A single-sided matte polyester film and a method for manufacturing the same

Abstract

This invention discloses a single-sided matte polyester film and its preparation method. The single-sided matte polyester film includes a polyester base film, one side of which has an online-coated matte coating. The online-coated matte coating is formed by online coating and curing of acrylic adhesive, calcium acetate particles, zinc sulfide particles, polydimethylsiloxane, ethyl acrylate, and sodium bicarbonate particles. An offline protective coating can be further coated on the outer side of the online-coated matte coating. The matte effect of the single-sided matte polyester film of this invention is obtained through online coating during the production process of the polyester base film. The polyester base film itself maintains its original properties and there is no weakening of its performance after stretching. Furthermore, since online coating is performed simultaneously with film stretching, chemicals are directly applied to the film using an online coating machine, eliminating the need to modify the film stretching production line. This method is simpler and less costly than multilayer co-extrusion processes.

Description

Technical Field

[0001] This invention relates to a single-sided matte polyester film and its preparation method. Background Technology

[0002] Single-sided matte polyester film has wide applications in product packaging, printing, art preservation, and architectural decoration, among others. Its matte surface gives products or materials a higher level of quality and grade. The versatility of single-sided matte polyester film is primarily due to its unique properties and characteristics. For example, in the packaging materials industry, single-sided matte polyester film is commonly used for packaging high-end goods such as electronics, food, and cosmetics. Its matte surface enhances the texture and appearance of the product. In printing and advertising, matte polyester film can be used for advertising materials, posters, flyers, etc., making the printed materials more exquisite and increasing their texture and tactile appeal. In lamination and coating, single-sided matte polyester film can enhance the protection of images, reduce reflectivity, and minimize light interference during the lamination of images, photographs, and documents. In the field of art or cultural relic preservation, matte polyester film can be used to cover the surface of artworks to prevent damage from dust and fingerprints. In the construction and decoration industries, matte polyester film, when coated on surfaces such as glass, metal, and plastic, can enhance the texture of the materials and improve the appearance of architectural and decorative products. In the labeling industry, single-sided matte polyester film is suitable for producing water-based labels, commonly used in bottled beverage and cosmetic packaging. Additionally, in the manufacturing of electronic devices, single-sided matte polyester film is frequently used to create buttons and panels, enhancing the product's appearance and tactile feel.

[0003] CN 106739367 B discloses a single-sided matte polyester film having a co-extruded double-layer structure composed of a matte film layer and a base film layer. The matte film layer consists of 10-100% polyester masterbatch containing additives and the remainder being polyester base material. The additive content in the polyester masterbatch accounts for 6-10% of the total mass of the polyester masterbatch. The additives in the polyester masterbatch consist of silica and auxiliary fillers, and the particle size of the additives is 6-8 μm. The auxiliary fillers are selected from at least one of calcium carbonate, hollow glass microspheres, alumina, kaolin, and titanium dioxide.

[0004] CN 114619745 B discloses a multilayer matte polyester film, comprising a base film and a matte film, wherein the middle layer is the base film and the matte films are located on both sides of the base film, obtained by co-extrusion technology; the raw material of the matte film includes matte additives, which are polymer-grafted modified silica microspheres and polystyrene microspheres, and the polymer-grafted modified monomers are (meth)acrylate alkyl ester and isobornyl acrylate; the D90 of the polymer-grafted modified silica microspheres is 50-500 nm, and the D90 of the polystyrene microspheres is 2-10 μm.

[0005] The aforementioned existing single-sided matte polyester film is prepared using a multi-layer co-extrusion process, wherein the matte layer is obtained by adding solid particles such as silica to the matte film. To achieve a sufficient matte effect, the particle size of the added solid particles generally needs to reach a certain level, and a sufficient amount is also required. Adding too many large-diameter solid particles will create voids within the matte layer during film stretching, reducing the density and strength of the matte layer. This results in insufficient tear resistance of the outer matte layer, making it prone to breakage and fragmentation. Furthermore, due to the porosity of the stretched film layer, it is easily permeated by colorants, resulting in patches and a rapid deterioration of the surface texture. Summary of the Invention

[0006] The technical problem to be solved by this application is to provide a single-sided matte polyester film and a method for preparing the same, so as to reduce or avoid the problems mentioned above.

