Temperature-resistant fiber-free super-tough modified PET material and preparation method thereof

Abstract

The invention belongs to the technical field of engineering plastics, and particularly discloses a temperature-resistant fiber-free super-tough modified PET (polyethylene terephthalate) material which comprises the following components in parts by weight: 73.5-80.5 parts of PET resin; 6 to 12 parts of a temperature-resistant synergist; 10 to 12 parts of a toughening agent; 0.5 to 1 part of an antioxidant; 0.5-1 part of a lubricant; 0.5-1 part of a nucleating agent; wherein the temperature-resistant synergist is prepared by compounding nano boron nitride and organic silicon modified polyimide according to a mass ratio of 2: 1. Nano boron nitride and organic silicon modified polyimide are compounded into a temperature-resistant synergist according to a proportion, and through synergistic cooperation, the temperature resistance and toughness of the PET material can be remarkably improved, so that the PET material keeps synergistic improvement of dimensional stability and impact resistance in a high-temperature environment, glass fibers do not need to be added, and meanwhile, excellent processing fluidity is kept.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastics, and particularly relates to a temperature-resistant fiber-free super-tough modified PET material and a preparation method thereof. Background Art

[0002] Polyethylene terephthalate (PET) is an engineering plastic with excellent comprehensive properties, having excellent mechanical properties such as wear resistance and creep resistance, as well as good chemical resistance, and is widely used in the fields of packaging, electronics and electrical appliances, and automobiles. However, in high-temperature and high-impact environments, PET materials have problems such as insufficient temperature resistance (the heat distortion temperature is usually lower than 80°C) and poor toughness (notched impact strength < 3 kJ / m²), which limit its application in high-temperature and high-impact environments.

[0003] In the prior art, glass fiber (GF) or mineral fillers are usually added to improve the rigidity and temperature resistance of PET. By adding glass fiber, the heat distortion temperature of the modified PET material is increased to 120°C, but the glass fiber (GF) will cause problems such as increased brittleness and decreased processing fluidity of the material, and floating fiber defects are likely to appear on the surface of the product; by adding mineral fillers, such as blending nano-clay with PET to improve the temperature resistance, but the nano-particles are difficult to disperse and easily agglomerate, resulting in further reduction of the material toughness. In addition, traditional toughening agents (such as POE) are prone to migration failure at high temperatures and cannot meet the long-term heat resistance requirements. Summary of the Invention

[0004] In order to overcome the defects existing in the prior art, the present invention provides a temperature-resistant fiber-free super-tough modified PET material and a preparation method thereof.

[0005] The technical solution adopted by the present invention to solve its technical problems is: The first solution of the present invention is to provide a temperature-resistant fiber-free super-tough modified PET material, comprising the following components in parts by weight: 73.5 - 80.5 parts of PET resin; 6 - 12 parts of temperature-resistant synergist; 10 - 12 parts of toughening agent; 0.5 - 1 part of antioxidant; 0.5 - 1 part of lubricant; 0.5 - 1 part of nucleating agent; Among them, the temperature-resistant synergist is compounded by nano-boron nitride and organosilicon-modified polyimide according to a mass ratio of 2:1.

[0006] In the solution of the present invention, nano boron nitride has good temperature resistance characteristics. In addition to excellent temperature resistance characteristics, the silicone-modified polyimide can also enhance the toughness of the PET material. The nano boron nitride and the silicone-modified polyimide are compounded in proportion to form a temperature-resistant synergist. Through synergistic cooperation, it can significantly improve the temperature resistance and toughness of the PET material, enabling the PET material to maintain the synergistic improvement of dimensional stability and impact resistance in a high-temperature environment, without adding glass fiber, and at the same time maintaining excellent processing fluidity. Among them, the mass ratio of nano boron nitride to silicone-modified polyimide is 2:1. Compounding according to this ratio, the obtained PET material has the best dimensional stability and impact resistance in a high-temperature environment.

[0007] As a further solution, the particle size of the nano boron nitride is 50 - 60 nm; the particle size of the silicone-modified polyimide is 2 - 5 μm.

