A PBT / PS composite resin with high notched impact strength, its preparation method and application

Abstract

The present invention discloses a PBT / PS composite resin with high notched impact strength, its preparation method and application. The PBT / PS composite resin with high notched impact strength comprises the following components calculated by weight: 30-70 parts of polybutylene terephthalate; 10-40 parts of high impact polystyrene; 10-45 parts of toughening agent; 1-8 parts of compatibilizer; 0.1-4 parts of lubricant; 0.1-0.5 parts of antioxidant. By adding a specific compatibilizer, the present invention improves the compatibility of the PS and PBT composite materials, and selects a suitable toughening agent to synergistically improve the notched impact strength of the PBT / PS composite resin. The toughness of the PBT / PS composite resin with high notched impact strength of the present invention can reach 24.5 KJ / m at normal temperature according to ISO 180 2 above.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, and particularly relates to a PBT / PS composite resin, a preparation method thereof, and an application thereof. Background Art

[0002] Polybutylene terephthalate (PBT) is a semi-crystalline thermoplastic polymer with a fast crystallization rate. It has good tensile properties, wear resistance, solvent resistance, chemical corrosion resistance, and good electrical insulation properties. It is commonly used in industries such as household appliances, precision parts, and instruments, and has now become the fifth largest general-purpose engineering plastic after nylon, polycarbonate, polyoxymethylene, and polyphenylene ether. The notched impact strength of PBT material is low and unstable, which greatly limits the popularization and application of PBT. In order to improve the notched impact strength of PBT and improve its processability, it is necessary to improve it by blending with other thermoplastic polymers. Styrene is a commonly used general-purpose plastic with good impact properties and processability, and a moderate price, and has a wide application in the household appliance industry, but its solvent resistance is poor. If the two are blended, an alloy product with relatively ideal comprehensive properties can be obtained.

[0003] In the prior art, there are very few reports on alloys made of PS and PBT because the compatibility between the two is not good. CN103865187A reports a flame-retardant reinforced and toughened PS / PBT alloy material and a preparation method thereof, but the notched impact strength of the alloy under this system is only 6 KJ / m 2 Although the notched impact strength has been improved compared with PBT itself, there is still room for improvement. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a PBT / PS composite resin with high notched impact strength.

[0005] Another object of the present invention is to provide a preparation method of the PBT / PS composite resin with high notched impact strength.

[0006] Another object of the present invention is to provide an application of the PBT / PS composite resin with high notched impact strength.

[0007] The above objects of the present invention are achieved by the following technical solutions:

[0008] A PBT / PS composite resin with high notched impact strength, comprising the following components calculated by weight:

[0009] 30 - 70 parts of polybutylene terephthalate;

[0010] 10 - 40 parts of high impact polystyrene;

[0011] 10 - 45 parts of toughening agent;

[0012] 1 - 8 parts of compatibilizer;

[0013] 0.1 - 4.0 parts of lubricant;

[0014] 0.1 - 0.5 parts of antioxidant;

[0015] The toughening agent is hydrogenated polystyrene - butadiene - styrene triblock copolymer (SEBS) and / or polystyrene - butadiene - styrene triblock copolymer (SBS);

[0016] The compatibilizer is polyethylene glycol and / or maleic anhydride grafted polypropylene.

[0017] The compatibilizer is preferably polyethylene glycol.

[0018] In the present invention, the polyethylene glycol preferably has a molecular weight of 1000 - 6000. Further preferably, the polyethylene glycol has a molecular weight of 2000 - 5000. Even more preferably, the polyethylene glycol has a molecular weight of 2000 - 3000.

[0019] In the present invention, maleic anhydride grafted polypropylene can also be used as a compatibilizer, but its improvement in compatibility is not as obvious as that of polyethylene glycol. In the present invention, the grafting rate of maleic anhydride grafted polypropylene is between 1% and 1.5%.

[0020] The compatibility between PBT and PS is poor, and a suitable compatibilizer is needed. The inventor unexpectedly found that the compatibilizer of the present invention has a better effect in improving the compatibility between PBT and PS. The toughening agent selected in the present invention can further improve the notched impact resistance of the PBT / PS composite material, making it reach a high notched impact strength. When the composite material is subjected to an impact load and the material is damaged (broken), its toughness depends on the amount of impact energy absorbed by the material and the ability to resist crack propagation. In the PBT / PS composite resin material, the SEBS / SBS elastomer directly absorbs energy. When the specimen is impacted, microcracks will be generated. At this time, the rubber particles span both sides of the crack. For the crack to develop, the rubber must be stretched, and a large amount of energy is absorbed during the deformation process of the rubber, thereby improving the impact strength of the plastic. In particular, the present invention finds that when only the SEBS / SBS elastomer is added for toughening and no compatibilizer is added, the notched impact strength performance of the system is not improved much, and increasing the amount of the toughening agent hardly changes the impact strength of the system. When the compatibilizer polyethylene glycol is added, the hydroxyl group in the polyethylene glycol chain segment has good compatibility with the carbonyl group in PBT, and the main chain segment vinyl group of polyethylene glycol also has good compatibility with PS and the toughening agent, thereby greatly improving the notched impact strength of the system.