[0007] To address the aforementioned technical problems, this application proposes a single-sided matte polyester film, comprising a polyester base film, wherein one side surface of the polyester base film has an online-coated matte coating layer, wherein the online-coated matte coating layer is formed by online coating and curing of acrylic adhesive, calcium acetate particles, zinc sulfide particles, polydimethylsiloxane, ethyl acrylate, and sodium bicarbonate particles.

[0008] Preferably, an offline protective coating is further applied to the outer side of the online matte coating.

[0009] Preferably, the offline protective coating is composed of 50-60 parts by weight of polymethyl methacrylate, 5-10 parts by weight of dimethyl terephthalate, 10-20 parts by weight of methyltriethoxysilane, and 5-10 parts by weight of calcium phosphate particles.

[0010] Preferably, the mass ratio of each component in the online matte coating is 100:(4-8):(5-10):(30-60):(20-40):(3-6).

[0011] This invention also proposes a method for preparing a single-sided matte polyester film. The single-sided matte polyester film includes a polyester base film, one side of which has an online-coated matte coating layer. The online-coated matte coating layer is formed by online coating and curing of acrylic adhesive, calcium acetate particles, zinc sulfide particles, polydimethylsiloxane, ethyl acrylate, and sodium bicarbonate particles. The preparation method includes the following steps: using polyester chips as raw material, a thick sheet is obtained by melt extrusion, preheated, and then longitudinally stretched into a stretched sheet, followed by transverse stretching, shaping, cooling, and winding. Alternatively, after obtaining the thick sheet and before longitudinal stretching, the components of the online-coated matte coating layer are mixed and coated onto the thick sheet, followed by longitudinal and transverse stretching to obtain a single-sided matte polyester film with an online-coated matte coating layer; or, after longitudinal stretching and before transverse stretching, the components of the online-coated matte coating layer are mixed and coated onto the stretched sheet, followed by transverse stretching to obtain a single-sided matte polyester film with an online-coated matte coating layer.

[0012] Preferably, the preparation method further includes the following steps: polyester chips are weighed by an electronic scale, preheated and dried at 160℃~180℃ and mixed, then the mixture is added to a twin-screw extruder, the temperature of the twin-screw extruder is adjusted to 270℃~280℃, after melting, filtered, and extruded into thick sheets; the above thick sheets are preheated at 50℃~90℃, and then placed in an infrared heating zone at 300℃~500℃, and longitudinally stretched at a linear speed of 40~150m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain stretched sheets; the stretched sheets are preheated at 90℃~120℃, and transversely stretched at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5; then shaped at 160℃~240℃, and then cooled at 100℃~50℃, and finally the single-sided matte polyester film of this application is obtained.

[0013] Preferably, the preparation method further includes the step of applying an offline protective coating to the outside of the online coated matte coating by offline coating, wherein the offline protective coating is composed of 50-60 parts by weight of polymethyl methacrylate, 5-10 parts by weight of dimethyl terephthalate, 10-20 parts by weight of methyltriethoxysilane, and 5-10 parts by weight of calcium phosphate particles.

[0014] Preferably, the preparation method further includes the following steps: the components constituting the offline protective coating are added to 50-200 parts by weight of diethyl ether and 50-100 parts by weight of deionized water at a ratio of 100 parts by weight, and then uniformly mixed. The mixture is then coated on the outer surface of the online matte coating by offline coating and cured at 90-130°C for 10-60 seconds to obtain the offline protective coating.

