PET (Polyethylene Terephthalate) composition as well as preparation method and application thereof

Abstract

The invention discloses a PET (Polyethylene Terephthalate) composition which comprises the following components in parts by weight: 51-61 parts of PET; 5 to 15 parts of PETG (polyethylene terephthalate glycol); 1-5 parts of carboxyl-terminated hyperbranched polyester; 25 to 35 parts of glass fiber; and 0.2 to 0.8 part of a nucleating agent. According to the invention, by adding a specific amount of PETG, hyperbranched polyester and nucleating agent, the torsion and torque performance of the screw column of the PET composition can be obviously improved, and the advantage of high torsion and torque of the screw column is further obtained, so that the PET composition disclosed by the invention is suitable for preparing products needing screw installation, such as household appliances, electronic appliances and the like.

Description

Technical Field

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

[0002] Polyethylene terephthalate (PET) is a semi-crystalline thermoplastic polyester. The modification of PET mainly includes reinforcement modification. Under normal conditions, it is necessary to add glass fiber to modify it to improve its practical applicability. Among them, the reinforced modified PET products are used in the household appliance industry (such as drying channels, air fryers, etc.), which require good temperature resistance and good mechanical properties (such as high impact strength) to meet the functional testing of the product. At the same time, since this type of product has more or less screw holes, it needs to be assembled with self-tapping screws, and it is required that no cracking occurs during the self-tapping process. Summary of the invention

[0003] The object of the present invention is to provide a PET composition with good notched impact strength and high torsional torque.

[0004] The present invention is achieved through the following technical solutions: A PET composition, comprising the following components in parts by weight: PET 51-61 parts; PETG 5-15 parts; 1-5 parts of carboxyl-terminated hyperbranched polyester; Glass fiber 25-35 parts; Nucleating agent 0.2-0.8 parts.

[0005] The nucleating agent is selected from at least one of sodium montanate and talc; preferably, the nucleating agent is selected from sodium montanate and talc, and the weight ratio is sodium montanate: talc = 1: (1.5-3.6).

[0006] The average particle size of the talcum powder is 2-10 microns. The average particle size of the talcum powder is tested by a laser particle size analyzer.

[0007] The number of terminal carboxyl groups per mole of the terminal carboxyl hyperbranched polyester in the terminal carboxyl hyperbranched polyester is 6-48 mol, and the number average molecular weight is 900-12500 g / mol; preferably, the number of terminal carboxyl groups per mole of the terminal carboxyl hyperbranched polyester in the terminal carboxyl hyperbranched polyester is 12-24 mol, and the number average molecular weight is 2100-6400 g / mol.

[0008] The carboxyl-terminated hyperbranched polyester may be at least one of an aromatic polyester polyether structure and an aromatic polyester structure. Preferably, the carboxyl-terminated hyperbranched polyester is selected from an aromatic polyester polyether structure.

[0009] The intrinsic viscosity range of the PET is 0.6-0.8 dL / g, and the intrinsic viscosity detection standard is 5.1.1 Method A in GB / T 14190-2017.

[0010] The intrinsic viscosity range of the PETG is 0.6-0.8 dL / g, and the viscosity detection standard is ISO 1628-5-2015.

[0011] The average diameter of the glass fibers is in the range of 10-13 microns.

[0012] It is possible to choose whether to add 0-2 parts of auxiliary agent according to actual needs; the auxiliary agent is selected from at least one of lubricant, antioxidant and colorant.

[0013] The preparation method of the PET composition of the present invention comprises the following steps: mixing the components uniformly according to the proportion, extruding and granulating through a twin-screw extruder, wherein the barrel temperature ranges from 220 to 270° C. and the screw speed ranges from 250 to 400 rpm to obtain the PET composition.

[0014] The PET composition of the present invention is used to prepare household appliances, electronic appliances and other products that need to be installed with self-tapping screws, such as drying channels, air fryers and the like.

[0015] The present invention has the following beneficial effects: In PET, PETG with specific requirements is added to inhibit the crystallization of PET resin, so that when the product is injected, the front end of the melt will not cool too quickly. When the two melts converge, they can be well fused to improve the binding force of the screw column joint, thereby improving the torsional torque of the screw column; at the same time, a specific terminal carboxyl hyperbranched polyester (with limited carboxyl number and molecular weight) is introduced into the system, and its addition amount is controlled. The terminal carboxyl hyperbranched polyester can react with the terminal hydroxyl group of the PET resin to form a partial micro-cross-linked structure, providing high toughness for the system, which can well absorb the energy of self-tapping screws, and due to the presence of the terminal carboxyl hyperbranched polyester, the fluidity of the system can be greatly improved, increasing the wetting and wrapping of the glass fiber, so that when the melt converges, the combination of resin and resin is more favorable, thereby improving the binding force of the screw column joint, thereby improving the torsional torque of the screw column. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : Schematic diagram of the screw column sample before and after the test in the failure torque test. DETAILED DESCRIPTION

[0017] 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.

