CN102303443A - Ultrathin polyester film and preparation method thereof - Google Patents

Abstract

The invention relates to a polyester film and a preparation method thereof, in particular to an ultra-thin polyester film and a preparation method thereof. In order to solve the defects in the process of improving the blocking resistance of the film by adding solid particles into the entire film in the prior art, the invention provides an ultra-thin polyester film, which comprises A polyester film substrate, the thickness of the substrate is 4-6 μm, the outer surface of the polyester film substrate is bonded with anti-adhesion particles through a water-based resin, and the friction coefficient (dynamic and static friction coefficient) of the film surface is 0.2-0.6 . The invention also provides a preparation method of the ultra-thin polyester film. The ultra-thin polyester film provided by the invention has excellent physical and mechanical properties and anti-blocking properties. The preparation method of the ultra-thin polyester film provided by the invention has the advantages of simple process, easy operation and low production cost.

Description

A kind of ultra-thin polyester film and preparation method thereof

technical field

The invention relates to a polyester film and a preparation method thereof, in particular to an ultra-thin polyester film and a preparation method thereof. the

Background technique

Due to its excellent mechanical properties, heat resistance, chemical resistance and dielectric properties, biaxially stretched polyester film can be used as an insulating material for electrical appliances and an insulating material for capacitors (also known as dielectrics). It is made of polyester film The capacitor has high capacitance, small size and high reliability. Among all insulating materials suitable for capacitors, such as polypropylene, polyphenylene sulfide, polystyrene, polycarbonate, polyimide, and polyester, polyester is the most cost-effective Insulating materials for capacitors with development potential. the

With the prominence and rapid development of the information industry, especially the basic level and miniaturization of components, capacitors used in these industries are developing towards miniaturization, so the demand for ultra-thin (thickness less than 6 μm) polyester film is increasing. From the perspective of the development trend of the thinnest film used in capacitors, it was 5 μm thick in the 1970s and 2 μm thick in the 1980s. The thinnest film that can be produced at present is 0.9 μm thick (produced by Toray). up to 0.2 μm thick. the

The technology of preparing polyester film with a thickness of less than 6 μm is called ultra-thin technology of polyester film, which is different from the production technology of polyester film with general thickness. In the production of ordinary polyester film, in order to meet the requirements of processability, the polyester surface layer must contain a small amount of fine solid particles to play an anti-blocking role when the film is unwound and unwound. The traditional method is to first add particles to polyester raw materials to make masterbatch slices (particle diameter between 2-4μm), and then add solid particles to the entire film (single-layer extrusion) or In the surface layer of the film (layer A in ABA three-layer co-extrusion). However, for ultra-thin films, since the particle size of the added particles is relatively large relative to the thickness of the film, it not only affects the film drawing process (such as easily causing film rupture), but also affects the performance of the finished film (such as uniform thickness properties, surface smoothness, etc.). Although the above-mentioned problems can be solved by reducing the particle size of the particles, as the particle size decreases, its anti-blocking property will also be greatly reduced. Moreover, as the thickness of the film continues to decrease, it is impossible to solve it by reducing the particle size all the time. the

Contents of the invention

In order to solve the existing technology, by adding solid particles to the whole film to improve the anti-blocking property of the film, the particle size of the added particles in this process is relatively large relative to the thickness of the film, which is easy to cause film rupture and affect the uniform thickness of the finished film In order to solve the defects of high-strength and surface smoothness, the invention provides an ultra-thin polyester film and a preparation method thereof. The present invention avoids the prior art of adding solid particles to the entire polyester film, and the ultra-thin polyester film provided by the present invention has excellent physical and mechanical properties and anti-blocking properties. The preparation method of the ultra-thin polyester film provided by the invention has simple process, easy operation and low production cost. the

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

Item 1, the present invention provides an ultra-thin polyester film, including a polyester film substrate, the thickness of the polyester film substrate is less than 6 μm, and the thickness of the polyester film substrate is preferably 4-6 μm, its The feature is that the outer surface of the polyester film substrate is bonded with anti-adhesion particles through the water-based resin. The particle size range of the anti-blocking particles is 0.2-0.8 μm, and the amount of the anti-blocking particles and the water-based resin on the surface of the film is 0.02-0.2 g/m ₂ . The water-based resin and the anti-blocking particles preferably form a bonding layer, and the thickness of the bonding layer is preferably 0.1-0.5 μm. The friction coefficient (dynamic and static friction coefficient) of the surface of the ultra-thin polyester film is 0.2-0.6. Refer to Table 9 for the performance indexes of the ultra-thin polyester film provided by the present invention.

