Anti-blocking matt masterbatch for polyester film and preparation method thereof

Abstract

The application discloses a kind of polyester film anti-adhesion matt masterbatch and preparation method thereof.The masterbatch includes PET polyester matrix, reactive composite particles, inorganic matt particles and reactive plasticizer;Reactive composite particles are prepared by solution polymerization from polymerizable olefin monomer, inorganic nanoparticles, surface-modified cage silsesquioxane, dynamic covalent chemistry network regulator and oil-soluble initiator.The reactive composite particles are prepared by solution polymerization first, and then melt-blended and granulated with the remaining components during preparation.The application solves the problem of poor interfacial compatibility of inorganic particles and polyester and easy falling off by constructing reactive organic-inorganic hybrid network, and introduces dynamic covalent bond to enhance the binding effect, and the step-by-step process avoids the mutual interference of multiple components during high-temperature processing.The obtained masterbatch has comprehensive properties such as anti-adhesion, matt and the like for polyester film, and is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to an anti-adhesion matte masterbatch for polyester film and its preparation method. Background Technology

[0002] Polyester film is widely used in packaging, electrical insulation, optoelectronic displays, and industrial release liner applications due to its excellent mechanical, optical, heat resistance, and electrical insulation properties. However, during the winding, storage, and use of the film, the film layers are prone to adhesion, causing the film to fail to open properly or resulting in surface damage, severely affecting subsequent processing and performance. Meanwhile, with the continuous development of industries such as consumer electronics and high-end packaging, the market has placed functional demands on the surface texture of films, including matte finishes, anti-reflective coatings, and anti-glare properties.

[0003] To address the film adhesion problem, existing technologies typically employ two methods: one is to coat the film surface with an anti-stick coating, and the other is to add inorganic anti-stick particles to prepare an anti-stick masterbatch. Among these, the masterbatch method has become the mainstream technology for industrial applications due to its advantages such as simple process, low cost, and good compatibility with existing film production lines. Traditional anti-stick matte masterbatches usually employ a simple physical blending method, mixing inorganic matte particles with a polyester matrix through melt extrusion granulation. However, this method has the following technical drawbacks:

[0004] First, the inorganic particles have poor interfacial compatibility with the polyester matrix. The inorganic particles are hydrophilic, while the polyester matrix is ​​oleophilic, resulting in weak interfacial bonding. During melt blending, the particles easily agglomerate, leading to uneven dispersion in the film. This not only affects the anti-sticking effect but also causes problems such as increased film haze, decreased transparency, and the appearance of crystal points on the surface. Second, the inorganic particles are prone to detachment. Due to the weak interfacial bonding, surface inorganic particles easily detach during film stretching or use, causing dust contamination and simultaneously reducing the anti-sticking performance.

[0005] Therefore, there is an urgent need for a production solution for anti-adhesion matte masterbatch for polyester film that combines excellent interfacial bonding, long-lasting and stable anti-sticking effect, simple preparation process, and suitability for industrial production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an anti-adhesion matte masterbatch for polyester films and its preparation method, thereby solving the problems of poor interfacial compatibility between anti-adhesion particles and polyester matrix, easy agglomeration and detachment, poor anti-adhesion effect and lack of durability in existing technologies.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A matte masterbatch for polyester film, comprising the following components by weight: 100 parts PET polyester matrix; 5-14 parts reactive composite particles; 1-8 parts inorganic matte particles; and 1-3 parts reactive plasticizer, wherein the reactive plasticizer contains epoxy groups in its molecule, which can react with the PET end groups.

[0009] The reactive composite particles are composed of the following substances in parts by weight: 100 parts polymerizable olefin monomers, 5-10 parts inorganic nanoparticles; 2-10 parts surface-modified cage-like silsesquioxanes with organic functional groups containing carbon-carbon unsaturated bonds bonded to their surface; 2-8 parts dynamic covalent chemical network regulators, whose molecules contain at least one dynamic covalent bond unit that can undergo reversible breakage and recombination in the temperature range of 180-280℃; 0.5-3 parts oil-soluble initiator; and an appropriate amount of organic solvent.