[0021] Preferably, the melt mass flow rate of the polybutylene terephthalate is 10 to 25 g / 10 min, the test standard is ISO 1133-1-2011, and the test conditions are 235 °C and 1.2 kg.

[0022] Preferably, the melt mass flow rate of the high impact polystyrene is 3 to 8 g / 10 min, the test standard is ISO 1133-1-2011, and the test conditions are 200 °C and 5 kg.

[0023] Preferably, the PBT / PS composite resin with high notched impact strength comprises the following components calculated by weight:

[0024] 45 to 65 parts of polybutylene terephthalate;

[0025] 15 to 35 parts of polystyrene;

[0026] 10 to 30 parts of toughening agent;

[0027] 2 to 6 parts of compatibilizer;

[0028] 0.5 to 2 parts of lubricant;

[0029] 0.1 to 0.5 part of antioxidant.

[0030] Preferably, the lubricant is a pentaerythritol ester lubricant.

[0031] Preferably, the antioxidant is one or a mixture of several of hindered amine type, hindered phenol type, phosphite type, calixarene type or thioester type antioxidants.

[0032] For the preparation method of the PBT / PS composite resin with high notched impact strength, after the PBT is dried, the components are mixed evenly, and then melt-extruded and pelletized through a twin-screw extruder to obtain the PBT / PS composite resin.

[0033] The melt extrusion of the twin-screw extruder is carried out at 180 to 260 °C.

[0034] Application of the PBT / PS composite resin with high notched impact strength in the preparation of household appliances and toy products. The addition of PS makes up for the shortcoming of the low notched impact strength of the PBT material. At the same time, the addition of PS also improves the processing performance of PBT to a certain extent. The PBT / PS composite resin of the present invention can expand the further application of PBT in the fields where there are requirements for notched impact strength.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] By adding a specific compatibilizer, the present invention improves the compatibility of the PS and PBT composite materials, and cooperates with a suitable toughening agent to synergistically improve the notched impact strength of the PBT / PS composite resin. The toughness of the high notched impact strength PBT / PS composite resin of the present invention can reach 24.5 KJ / m at room temperature according to ISO 180. 2 Above, it can expand the further application of PBT in the fields where requirements for notched impact strength are required. Specific embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely, but the implementation manners of the present invention are not limited thereto.

[0038] The reagents, methods, and equipment used in the present invention are all commercially available conventional reagents, methods, and equipment in the technical field, unless otherwise specified.

[0039] The raw materials used in the following examples and comparative examples are as follows:

[0040] Polybutylene terephthalate 1, melt mass flow rate 10 g / 10 min, PBT GL236, Sinopec Yizheng Chemical Fiber Co., Ltd.;

[0041] Polybutylene terephthalate 2, melt mass flow rate 18 g / 10 min, PBT 1100-211M, Changchun Chemical (Jiangsu) Co., Ltd.;

[0042] Polybutylene terephthalate 3, melt mass flow rate 25 g / 10 min, Nantong Xingchen Synthetic Materials Co., Ltd., PBT 1100A;

[0043] High impact polystyrene 1, melt mass flow rate 3 g / 10 min, Polystyrene 4241, Total Petrochemical (Foshan) Co., Ltd.;

[0044] High impact polystyrene 2, melt mass flow rate 5 g / 10 min, PS-350K, Formosa Petrochemical Corporation;

[0045] High impact polystyrene 3, melt mass flow rate 13 g / 10 min, 4440H, Total Petrochemical (Ningbo) Co., Ltd.;

[0046] Hydrogenated polystyrene-butadiene-styrene triblock copolymer (SEBS), YH-501, Sinopec Baling Petrochemical Company;

[0047] Polystyrene-butadiene-styrene triblock copolymer (SBS), YH-792, Sinopec Baling Petrochemical Company;

[0048] Methyl methacrylate-butadiene-styrene terpolymer, EM500, LG Chem Ltd.;

[0049] Polyethylene glycol PEG1, molecular weight 2000, Jining Tangyi Chemical Co., Ltd.;

[0050] Polyethylene glycol PEG2, molecular weight 5000, Jining Tangyi Chemical Co., Ltd.;

[0051] Maleic anhydride grafted polypropylene, AD-105, grafting rate 1.05 - 1.35, Foshan Chenbai New Polymer Materials Co., Ltd.;

[0052] Styrene maleic anhydride copolymer, SMA1000P, Total Petrochemical (Ningbo) Co., Ltd.;

[0053] The lubricant and antioxidant are the same commercially available products.

[0054] The test standard for the melt mass flow rate of the said polybutylene terephthalate is ISO 1133-1-2011, and the test conditions are 250 °C and 2.16 kg.

