High-gas-barrier composite PET (Polyethylene Terephthalate) material as well as preparation method and application thereof

Abstract

The invention discloses a high-gas-barrier composite PET (polyethylene terephthalate) material as well as a preparation method and application thereof, and relates to the technical field of high polymer materials, and the high-gas-barrier composite PET material comprises PET resin, PA-MXD6, glass flakes and alkyl polyol. According to the high-gas-barrier composite PET material disclosed by the invention, the PET resin is taken as a matrix, and PA-MXD6 is added to fill molecular gaps of the PET resin, so that a more compact composite material structure is formed, permeation channels of gas molecules are reduced, and the overall gas barrier property is improved. Meanwhile, a specific amount of alkyl polyol is added to serve as a third monomer, a gas barrier micro-network is formed in the material, and glass flakes of a compound thin-wall structure serve as a gas barrier medium, so that the gas barrier property and the mechanical strength of the material are improved, and the loss of light transmission is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more specifically, to a high gas barrier composite PET material and a preparation method and application thereof. Background Art

[0002] Polyethylene terephthalate (PET) resin has many advantages such as high strength, high transparency and low price. It is a widely used high molecular polyester resin, especially in the field of film and beverage bottles. However, compared with inorganic materials such as glass, the gas barrier property of pure PET material is still slightly insufficient, and it is difficult to meet the gas barrier property requirements of organic beverages such as beer and yogurt.

[0003] The existing methods for improving the gas barrier properties of PET include: multi-layer composite method, surface spraying method and single-layer blending modification method. Although the PET bottles developed by the multi-layer composite method can meet the barrier properties requirements of beverages such as beer, the multi-layer structure is prone to delamination between layers, and the technical requirements for production equipment are also high, requiring increased equipment investment. Moreover, no matter which barrier material is used in the interlayer, due to the coexistence of multiple layers of materials, there is a problem of difficulty in material recycling. The PET bottles produced by the surface spraying method have good transparency and are easy to recycle. However, because the coating is very thin, the coating is prone to cracks, shedding and delamination when the bottle is impacted by external force, affecting its barrier properties. Moreover, this technology requires the addition of surface coating equipment, and the product cost is relatively high. When the PET bottles prepared by the single-layer blending modification method improve the gas barrier properties, the light transmittance and mechanical strength of the bottles will be significantly reduced. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects and shortcomings of existing PET materials and provide a composite PET material that can have both light transmittance and gas barrier properties.

[0005] Another object of the present invention is to provide a method for preparing a high gas barrier composite PET material.

[0006] Another object of the present invention is to provide a high gas barrier composite PET material for use in preparing packaging films or beverage bottles.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] The present invention protects a high gas barrier composite PET material, comprising the following components in parts by weight:

[0009]

[0010]

[0011] Preferably, the minimum mass fraction of the PET in the composite PET material is 88%.

[0012] The high gas barrier composite PET material of the present invention uses PET resin as a matrix, and the addition of PA-MXD6 can fill the microcrystalline structure gap of the PET resin to form a denser composite material structure, reduce the permeation channel of gas molecules, and thus improve the overall gas barrier performance. At the same time, a specific amount of alkyl polyol is added as the third monomer to form a gas barrier micro-network in the material, and glass flakes with a thin-walled structure are compounded as a gas barrier medium, thereby improving the gas barrier and mechanical strength of the material and reducing the loss of light transmittance.

[0013] In some embodiments, the PET resin content that can achieve the purpose of the present invention can be 88 parts, 89 parts, 90 parts, 91 parts, 92 parts, 93 parts, 94 parts, and 95 parts.

[0014] In some embodiments, the intrinsic viscosity of the PET resin is 0.5-1 dl / g; preferably, the intrinsic viscosity is 0.7-0.9 dl / g.

[0015] Preferably, the melting point of the PET resin measured by a DSC primary heating curve is ≥248°C.

