Polyester-based composite calendering film material and preparation method thereof

Abstract

The invention relates to the field of polymer composite materials, discloses a polyester-based composite calendering film material and a preparation method thereof, and particularly discloses a nano composite calendering film material based on a polyester / polyolefin blending system. The material is mainly composed of 60-80% of low-melting-point PET / HDPE, 10-25% of light nano calcium carbonate, 1-5% of calcium stearate, 5% of needle-like wollastonite, 3-8% of nano TiO2, 2-5% of PE-g-MAH and 2-5% of GMA-polyester, and a plasticizer, a heat stabilizer, a softening agent and an antioxidant are not needed. The tensile strength of the obtained film is larger than or equal to 45 MPa in the longitudinal direction, larger than or equal to 38 MPa in the transverse direction (ASTM D882), the right-angle tearing strength is larger than or equal to 120 kN / m (GB / T16578.2), and the film passes FDA 21 CFR 177.1520 food contact safety certification. The material adopts non-toxic, harmless and recyclable infant-grade green and environment-friendly raw materials, has the characteristics of high strength, high toughness, good processability, no toxicity, environment friendliness and the like, and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the field of polymer composite materials, discloses a polyester-based composite calendered film material and a preparation method thereof, and specifically discloses a nano-composite calendered film material based on a polyester / polyolefin blend system. Background Art

[0002] Traditional PVC film materials present numerous challenges, including the presence of heavy metal stabilizers and hazardous volatile substances, the need for the use of plasticizers and other small-molecule oils, the environmentally unfriendly effects of precipitation, and the generation of toxic and harmful gases upon combustion, posing a threat to the environment and human health. Furthermore, their stability, processing, and mechanical properties struggle to meet growing market demands, necessitating the development of a new, non-toxic, environmentally friendly, and high-performance material. Summary of the Invention

[0003] In view of this, the present invention discloses a polyester-based composite calendering film material and a preparation method thereof.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A polyester-based composite calendered film material, comprising the following components by mass percentage:

[0006] Low melting point PET / HDPE 60-80%, lightweight nano calcium carbonate 10-25%, calcium stearate 1-5%, needle-shaped wollastonite 5%, nano-TiO2 3-8%, PE-g-MAH 2-5%, GMA-polyester 2-5%.

[0007] Furthermore, in the low-melting-point PET / HDPE, the mass ratio of low-melting-point PET to HDPE is 65-95:35-5.

[0008] Furthermore, the particle size of the light nano-calcium carbonate is in the range of 200-800 nm.

[0009] Furthermore, the particle size of the nano-TiO2 ranges from 30 to 100 nm.

[0010] The present invention also seeks to protect a method for preparing the polyester-based composite calendered film material as described above, comprising the following steps:

[0011] (1) low melting point PET / HDPE, light nano calcium carbonate, calcium stearate, needle-shaped wollastonite, nano TiO2, PE-g-MAH, and GMA-PET are mixed uniformly in proportion;

[0012] (2) The mixed material is formed into a film through a calendering process, with a calendering temperature of 140-195° C. and a calendering speed of 30-100 m / min.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The core of the present invention is to develop a new polyester-based composite calendered film material and its preparation method. In terms of raw material selection, heavy metal stabilizers, volatile harmful substances, and small molecule oil agents such as plasticizers that need to be added in traditional PVC film materials are discarded. Low-melting-point PET / HDPE is selected as the main component, and light nano-calcium carbonate, calcium stearate, needle-shaped wollastonite, nano-TiO2, PE-g-MAH, GMA-polyester and other non-toxic, harmless, recyclable and green raw materials for infants and children are used.

[0015] (2) Through rational formulation design, the various components work synergistically to impart numerous excellent properties to the material. Low-melting-point PET / HDPE provides excellent basic performance, lightweight nano-calcium carbonate enhances the material's hardness and dimensional stability, needle-shaped wollastonite further improves the material's strength and toughness, and nano-TiO2 not only improves the material's weather resistance but also enhances its antibacterial properties. PE-g-MAH and GMA-polyester act as compatibilizers, effectively improving the compatibility between the various components and enabling the material to form a stable structure.