[0018] The sources of raw materials used in the examples and comparative examples of the present invention are as follows: PET: intrinsic viscosity 0.64 dL / g, PET WK631, Wankai New Materials Co., Ltd.; PETG-1: intrinsic viscosity 0.65 dL / g, FLOW™ 65, Selenis Portugal, SA; PETG-2: intrinsic viscosity 0.7dL / g, PETG GN821, Sinopec Yizheng Chemical Fiber Co., Ltd.; PETG-3: intrinsic viscosity 1.15 dL / g, GEO™ LF 451, Selenis Portugal, SA; HyPer C101: aromatic polyester polyether structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 6 mol, and the number average molecular weight is 1000 g / mol; HyPer C102: aromatic polyester polyether structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 12 mol, and the number average molecular weight is 2600 g / mol; HyPer C103: aromatic polyester polyether structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 24 mol, and the number average molecular weight is 6400 g / mol; HyPer C104: aromatic polyester polyether structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 48 mol, and the number average molecular weight is 12000 g / mol; HyPer C201: aromatic polyester structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 6 mol, and the number average molecular weight is 950 g / mol; HyPer C202: aromatic polyester structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 12 mol, and the number average molecular weight is 2100 g / mol; HyPer C203: aromatic polyester structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 24 mol, and the number average molecular weight is 5200 g / mol; HyPer C204: aromatic polyester structure carboxyl-terminated hyperbranched polyester, the number of carboxyl groups per mole of carboxyl-terminated hyperbranched polyester is 12 mol, and the number average molecular weight is 11000 g / mol; HyPer H302: Aromatic polyester structure hydroxyl-terminated hyperbranched polyester, the number of hydroxyl groups per mole of hydroxyl-terminated hyperbranched polyester is 12 mol, and the number average molecular weight is 2500 g / mol; HyPer H303: Aromatic polyester structure hydroxyl-terminated hyperbranched polyester, the number of hydroxyl groups per mole of hydroxyl-terminated hyperbranched polyester is 24 mol, and the number average molecular weight is 2500 g / mol; Glass fiber: diameter 11um, glass fiber ECS11-4.5-534A, China Jushi Co., Ltd. Sodium montanate: LICOMONT NAV101 PWD, Guangzhou Fengtian Chemical Co., Ltd.; Talc: SDC-9489, average particle size about 5 microns, Liaoning Xinda Talc Group Co., Ltd. Lubricant: Pentaerythritol tetrastearate, PETS-AP, Faki Asia Pacific Pte Ltd.

[0019] Preparation method of the PET composition of the embodiment and the comparative example: According to the ratio, the components are mixed uniformly, and granulated by extrusion through a twin-screw extruder. The temperatures of the barrels of the twin-screw extruder from the feeding port to the die are: 220-240°C, 230-250°C, 230-250°C, 230-250°C, 240-260°C, 240-260°C, 250-270°C, 250-270°C, 250-270°C, and the screw speed range is 250-400 rpm to obtain a PET composition.

[0020] Various test methods: (1) Notched impact strength: test standard ISO 180-2019, pendulum energy: 2.75J.

[0021] (2) Failure torque: The material was dried at 120℃ / 4h, and a screw column sample was injection molded at 270℃ (the inner diameter of the screw column mold was 3.2mm and the outer diameter was 10.0mm). Standard M4 screws were used and a screw column torque machine was used to tap the screws. The failure torque of the screw column sample was tested (unit: N*m).

[0022] Table 1: Weight parts of each component of PET composition of Examples 1-6 and test results Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 PET 51 55 61 55 55 55 PETG-1 5 10 10 10 10 PETG-2 15 HyPer C101 1 3 5 HyPer C102 3 HyPer C103 3 HyPer C104 3 Fiberglass 25 30 35 30 30 30 Sodium montanate 0.05 0.125 0.2 0.125 0.125 0.125 talcum powder 0.15 0.375 0.6 0.375 0.375 0.375 Lubricants 0.5 0.5 <![CDATA[Notched impact strength, kJ / m 2 > 10.2 11.8 12.3 13.2 14.1 12.1 Failure torque N*m 2.85 3.12 3.22 3.82 3.91 3.23 Table 2: Weight parts of each component of PET composition of Examples 7-10 and test results Example 7 Example 8 Example 9 Example 10 PET 55 55 55 55 PETG-1 10 10 10 10 HyPer C201 3 HyPer C202 3 HyPer C203 3 HyPer C204 3 Fiberglass 30 30 30 30 Sodium montanate 0.125 0.125 0.125 0.125 talcum powder 0.375 0.375 0.375 0.375 <![CDATA[Notched impact strength, kJ / m 2 > 11.1 12.7 13.7 11.4 Failure torque N*m 3.02 3.64 3.71 3.05 It can be seen from Examples 2 / 4-10 that the terminal carboxyl group number of the carboxyl-terminated hyperbranched polyester is preferably 12-24 mol, and the molecular weight is 2100-6400 g / mol; and an aromatic polyester polyether structure is preferred.