[0010] Furthermore, the inorganic matte particles are selected from at least one of silica, diatomaceous earth, talc, and calcium carbonate, with an average particle size of 1-10 μm; the inorganic nanoparticles are nano-silica or nano-alumina, with an average particle size of 10-100 nm.

[0011] Furthermore, the reactive plasticizer is at least one of epoxidized soybean oil, glycidyl ether compounds, or epoxidized fatty acid esters.

[0012] Furthermore, the polymerizable olefin monomer is at least one of methacrylate monomers, styrene, or vinyl acetate.

[0013] Furthermore, the surface-modified cage-like silsesquioxane is at least one of methacryloxypropyl cage-like silsesquioxane, acryloxypropyl cage-like silsesquioxane, or vinyl cage-like silsesquioxane, and the surface-modified cage-like silsesquioxane has organic functional groups containing carbon-carbon unsaturated bonds bonded to its surface.

[0014] Furthermore, the dynamic covalent chemical network modifier is at least one of a furan-maleimide adduct based on the Diels-Alder reaction and an aromatic disulfide.

[0015] Furthermore, the oil-soluble initiator is at least one of azobisisobutyronitrile, azobisisoheptanenitrile, or benzoyl peroxide.

[0016] Furthermore, the organic solvent is at least one of toluene, xylene, ethyl acetate, or acetone.

[0017] This invention also provides a method for preparing an anti-adhesion matte masterbatch for polyester film, comprising the following steps:

[0018] Step S1, Preparation of reactive composite particles:

[0019] a. Disperse polymerizable olefin monomers, inorganic nanoparticles, surface-modified cage-like silsesquioxanes, and dynamic covalent chemical network regulators in an organic solvent to obtain a uniform dispersion for 30-60 minutes.

[0020] b. Add an oil-soluble initiator to the dispersion, heat to 60-100℃ under an inert atmosphere, stir and react for 4-12 hours to obtain a reaction slurry;

[0021] c. Remove the organic solvent from the reaction slurry, dry it, and obtain reactive composite particles;

[0022] Step S2, Preparation of masterbatch:

[0023] d. Mix the PET polyester matrix, the reactive composite particles obtained in step c, the inorganic matte particles, and the reactive plasticizer evenly to obtain a premix. The mixing time is 5-15 minutes.

[0024] e. Add the premix to a twin-screw extruder for melt blending and extrusion, then granulate to obtain an anti-sticking matte masterbatch.

[0025] Compared with the prior art, the present invention has the following beneficial effects: by pre-preparing reactive composite particles and then melt-blending them with PET matrix, the present invention not only solves the problem of poor compatibility between inorganic particles and polyester interface and easy agglomeration and shedding, but also achieves a synergistic improvement in anti-sticking, matte finish and long-lasting durability. Detailed Implementation

[0026] The present invention will now be described in detail through specific embodiments:

[0027] Example 1

[0028] This embodiment provides an anti-adhesion matte masterbatch and its preparation method.

[0029] (1) Preparation of reactive composite particles:

[0030] By weight, 100 parts of polymerizable olefin monomer, 5 parts of inorganic nanoparticles, 2 parts of surface-modified cage-like silsesquioxane, and 2 parts of dynamic covalent chemical network regulator were dispersed in an organic solvent and ultrasonically dispersed for 40 minutes to obtain a uniform dispersion. 0.5 parts of oil-soluble initiator were added to the dispersion, and the mixture was heated to 75°C under nitrogen protection and stirred for 8 hours to obtain a reaction slurry. The organic solvent was removed from the reaction slurry by spray drying, and the reactive composite particles were obtained after drying.