[0016] (3) In terms of preparation method, a specific mixing process is used to uniformly mix the raw materials, and then a calendering process with precisely controlled calendering temperature and speed is used to produce a calendered film material with specific properties. The entire process does not require plasticizers, heat stabilizers, softeners, or antioxidants, ensuring that the material is non-toxic and environmentally friendly. At the same time, its tensile strength is ≥45MPa and it has passed FDA 21CFR177.1520 food contact safety certification, which has broad application prospects in various fields such as packaging and food contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0018] Figure 1 These are scanning electron microscope (SEM) images of a PVC calendered film and a polyester-based composite calendered film of the present invention, wherein A and B are the surface and cross-sectional micromorphologies of the PVC calendered film, respectively; C and D are the surface and cross-sectional micromorphologies of the polyester-based composite calendered film, respectively. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The term "embodiment" is used herein specifically to describe any embodiment as "exemplary," and should not be construed as superior or preferable to other embodiments. Performance indicators in the embodiments of this application were tested using conventional testing methods in the art, unless otherwise specified. It should be understood that the terms used in this application are intended solely to describe specific implementations and are not intended to limit the disclosure herein.

[0021] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0022] In order to better illustrate the content of this application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that this application can be implemented without certain specific details. In the examples, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of this application.

[0023] Under the premise of no conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of this application.

[0024] The invention discloses a polyester-based composite calendering film material and a preparation method thereof.

[0025] Physical and chemical parameters of raw materials and manufacturer information:

[0026] 1. Low melting point PET: The melting point is generally 110-190℃, the intrinsic viscosity is 0.65-0.85dL / g, Sinopec Yizheng Branch.

[0027] HDPE (high-density polyethylene), melt index (MI) 0.62-1.3g / 10min, Yangzi Petrochemical.

[0028] 2. Lightweight nano calcium carbonate: average particle size is 500nm, specific surface area is 20-50m 2 / g, whiteness>90%, calcium carbonate content ≥98%, Jiangxi Guangyuan Chemical Co., Ltd.

[0029] 3. Calcium stearate: calcium content is 6.5%-7.0%, free acid (calculated as stearic acid) ≤0.5%, Jiangxi Hongyuan Chemical.

[0030] 4. Needle-shaped wollastonite: aspect ratio 25, SiO2 content ≥45%, CaO content ≥40%, Jilin Yuantong Mine Co., Ltd.

[0031] 5. Nano-TiO2: average particle size 80nm, specific surface area 10-30m 2 / g, TiO2 content ≥99%, Nanjing Hitech Nanomaterials Co., Ltd.

[0032] 6. PE-g-MAH (maleic anhydride grafted polyethylene): maleic anhydride grafting rate 1.5%, melt flow rate (MFR) 5.5 g / 10 min (190°C, 2.16 kg), Hangzhou Sumengte Chemical Co., Ltd.

[0033] 7. GMA-polyester (glycidyl methacrylate-polyester): GMA content is 8-12%, glass transition temperature (Tg) is 50°C, Jiangsu Sanmu Group Co., Ltd.

[0034] For a better understanding of the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content are also considered to fall within the scope of protection of the present invention.

[0035] Example 1

[0036] 1. Raw material preparation: By mass percentage, prepare 66% low-melting point PET / HDPE (mass ratio is 90:10), 15% lightweight nano-calcium carbonate (particle size is 500nm), 3% calcium stearate, 5% needle-shaped wollastonite, 5% nano-TiO2 (particle size is 80nm), 3% PE-g-MAH, and 3% GMA-polyester.

[0037] 2. Mixing process: Add the above raw materials into a high-speed mixer and mix them at a speed of 2600 rpm for 3 minutes to ensure that the raw materials are fully mixed.

[0038] 3. Calendering: The mixed materials are fed into the calendering machine. The temperature settings of each section are: planetary machine 180℃, rolling mill 165℃, filter 158℃, I roller 178℃, II roller 185℃, III roller 189℃, IV roller 155℃. Calendering is carried out at a calendering speed of 79m / min to produce a polyester-based composite calendered film material with a thickness of 90 microns.

[0039] 4. Performance test: The prepared film was subjected to performance testing, and the tensile strength reached 47 MPa, and the yellowing index ΔYI after 2000 hours of QUV aging was 2.0, and it passed FDA 21CFR 177.1520 food contact safety certification.

[0040] Heavy metal detection: Using inductively coupled plasma emission spectrometry, no heavy metals such as lead, mercury, and cadmium were detected, meeting strict environmental safety requirements.

[0041] VOC detection: Gas chromatography-mass spectrometry did not detect any volatile organic compounds, indicating that the material will not generate VOC pollution during use.

