC 14.3 25 14.3 10 16.7 14.3 14.2 12.5 Maleic anhydride-styrene block copolymer A 2 2 2 2 2 2 2 2 Talc A 9 9 9 9 9 9 9 9 Styrene-butadiene block copolymer A 6 6 6 6 6 6 6 6 CLTE (μm / m / ℃) 60.4 61.3 62.7 63.2 57.8 57.2 59.8 60.1 RPN 3 3 3 3 1 1 2 2

[0048] It can be seen from Examples 1-8 that the weight ratio of PBT / ABS / PC in Examples 5-8 is preferably in the range of (2-3):(3-4):1.

[0049] Table 2: Content of each component (parts by weight) and test results of PBT alloys in Examples 9-16

[0050] Example 9 Example 10 Embodiment 11 Example 12 Example 13 Embodiment 14 Embodiment 15 Example 16 PBT 14.3 14.3 14.3 14.3 14.3 14.3 40 40 ABS-1 71.4 71.4 71.4 40 40 ABS-2 71.4 ABS-3 71.4 ABS-4 71.4 PC 14.3 14.3 14.3 14.3 14.3 14.3 20 20 Maleic anhydride-styrene block copolymer A 2 2 2 2 2 2 5 Maleic anhydride-styrene block copolymer B 1 Talc A 13.5 11.25 12.84 9 9 9 4 16 Styrene-butadiene block copolymer A 1.5 3.75 2.14 6 6 6 4 Styrene-butadiene block copolymer B 2 CLTE (μm / m / ℃) 58.2 56.1 55.2 60.9 61.8 64.5 64.1 48.2 RPN 3 2 2 2 2 2 3 3

[0051] It can be seen from Examples 1 / 9-11 that the preferred weight ratio of talc to styrene-butadiene block copolymer is (3-6):1.

[0052] It can be seen from Examples 1 / 12-14 that as the ABS rubber content increases, CLTE increases and RPN decreases, and the preferred ABS rubber content is 10-20wt%.

[0053] Table 3: Content of each component (parts by weight) and test results of PBT alloys in Examples 17-19

[0054] Embodiment 17 Embodiment 18 Embodiment 19 PBT 14.3 14.3 14.3 ABS-1 71.4 71.4 71.4 PC 14.3 14.3 14.3 Maleic anhydride-styrene block copolymer A 2 2 2 Talc B 9 Talc 9 Talc 9 Styrene-butadiene block copolymer A 6 6 6 CLTE (μm / m / ℃) 60.8 61.1 62.5 RPN 2 2 3

[0055] It can be seen from Examples 1 / 17-19 that the preferred average particle size range of talcum powder is 5-15 microns, and the noise is lower.

[0056] Table 4: Content of each component (parts by weight) and test results of comparative PBT alloy

[0057] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 PBT 14.3 14.3 14.3 14.3 14.3 ABS-1 71.4 71.4 71.4 71.4 71.4 PC 14.3 14.3 14.3 14.3 14.3 Maleic anhydride-styrene block copolymer A 0 7.5 2 2 2 Talc A 9 9 9 7.5 13.75 Styrene-butadiene block copolymer A 6 6 0 7.5 1.25 CLTE (μm / m / ℃) 67.8 63.6 62.1 72.1 58.9 RPN 4 5 8 3 6

[0058] It can be seen from Comparative Example 1 / 2 that if no maleic anhydride-styrene block copolymer is added, the compatibility is poor, which will lead to an excessively high CLTE, while the noise increases when the maleic anhydride-styrene block copolymer is excessive.

[0059] Styrene-butadiene block copolymers allow the complex ternary system molecular chains to crosslink and intersperse with each other to form a network structure, absorb external energy, and reduce noise. Specifically, as shown in Comparative Example 3, the noise level is extremely high when no styrene-butadiene block copolymer is added. As shown in Comparative Example 4, the CLTE value is too high when the proportion of styrene-butadiene block copolymer is too high. As shown in Comparative Example 5, the noise is serious when the proportion of styrene-butadiene block copolymer is too low.

[0060] Table 4 continued:

[0061] Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 PBT 8.3 80 20 62.5 ABS-1 83.4 20 40 25 PC 8.3 0 40 12.5 Maleic anhydride-styrene block copolymer A 2 2 2 2 Talc A 9 9 9 9 Styrene-butadiene block copolymer A 6 6 6 6 CLTE (μm / m / ℃) 65.1 68.1 61.2 67.7 RPN 6 5 5 3

[0062] It can be seen from Comparative Examples 6-9 that when the contents of PBT, ABS and PC are not within the scope of the present invention, the characteristics of low CLTE and low RPN cannot be achieved simultaneously.

Claims

1. A PBT alloy, characterized in that: By weight, it includes the following components: PBT / ABS / PC mixed resin 100 parts; 1-5 parts of maleic anhydride-styrene block copolymer; 5-20 parts of talc and styrene-butadiene block copolymer; Among them, the weight ratio range of PBT / ABS / PC is (1-4): (2-5): 1; The weight ratio of talc to styrene-butadiene block copolymer is in the range of (1.5-9):

1.

2. The PBT alloy according to claim 1, characterized in that The weight ratio range of PBT / ABS / PC is (2-3):(3-4):

1.

3. The PBT alloy according to claim 1, characterized in that The weight ratio of talc to styrene-butadiene block copolymer is in the range of (3-6):

1.

4. The PBT alloy according to claim 1, characterized in that The rubber weight content of the ABS is 5-25wt%.

5. The PBT alloy according to claim 4, characterized in that: The rubber weight content of the ABS is 10-20wt%.

6. The PBT alloy according to claim 1, characterized in that: The average particle size of the talcum powder is in the range of 1-30 microns.

7. The PBT alloy according to claim 6, characterized in that: The average particle size of the talcum powder is in the range of 5-15 microns.

8. The PBT alloy according to claim 1, characterized in that The viscosity range of the PBT is 0.5-2 dL / g; the melt index range of the PC is 8-15 g / 10 min, and the test conditions are 300° C. and 1.2 kg.

9. The PBT alloy according to claim 1, characterized in that: By weight, 0-1 part of lubricant is also included.

10. The method for preparing the PBT alloy according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: mixing the components uniformly according to the proportion, extruding and granulating through a twin-screw extruder, wherein the screw temperature range is 240-260° C. and the screw speed range is 200-400 rpm to obtain a PBT alloy.

11. Use of the PBT alloy according to any one of claims 1 to 9, characterized in that: Used to prepare automotive interior parts.