Modified polyethylene glycol terephthalate as well as preparation method and application thereof

Abstract

The invention discloses modified polyethylene glycol terephthalate, which is prepared from the following raw materials in parts by weight: 85 to 98 parts of polyethylene glycol terephthalate, 1 to 5 parts of nucleating agent, 0.1 to 1 part of antioxidant and 0.1 to 0.5 part of crystallization accelerant. The beta-crystal nucleating agent, the talcum powder and the crystallization accelerant have a synergistic effect to modify the polyethylene glycol terephthalate, the formed polyethylene glycol terephthalate material can be prepared into full packaging bottles and is small in shrinkage rate, cold mold injection molding at the temperature of 120-140 DEG C is adopted, the crystallization speed of the polyethylene glycol terephthalate is reduced, and the service life of the packaging bottles is prolonged. Therefore, the glue inlet and outlet positions of the polyethylene glycol terephthalate are not easy to whiten in the fixed mold forming process, and the crystallization transparency is high and uniform.

Description

Technical Field

[0001] The present invention relates to the field of polymer compound compositions, and in particular to modified polyethylene terephthalate, a preparation method and an application thereof. Background Art

[0002] Polyethylene terephthalate (PET) is a milky white or light yellow, highly crystalline polymer widely used in packaging. However, as living standards improve, the demand for polymer packaging materials is becoming increasingly demanding. Improving the transparency and formability of PET can optimize its packaging performance. Existing PET packaging materials are mostly milky white, resulting in partial shrinkage in the processed bottles, variations between batches, and process instability. Therefore, developing a modified PET material with high transparency and excellent formability is crucial.

[0003] Chinese invention patent CN103834150A discloses a material composition for producing beer bottles and a method for producing the same. The composition contains a layered silicate nanocomposite PET material, an antioxidant, a colorant, and a dispersant, and can be mixed with ordinary PET bottle recycled material in any proportion for recycling and reuse. The product and production process are environmentally friendly and highly competitive in the market. However, the transparency is poor and the material has a certain light-blocking property. Chinese invention patent CN114410074B discloses a transparent, heat-resistant PET material, its preparation method, and its application. Polyethylene terephthalate is modified with poly(m-phenylenediamine) adipic acid and polyethylene isophthalate, achieving high transparency and good heat resistance, but with low toughness and poor impact resistance. Summary of the Invention

[0004] In order to develop a modified polyethylene terephthalate material with high transparency and good formability, the first aspect of the present invention provides a modified polyethylene terephthalate, which is prepared by raw materials including, by weight: 85-98 parts of polyethylene terephthalate, 1-5 parts of a nucleating agent, 0.1-1 parts of an antioxidant and 0.1-0.5 parts of a crystallization accelerator.

[0005] As an embodiment, the intrinsic viscosity of the polyethylene terephthalate at 100° C. is 0.5-1 dL / g.

[0006] As an embodiment, the melting point of the polyethylene terephthalate is 240-250°C.

[0007] As an embodiment, the nucleating agent includes a β-crystal nucleating agent and an α-crystal nucleating agent, and the α-crystal nucleating agent includes at least one of an inorganic nucleating agent, a polymer nucleating agent, or a carboxylic acid metal salt nucleating agent.

[0008] As an embodiment, the β-crystal nucleating agent includes at least one of a phosphate nucleating agent, a carbonate nucleating agent, an amide nucleating agent, a nitrogen nucleating agent or a cobalt nucleating agent.

[0009] As an embodiment, the β-crystal nucleating agent is an amide nucleating agent.

[0010] As an embodiment, the type of the β-crystal nucleating agent includes at least one of Millad NX 8000 and Clariant NaV101.

[0011] As an embodiment, the inorganic nucleating agent includes at least one of talc, calcium carbonate, mica, silica, calcium oxide or carbon black.

[0012] As an embodiment, the nucleating agent includes a combination of a β-crystalline nucleating agent and talc.

[0013] As an embodiment, the weight ratio of the β-crystal nucleating agent to talc is (0.3-0.8): (1-3).