[0042] Example 2

[0043] 1. Raw material preparation: By mass percentage, prepare 60% low-melting point PET / HDPE (mass ratio is 80:20), 20% lightweight nano calcium carbonate (particle size is 500nm), 3% calcium stearate, 5% needle-shaped wollastonite, 4% nano TiO2 (particle size is 80nm), 4% PE-g-MAH, and 4% GMA-polyester.

[0044] 2. Mixing process: Add the above raw materials into a high-speed mixer and mix them at a speed of 1200 rpm for 5 minutes to ensure that the raw materials are fully mixed.

[0045] 3. Calendering: The mixed materials are fed into the calender. The temperature settings of each section are: planetary machine 175°C, rolling mill 160°C, filter 149°C, I roller 168°C, II roller 175°C, III roller 182°C, IV roller 150°C. The calendering is carried out at a calendering speed of 92 m / min to produce a polyester-based composite calendered film material with a thickness of 70 μm.

[0046] 4. Performance test: The prepared film was subjected to performance testing, and the tensile strength reached 45 MPa, and the yellowing index ΔYI after 2000 hours of QUV aging was 1.8, and it passed FDA 21CFR 177.1520 food contact safety certification.

[0047] Example 3

[0048] 1. Raw material preparation: By mass percentage, prepare 70% low-melting point PET / HDPE (mass ratio is 70:30), 18% lightweight nano-calcium carbonate (particle size is 300nm), 2% calcium stearate, 5% needle-shaped wollastonite, 3% nano-TiO2 (particle size is 50nm), 1.5% PE-g-MAH, and 0.5% GMA-polyester.

[0049] 2. Mixing process: Add the above raw materials into a high-speed mixer and mix them at a speed of 2000 rpm for 4 minutes to ensure that the raw materials are fully mixed.

[0050] 3. Calendering: The mixed materials are fed into the calendering machine. The temperature settings of each section are: planetary machine 170℃, rolling mill 155℃, filter 145℃, I roller 165℃, II roller 172℃, III roller 178℃, IV roller 148℃. The calendering is carried out at a calendering speed of 60m / min to produce a polyester-based composite calendered film material with a thickness of 80 microns.

[0051] 4. Performance Testing

[0052] Tensile strength: 46 MPa in longitudinal direction and 40 MPa in transverse direction (ASTM D882).

[0053] Right-angle tear strength: 125kN / m (GB / T 16578.2).

[0054] Chemical corrosion resistance: The film was immersed in 5% hydrochloric acid solution, 5% sodium hydroxide solution and 95% ethanol solution. After immersion at room temperature for 72 hours, no obvious swelling, discoloration or damage was observed on the surface of the film, indicating that the material has good chemical corrosion resistance.

[0055] Puncture resistance: The film was tested using a falling dart impact tester with a dart mass of 300g and a height of 1m. No puncture damage was found on the film, indicating that the material has good puncture resistance.

[0056] The yellowing index ΔYI after 2000 hours of QUV aging is 2.2.

[0057] Other properties: Passed FDA 21CFR 177.1520 food contact safety certification, heavy metal testing did not detect heavy metals such as lead, mercury, cadmium, and VOC testing did not detect any volatile organic compounds.

[0058] Example 4

[0059] 1. Raw material preparation: By mass percentage, prepare 75% low-melting point PET / HDPE (mass ratio of 85:15), 12% lightweight nano-calcium carbonate (particle size of 600nm), 4% calcium stearate, 5% needle-shaped wollastonite, 2.5% nano-TiO2 (particle size of 70nm), 1% PE-g-MAH, and 0.5% GMA-polyester.

[0060] 2. Mixing process: Add the above raw materials into a high-speed mixer and mix them at a speed of 1800 rpm for 3.5 minutes to ensure that the raw materials are fully mixed.

[0061] 3. Calendering: The mixed materials are fed into the calendering machine. The temperature settings of each section are: planetary machine 185°C, rolling mill 168°C, filter 155°C, I roller 175°C, II roller 182°C, III roller 186°C, IV roller 152°C. The calendering is carried out at a calendering speed of 80m / min to produce a polyester-based composite calendered film material with a thickness of 75 microns.

[0062] 4. Performance Testing

[0063] Tensile strength: 48 MPa in longitudinal direction and 42 MPa in transverse direction (ASTM D882).

[0064] Right-angle tear strength: 130kN / m (GB / T 16578.2).

[0065] The yellowing index ΔYI after 2000 hours of QUV aging is 1.9.

[0066] Other properties: Passed FDA 21CFR 177.1520 food contact safety certification, heavy metal test and VOC test results meet environmental protection standards.