[0008] As a further solution, the toughening agent is one or more of POE-g-GMA, POE grafted maleic anhydride, ethylene-methyl acrylate-glycidyl methacrylate, and ethylene-butyl acrylate-glycidyl methacrylate. POE-g-GMA is POE melt grafted with glycidyl methacrylate. Adding the toughening agent can enhance the interfacial compatibility through chemical bonding, realizing the uniform dispersion of the PET matrix and the toughening agent, and there is no migration failure at high temperature.

[0009] As a further solution, the antioxidant is one or several of 1010, 168, and 1098.

[0010] As a further solution, the lubricant is one or several of PETS, Honeywell 540A, and silicone powder. PETS is pentaerythritol stearate.

[0011] As a further solution, the nucleating agent is the polyester nucleating agent Sanulater HK250, which is produced by Dongguan Sanhe Chemical Co., Ltd. The appearance of Sanulater HK250: white powder, particle size: >800 mesh, melting point: >120 °C. Sanulater HK250 is a mixture. Calculated by weight, its composition components are: Polyamide wax: CAS NO is 63428-84-2, content is 30 - 60 parts; Long-chain stearate: CAS NO is 3159-62-4, content is 40 - 70 parts; Talc powder: CAS NO is 14807-96-6, content is 10 - 30 parts.

[0012] By adding a polyester nucleating agent, the thermal crystallization temperature of the PET material melt is effectively increased during the cooling and crystallization process, the crystallization speed is accelerated, the mucosal problem is solved; the dimensional stability of the product is improved, the post-shrinkage of the product is reduced, and at the same time, the surface gloss of the product is improved.

[0013] As a further solution, the intrinsic viscosity of the PET resin is 0.660 - 0.700 dl / g, and the melt flow rate is 90 - 110 g / (10 min) under the test conditions of 265°C / 2.16 kg.

[0014] The second solution of the present invention is to provide a preparation method of a temperature-resistant fiber-free super-tough modified PET material. The preparation method is used to prepare the above-mentioned temperature-resistant fiber-free super-tough modified PET material, and the preparation method includes the following steps: 1) After proportioning nano boron nitride and organosilicon-modified polyimide, use a powder mixer to stir for 5 - 10 minutes to obtain a pretreated temperature-resistant synergist; 2) Put the PET resin, the pretreated temperature-resistant synergist obtained in step 1), a toughening agent, an antioxidant, a lubricant, and a nucleating agent into a mixer, mix and stir evenly to obtain a mixture; 3) Put the mixture obtained in step 2) into a twin-screw extruder, heat it to melt and extrude to obtain a temperature-resistant fiber-free super-tough modified PET material.

[0015] Specifically, the pretreatment of the temperature-resistant synergist can significantly improve the stability of the temperature resistance of the PET material.

[0016] As a further solution, in step 3), the temperature of the melt extrusion is 220 - 280°C, and the screw speed is 300 - 500 r / min.

[0017] The beneficial effects of the present invention are as follows: Nano boron nitride has good temperature resistance characteristics. In addition to excellent temperature resistance characteristics, organosilicon-modified polyimide can also enhance the toughness of the PET material. Nano boron nitride and organosilicon-modified polyimide are compounded in proportion to form a temperature-resistant synergist. Through synergistic cooperation, the temperature resistance and toughness of the PET material can be significantly improved, enabling the PET material to maintain the coordinated improvement of dimensional stability and impact resistance in a high-temperature environment, without the need to add glass fiber, and at the same time maintaining excellent processing fluidity. Among them, the mass ratio of nano boron nitride to organosilicon-modified polyimide is 2:1. Compound according to this ratio, and the obtained PET material has the best dimensional stability and impact resistance in a high-temperature environment. Specific Embodiments

[0018] It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but do not constitute a limitation to the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] It should be noted that in the following examples and comparative examples, the intrinsic viscosity of the selected PET resin is 0.680 dl / g, and the melt flow rate is 100 g / (10 min) under the test conditions of 265 °C / 2.16 kg.

[0020] Example 1 A heat-resistant fiber-free super-tough modified PET material, comprising the following components in parts by weight: 80.5 parts of PET resin; 6 parts of heat-resistant synergist; 12 parts of toughening agent; 0.5 part of antioxidant; 0.5 part of lubricant; 0.5 part of nucleating agent; Among them, the heat-resistant synergist is compounded by nano boron nitride and organosilicon-modified polyimide in a mass ratio of 2:1. The particle size of nano boron nitride is controlled between 50-60 nm; the particle size of organosilicon-modified polyimide is controlled between 2-5 μm. The toughening agent is POE-g-GMA; the antioxidant is antioxidant 1010; the lubricant is PETS; the nucleating agent is polyester nucleating agent Sanulater HK250.