Item 2, the present invention provides an ultra-thin polyester film as described in Item 1, which is characterized in that the polyester raw material used for the base material of the polyester film includes polyethylene terephthalate (PET ), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN) or its copolymerized modified polyester; preferably PET or PEN. The intrinsic viscosity value of the polyester raw material is: 0.55-0.70dl/g, the glass transition temperature is generally required to be greater than 65°C, preferably greater than 70°C, the melting point is generally required to be greater than 250°C, preferably greater than 260°C, other performance indicators Conform to relevant national standards. The water-based resin is used as an adhesive. The water-based resin generally adopts water-soluble or water-dispersible polymer substances, mainly including water-soluble polyacrylate, water-soluble polyurethane, and water-soluble sulfonated polyester. These resin materials After drying, it has a certain bonding effect with the polyester film substrate. The anti-blocking particles are inorganic substances. the

Item 3, an ultra-thin polyester film as described in Item 2, which is characterized in that the anti-blocking particles are silicon dioxide particles. the

Item 4, an ultra-thin polyester film as described in one of items 1 to 3, is characterized in that, before the water-based resin and anti-adhesion particles are bonded to the surface of the polyester film substrate, That is, before use, it is first prepared as a coating solution, which is coated on the surface of the polyester film substrate by coating technology, and after drying, the anti-blocking particles are bonded to the surface of the polyester film substrate by the water-based resin; The composition of said coating solution is as follows (the following percentages are percentages by weight):

Water-based resin 0.9-8%

Colloidal silicon 0.1-2%

The rest is pure water; the water-based resin refers to the solid active ingredients in the resin aqueous solution; the colloidal silicon refers to the solid active ingredients in the colloidal silicon aqueous solution. the

The above-mentioned water-based resin and anti-blocking particles are the active ingredients (or coating materials) of the coating liquid used in the coating technology, and the water-based resin therein acts as an adhesive to fix the colloidal silicon to the surface of the film. After drying, Colloidal silica can be agglomerated into silica particles. the

Before the coating liquid is used, the coating materials (water-based resin and colloidal silicon) are first mixed and prepared into an aqueous solution with a solid weight percentage of 1-10%, wherein the content of the water-based resin (solid active ingredient in the resin aqueous solution) The content of colloidal silicon (solid active ingredient in colloidal silicon aqueous solution) is 0.1-2% (weight percentage). The amount of coating material used depends on the coating process and target properties. Generally speaking, the higher the content of colloidal silicon, the higher the anti-blocking property of the film surface, but the coating process is relatively difficult. the

Item 5, a kind of ultra-thin polyester film as described in Item 4, it is characterized in that, the composition of described coating solution is as follows (following percentages are percentages by weight):

Water-based resin 1.5-6%

Colloidal silicon 0.5-1.5%

The rest is pure water; the water-based resin refers to the solid active ingredient in the resin aqueous solution; the colloidal silicon refers to the solid active ingredient in the colloidal silicon aqueous solution. the

Item 6, an ultra-thin polyester film as described in item 4, is characterized in that the composition of the coating solution is as follows (the following percentages are percentages by weight):

Water-based resin 3-5%

Colloidal silicon 0.8-1.2%

The rest is pure water; the water-based resin refers to the solid active ingredients in the resin aqueous solution; the colloidal silicon refers to the solid active ingredients in the colloidal silicon aqueous solution. the