[0067] Example 5

[0068] 1. Raw material preparation: By mass percentage, prepare 80% low-melting point PET / HDPE (mass ratio of 65:35), 10% lightweight nano-calcium carbonate (particle size of 800nm), 5% calcium stearate, 5% needle-shaped wollastonite, 3% nano-TiO2 (particle size of 100nm), 1.5% PE-g-MAH, and 0.5% GMA-polyester.

[0069] 2. Mixing process: Add the above raw materials into a high-speed mixer and mix them for 2.5 minutes at a speed of 2200 rpm to ensure that the raw materials are fully mixed.

[0070] 3. Calendering: The mixed materials are fed into the calendering machine. The temperature settings of each section are: planetary machine 190℃, rolling mill 172℃, filter 160℃, I roller 180℃, II roller 187℃, III roller 190℃, IV roller 158℃. The calendering is carried out at a calendering speed of 90m / min to produce a polyester-based composite calendered film material with a thickness of 85 microns.

[0071] 4. Performance Testing

[0072] Tensile strength: 45 MPa in longitudinal direction and 39 MPa in transverse direction (ASTM D882).

[0073] Right-angle tear strength: 122kN / m (GB / T 16578.2).

[0074] Other properties: Passed FDA 21CFR 177.1520 food contact safety certification, and after testing, heavy metals and VOCs are within the standard.

[0075] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples are provided to further illustrate the technical features disclosed in the present invention, but they should not be construed as limiting the present invention. Other improvements made by those skilled in the art based on the above invention without inventive work are also considered to fall within the scope of protection of the present invention.

[0076] Comparative Example

[0077] A traditional PVC calendering film material commonly found on the market was selected as a comparative example.

[0078] 1. Performance test: The performance test of traditional PVC calendered film materials under the same conditions showed that the tensile strength was only 30MPa, the yellowing index ΔYI after 2000 hours of QUV aging was 5.0, and it was detected to contain heavy metal stabilizers (lead content 80ppm, cadmium content 120ppm) and volatile harmful substances, and failed to pass FDA 21CFR 177.1520 food contact safety certification. In the combustion test, the traditional PVC calendered film material produced a large amount of black smoke and toxic and harmful gases (hydrogen chloride 1350ppm, dioxins 2.0ng TEQ / m 3 ).

[0079] 2. Comparative analysis: Compared with the polyester-based composite calendered film material of the present invention, the traditional PVC calendered film material has obvious disadvantages in terms of strength, aging resistance, environmental performance and food contact safety, which fully demonstrates the superiority of the material of the present invention.

[0080] Furthermore, if Figure 1 A and Figure 1 B shows that there are particles protruding on the surface of the PVC film, and the surface is not smooth and delicate enough; the filler is randomly distributed in the PVC matrix, and the compatibility and bonding between the filler and the matrix are poor. In contrast, the surface of the polyester-based composite calendered film prepared by the present invention is smooth and flat ( Figure 1 C), and the cross-sectional morphology shows that the membrane matrix material is uniform and continuous, the filler has good compatibility with the matrix material, and the filler is evenly distributed; the needle-shaped wollastonite and the calcium powder filler overlap to form a continuous network structure ( Figure 1 D) to improve the mechanical properties of the membrane material while ensuring the dimensional stability of the material.

[0081] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A polyester-based composite calendered film material, characterized in that: By mass percentage, it is composed of the following ingredients: Low melting point PET / HDPE 60-80%, lightweight nano calcium carbonate 10-25%, calcium stearate 1-5%, needle-shaped wollastonite 5%, nano-TiO2 3-8%, PE-g-MAH 2-5%, GMA-polyester 2-5%.

2. The polyester-based composite calendered film material according to claim 1, characterized in that: In the low-melting-point PET / HDPE, the mass ratio of low-melting-point PET to HDPE is 65-95:35-5.

3. The polyester-based composite calendered film material according to claim 1, characterized in that: The particle size of the light nano calcium carbonate is in the range of 200-800 nm.

4. The polyester-based composite calendered film material according to claim 1, characterized in that: The particle size of the nano-TiO2 ranges from 30 to 100 nm.

5. A method for preparing a polyester-based composite calendered film material according to claim 1, characterized in that: The following steps are involved: (1) low melting point PET / HDPE, light nano calcium carbonate, calcium stearate, needle-shaped wollastonite, nano TiO2, PE-g-MAH, and GMA-PET are mixed uniformly in proportion; (2) The mixed material is formed into a film through a calendering process, with a calendering temperature of 140-195° C. and a calendering speed of 30-100 m / min.

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