[0021] The preparation method of the heat-resistant fiber-free super-tough modified PET material comprises the following steps: 1) After compounding nano boron nitride and organosilicon-modified polyimide in a mass ratio of 2:1, stir with a powder mixer for 5-10 minutes to obtain a pretreated heat-resistant synergist; 2) Put the PET resin, the pretreated heat-resistant synergist obtained in step 1), toughening agent, antioxidant, lubricant, and nucleating agent into a blender, mix and stir evenly to obtain a mixture; 3) Put the mixture obtained in step 2) into a twin-screw extruder, the melting and extrusion temperature is 220-280 °C, the screw speed is 300-500 r / min, heat to melt and extrude to obtain the heat-resistant fiber-free super-tough modified PET material.

[0022] Example 2 A heat-resistant fiber-free super-tough modified PET material, comprising the following components in parts by weight: 78.5 parts of PET resin; 8 parts of heat-resistant synergist; 12 parts of toughening agent; 0.5 part of antioxidant; 0.5 part of lubricant; 0.5 part of nucleating agent; Among them, the temperature-resistant synergist is prepared by compounding nano boron nitride and organosilicon-modified polyimide according to a mass ratio of 2:1. The particle size of nano boron nitride is controlled between 50 - 60 nm; the particle size of organosilicon-modified polyimide is controlled between 2 - 5 μm. The toughening agent is selected as POE grafted maleic anhydride; the antioxidant is antioxidant 1010; the lubricant is selected as Honeywell 540A; the nucleating agent is selected as polyester nucleating agent Sanulater HK250.

[0023] The preparation method of the temperature-resistant fiber-free super-tough modified PET material includes the following steps: 1) After compounding nano boron nitride and organosilicon-modified polyimide according to a mass ratio of 2:1, use a powder mixer to stir for 5 - 10 minutes to obtain a pretreated temperature-resistant synergist; 2) Put PET resin, the pretreated temperature-resistant synergist obtained in step 1), toughening agent, antioxidant, lubricant, and nucleating agent into a mixer, mix and stir evenly to obtain a mixture; 3) Put the mixture obtained in step 2) into a twin-screw extruder, the melting and extrusion temperature is 220 - 280 °C, the screw speed is 300 - 500 r / min, heat to melt and extrude to obtain the temperature-resistant fiber-free super-tough modified PET material.

[0024] Example 3 A temperature-resistant fiber-free super-tough modified PET material, comprising the following components in parts by weight: 73.5 parts of PET resin; 12 parts of temperature-resistant synergist; 12 parts of toughening agent; 0.5 part of antioxidant; 1 part of lubricant; 1 part of nucleating agent; Among them, the temperature-resistant synergist is prepared by compounding nano boron nitride and organosilicon-modified polyimide according to a mass ratio of 2:1. The particle size of nano boron nitride is controlled between 50 - 60 nm; the particle size of organosilicon-modified polyimide is controlled between 2 - 5 μm. The toughening agent is selected as ethylene-methyl acrylate-glycidyl methacrylate; the antioxidant is antioxidant 168; the lubricant is selected as PETS; the nucleating agent is selected as polyester nucleating agent Sanulater HK250.

[0025] The preparation method of the temperature-resistant fiber-free super-tough modified PET material includes the following steps: 1) After compounding nano boron nitride and organosilicon-modified polyimide according to a mass ratio of 2:1, use a powder mixer to stir for 5 - 10 minutes to obtain a pretreated temperature-resistant synergist; 2) Put PET resin, the pretreated temperature-resistant synergist obtained in step 1), toughening agent, antioxidant, lubricant, and nucleating agent into a mixer, mix and stir evenly to obtain a mixture; 3) Put the mixture obtained in step 2) into a twin-screw extruder, with a melting and extrusion temperature of 220 - 280 °C, a screw speed of 300 - 500 r / min, and heat it to melt and extrude, thus obtaining the temperature-resistant fiber-free super-tough modified PET material.