[0031] In this step, the polymerizable olefin monomer is methyl methacrylate, the inorganic nanoparticles are nano-silica, the surface-modified cage-like silsesquioxane is methacryloyloxypropyl cage-like silsesquioxane, the dynamic covalent chemical network regulator is a furan-maleimide adduct based on the Diels-Alder reaction, the organic solvent is xylene, and the oil-soluble initiator is azobisisobutyronitrile.

[0032] (2) Preparation of anti-adhesion matte masterbatch:

[0033] By weight, take 100 parts of PET polyester matrix, 5 parts of reactive composite particles obtained in step (1), 1 part of inorganic matte particles, and 1 part of reactive plasticizer, mix them in a high-speed mixer for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, melt-blend and extrude at 260°C and 300 rpm, and after water cooling, air drying and pelletizing, obtain an anti-sticking matte masterbatch.

[0034] In this step, the inorganic matte particles are calcium carbonate, and the reactive plasticizer is epoxidized soybean oil.

[0035] Example 2

[0036] The difference between this embodiment and Example 1 lies in the amount of components used, the type of polymerizable olefin monomer, the type of dynamic covalent chemical network regulator, and the type of cage-like silsesquioxane for surface modification.

[0037] (1) Preparation of reactive composite particles:

[0038] By weight, 100 parts of polymerizable olefin monomer, 10 parts of inorganic nanoparticles, 10 parts of surface-modified cage-like silsesquioxane, and 8 parts of dynamic covalent chemical network regulator were dispersed in an organic solvent and ultrasonically dispersed for 40 minutes to obtain a uniform dispersion. 3 parts of oil-soluble initiator were added to the dispersion, and the mixture was heated to 75°C under nitrogen protection and stirred for 8 hours to obtain a reaction slurry. The organic solvent was removed from the reaction slurry by spray drying, and the reactive composite particles were obtained after drying.

[0039] In this step, the polymerizable olefin monomer is a mixture of methyl methacrylate and styrene in a 1:1 mass ratio, the inorganic nanoparticles are nano-silica, the surface-modified cage-like silsesquioxane is acryloyloxypropyl cage-like silsesquioxane, the dynamic covalent chemical network regulator is an aromatic disulfide, the organic solvent is xylene, and the oil-soluble initiator is azobisisobutyronitrile.

[0040] (2) Preparation of anti-adhesion matte masterbatch:

[0041] By weight, take 100 parts of PET polyester matrix, 14 parts of reactive composite particles obtained in step (1), 8 parts of inorganic matte particles, and 3 parts of reactive plasticizer, mix them in a high-speed mixer for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, melt-blend and extrude at 260°C and 300 rpm, and after water cooling, air drying and pelletizing, obtain an anti-sticking matte masterbatch.

[0042] In this step, the inorganic matte particles are calcium carbonate, and the reactive plasticizer is epoxidized soybean oil.

[0043] Example 3

[0044] The difference between this embodiment and Example 1 lies in the amount of components used, the type of polymerizable olefin monomer, and the type of cage-like silsesquioxane used for surface modification.

[0045] (1) Preparation of reactive composite particles:

[0046] By weight, 100 parts of polymerizable olefin monomer, 8 parts of inorganic nanoparticles, 7 parts of surface-modified cage-like silsesquioxane, and 5 parts of dynamic covalent chemical network regulator were dispersed in an organic solvent and ultrasonically dispersed for 40 minutes to obtain a uniform dispersion. 1 part of oil-soluble initiator was added to the dispersion, and the mixture was heated to 75°C under nitrogen protection and stirred for 8 hours to obtain a reaction slurry. The organic solvent was removed from the reaction slurry by spray drying, and the reactive composite particles were obtained after drying.

[0047] In this step, the polymerizable olefin monomer is vinyl acetate, the inorganic nanoparticles are nano-silica, the surface-modified cage-like silsesquioxane is vinyl cage-like silsesquioxane, the dynamic covalent chemical network regulator is an aromatic disulfide, the organic solvent is xylene, and the oil-soluble initiator is azobisisobutyronitrile.