[0014] As an embodiment, the weight ratio of the β-crystal nucleating agent to talc is (0.4-0.6): (1.5-2.5).

[0015] As an embodiment, the weight ratio of the β-crystal nucleating agent to talc is 0.5:2.

[0016] As an embodiment, the antioxidant includes at least two of hindered phenol antioxidants, phosphite antioxidants or hindered amine antioxidants.

[0017] As an embodiment, the antioxidant is a combination of a hindered phenol antioxidant and a phosphite antioxidant.

[0018] As an embodiment, the weight ratio of the hindered phenol antioxidant to the phosphite antioxidant is (0.1-0.3): (0.1-0.3).

[0019] As an embodiment, the weight ratio of the hindered phenol antioxidant to the phosphite antioxidant is 0.3:0.2.

[0020] As an embodiment, the crystallization accelerator includes at least one of acetate copolymer, terephthalamide or aromatic diamide compound.

[0021] As an embodiment, the acetate copolymer is a diallyl anhydride-acetyl acetate copolymer.

[0022] As an embodiment, the diallyl anhydride-acetyl acetate copolymer has a hydroxyl value of 25-52 mgKOH / g.

[0023] During experiments, the inventors discovered that by modifying polyethylene terephthalate (PET) using a β-crystal nucleating agent, talc, and a crystallization accelerator, a highly transparent and uniform PET material can be obtained. This PET material can be used to form full-bodied bottles with minimal shrinkage. The inventors speculate that the addition of a β-crystal nucleating agent, talc, and a crystallization accelerator to PET can miniaturize the PET's crystallite size. The hydroxyl groups of the crystallization accelerator react with the end groups of the PET molecules, reacting with the polar groups at the ends of the PET molecular chains to form homogeneous nucleation sites. These nuclei, provided in the molten state, transform from homogeneous nucleation to heterogeneous nucleation, resulting in the PET material having excellent formability, lower frictional resistance, and a full, tough, and non-shrinkable bottle body.

[0024] A second aspect of the present invention provides a method for preparing modified polyethylene terephthalate, comprising the following steps:

[0025] S1: Weigh polyethylene terephthalate, nucleating agent, antioxidant and crystallization accelerator in proportion and mix them evenly;

[0026] S2: melt blending is then performed, with the temperature controlled at 230-280°C;

[0027] S3: Extrusion, cooling and granulation to obtain modified polyethylene terephthalate.

[0028] As an embodiment, during melt blending in step S2, the temperature of the feeding zone is 230-250°C, the temperature of the compression zone is 250-270°C, and the temperature of the metering zone is 265-280°C.

[0029] As an embodiment, the rotation speed during melt blending in step S2 is 80-150 rpm.

[0030] As an embodiment, the extrusion temperature in step S3 is 270-275°C.

[0031] The third aspect of the present invention provides an application of modified polyethylene terephthalate, which is applied to modified polyethylene terephthalate packaging bottles.

[0032] As an embodiment, the modified polyethylene terephthalate packaging bottle includes but is not limited to skin care product shells, cosmetic shells, and perfume shells.

[0033] As an embodiment, the method for preparing the modified polyethylene terephthalate packaging bottle includes the following steps: injecting the modified polyethylene terephthalate into a mold under high pressure, maintaining the pressure and cooling to shape, thereby obtaining a modified polyethylene terephthalate shell.

[0034] As an embodiment, the mold temperature is 120-140°C.

[0035] During the experiment, the inventors further discovered that the addition of a β-crystal nucleating agent, talcum powder, and a crystallization accelerator accelerated the crystallization rate and shortened the molding cycle, which could cause polyethylene terephthalate to fog and whiten. The inventors used cold mold injection molding at 120-140°C to reduce the crystallization rate of polyethylene terephthalate, thereby preventing the polyethylene terephthalate from whitening at the injection and discharge points during the fixed mold molding process, and achieving high and uniform crystal transparency. Furthermore, the bottles produced using cold mold molding have greater impact resistance. When the mold temperature is less than 80°C, the product has high transparency, but the material is prone to warping. When the mold temperature is greater than 140°C, the product fully crystallizes, but the cooling time is prolonged, increasing costs.