[0026] Example 4 A temperature-resistant fiber-free super-tough modified PET material, comprising the following components in parts by weight: 75.5 parts of PET resin; 12 parts of temperature-resistant synergist; 10 parts of toughening agent; 1 part of antioxidant; 1 part of lubricant; 0.5 part of nucleating agent; Among them, the temperature-resistant synergist is compounded by nano boron nitride and organosilicon-modified polyimide in a mass ratio of 2:1. The particle size of nano boron nitride is controlled between 50 - 60 nm; the particle size of organosilicon-modified polyimide is controlled between 2 - 5 μm. The toughening agent is selected as ethylene-butyl acrylate-glycidyl methacrylate; the antioxidant is antioxidant 1098; the lubricant is selected as silicone powder; the nucleating agent is selected as polyester nucleating agent Sanulater HK250.

[0027] The preparation method of the temperature-resistant fiber-free super-tough modified PET material comprises the following steps: 1) After compounding nano boron nitride and organosilicon-modified polyimide in a mass ratio of 2:1, use a powder mixer to stir for 5 - 10 minutes to obtain a pretreated temperature-resistant synergist; 2) Put the PET resin, the pretreated temperature-resistant synergist obtained in step 1), toughening agent, antioxidant, lubricant, and nucleating agent into a mixer, mix and stir evenly to obtain a mixture; 3) Put the mixture obtained in step 2) into a twin-screw extruder, with a melting and extrusion temperature of 220 - 280 °C, a screw speed of 300 - 500 r / min, and heat it to melt and extrude, thus obtaining the temperature-resistant fiber-free super-tough modified PET material.

[0028] Comparative Example 1 Compared with Example 2, the difference lies in that: the temperature-resistant synergist only selects nano boron nitride, and other components and preparation methods are the same as those in Example 2.

[0029] Comparative Example 2 Compared with Example 2, the difference lies in that: the temperature-resistant synergist only selects organosilicon-modified polyimide, and other components and preparation methods are the same as those in Example 2.

[0030] Comparative Example 3 Compared with Example 2, the difference lies in that: the temperature-resistant synergist is compounded by nano boron nitride and organosilicon-modified polyimide in a mass ratio of 3:2, and other components and preparation methods are the same as those in Example 2.

[0031] Comparative Example 4 Compared with Example 2, the difference is that the temperature resistance synergist is compounded by nano boron nitride and organosilicon modified polyimide in a mass ratio of 5:2, and the other components and preparation method are consistent with those of Example 2.

[0032] Comparative Example 5 Compared with Example 2, the difference is that in the preparation method, the temperature-resistant synergist is not pretreated, and the other components are consistent with Example 2. The specific steps are as follows: 1) Mix nano boron nitride and organosilicon modified polyimide in a mass ratio of 2:1; 2) Put PET resin, nano boron nitride, organosilicon modified polyimide, toughening agent, antioxidant, lubricant and nucleating agent into a blender, mix and stir evenly to obtain a mixture; 3) The mixture obtained in step 2) is put into a twin-screw extruder, the melt extrusion temperature is 220-280° C., the screw speed is 300-500 r / min, and heated to melt extrusion to obtain a heat-resistant fiber-free ultra-tough modified PET material.

[0033] Comparative Example 6 Compared with Example 2, the difference is that the weight portion of the nucleating agent is selected to be 0.4 parts, and the other components and preparation method are consistent with Example 2.

[0034] Comparative Example 7 Compared with Example 2, the difference is that the weight portion of the nucleating agent is 1.1 parts, and the other components and preparation method are consistent with Example 2.

[0035] Performance Testing The modified PET materials corresponding to Examples 1-4 and Comparative Examples 1-7 were subjected to the following performance tests, and the standards cited for the tests and the experimental data obtained are shown in Tables 1 and 2 below: Table 1: Test data obtained in Examples 1-4 Table 2: Test data obtained from comparative examples 1-7 Combined with the test data obtained in Examples 1-4, it can be seen that the heat-resistant synergist composed of nano-boron nitride and silicone-modified polyimide is added to the PET material to modify the PET material, effectively improve the material's heat resistance and toughness, and there is no need to add glass fiber to avoid floating fiber defects on the surface of the product.