[0015] The matte effect of the single-sided matte polyester film of this application is achieved through online coating of a matte coating during the production process of the polyester base film. The polyester base film itself maintains its original properties and there is no weakening of its performance after stretching. Furthermore, since online coating involves applying chemicals directly to the film using an online coating machine during film stretching, it eliminates the need to modify the film stretching production line, making it simpler and less costly than multi-layer co-extrusion processes. Online coating also reduces the film rewinding step, resulting in faster operation, higher efficiency, and lower costs. Additionally, due to the matte coating, the finished product achieves an anti-blocking effect without the need to add anti-blocking particles to the polyester base film. Attached Figure Description

[0016] The accompanying drawings are intended only to illustrate and explain this application and do not limit the scope of this application.

[0017] Figure 1 The diagram shown is a cross-sectional schematic of a single-sided matte polyester film according to a specific embodiment of this application.

[0018] Figure 2 The diagram shown is a cross-sectional schematic of a single-sided matte polyester film according to another specific embodiment of this application.

[0019] Figure 3 The diagram shown is a structural schematic of a manufacturing apparatus for a single-sided matte polyester film according to a specific embodiment of this application.

[0020] Figure 4 What is displayed is Figure 3 A schematic diagram of the offline protective coating application mechanism set up on the basis. Detailed Implementation

[0021] To provide a clearer understanding of the technical features, objectives, and effects of this application, specific embodiments are now described with reference to the accompanying drawings. Identical components are denoted by the same reference numerals.

[0022] Due to the shortcomings of existing multilayer co-extruded matte films, this application proposes a single-sided matte polyester film and its preparation method. In a specific embodiment of this application, the single-sided matte polyester film includes a polyester base film 1, and one side surface of the polyester base film 1 has an online-coated matte coating 2, such as... Figure 1 As shown. In another specific embodiment of this application, the single-sided matte polyester film of this application includes a polyester base film 1, one side surface of the polyester base film 1 has an online-coated matte coating 2, and the outer side of the online-coated matte coating 2 is coated with an offline protective coating 3, as shown. Figure 2 As shown.

[0023] The matte effect of the single-sided matte polyester film of this application is achieved through online coating of a matte coating during the production process of the polyester base film. The polyester base film itself maintains its original properties and there is no weakening of its performance after stretching. Furthermore, since online coating involves applying chemicals directly to the film using an online coating machine during film stretching, it eliminates the need to modify the film stretching production line, making it simpler and less costly than multi-layer co-extrusion processes. Online coating also reduces the film rewinding step, resulting in faster operation, higher efficiency, and lower costs. Additionally, due to the matte coating, the finished product achieves an anti-blocking effect without the need to add anti-blocking particles to the polyester base film.

[0024] In addition, Figure 2 In the illustrated embodiment, in order to improve the durability of the online coated matte coating 2, an offline protective coating 3 can be added to its outer side by offline coating. The offline protective coating 3 can not only provide sufficient protection, but also fill the areas of uneven thickness caused by the stretching of the online coated matte coating 2, so that the thickness of the entire finished film layer is consistent, avoiding the problem of inconsistent matte effect caused by uneven film thickness, and further improving the product texture and durability.

[0025] As mentioned earlier, the components of the primer liquid constituting the online-coated matte coating 2 are not applied to the surface of the already prepared polyester film, but rather during the preparation of the polyester base film 1. That is, after the raw materials constituting the polyester base film 1 are melt-extruded into a base film sheet, the mixed primer liquid is applied onto the base film sheet. Then, as the base film sheet is stretched into a film of the required thickness, the primer liquid components coated on its surface become thinner with stretching. During the stretching process, it simultaneously undergoes mechanical deformation and high-temperature chemical changes before curing to form the online-coated matte coating 2.