[0036] As an embodiment, the pressure of the high-pressure injection is 60-120 MPa, the holding pressure is 30-84 MPa, and the holding time is 2-5 s.

[0037] As an embodiment, the thickness of the modified polyethylene terephthalate shell is 1-2 mm, and the cooling time is 10-20 s.

[0038] As an embodiment, the thickness of the modified polyethylene terephthalate shell is greater than 3 mm, and the cooling time is 30-50 s.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The modified polyethylene terephthalate of the present invention adopts the synergistic effect of a β-crystal nucleating agent, talc powder and a crystallization accelerator to modify polyethylene terephthalate. The resulting polyethylene terephthalate material can be prepared into full packaging bottles with a small shrinkage rate.

[0041] (2) The modified polyethylene terephthalate of the present invention is injection molded by a cold mold at 120-140°C, which reduces the crystallization rate of the polyethylene terephthalate, thereby making it less likely for the polyethylene terephthalate to turn white at the injection and discharge positions during the fixed mold molding process, and the crystallization transparency is high and uniform.

[0042] (3) The modified polyethylene terephthalate of the present invention is injection molded by a cold mold at 120-140°C. The water flow in the mold is good, and the cold mold molding has higher impact strength.

[0043] (4) The modified polyethylene terephthalate of the present invention adopts a combination of a β-crystal nucleating agent, talc powder and an antioxidant, has good moldability, lower molding friction resistance, and the formed bottle has good toughness and is not easy to shrink.

[0044] (5) The modified polyethylene terephthalate of the present invention can be electroplated, sprayed, and welded, and can be used to prepare skin care product shells, cosmetic shells, and perfume shells. It has a wide range of applications, a high heat deformation temperature, and good high temperature resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The bottle prepared from the modified polyethylene terephthalate of Example 1 has a transparent appearance;

[0046] Figure 2 The appearance of the bottle prepared from the modified polyethylene terephthalate of Example 1;

[0047] Figure 3 The bottle prepared from the modified polyethylene terephthalate of Comparative Example 1 has a transparent appearance;

[0048] Figure 4 The appearance of the bottle prepared from the modified polyethylene terephthalate of Comparative Example 1;

[0049] Figure 5 The bottle prepared from the modified polyethylene terephthalate of Comparative Example 2 has a transparent appearance.

[0050] Figure 5 Middle: Left: Comparative Example 2; Right: Example 1. DETAILED DESCRIPTION

[0051] Example 1

[0052] A modified polyethylene terephthalate is prepared from raw materials comprising, by weight, 95 parts of polyethylene terephthalate, 2.5 parts of a nucleating agent, 0.5 parts of an antioxidant and 0.4 parts of a crystallization accelerator.

[0053] The polyethylene terephthalate has an intrinsic viscosity of 0.8 dL / g at 100° C. and a melting point of 248° C. It was purchased from Changzhou China Resources and has a brand name of PET8816.

[0054] The nucleating agent includes a β-crystal nucleating agent and talc powder in a weight ratio of 0.5:2; the β-crystal nucleating agent is purchased from Milliken and the brand is Millad NX 800; the talc powder is purchased from Xufeng and the brand is BHS-170.

[0055] The antioxidant is a combination of a hindered phenol antioxidant and a phosphite antioxidant, with a weight ratio of 0.3:0.2.

[0056] The hindered phenol antioxidant is antioxidant Irganox 1076; the phosphite antioxidant is antioxidant Irgafos 168.

[0057] The crystallization accelerator is diallyl anhydride-acetyl acetate copolymer with a hydroxyl value of 25-52 mgKOH / g, purchased from Dongguan Tailong New Material Technology Co., Ltd. with the brand name PX-520.