[0036] Combining the test data obtained from Example 2 and Comparative Examples 1-4, it can be seen that adding single nano boron nitride or silicone modified polyimide into the PET material does not significantly improve the heat resistance of the material. Moreover, by comparing the test data obtained from Example 2 and Comparative Examples 3-4, it can be known that when the heat resistance synergist is compounded by nano boron nitride and silicone modified polyimide according to the mass ratio of 2:1, the improvement of the heat resistance and toughness of the material is the best, meeting the usage requirements of the material.

[0037] Combining the test data obtained from Example 2 and Comparative Example 5, it can be seen that compared with simply mixing the components, the pre-mixing treatment of nano boron nitride and silicone modified polyimide can make the two fully contact and have better surface bonding through the high-speed operation and heating effect of the powder mill, thereby improving the heat resistance and toughness of the material.

[0038] Combining the test data obtained from Examples 1-4 and Comparative Examples 6-7, it can be seen that the addition of the nucleating agent significantly improves the mold sticking situation of the material and the surface of the product. The reason is that the nucleating agent can be evenly dispersed into the material melt, provide and generate tiny crystal nuclei, form a uniform and dense crystal structure, accelerate the crystallization of PET, has a very high nucleation efficiency for PET, and reduces the molecular weight very little. During the melt cooling and crystallization process, it effectively increases its thermal crystallization temperature, speeds up the crystallization rate, can significantly improve the mold sticking situation, and improve the surface of the product. However, too much or too little nucleating agent does not achieve good results. Therefore, an appropriate addition ratio of the nucleating agent should be selected to meet the usage requirements of the material.

[0039] The above has described the embodiments of the present invention in detail, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations to these embodiments still fall within the protection scope of the present invention.

Claims

1. A temperature-resistant fiber-free super-tough modified PET material, characterized in that, It comprises the following components in parts by weight: 73.5 - 80.5 parts of PET resin; 6 - 12 parts of heat - resistant synergist; 10 - 12 parts of toughening agent; 0.5 - 1 part of antioxidant; 0.5 - 1 part of lubricant; 0.5 - 1 part of nucleating agent; Among them, the heat - resistant synergist is prepared by compounding nano - boron nitride and organosilicon - modified polyimide according to a mass ratio of 2:

1.

2. The heat-resistant and fiber-free super-tough modified PET material according to claim 1, wherein: The particle size of the nano - boron nitride is 50 - 60 nm; the particle size of the organosilicon - modified polyimide is 2 - 5 μm.

3. The heat-resistant fiber-free super-tough modified PET material according to claim 1, characterized in that: The toughening agent is one or more of POE - g - GMA, POE grafted maleic anhydride, ethylene - methyl acrylate - glycidyl methacrylate, and ethylene - butyl acrylate - glycidyl methacrylate.

4. A heat-resistant fiber-free super-tough modified PET material according to claim 1, characterized in that: The antioxidant is one or several of 1010, 168, and 1098.

5. A temperature-resistant and fiber-free super-tough modified PET material according to claim 1, characterized in that: The lubricant is one or several of PETS, Honeywell 540A, and silicone powder.

6. The heat-resistant fiber-free super-tough modified PET material according to claim 1, characterized in that: The intrinsic viscosity of the PET resin is 0.660 - 0.700 dl / g, and the melt flow rate is 90 - 110 g / (10 min) under the test conditions of 265°C / 2.16 kg.

7. A preparation method of a temperature-resistant fiber-free super-tough modified PET material, characterized in that: The preparation method is used to prepare a heat - resistant fiber - free super - tough modified PET material as described in any one of claims 1 - 6. The preparation method includes the following steps: 1) After proportionally blending nano - boron nitride and organosilicon - modified polyimide, use a powder mixer to stir for 5 - 10 minutes to obtain a pretreated heat - resistant synergist; 2) Put the PET resin, the pretreated heat - resistant synergist obtained in step 1), toughening agent, antioxidant, lubricant, and nucleating agent into a mixer, and mix and stir evenly to obtain a mixture; 3) Put the mixture obtained in step 2) into a twin - screw extruder, heat it to melt and extrude, and then a heat - resistant fiber - free super - tough modified PET material is obtained.

8. The preparation method of a temperature-resistant fiber-free super-tough modified PET material according to claim 7, characterized in that: In step 3), the melt extrusion temperature is 220 - 280°C, and the screw speed is 300 - 500 r / min.

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