Item 7, a method for preparing an ultra-thin polyester film, which is characterized in that the ultra-thin polyester film includes a polyester film substrate, and the thickness of the polyester film substrate is 4-6 μm, so The outer surface of the polyester film base material is bonded with anti-blocking particles through a water-based resin, and the preparation method of the ultra-thin polyester film is as follows:

The polyester film substrate is prepared by a biaxial stretching process, and the biaxial stretching process includes: raw material drying, melt extrusion, casting, longitudinal stretching, transverse stretching, heat setting, cooling, pulling, and winding processes A coating process is added between the longitudinal stretching and transverse stretching processes, after the longitudinal stretching process is completed, in the coating process, the coating containing the water-based resin and anti-blocking particles Cloth liquid is coated on polyester film base material surface, and the solid matter weight percentage of described coating liquid is 1%-10%, and the composition of described coating liquid is as follows (following percentages are weight percentages ):

Water-based resin 0.9-8%

Colloidal silicon 0.1-2%

The rest is pure water; the water-based resin refers to the solid active ingredients in the resin aqueous solution; the colloidal silicon refers to the solid active ingredients in the colloidal silicon aqueous solution; the coating liquid is dried in the preheating section of the transverse stretching. the

The above-mentioned biaxial stretching process is the same as the existing polyester film biaxial stretching process. The thickness of the above-mentioned polyester film is not more than 6 μm. One surface or both surfaces of the film are coated with a coating liquid, and the above-mentioned polyester film Anti-blocking particles do not need to be added to the film substrate. Refer to Table 8 for the biaxial stretching process parameters. Properly adjusting the biaxial stretching process of the polyester film can produce a polyester film with a thickness of 4-6 μm. the

The friction coefficient (dynamic and static friction coefficient) of the surface of the above-mentioned ultra-thin polyester film prepared by the present invention is generally 0.2-0.6, and the best case is 0.3-0.5. In addition, the prepared polyester film also has the following basic properties: tensile strength (transverse, longitudinal) greater than 180MPa, elongation at break (transverse, longitudinal) greater than 90%, heat shrinkage at 150°C, 30min The transverse direction is less than 1.5%, the longitudinal direction is less than 2.5%, and the surface resistivity is greater than 1×10 ¹⁵ Ω.

Item 8, a method for preparing an ultra-thin polyester film as described in item 7, is characterized in that the composition of the coating solution is as follows (the following percentages are percentages by weight):

Water-based resin 1.5-6%

Colloidal silicon 0.5-1.5%

The rest is pure water; the water-based resin refers to the solid active ingredients in the resin aqueous solution; the colloidal silicon refers to the solid active ingredients in the colloidal silicon aqueous solution. the

Item 9, a method for preparing an ultra-thin polyester film as described in item 7, is characterized in that the coating process is carried out synchronously with the production of the polyester film, and the coating is carried out after the film is stretched longitudinally. Cloth treatment, after the film is coated, it enters the stage of transverse stretching, and the coating method is gravure coating or rod coating. the

Item 10, an ultra-thin polyester film as described in Items 1-6, is characterized in that the polyester film is used as an insulating material for capacitors. the

The production process parameters of the above-mentioned polyester film substrate are shown in Table 8, and the process parameters shown in the table can be appropriately adjusted according to the properties of the substrate raw materials, the composition and the amount of the coating solution. the