[0058] A method for preparing modified polyethylene terephthalate comprises the following steps:

[0059] S1: Weigh polyethylene terephthalate, nucleating agent, antioxidant and crystallization accelerator in proportion and mix them evenly;

[0060] S2: melt blending is then performed, and the temperature is controlled;

[0061] S3: Extrusion, cooling and granulation to obtain modified polyethylene terephthalate.

[0062] During the melt blending in step S2, the temperature of the feeding zone is 230-250°C, the temperature of the compression zone is 250-270°C, and the temperature of the metering zone is 265-280°C.

[0063] The rotation speed during melt blending in step S2 is 100 rpm.

[0064] The extrusion temperature in step S3 is 270-275°C.

[0065] A method for preparing a modified polyethylene terephthalate packaging bottle comprises the following steps: injecting the modified polyethylene terephthalate into a mold under high pressure, maintaining the pressure, cooling and shaping the mold, and obtaining a modified polyethylene terephthalate shell.

[0066] The mold temperature is 120-140°C.

[0067] The pressure of the high-pressure injection is 100 MPa, the holding pressure is 50 MPa, and the holding time is 3 s.

[0068] The thickness of the modified polyethylene terephthalate shell is 1-2 mm, and the cooling time is 15 seconds.

[0069] Comparative Example 1

[0070] A modified polyethylene terephthalate is prepared from raw materials comprising, by weight, 95 parts of polyethylene terephthalate, 2.5 parts of a nucleating agent and 0.3 parts of an antioxidant.

[0071] The polyethylene terephthalate has an intrinsic viscosity of 0.8 dL / g at 100° C. and a melting point of 250° C. It was purchased from Shanghai Yuanfang with the brand name PETCB602.

[0072] The nucleating agent includes a β-crystal nucleating agent and talc powder in a weight ratio of 0.5:2; the β-crystal nucleating agent is purchased from Milliken and the brand is Millad NX 800; the talc powder is purchased from Xufeng and the brand is BHS-170.

[0073] The antioxidant is a hindered phenol antioxidant.

[0074] The hindered phenol antioxidant is the antioxidant Irganox 1076.

[0075] A method for preparing modified polyethylene terephthalate is the same as that in Example 1.

[0076] A method for preparing a modified polyethylene terephthalate packaging bottle is the same as that in Example 1.

[0077] Comparative Example 2

[0078] A modified polyethylene terephthalate is prepared from raw materials comprising, by weight, 90 parts of polyethylene terephthalate, 2.8 parts of a nucleating agent and 0.3 parts of an antioxidant.

[0079] The polyethylene terephthalate has an intrinsic viscosity of 0.8 dL / g at 100° C. and a melting point of 248° C. It was purchased from Changzhou China Resources and has a brand name of PET8816.

[0080] The nucleating agent includes a β-crystal nucleating agent and talc powder in a weight ratio of 0.8:2; the β-crystal nucleating agent is purchased from Clariant with a brand name of NaV 101; the talc powder is purchased from Xufeng with a brand name of BHS-170.

[0081] The antioxidant is a hindered phenol antioxidant.

[0082] The hindered phenol antioxidant is Irganox 1076.

[0083] A method for preparing modified polyethylene terephthalate is the same as that in Example 1.

[0084] A method for preparing a modified polyethylene terephthalate packaging bottle is the same as that in Example 1.

[0085] Performance Testing

[0086] 1. Density: The density of Example 1 was tested with reference to GB / T1033.2-2010.

[0087] 2. Viscosity: The viscosity of Example 1 was tested with reference to GB / T10247-2008 standard.

[0088] 3. Melt index: Refer to the melt index of Example 1 tested in accordance with GB / T3682.1-2018.

[0089] 4. Tensile strength: The tensile strength of Example 1 was tested with reference to GB / T1040.2-2006 standard.

[0090] 5. Elongation at break: The elongation at break of Example 1 was tested with reference to GB / T1040.3-2006.

[0091] 6. Bending strength: The bending strength of Example 1 was tested with reference to GB / T8812.2-2007.