[0026] The polyester film of the present invention may be selected from one or more polycarboxylic acids containing diacids and their esterifying derivatives, and a polyester film formed with one or more polyols containing diols; or a polyester film formed from hydroxycarboxylic acids and their esterifying derivatives; or a polyester film formed from cyclic esters. The polyester film can be manufactured according to known methods. For example, the polyester in the polyester film may be formed by polycondensation of diacids and diols. For example, the dicarboxylic acid components include, but are not limited to, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 3,4'-diphenyl ether dicarboxylic acid, hexahydrophthalic acid, 2,7-naphthalenedicarboxylic acid, phthalic acid, 4,4'-methylenebisbenzoic acid, oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 3-methyl adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, 1,11-undecanedicarboxylic acid, 1,10-decanedicarboxylic acid, undecanediic acid, 1,12-dodecanedicarboxylic acid, hexadecanediic acid, docosanodiic acid, tetradecanediic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,1-cyclohexanediacetic acid, fumaric acid, maleic acid, and hexahydrophthalic acid. Furthermore, it can be used alone or in combination with two or more other acids. For example, the diol components include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, glycol, diethylene glycol, triethylene glycol, poly(ethylene ether) glycol, and poly(butylene ether) glycol. Alcohols, branched diols, hexanediol or combinations thereof or their derivatives, 1,4-cyclohexanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-2,4-pentanediol, neopentanediol, 2-methyl-1,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,5-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 1,3-hexanediol. Alternatively, they can be used alone or in combination of two or more.

[0027] The polyester in the polyester-based film of the present invention can also be formed by hydroxycarboxylic acids and their esterifying derivatives, or by cyclic esters. For example, the hydroxycarboxylic acid components include, but are not limited to: lactic acid, citric acid, malic acid, tartaric acid, glycolic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, 4-hydroxycyclohexanecarboxylic acid, etc. The esterifying derivatives of the hydroxycarboxylic acids include, but are not limited to: dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl 3,4'-diphenyl ether dicarboxylate, dimethyl hexahydrophthalate, dimethyl 2,7-naphthalenedicarboxylate, dimethyl phthalate, dimethyl 4,4'-methylenebisbenzoate, dimethyl oxalate, dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl azelaate, dimethyl 1,3-cyclohexanedicarboxylate, and dimethyl 5-sulfoisophthalate. Furthermore, they can be used alone or in combination. For example, the cyclic esters include, but are not limited to: ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, lactide, etc. Additionally, they can be used alone or in combination.

[0028] The polyester in the polyester-based film of the present invention is preferably polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, poly(1,4-cyclohexanediol) terephthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate and copolymers thereof, and particularly preferably polyethylene terephthalate (PET) and copolymers thereof.

[0029] The polyester in the polyester-based film of the present invention, taking PET as an example, is preferably prepared by esterification or transesterification of terephthalic acid or dimethyl terephthalate and ethylene glycol to produce diethyl terephthalate, and industrially manufactured by polycondensation using a catalyst under high temperature and vacuum. In one specific embodiment, esterification can be carried out using terephthalic acid, ethylene glycol, cyclohexanediol, a catalyst, and a heat stabilizer as raw materials; or esterification can be carried out using terephthalic acid, ethylene glycol, isophthalic acid, a catalyst, and a heat stabilizer as raw materials. In another specific embodiment, the catalyst is any one of Ti / Si non-heavy metal catalysts and antimony trioxide, and its addition amount is 0.01-0.09% of the polyester mass. In another specific embodiment, the heat stabilizer is a phosphoric acid compound, and its addition amount is 0.0003-0.030% of the polyester mass; the phosphoric acid compound includes any one of phosphoric acid, phosphorous acid, polyphosphoric acid, trimethyl phosphate, triphenyl phosphate, and triethyl phosphate. Another specific embodiment of the polyester preparation method is as follows: 5.0 kg of terephthalic acid, 2.2 kg of ethylene glycol, and 1.10 g of germanium dioxide are added to a 20 L general-purpose polymerization reactor. The esterification reaction is carried out at 230–265 °C and 0.2–0.3 MPa (gauge pressure). When the water output reaches 1200 ml, the pressure is released to atmospheric pressure, and 1.025 g of triethyl phosphate is added. The mixture is stirred at atmospheric pressure for 10 minutes, the temperature is raised to 280 °C and the pressure is lowered to below 100 Pa. After the reaction is completed in 1–3 hours, the mixture is extruded, granulated, and dried to obtain polyester chips.