[0023] Table 3: Weight parts of each component of PET composition of Examples 11-14 and test results Embodiment 11 Example 12 Embodiment 13 Embodiment 14 PET 55 55 55 55 PETG-1 10 10 10 10 HyPer C201 3 3 3 3 Fiberglass 30 30 30 30 Sodium montanate 0.2 0.11 0.5 talcum powder 0.3 0.39 0.5 <![CDATA[Notched impact strength, kJ / m 2 > 10.4 10.8 10.0 9.1 Failure torque N*m 2.91 2.97 2.77 2.62 It can be seen from Examples 7 / 11-14 that the preferred nucleating agent is sodium montanate: talc powder weight ratio = 1: (1.5-3.5).

[0024] It can be seen from the above examples that the notched impact strength of the PET composition of the present invention is > 9 kJ / m 2 , failure torque>2.5N*m Table 4: Weight parts of each component of comparative PET composition and test results Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 PET 55 55 55 55 55 55 55 PETG-1 10 10 3 22 10 10 PETG-3 10 HyPer C101 3 3 3 0.5 7 HyPer H302 3 HyPer H303 3 Fiberglass 30 30 30 30 30 30 30 Sodium montanate 0.125 0.125 0.125 0.125 0.125 0.125 0.125 talcum powder 0.375 0.375 0.375 0.375 0.375 0.375 0.375 <![CDATA[Notched impact strength, kJ / m 2 > 5.5 4.9 4.5 6.2 5.8 5.2 5.6 Failure torque N*m 1.31 1.13 0.82 1.55 1.43 1.25 1.56 It can be seen from Comparative Example 1 that when the intrinsic viscosity of PETG is too high, the notched impact strength and failure torque of the PET composition are very low.

[0025] It can be seen from Comparative Examples 2 / 3 that the terminal hydroxyl hyperbranched polyester cannot achieve the purpose of the present invention.

[0026] It can be seen from Comparative Examples 4 / 5 that when the PETG content is too low or too high, the notched impact strength and failure torque of the PET composition are very low.

[0027] It can be seen from Comparative Examples 6 / 7 that when the content of hyperbranched polyester is too low or too high, the failure torque will be significantly reduced.

Claims

1. A PET composition, characterized in that By weight, it includes the following components: PET 51-61 parts; PETG 5-15 parts; 1-5 parts of carboxyl-terminated hyperbranched polyester; Glass fiber 25-35 parts; Nucleating agent 0.2-0.8 parts.

2. The PET composition according to claim 1, characterized in that The nucleating agent is selected from at least one of sodium montanate and talc; preferably, the nucleating agent is selected from sodium montanate and talc, and the weight ratio is sodium montanate: talc = 1: (1.5-3.6).

3. The PET composition according to claim 2, characterized in that The average particle size of the talcum powder is 2-10 microns.

4. The PET composition according to claim 1, characterized in that The carboxyl-terminated hyperbranched polyester may be at least one of an aromatic polyester polyether structure and an aromatic polyester structure; preferably, the carboxyl-terminated hyperbranched polyester is selected from an aromatic polyester polyether structure.

5. The PET composition according to claim 1, characterized in that The number of terminal carboxyl groups per mole of the terminal carboxyl hyperbranched polyester is 6-48 mol, and the number average molecular weight is 900-12500 g / mol; the number of terminal carboxyl groups per mole of the terminal carboxyl hyperbranched polyester is 12-24 mol, and the number average molecular weight is 2100-6400 g / mol.

6. The PET composition according to claim 1, characterized in that The intrinsic viscosity of the PET is in the range of 0.6-0.8 dL / g; the intrinsic viscosity of the PETG is in the range of 0.6-0.8 dL / g.

7. The PET composition according to claim 1, characterized in that The average diameter of the glass fibers is in the range of 10-13 microns.

8. The PET composition according to claim 1, characterized in that By weight, the invention further comprises 0-2 parts of auxiliary agents; the auxiliary agents are selected from at least one of lubricants, antioxidants and colorants.

9. The method for preparing the PET composition according to any one of claims 1 to 8, 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 barrel temperature range is 220-270° C., and the screw speed range is 250-400 rpm, to obtain a PET composition.

10. Use of the PET composition according to any one of claims 1 to 8, characterized in that: Used to prepare household appliances and electronic appliances that have screw columns and need to be installed with self-tapping screws.

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