[0016] In some embodiments, the PA-MXD6 content that can achieve the purpose of the present invention can be 3 parts, 4 parts, 5 parts, 6 parts, or 7 parts.

[0017] In some embodiments, the relative viscosity of the PA-MXD6 is 2.0-2.8, and the relative viscosity is measured by 96% concentrated sulfuric acid using an Ubbelohde viscometer, and the test standard is ISO 307: 2007. Preferably, the relative viscosity is 2.0-2.5.

[0018] In some embodiments, the alkyl polyol is a C3-C10 alkyl polyol; preferably a C3-C5 alkyl polyol,

[0019] In some embodiments, the alkyl polyol is one or more of a diol or a triol.

[0020] In some embodiments, the alkyl polyol is one or more of glycerol, 1,2,3-butanetriol, 1,2,5-pentanetriol or 1,2-propylene glycol.

[0021] In some of the embodiments, the glass flake content capable of achieving the purpose of the present invention may be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts.

[0022] In some embodiments, the average thickness of the glass flakes is ≤6μm, and the average particle size is ≥100μm; the proportion of particles with a particle size of 45 to 300 microns is more than 80%, specifically more than 85%, more than 90%. Preferably, the average thickness of the glass flakes is 0.3 to 6μm, and the average particle size is 100 to 300μm; more preferably, the average thickness of the glass flakes is 0.5 to 1μm, and the average particle size is 140 to 200μm; the thickness is measured by electron microscopy, and the average particle size is measured by laser particle size analyzer.

[0023] In some embodiments, 0.02 to 0.1 parts of a color stabilizer are also included.

[0024] In some embodiments, the color stabilizer is at least one of a phosphite stabilizer, a hindered phenol stabilizer, and an amide stabilizer.

[0025] Preferably, the amide stabilizer is at least one of o-aminobenzamide, 1,8-diaminonaphthalene, allantoin and N,N'-1,6-hexanediylbis(2-amino-benzamide).

[0026] The PET material may also be added with conventional additives in the art, including but not limited to antioxidants, lubricants and processing aids; preferably, the content of the additives is ≤5wt.%.

[0027] The invention protects a preparation method of a high gas barrier composite PET material, comprising the following steps: uniformly mixing the raw material components in the formula, granulating by melt extrusion, and vacuum solid phase reaction (SSP) to obtain the composite PET material.

[0028] In some embodiments, the melt extrusion granulation is processed by a twin-screw extruder, wherein the temperature of zone 1 of the twin-screw extruder is 30-200°C, the temperature of zone 2 is 220-260°C, the temperature of zone 3 is 220-260°C, the temperature of zone 4 is 200-240°C, the temperature of zone 5 is 170-240°C, the temperature of zone 6 is 170-230°C, the temperature of zone 7 is 170-230°C, the temperature of zone 8 is 170-230°C, the temperature of zone 9 is 170-240°C, the temperature of the die head is 210-250°C, the residence time is 1-3 minutes, and the main engine speed is 300-500 rpm.

[0029] In some embodiments, the temperature of the vacuum solid phase reaction is 200-240°C.

[0030] In some embodiments, the vacuum solid phase reaction time is 4-6 hours.

[0031] In some embodiments, the high gas barrier composite PET material has an intrinsic viscosity of 0.78 to 0.90 dl / g.

[0032] The invention protects the use of a high gas barrier composite PET material in preparing packaging films or beverage bottles.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a high gas barrier composite PET material, which uses PET resin as a matrix, adds PA-MXD6 to fill the molecular gap of the PET resin, forms a denser composite material structure, reduces the permeation channel of gas molecules, and thus improves the overall gas barrier performance. At the same time, a specific amount of alkyl polyol is added as a third monomer to form a gas barrier micro-network in the material, and glass flakes with a thin-walled structure are compounded as a gas barrier medium, thereby improving the gas barrier and mechanical strength of the material and reducing the loss of light transmittance. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0036] The raw materials used in the following examples and comparative examples are as follows:

[0037] PET resin (A):

[0038] PET 1#: PET BG801, Sinopec Yizheng Chemical Fiber Co., Ltd.; intrinsic viscosity 0.80 dL / g;

[0039] PET 2#: PET BG85, Sinopec Yizheng Chemical Fiber Co., Ltd.; intrinsic viscosity 0.87 dL / g.