[0055] The test standard for the melt mass flow rate of the said high impact polystyrene is ISO 1133-1-2011, and the test conditions are 200 °C and 5 kg.

[0056] The PBT / PS composite resin of the examples and comparative examples is prepared by the following method: PBT is first dried in an oven at 120 °C for 4 h, then each component is dried and mixed evenly, put into a twin-screw extruder, the length-diameter ratio of the screw is 40:1, the diameter is 35 mm, the rotation speed of the extruder is controlled at 300 revolutions per minute, the processing temperature is 180 - 260 °C, and it is extruded, cooled and pelletized to obtain the PBT / PS composite resin. For the resin formulations of Examples 1 - 11 and Comparative Examples 1 - 6, see Tables 1 and 2, and for the performance test results, see Table 3.

[0057] Performance test of PBT / PS composite resin:

[0058] Impact strength: The test standard for the Izod notched impact strength is ISO 180-2019, the test condition is normal temperature, and the unit is KJ / m 2 。

[0059] Table 1

[0060]

[0061]

[0062] Table 2

[0063]

[0064] Table 3

[0065]

[0066]

[0067] It can be seen from the comparison between Comparative Example 1 and Example 1 that when the toughening agent of the present invention is not selected, although the notched impact resistance is improved, the notched impact resistance is only 11.2 KJ / m 2 , and the improvement effect is far less significant than that of the solution of the present invention. It can be seen from the comparison between Comparative Example 2 and Example 1 that when the compatibilizer of the present invention is not selected, although the notched impact resistance is improved, the notched impact resistance is only 9.6 KJ / m 2 , and the improvement effect is far less significant than that of the solution of the present invention. It can be seen from the comparison between Comparative Example 3 and Comparative Example 4 and Example 1 that when the dosage of the toughening agent or the compatibilizer is too small, the improvement of the notched impact resistance is not significant.

[0068] From the comparison of Example 1, Example 11 and Example 3, polyethylene glycol as a compatibilizer has a more obvious improvement effect relative to maleic anhydride grafted polypropylene. And polyethylene glycol with a molecular weight of 2000-3000 has a better improvement effect.

[0069] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements and improvements made within the spirit and principle of the original Example 1 of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A PBT / PS composite resin with high notched impact strength, characterized in that, it comprises the following components calculated by weight: 30 - 70 parts of polybutylene terephthalate; 10 - 40 parts of high impact polystyrene; 10 - 45 parts of toughening agent; 1 - 8 parts of compatibilizer; 0.1 - 4 parts of lubricant; 0.1 - 0.5 parts of antioxidant; the toughening agent is hydrogenated polystyrene - butadiene - styrene triblock copolymer and / or polystyrene - butadiene - styrene triblock copolymer; the compatibilizer is polyethylene glycol and / or maleic anhydride grafted polypropylene.

2. The PBT / PS composite resin with high notched impact strength according to claim 1, characterized in that, the melt mass flow rate of the polybutylene terephthalate is 10 - 25 g / 10 min, the test standard is ISO 1133 - 1 - 2011, and the test conditions are 235 °C and 1.2 kg.

3. The PBT / PS composite resin with high notched impact strength according to claim 1, characterized in that, the melt mass flow rate of the high impact polystyrene is 3 - 8 g / 10 min, the test standard is ISO 1133 - 1 - 2011, and the test conditions are 200 °C and 5 kg.

4. The PBT / PS composite resin with high notched impact strength according to claim 1, characterized in that, the molecular weight of the polyethylene glycol is 1000 - 6000.

5. The PBT / PS composite resin with high notched impact strength according to claim 1, characterized in that, it comprises the following components calculated by weight: 45 - 65 parts of polybutylene terephthalate; 15 - 35 parts of polystyrene; 10 - 30 parts of toughening agent; 2 - 6 parts of compatibilizer; 0.5 - 2 parts of lubricant; 0.1 - 0.5 parts of antioxidant.

6. The PBT / PS composite resin with high notched impact strength according to claim 1, characterized in that, the lubricant is an ester lubricant.

7. The PBT / PS composite resin with high notched impact strength according to claim 1, characterized in that, the antioxidant is one or a mixture of several of hindered amine type, hindered phenol type or phosphite type, calixarene type or thioester type antioxidants.

8. The preparation method of the PBT / PS composite resin with high notched impact strength according to any one of claims 1 - 7, characterized in that, after the PBT is dried, the components are mixed evenly, and the PBT / PS composite resin is obtained by melt extrusion and pelletizing through a twin - screw extruder.

9. The preparation method according to claim 8, characterized in that, the melt extrusion by the twin - screw extruder is carried out at 180 - 260 °C.

10. The application of the PBT / PS composite resin with high notched impact strength according to any one of claims 1 - 7 in the preparation of outer shells of household appliances, toy products, and outer shells of office equipment.

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