[0048] (2) Preparation of anti-adhesion matte masterbatch:

[0049] By weight, take 100 parts of PET polyester matrix, 10 parts of reactive composite particles obtained in step (1), 5 parts of inorganic matte particles, and 2 parts of reactive plasticizer, mix them in a high-speed mixer for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, melt-blend and extrude at 260℃ and screw speed of 300 rpm, and after water cooling, air drying and pelletizing, obtain an anti-sticking matte masterbatch.

[0050] In this step, the inorganic matte particles are calcium carbonate, and the reactive plasticizer is epoxidized soybean oil.

[0051] Comparative Example 1

[0052] Comparative Example 1 uses a traditional physical blending method to prepare an anti-adhesion matte masterbatch that does not contain reactive composite particles.

[0053] Take 100 parts of PET polyester matrix, 5 parts of inorganic matte particles, 8 parts of inorganic nanoparticles, and 2 parts of plasticizer, mix them in a high-speed mixer for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, melt-blend and extrude at 260℃ and screw speed of 300rpm, and after water cooling, air drying, and pelletizing, obtain an anti-sticking matte masterbatch.

[0054] In this step, the inorganic matte particles are calcium carbonate, the inorganic nanoparticles are nano-silica, and the reactive plasticizer is epoxidized soybean oil.

[0055] Comparative Example 2

[0056] The difference between Comparative Example 2 and Example 3 is that no dynamic covalent chemical network modifier is added to the reactive composite particles.

[0057] (1) Preparation of reactive composite particles:

[0058] By weight, 100 parts of polymerizable olefin monomer, 8 parts of inorganic nanoparticles, and 7 parts of surface-modified cage-like silsesquioxane were dispersed in an organic solvent and ultrasonically dispersed for 40 minutes to obtain a uniform dispersion. 1 part of oil-soluble initiator was added to the dispersion, and the mixture was heated to 75°C under nitrogen protection and stirred for 8 hours to obtain a reaction slurry. The organic solvent was removed from the reaction slurry by spray drying, and the reactive composite particles were obtained after drying.

[0059] In this step, the polymerizable olefin monomer is vinyl acetate, the inorganic nanoparticles are nano-silica, the surface-modified cage-like silsesquioxane is vinyl cage-like silsesquioxane, the organic solvent is xylene, and the oil-soluble initiator is azobisisobutyronitrile.

[0060] (2) Preparation of anti-adhesion matte masterbatch:

[0061] By weight, take 100 parts of PET polyester matrix, 10 parts of reactive composite particles obtained in step (1), 5 parts of inorganic matte particles, and 2 parts of reactive plasticizer, mix them in a high-speed mixer for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, melt-blend and extrude at 260℃ and screw speed of 300 rpm, and after water cooling, air drying and pelletizing, obtain an anti-sticking matte masterbatch.

[0062] In this step, the inorganic matte particles are calcium carbonate, and the reactive plasticizer is epoxidized soybean oil.

[0063] Comparative Example 3

[0064] The difference between Comparative Example 3 and Example 3 is that no surface-modified cage-like silsesquioxane is added to the reactive composite particles.

[0065] (1) Preparation of reactive composite particles:

[0066] By weight, 100 parts of polymerizable olefin monomer, 8 parts of inorganic nanoparticles, and 5 parts of dynamic covalent chemical network regulator were dispersed in an organic solvent and ultrasonically dispersed for 40 minutes to obtain a uniform dispersion. 1 part of oil-soluble initiator was added to the dispersion, and the mixture was heated to 75°C under nitrogen protection and stirred for 8 hours to obtain a reaction slurry. The organic solvent was removed from the reaction slurry by spray drying, and the reactive composite particles were obtained after drying.