[0040] PA-MXD6 resin (B):

[0041] PA-MXD6 1#: Nylon-MXD6 CM001, Anshan Qicai Chemical Co., Ltd.; relative viscosity is 2.1.

[0042] PA-MXD6 2#: INGOO-MXD6-24, Shanghai Yinggu Chemical Co., Ltd.; relative viscosity is 2.4.

[0043] PA-MXD6 3#: Nylon-MXD6 CM007, Anshan Qicai Chemical Co., Ltd.; relative viscosity is 2.7.

[0044] PA66: PA66 U4800 NC01 SS, INVISTA Nylon Chemical (China) Co., Ltd.; relative viscosity is 2.7;

[0045] PA612: A120, Shanghai Yinggu Chemical Co., Ltd.; relative viscosity is 2.4;

[0046] The relative viscosity is measured by 96% concentrated sulfuric acid using an Ubbelohde viscometer, and the test standard is ISO 307:2007.

[0047] Glass Flakes (C):

[0048] Glass flake 1#: MEG160FY-M01, Nippon Sheet Glass Co., Ltd.; average thickness is 0.7 microns, average particle size is 160 microns, and the laser particle size analyzer measured that the proportion of 45 to 300 microns accounts for 90%.

[0049] Glass flake 2#: REF-160, Nippon Sheet Glass Co., Ltd.; average thickness is 5 microns, average particle size is 165 microns, and the proportion of 45 to 300 microns measured by a laser particle size analyzer is 92%.

[0050] Montmorillonite: MDH-6, Shanghai Zhuangjing Chemical Co., Ltd.

[0051] Alkyl polyol (D):

[0052] D1: glycerol, Suzhou Minghua Sugar Alcohol Co., Ltd.;

[0053] D2: 1,2,3-butanetriol, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0054] D3: 1,2,5-pentanetriol, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0055] D4: 1,2-propylene glycol, Henan Dingchi Chemical Co., Ltd.;

[0056] 1-Propanol, Jinan Qichen Chemical Co., Ltd.

[0057] Polyester polyol, molecular weight 300; CAPA 3031, Perstorp Group, France.

[0058] Color Stabilizer (E):

[0059] Color stabilizer 1#: 168, commercially available;

[0060] Color stabilizer 2#: N,N'-1,6-hexanediylbis(2-amino-benzamide), commercially available.

[0061] The following examples and comparative examples provide a method for preparing a high gas barrier composite PET material, comprising the following steps:

[0062] (1) The raw material components in the formula are mixed uniformly, and melt-extruded and granulated by a twin-screw extruder to obtain the high gas barrier composite PET material.

[0063] The temperature of zone 1 of the twin-screw extruder is 115°C, the temperature of zone 2 is 240°C, the temperature of zone 3 is 240°C, the temperature of zone 4 is 220°C, the temperature of zone 5 is 205°C, the temperature of zone 6 is 200°C, the temperature of zone 7 is 200°C, the temperature of zone 8 is 200°C, the temperature of zone 9 is 205°C, the head temperature is 230°C, the residence time is 2 minutes, and the main engine speed is 400 rpm.

[0064] (2) subjecting the high gas barrier composite PET material to vacuum solid phase reaction (SSP) at 220° C. for 5 hours to obtain a high gas barrier composite PET material.

[0065] Examples 1 to 13

[0066] This embodiment provides a high gas barrier composite PET material, and the raw material components are shown in Table 1.