[0030] In one specific embodiment, the polyester-based film of the present invention can be prepared by the following steps.

[0031] For example, using polyester chips as raw material, a thick sheet is obtained through melt extrusion, preheated, and then longitudinally stretched into a stretched sheet. This stretched sheet is then transversely stretched, shaped, cooled, and wound to obtain a polyester-based film. Of course, since online coating is required during the preparation of the polyester-based film, the components for the online matte coating can be mixed and coated onto the thick sheet after obtaining the sheet but before longitudinal stretching. Then, through longitudinal and transverse stretching, a single-sided matte polyester film with an online matte coating is obtained. Alternatively, the components for the online matte coating can be mixed and coated onto the stretched sheet after longitudinal stretching but before transverse stretching. Then, through transverse stretching, a single-sided matte polyester film with an online matte coating is obtained. If necessary, an offline protective coating can be further applied to the outside of the online matte coating using an offline coating method.

[0032] In one specific embodiment, the online-coated matte coating 2 can be formed by online coating and curing of acrylic adhesive, calcium acetate particles, zinc sulfide particles, polydimethylsiloxane, ethyl acrylate, and sodium bicarbonate particles.

[0033] Specifically, the mass ratio of each component in the online matte coating 2 is as follows: acrylic adhesive: calcium acetate particles: zinc sulfide particles: polydimethylsiloxane: ethyl acrylate: sodium bicarbonate 100:(4-8):(5-10):(30-60):(20-40):(3-6). The acrylic adhesive can be, for example, SAA1451 acrylic adhesive produced by Xi'an Aerospace Sanwo Chemical Co., Ltd., with a solid content of 40%-45% by mass. The particle size of the calcium acetate particles, zinc sulfide particles, and sodium bicarbonate is 100-500 nm.

[0034] Example 1

[0035] PET chips are preheated and dried at 160℃~180℃ and then fed into a twin-screw extruder. The temperature of the twin-screw extruder is adjusted to 270℃~280℃. After melting, the chips are filtered and extruded into thick sheets. The components of the online matte coating of this application are uniformly mixed and coated onto the thick sheet. Then, the thick sheet is preheated at 50℃~90℃ and placed in an infrared heating zone at 300℃~500℃. It is then longitudinally stretched at a linear speed of 40~150m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain a stretched sheet. The stretched sheet is preheated at 90℃~120℃ and transversely stretched at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5. It is then shaped at 160℃~240℃, cooled at 100℃~50℃, and finally wound up to obtain the single-sided matte polyester film of this application.

[0036] Polyester base film: PET, thickness 20μm

[0037] Online matte coating: 1μm thickness

[0038] Example 2

[0039] PETG chips are preheated and dried at 160℃~180℃ and then fed into a twin-screw extruder. The temperature of the twin-screw extruder is adjusted to 270℃~280℃. After melting, the chips are filtered and extruded into thick sheets. The thick sheets are preheated at 50℃~90℃ and then placed in an infrared heating zone at 300℃~500℃. They are then longitudinally stretched at a linear speed of 40~150m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain stretched sheets. The components of the online matte coating of this application are uniformly mixed and coated onto the stretched sheets. Then, the stretched sheets are preheated at 90℃~120℃ and transversely stretched at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5. After setting at 160℃~240℃, they are cooled at 100℃~50℃. After setting, cooling, and finally winding, the single-sided matte polyester film of this application is obtained.

[0040] Polyester base film: PETG, thickness 50μm

[0041] Online matte coating: 2μm thickness

[0042] The following reference Figure 3 The manufacturing equipment further illustrates the preparation method of the single-sided matte polyester film of this application, wherein, Figure 3 The diagram shown is a structural schematic of a manufacturing apparatus for a single-sided matte polyester film according to a specific embodiment of this application.