[0067] In this step, the polymerizable olefin monomer is vinyl acetate, the inorganic nanoparticles are nano-silica, the dynamic covalent chemical network regulator is an aromatic disulfide, the organic solvent is xylene, and the oil-soluble initiator is azobisisobutyronitrile.

[0068] (2) Preparation of anti-adhesion matte masterbatch:

[0069] By weight, take 100 parts of PET polyester matrix, 10 parts of reactive composite particles obtained in step (1), 5 parts of inorganic matte particles, and 2 parts of reactive plasticizer, mix them in a high-speed mixer for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, melt-blend and extrude at 260℃ and screw speed of 300 rpm, and after water cooling, air drying and pelletizing, obtain an anti-sticking matte masterbatch.

[0070] In this step, the inorganic matte particles are calcium carbonate, and the reactive plasticizer is epoxidized soybean oil.

[0071] Comparative Example 4

[0072] Comparative Example 4 uses a water-soluble initiator and a one-step melt blending method.

[0073] By weight, 100 parts of PET polyester matrix, 12 parts of polymerizable olefin monomer, 1.2 parts of inorganic nanoparticles, 0.6 parts of surface-modified cage-like silsesquioxane, 0.6 parts of dynamic covalent chemical network regulator, 0.18 parts of water-soluble initiator (ammonium persulfate), 0.5 parts of pH buffer, 5 parts of inorganic matte particles, and 2 parts of reactive plasticizer were mixed evenly in a high-speed mixer and then directly added to a twin-screw extruder for melt blending and extrusion at 260°C and a screw speed of 300 rpm. During the extrusion process, unstable die discharge and the generation of a large number of bubbles were observed, resulting in a rough surface of the extrudate. After water cooling, air drying, and pelletizing, masterbatch granules were obtained, but the granules contained obvious pores.

[0074] Performance testing and results analysis:

[0075] The masterbatches obtained in Examples 1-3 and Comparative Examples 1-4 were prepared into films using the same process. Specifically, the masterbatches and pure PET resin were mixed at a mass ratio of 1:8, dried, melt-extruded, and biaxially stretched to produce film samples with a thickness of 25 μm. The following performance tests were then performed:

[0076] 1. Anti-stick performance test: The test is conducted in accordance with GB / T 16276-1996 "Test method for adhesion of plastic films". Two film samples are stacked together and placed at 60℃ and 0.5 MPa pressure for 24 hours. The peel force (N / m) is measured. The smaller the peel force, the better the anti-stick performance.

[0077] 2. Matteness test: According to GB / T 8807-1988 "Test method for specular gloss of plastic", the gloss value of the film is measured at a 60° angle using a gloss meter. The lower the gloss value, the better the matte effect.

[0078] Surface defect evaluation: The surface of the thin film is observed under a 100x optical microscope to evaluate the number of defects such as crystal points and agglomerates, and rated as "none", "few" or "more".

[0079] Interface bonding strength test: The tape peeling method was used. 3M tape was pasted on the film surface, compacted, and then quickly peeled off at a 180° angle. The surface particles were observed with a scanning electron microscope and rated as "no peeling", "minor peeling", and "major peeling".

[0080] The test results are shown in the table below:

[0081]

[0082] Results analysis:

[0083] The overall performance of Examples 1-3 is superior to that of the comparative examples. The peel strength of Examples 1-3 is significantly lower than that of Comparative Examples 1-4, indicating that the masterbatch of the present invention has a good anti-sticking effect; the gloss value is low, and the matte effect is significant; there are few surface defects, and the inorganic particles are uniformly dispersed; the interfacial bonding is strong, and the particles are not easy to fall off.