[0092] 7. Flexural modulus: The flexural modulus of Example 1 was tested with reference to GB / T8812.2-2007.

[0093] 8. Impact strength: The impact strength of Example 1 was tested with reference to GB / T19466.3-2004.

[0094] 9. Heat Deformation Temperature: Refer to the heat deformation temperature of Example 1 tested in accordance with GB / T 1634.

[0095] The test results are shown in Table 1.

[0096] Table 1

[0097] Example 1 <![CDATA[Density (g / cm 3 )]]> 1.35 Viscosity (dl / L) 0.6 Melt index (g / 10min) 60 Tensile strength (MPa) 57 Elongation at break (%) 114 Flexural strength (MPa) 62 Flexural modulus (MPa) 2700 <![CDATA[Impact strength (kj / m 2 )]]> 6 Heat deformation temperature / ℃ 80

[0098] The bottle made of modified polyethylene terephthalate in Example 1 has a transparent appearance. Figure 1 , Figure 1 The bottom of the product is transparent; the appearance of the bottle prepared by the modified polyethylene terephthalate of Example 1 is shown in FIG. Figure 2 , Figure 2 The bottle of the product is full and has little shrinkage; the bottle prepared from the modified polyethylene terephthalate of comparative example 1 has a transparent appearance. Figure 3 , Figure 3 The bottom of the product is white; the appearance of the bottle prepared by the modified polyethylene terephthalate of Comparative Example 1 is shown in Figure 4 , Figure 4 The bottle of the product is shrunk and not full enough; the bottle prepared by the modified polyethylene terephthalate in comparative example 2 has a transparent appearance. Figure 5 , Figure 5 The bottle on the left side of the middle is not very transparent and is foggy, while the bottle on the right side is transparent.

Claims

1. A modified polyethylene terephthalate, characterized in that: The raw materials prepared include, by weight, 85-98 parts of polyethylene terephthalate, 1-5 parts of a nucleating agent, 0.1-1 parts of an antioxidant and 0.1-0.5 parts of a crystallization accelerator.

2. The modified polyethylene terephthalate according to claim 1, characterized in that The intrinsic viscosity of the polyethylene terephthalate at 100° C. is 0.5-1 dL / g.

3. The modified polyethylene terephthalate according to claim 1, characterized in that: The nucleating agent includes a β-crystal nucleating agent and an α-crystal nucleating agent, and the α-crystal nucleating agent includes at least one of an inorganic nucleating agent, a polymer nucleating agent or a carboxylic acid metal salt nucleating agent.

4. The modified polyethylene terephthalate according to claim 3, characterized in that: The β-crystal nucleating agent includes at least one of a phosphate nucleating agent, a carbonate nucleating agent, an amide nucleating agent, a nitrogen nucleating agent or a cobalt nucleating agent.

5. The modified polyethylene terephthalate according to claim 1, characterized in that: The antioxidant includes at least two of hindered phenol antioxidants, phosphite antioxidants or hindered amine antioxidants.

6. The modified polyethylene terephthalate according to claim 1, characterized in that: The crystallization accelerator includes at least one of acetate copolymer, terephthalamide or aromatic diamide compounds.

7. The modified polyethylene terephthalate according to claim 6, characterized in that: The acetate copolymer is a diallyl anhydride-acetyl acetate copolymer.

8. The modified polyethylene terephthalate according to claim 7, characterized in that: The hydroxyl value of the diallyl anhydride-acetyl acetate copolymer is 25-52 mgKOH / g.

9. A method for preparing the modified polyethylene terephthalate according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Weigh polyethylene terephthalate, nucleating agent, antioxidant and crystallization accelerator in proportion and mix them evenly; S2: melt blending is then performed, with the temperature controlled at 230-280°C; S3: Extrusion, cooling and granulation to obtain modified polyethylene terephthalate.

10. Use of the modified polyethylene terephthalate according to any one of claims 1 to 8, characterized in that: Used in modified polyethylene terephthalate packaging bottles.

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