[0043] As shown in the figure, the manufacturing equipment for the single-sided matte polyester film of this application, in accordance with the film stretching process, includes, in sequence, a chip preheating and drying device 100, a twin-screw extruder 200, a longitudinal stretching mechanism 300, a transverse stretching mechanism 400, a heat setting mechanism 401, a cooling mechanism 402, and a first take-up roller 500. An online coating mechanism 600 is disposed between the twin-screw extruder 200 and the longitudinal stretching mechanism 300; or, as shown by the dotted line in the figure, the online coating mechanism 600 may also be disposed between the longitudinal stretching mechanism 300 and the transverse stretching mechanism 400.

[0044] The method for preparing the single-sided matte polyester film in this embodiment includes the following steps.

[0045] Polyester chips are weighed using an electronic scale and then preheated and dried in a chip preheating and drying equipment 100 at 160℃~180℃. The mixture is then added to a twin-screw extruder 200, and the temperature of the extruder is adjusted to 270℃~280℃. After melting, the mixture is filtered and extruded into thick sheets. These sheets are preheated at 50℃~90℃ and then enter the infrared heating zone of a longitudinal stretching mechanism 300 at a heating temperature of 300℃~500℃. They are then longitudinally stretched at a linear speed of 40~150 m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain stretched sheets. The stretched sheets are preheated at 90℃~120℃ and then enter a transverse stretching mechanism 400 at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5. The film is then set at 160°C to 240°C in the heat setting mechanism 401, cooled at 100°C to 50°C in the cooling mechanism 402, and finally wound up by the first take-up roller 500 to obtain the single-sided matte polyester film of this application.

[0046] In this process, online coating can be performed after extruding the thick sheet and before longitudinal stretching. Alternatively, online coating can be performed after longitudinal stretching and before transverse stretching. The specific steps are as follows: uniformly mix the components of the online coating to form a primer, preheat it to 80°C, and then apply the online coating primer to the thick sheet or stretched sheet.

[0047] Furthermore, in Figure 2 In the specific embodiment shown, an offline protective coating 3 can also be applied to the outside of the online matte coating 2 by offline coating. The offline protective coating 3 is used to protect the online matte coating 2 and cover the uneven areas on the surface of the online matte coating 2 to maintain a consistent thickness of the final product.

[0048] In one specific embodiment, the offline protective coating 3 may be composed of 50-60 parts by weight of polymethyl methacrylate, 5-10 parts by weight of dimethyl terephthalate, 10-20 parts by weight of methyltriethoxysilane, and 5-10 parts by weight of calcium phosphate particles (particle size 100-500 nm). The components constituting the offline protective coating 3 may be added to 50-200 parts by weight of diethyl ether and 50-100 parts by weight of deionized water at a ratio of 100 parts by weight, mixed uniformly, and then coated onto the outer surface of the online-coated matte coating 2 by offline coating. Curing at 90-130°C for 10-60 seconds yields the offline protective coating 3 of the present invention.

[0049] Therefore, in Figure 3 Based on the manufacturing equipment shown, the manufacturing equipment of this application is further provided with an offline protective coating coating mechanism 700 for forming an offline protective coating, such as... Figure 4 As shown.

[0050] like Figure 4 As shown, the manufacturing equipment for the single-sided matte polyester film of this embodiment further includes an offline protective coating mechanism 700 disposed downstream of the first take-up roller 500. To cure the offline protective coating, an infrared heating device 701 is further included downstream of the offline protective coating mechanism 700 for infrared irradiation curing of the offline protective coating. Additionally, the manufacturing equipment of this application may further include a second take-up roller 800 for winding the prepared single-sided matte polyester film into a roller shape, after which it can be packaged for transportation, sales, etc.