[0084] Comparative Example 1 exhibited the highest peel strength but the worst anti-sticking effect, numerous surface defects, severe particle detachment, and no repair properties. This indicates that simple physical blending cannot solve the interfacial compatibility problem between inorganic particles and the PET matrix. Comparative Example 2 showed poor repair performance with no obvious healing phenomenon, and its anti-sticking performance and interfacial bonding strength were also slightly worse than Example 3, indicating that the introduction of dynamic covalent bonds also had a synergistic enhancing effect on interfacial bonding. Comparative Example 3 had both inferior anti-sticking performance and interfacial bonding strength compared to Example 3, indicating that the introduction of surface-modified cage-like silsesquioxane plays an important role in constructing a stable organic-inorganic hybrid network and improving the dispersibility of inorganic particles and interfacial bonding strength. Comparative Example 4 showed obvious bubbles during extrusion, with pores in the masterbatch particles, resulting in numerous surface defects, poor interfacial bonding, and poor anti-sticking performance in the final film, verifying the necessity of using the two-step process of this invention.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A matte anti-adhesion masterbatch for polyester film, characterized in that, The product comprises the following components by weight: 100 parts PET polyester matrix; 5-14 parts reactive composite particles; 1-8 parts inorganic matte particles; and 1-3 parts reactive plasticizer. The reactive plasticizer contains epoxy groups in its molecule, which can react with the end groups of PET. The reactive composite particles are composed of the following substances in parts by weight: 100 parts polymerizable olefin monomers; 5-10 parts inorganic nanoparticles; 2-10 parts surface-modified cage-like silsesquioxanes with organic functional groups containing carbon-carbon unsaturated bonds bonded to their surface; 2-8 parts dynamic covalent chemical network regulators, whose molecules contain at least one dynamic covalent bond unit that can undergo reversible breakage and recombination in the temperature range of 180-280℃; 0.5-3 parts oil-soluble initiator; and an appropriate amount of organic solvent.

2. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The inorganic matte particles are selected from at least one of silica, diatomaceous earth, talc, and calcium carbonate, with an average particle size of 1-10 μm; the inorganic nanoparticles are nano-silica or nano-alumina, with an average particle size of 10-100 nm.

3. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The reactive plasticizer is at least one of epoxidized soybean oil, glycidyl ether compounds, or epoxidized fatty acid esters.

4. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The polymerizable olefin monomer is at least one of methacrylate monomers, styrene, or vinyl acetate.

5. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The surface-modified cage-like silsesquioxane is at least one of methacryloxypropyl cage-like silsesquioxane, acryloxypropyl cage-like silsesquioxane, or vinyl cage-like silsesquioxane.

6. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The dynamic covalent chemical network modifier is at least one of a furan-maleimide adduct based on the Diels-Alder reaction and an aromatic disulfide.

7. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The oil-soluble initiator is at least one of azobisisobutyronitrile, azobisisoheptanenitrile, or benzoyl peroxide.

8. The anti-adhesion matte masterbatch for polyester film according to claim 1, characterized in that, The organic solvent is at least one of toluene, xylene, ethyl acetate, or acetone.

9. A method for preparing an anti-adhesion matte masterbatch for polyester film as described in any one of claims 1-8, characterized in that, Includes the following steps: Step S1, Preparation of reactive composite particles: a. Disperse polymerizable olefin monomers, inorganic nanoparticles, surface-modified cage-like silsesquioxanes, and dynamic covalent chemical network regulators in an organic solvent to obtain a uniform dispersion for 30-60 minutes. b. Add an oil-soluble initiator to the dispersion, heat to 60-100℃ under an inert atmosphere, stir and react for 4-12 hours to obtain a reaction slurry; c. Remove the organic solvent from the reaction slurry, dry it, and obtain reactive composite particles; Step S2, Preparation of masterbatch: d. Mix the PET polyester matrix, the reactive composite particles obtained in step c, the inorganic matte particles, and the reactive plasticizer evenly to obtain a premix. The mixing time is 5-15 minutes. e. Add the premix to a twin-screw extruder for melt blending and extrusion, then granulate to obtain an anti-sticking matte masterbatch.

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