Preferably, the above-mentioned polyester film substrate is prepared by a biaxial stretching method, and a coating process is added between the longitudinal stretching and the transverse stretching in the biaxial stretching process, and the coating process is located in the above-mentioned biaxial stretching process. After the longitudinal stretching of the process, before the transverse stretching. The coating process is carried out immediately after the film is stretched in the longitudinal direction. After the film substrate is coated, it enters the stage of transverse stretching. In order to make the coating material (water-based resin and colloidal silicon) dry and adhere to the surface of the polyester film substrate, corresponding process adjustments must be made in the preheating section of the horizontal stretching. Generally speaking, the preheating section can be lengthened (such as from the original three sections to four sections) or heated (such as from the original 100°C to 110°C) to meet the needs of coating drying. After that, the treatment process of the diaphragm is the same as that of the ordinary film stretching process. The above-mentioned coating step may be one-sided coating or double-sided coating. The coating method can be any one of gravure roll coating (Gravure Roll, or gravure roll coating) or rod coating (Mayer Bar). Gravure coating uses a coating roller with fine mesh on the surface, and the coating liquid is transferred to the substrate film through the mesh of the coating roller. Rod coating uses a coating rod (or wire rod coater) with thin steel wires evenly wound on the surface, and the coating liquid is transferred to the substrate film through the grooves between the steel wires. Whether one-sided coating or double-sided coating depends on the function of the coating equipment. If the coating equipment can realize simultaneous double-sided coating function, double-sided coating is recommended. Generally speaking, the anti-blocking property of double-sided coated film surface is better and more stable. If it can only be coated on one side, it is recommended to increase the coating amount as much as possible to ensure sufficient anti-blocking of the film surface. the

Compared with the prior art, the present invention has the advantage of not needing to directly add anti-blocking particles in the polyester film base material, so as to keep the original physical and mechanical properties of the polyester film well, so that the ultra-thin film can be produced easily The stretching process operation can be carried out smoothly. The coated anti-blocking substances (anti-blocking particles or granules) only adhere to the outer surface of the film, so that the prepared ultra-thin polyester film has better anti-blocking property. Moreover, the size of the anti-blocking particles and the amount distributed on the surface of the film can be adjusted by adjusting the formulation of the coating solution, so the anti-blocking property of the film can be adjusted conveniently. In addition, the preparation method of the ultra-thin polyester film provided by the invention has simple process, easy operation and low production cost. the

Description of drawings

Fig. 1 is the film structure schematic diagram that is added with anti-adhesion particles in the existing film;

Fig. 2 is the ultra-thin type polyester film structural representation that the surface of the present invention is bonded with anti-blocking particles;

Fig. 3 is that a surface provided by the present invention is bonded with the ultra-thin type polyester film sectional schematic diagram of anti-blocking particle;

Fig. 4 is a schematic cross-sectional view of an ultra-thin polyester film with two surfaces bonded with anti-adhesion particles provided by the present invention. the

In the figure, 1 is a biaxially stretched polyester film substrate, 2 is an anti-blocking particle in the prior art, 3 is an anti-blocking particle according to the present invention, and 4 is a water-based resin bonding layer according to the present invention. the

Detailed ways

The technical scheme of the present invention is described in more detail below in conjunction with the examples, wherein, polyester film preparation raw material is generally polyethylene terephthalate (PET), polybutylene terephthalate (PET) sold on the market PBT), polyethylene naphthalate (PEN) or its copolymerized modified polyester; the water-based resin can be water-soluble polyacrylate, water-soluble polyurethane, water-soluble sulfonated polyester; colloidal silicon is commonly used in the market See aqueous colloidal silica. The raw material of the polyester film base material adopts the film-grade polyester chips sold on the market. the

The percentages stated in the examples are percentages by weight. The percentage composition of described water-based resin is the percentage composition of active ingredient (water-based resin solid part) in water-based resin solution; The percentage composition of described colloidal silicon is the percentage composition of active ingredient (colloidal silicon solid part) in silica gel solution Content, for example, the coating solution is 10% solid content of water-based resin and colloidal silicon aqueous solution, the main components: 8% water-based resin, 2% colloidal silicon, and the balance is pure water. Wherein, 8% water-based resin refers to 8% water-based resin solids, and 2% colloidal silicon refers to 2% colloidal silicon solids. The metering method of preparing 100 kilograms of above-mentioned exemplified coating solutions is as follows: need to add 8 kilograms of water-based resin solids, 2 kilograms of colloidal silicon solids; if the active ingredient of water-based resin solution (raw material) is 28%, then: 8/ 0.28=28.57 kg, that is, 28.57 kg of water-based resin solution needs to be added; if the active ingredient of colloidal silicon solution (raw material) is 34%, then: 2/0.34=5.88 kg, that is, 5.88 kg of colloidal silicon solution needs to be added, and the remaining pure Water is: 100-28.57-5.88=65.55 kilograms, promptly need to add 65.55 kilograms of water. the