[0051] Correspondingly, the preparation method of this embodiment further includes the following steps:

[0052] The raw material components of the offline protective coating are uniformly mixed to obtain the offline protective coating primer. The mixed offline protective coating primer is uniformly coated onto the surface of the polyester base film, and finally cured by heating with infrared heating equipment 701 to form the offline protective coating, thereby obtaining the single-sided matte polyester film of this application. Finally, it is taken into rolls by the second take-up roller 800 for subsequent transportation and sales.

[0053] Example 3

[0054] PET chips are preheated and dried at 160℃~180℃ and then fed into a twin-screw extruder. The temperature of the twin-screw extruder is adjusted to 270℃~280℃. After melting, the chips are filtered and extruded into thick sheets. The components of the online matte coating of this application are uniformly mixed and coated onto the thick sheets. Then, the thick sheets are preheated at 50℃~90℃ and placed in an infrared heating zone at 300℃~500℃. They are then longitudinally stretched at a linear speed of 40~150m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain stretched sheets. The stretched sheets are preheated at 90℃~120℃ and transversely stretched at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5. They are then shaped at 160℃~240℃, cooled at 100℃~50℃, and finally wound up. Each component constituting the offline protective coating is added to 50 parts by weight of ether and 50 parts by weight of deionized water at a ratio of 100 parts by weight, and then uniformly mixed. The mixture is then coated onto the outer surface of the online matte coating by offline coating and cured at 90-130°C for 30 seconds to obtain the single-sided matte polyester film of this application.

[0055] Polyester base film: PET, thickness 80μm

[0056] Online matte coating: 1.5μm thickness

[0057] Offline protective coating: 2μm thick

[0058] Example 4

[0059] PETG chips are preheated and dried at 160℃~180℃ and then fed into a twin-screw extruder. The temperature of the twin-screw extruder is adjusted to 270℃~280℃. After melting, the chips are filtered and extruded into thick sheets. The thick sheets are preheated at 50℃~90℃ and then placed in an infrared heating zone at 300℃~500℃. They are then longitudinally stretched at a linear speed of 40~150m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain stretched sheets. The components of the online matte coating of this application are uniformly mixed and coated onto the stretched sheets. The stretched sheets are then preheated at 90℃~120℃ and transversely stretched at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5. Afterward, they are shaped at 160℃~240℃, cooled at 100℃~50℃, and finally wound up. Each component constituting the offline protective coating is added to 200 parts by weight of ether and 100 parts by weight of deionized water at a ratio of 100 parts by weight, and then uniformly mixed. The mixture is then coated onto the outer surface of the online matte coating by offline coating and cured at 90-130°C for 60 seconds to obtain the single-sided matte polyester film of this application.

[0060] Polyester base film: PETG, thickness 100μm

[0061] Online matte coating: 0.5μm thickness

[0062] Offline protective coating: 3μm thick

[0063] The raw material components (parts by weight) and performance parameters of Examples 1 to 4 above are shown in the table below.

[0064]

[0065] The raw material components (parts by weight) and performance parameters of the comparative examples of the above embodiments are shown in the table below.

[0066]

[0067] In summary, the matte effect of the single-sided matte polyester film of this application is achieved through online coating of a matte coating during the production process of the polyester base film. The polyester base film itself maintains its original properties and there is no weakening of its performance after stretching. Furthermore, since online coating involves directly applying chemicals to the film using an online coating machine during film stretching, it eliminates the need to modify the film stretching production line, making it simpler and less costly than multi-layer co-extrusion. Online coating also reduces the film rewinding process, resulting in faster operation, higher efficiency, and lower costs. Additionally, due to the matte coating, the finished product achieves an anti-blocking effect without the need to add anti-blocking particles to the polyester base film.

[0068] Those skilled in the art should understand that although this application is described by way of multiple embodiments, not every embodiment contains only one independent technical solution. This description is merely for clarity, and those skilled in the art should understand the specification as a whole and consider the technical solutions involved in each embodiment as being able to be combined with each other to form different embodiments to understand the scope of protection of this application.