[0067] Table 1 Raw material components of Examples 1 to 13 (parts by weight)

[0068]

[0069]

[0070] Comparative Examples 1 to 10

[0071] This comparative example provides a high gas barrier composite PET material, and the raw material components are shown in Table 2.

[0072] Table 2 Raw material components of comparative examples 1 to 10 (parts by weight)

[0073]

[0074] Performance Testing

[0075] The high gas barrier composite PET materials of Examples 1-13 and Comparative Examples 1-10 were subjected to the following tests:

[0076] 1. Oxygen permeability test: The test is carried out in accordance with GB / T 1038-2000 standard, the sample thickness is 0.25mm, and the test temperature is 23℃.

[0077] 2. Visible light transmittance: tested according to ISO 13468-1 standard, sample thickness is 2mm;

[0078] 3. Burst pressure test: Blow the sample into a beverage bottle and test the internal pressure resistance value according to QB-T 1868-2004 standard.

[0079] The results are shown in Table 3-4.

[0080] Table 3

[0081]

[0082] Table 4

[0083]

[0084] As can be seen from Table 3-4, the high gas barrier composite PET material of the present invention has high light transmittance, gas barrier and internal pressure resistance. Its visible light transmittance is more than 64%, and its oxygen permeability is less than 3.3cm 3 / (m 2 ·d·MPa), bursting pressure above 5.8Mpa.

[0085] Compared with Example 1, in Comparative Example 1, PA-MXD6 and glass flakes are not added, and its oxygen permeability is too high, the bursting pressure is reduced, and the gas barrier property and mechanical strength are poor.

[0086] Compared with Example 1, when polyamide PA66 or PA612 is used instead of PA-MXD6 in Comparative Examples 2-3, the oxygen permeability is too high and the gas barrier property is poor.

[0087] Compared with Example 1, when the propylene glycol in Comparative Example 4 is excessive, it will cause partial degradation of PET, significantly reduce the bursting pressure, and reduce the transparency and gas barrier properties; when the PA-MXD6 or glass flake content in Comparative Examples 5-6 is too high, its gas barrier properties are not significantly improved, but its visible light transmittance is significantly reduced. In Comparative Example 7, PA-MXD6 is used to replace glass flakes and propylene glycol. At this time, the light transmittance of the material is poor, and the gas barrier performance is reduced; in Comparative Example 8, montmorillonite is used to replace glass flakes, which not only greatly reduces the visible light transmittance of the material, reduces the gas barrier performance, but also greatly reduces the bursting pressure. In Comparative Examples 9-10, polyester polyols and propanol are used to replace propylene glycol, and the gas barrier performance of the material is reduced.

[0088] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A composite PET material, characterized in that: The composition includes the following components in parts by weight:

2. The composite PET material according to claim 1, characterized in that: The intrinsic viscosity of the PET resin is 0.5 to 1 dl / g.

3. The composite PET material according to claim 1, characterized in that: The relative viscosity of the PA-MXD6 is 2.0-2.

5.

4. The composite PET material according to claim 1, characterized in that: The alkyl polyol is a C3-C10 alkyl polyol.

5. The composite PET material according to claim 1, characterized in that: The alkyl polyol is a diol and / or a triol.

6. The composite PET material according to claim 1 or 4-5, characterized in that: The alkyl polyol is one or more of glycerol, 1,2,3-butanetriol, 1,2,5-pentanetriol or 1,2-propylene glycol.

7. The composite PET material according to claim 1, characterized in that: The average thickness of the glass flakes is 0.3 to 6 μm, and the average particle size is 100 to 300 μm.

8. A method for preparing the composite PET material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: uniformly mixing the raw material components in the formula amount, granulating by melt extrusion, and performing vacuum solid phase reaction to obtain the composite PET material.

9. The method for preparing the composite PET material according to claim 8, characterized in that: The temperature of the vacuum solid phase reaction is 200-240°C.

10. Use of the composite PET material according to any one of claims 1 to 7 in preparing packaging films or beverage bottles.

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