The raw materials and preparation process of the coating solution used in the examples, the raw materials and preparation process of the polyester film substrate, the surface properties and evaluation of the obtained film, etc. are as follows. the

(1) Coating liquid raw materials and their preparation

The water-based resin uses polyurethane aqueous solution produced by Dutch DSM NeoResins B.V. company, trade name NeoRez R-610 (DSM NeoResins), and the active ingredient content is 28%. The colloidal silicon uses the nano-colloidal silicon produced by EKA (Eka) Chemical Company, the trade name is NYACOL 2034DI, and the active ingredient content is 34% (it can be directly purchased by EKA Chemical Company, and can also be provided by China Guangzhou Hersbit Chemical Materials Co., Ltd.). the

The coating solution is water-based resin and colloidal silicon aqueous solution with a solid content of 1-10%, and the main components are: 0.9-8% water-based resin, 0.1-2% colloidal silicon, and the balance is pure water. the

Coating solution preparation process: mix the calculated amount of water and water-based resin solution evenly, slowly add the calculated amount of colloidal silicon aqueous solution, stir evenly, and filter for later use. the

(2) Raw material and preparation process of polyester film

The raw material of the polyester film base material is the film-grade polyester chip produced by China Yizheng Chemical Fiber Co., Ltd., and the trade name is FG620. the

The above-mentioned polyester film base material is prepared on a polyester film stretching production line produced by Mitsubishi Heavy Industries, Japan. The preparation steps of the film are as follows: the polyester raw material is melted and extruded into a cast sheet after being dried, and the obtained thick sheet is stretched 4 times in the longitudinal direction at 100°C, and the prepared coating solution is used for double-sided or single-sided coating, and the film is pre-coated in the transverse direction. After the hot section is dried at 98°C, it is stretched 3.8 times in the transverse direction at 104°C, heat-set at 225°C, and wound after cooling to finally make a polyester film with a thickness of 5 μm. the

(3) The surface anti-blocking property of the prepared polyester film is evaluated by measuring the coefficient of friction, and the higher the anti-blocking property, the lower the corresponding coefficient of friction. The determination of friction coefficient is based on GB 10006-88 Determination of friction coefficient of plastic film and sheet. the

(4) The particle size of the anti-blocking particles on the surface of the prepared polyester film is measured by a scanning electron microscope (SEM), and is 0.2-0.8 μm. the

(5) The consumption of described anti-blocking particles and water-based resin on the surface of the film is calculated by the following method:

During the coating process, the speed of the film substrate is 150m/min, the film width is 4m, and the total area coated per hour is 150×4×60=36000m ₂ . The coating liquid consumed per hour is 72kg, and the average coating liquid per square meter is 72/36000=0.002kg=2g, which is the wet weight. The solid content range of the coating liquid is 1-10%. When the solid content of the coating liquid is 1%, after drying, the amount of the anti-blocking particles and water-based resin on the surface of the film is 2×0.01=0.02g/m ₂ ; When the solid content of the coating solution is 10%, after drying, the amount of the anti-blocking particles and water-based resin on the surface of the film is 2×0.1=0.2g/m ₂ . Therefore, the amount of anti-blocking particles and water-based resin on the surface of the film is 0.02g-0.2g/m ₂ .

Example 1

The film is prepared according to the aforementioned method, wherein the coating process is single-side coating, and the formula of the active ingredients of the coating liquid used is: 4.0% water-based resin and 0.8% colloidal silicon. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking performance of the obtained film surface are shown in Table 1. the

Example 2

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the active ingredients of the coating liquid used are: 8.0% water-based resin and 1.6% colloidal silicon. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking performance of the obtained film surface are shown in Table 1. the

Example 3

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 2.5% water-based resin and 0.5% colloidal silicon. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the anti-blocking performance of the obtained film surface are shown in Table 1. the

Example 4

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating material used is: 5.0% water-based resin and 1.0% colloidal silicon. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking performance of the obtained film surface are shown in Table 1. the