[0069] The above description is merely an illustrative embodiment of this application and is not intended to limit the scope of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of this application shall fall within the scope of protection of this application.

Claims

1. A single-sided matte polyester film, comprising a polyester base film, wherein one surface of the polyester base film has an online-coated matte coating, characterized in that, The online matte coating is formed by online coating and curing of acrylic adhesive, calcium acetate particles, zinc sulfide particles, polydimethylsiloxane, ethyl acrylate, and sodium bicarbonate particles; the mass ratio of each component of the online matte coating is 100: (4~8): (5~10): (30~60): (20~40): (3~6).

2. The single-sided matte polyester film as described in claim 1, characterized in that, An offline protective coating is further applied to the outer side of the online matte coating.

3. The single-sided matte polyester film as described in claim 2, characterized in that, The offline protective coating consists of 50-60 parts by weight of polymethyl methacrylate, 5-10 parts by weight of dimethyl terephthalate, 10-20 parts by weight of methyltriethoxysilane, and 5-10 parts by weight of calcium phosphate particles.

4. A method for preparing a single-sided matte polyester film, wherein the single-sided matte polyester film comprises a polyester base film, one side surface of which has an online-coated matte coating layer, the online-coated matte coating layer being formed by online coating and curing of acrylic adhesive, calcium acetate particles, zinc sulfide particles, polydimethylsiloxane, ethyl acrylate, and sodium bicarbonate particles, wherein the mass ratio of each component of the online-coated matte coating layer is 100:(4~8):(5~10):(30~60):(20~40):(3~6); characterized in that, The preparation method includes the following steps: using polyester chips as raw material, a thick sheet is obtained by melt extrusion, preheated, and then longitudinally stretched into a stretched sheet, followed by transverse stretching, shaping, cooling, and winding; wherein, after obtaining the thick sheet and before longitudinal stretching, the components of the online matte coating are mixed and coated onto the thick sheet, and then longitudinally and transversely stretched to prepare a single-sided matte polyester film with an online matte coating; or, after longitudinal stretching and before transverse stretching, the components of the online matte coating are mixed and coated onto the stretched sheet, and then transversely stretched to prepare a single-sided matte polyester film with an online matte coating.

5. The preparation method according to claim 4 further comprises the following steps: measuring polyester chips with an electronic scale, preheating and drying them at 160℃~180℃, then adding the mixture to a twin-screw extruder, adjusting the temperature of the twin-screw extruder to 270℃~280℃, melting the mixture, filtering it, and extruding it into a thick sheet; preheating the thick sheet at 50℃~90℃, entering an infrared heating zone at 300℃~500℃, and longitudinally stretching it at a linear speed of 40~150m / min, with a longitudinal stretching ratio of 3.0~4.5, to obtain a stretched sheet; preheating the stretched sheet at 90℃~120℃, and transversely stretching it at 100℃~160℃, with a transverse stretching ratio of 3.0~4.5; then shaping it at 160℃~240℃, and then cooling it at 100℃~50℃, shaping, cooling, and finally obtaining the single-sided matte polyester film of this application.

6. The preparation method according to any one of claims 4-5, further comprising the step of applying an offline protective coating to the outside of the online coated matte coating by offline coating, wherein the offline protective coating is composed of 50-60 parts by weight of polymethyl methacrylate, 5-10 parts by weight of dimethyl terephthalate, 10-20 parts by weight of methyltriethoxysilane, and 5-10 parts by weight of calcium phosphate particles.

7. The preparation method according to claim 6 further comprises the following steps: the components constituting the offline protective coating are added to 50-200 parts by weight of diethyl ether and 50-100 parts by weight of deionized water at a ratio of 100 parts by weight, and then uniformly mixed. The mixture is then coated on the outer surface of the online matte coating by offline coating and cured at 90-130°C for 10-60 seconds to obtain the offline protective coating.

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