Table 1

the Example 1 Example 2 Example 3 Example 4 Single side or double side coating single sided single sided double sided double sided  Water-based resin solid content (%) 4.0 8.0 2.5 5.0 Colloidal silica solid content (%) 0.8 1.6 0.5 1.0 Static friction coefficient 0.56 0.42 0.48 0.32 Kinetic friction coefficient 0.53 0.39 0.44 0.30

Example 5

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 0.9% water-based resin and 0.1% colloidal silicon. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 2. the

Example 6

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the formula of the active ingredients of the coating liquid used is: 6.0% water-based resin and 2.0% colloidal silicon. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 2. the

Example 7

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the formula of the active ingredients of the coating liquid used is: 8% water-based resin and 2% colloidal silicon. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-blocking particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 2. the

Example 8

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 8% water-based resin and 0.1% colloidal silicon. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 2. the

Table 2

the Example 5 Example 6 Example 7 Example 8 Single side or double side coating double sided single sided single sided double sided  Water-based resin solid content (%) 0.9 6.0 8.0 8.0 Colloidal silica solid content (%) 0.1 2.0 2.0 0.1 Static friction coefficient 0.56 0.39 0.37 0.58 Kinetic friction coefficient 0.53 0.35 0.37 0.54

Example 9

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 1.5% water-based resin and 0.5% colloidal silicon. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 3. the

Example 10

The film is prepared according to the aforementioned method, wherein the coating process is single-side coating, and the active ingredients of the coating liquid are formulated as follows: 6.0% water-based resin and 1.5% colloidal silicon. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 3. the

Example 11

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 3.0% water-based resin and 1.0% colloidal silicon. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 3. the

Example 12

Film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the formula of the active ingredients of the coating solution used is: 6% water-based resin and 1.2% colloidal silicon. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 3. the

table 3

the Example 9 Example 10 Example 11 Example 12 Single side or double side coating double sided single sided double sided single sided  Water-based resin solid content (%) 1.5 6 3.0 6.0 Colloidal silica solid content (%) 0.5 1.5 1.0 1.2 Static friction coefficient 0.50 0.44 0.37 0.49 Kinetic friction coefficient 0.48 0.40 0.36 0.46

Example 13

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 3.0% water-based resin and 0.8% colloidal silicon. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 4. the

Example 14

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the active ingredients of the coating liquid are formulated as follows: 5.0% water-based resin and 1.2% colloidal silicon. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 4. the

Example 15

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the formula of the active ingredients of the coating liquid used is: 4.0% water-based resin and 1.0% colloidal silicon. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 4. the

Example 16

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the active ingredients of the coating liquid are formulated as follows: 5.0% water-based resin and 0.8% colloidal silicon. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the determination of the anti-blocking properties of the obtained film surface are shown in Table 4. the

Table 4

the Example 13 Example 14 Example 15 Example 16 Single side or double side coating double sided single sided double sided single sided  Water-based resin solid content (%) 3.0 5.0 4.0 5.0 Colloidal silica solid content (%) 0.8 1.2 1.0 0.8 Static friction coefficient 0.46 0.48 0.35 0.54 Kinetic friction coefficient 0.45 0.47 0.32 0.52

Raw materials used in the above-mentioned embodiments 1 to 16: the water-based resin uses polyurethane aqueous solution produced by DSM NeoResins B.V. company in the Netherlands, the trade name NeoRez R-610 (Disman Resin), and the active ingredient content is 28%. The colloidal silicon uses nano-colloidal silicon produced by EKA (Eka) Chemical Company, the trade name is NYACOL 2034DI, and the active ingredient content is 34% (provided by China Guangzhou Hersbit Chemical Materials Co., Ltd.). The raw material of the polyester film base material is the film-grade polyester chip produced by China Yizheng Chemical Fiber Co., Ltd., and the trade name is FG620. the

Example 17

Film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the raw material of the polyester film base material is polybutylene terephthalate (PBT) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 0.9% water soluble polyacrylate and 0.1% colloidal silicon dispersion. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the anti-blocking test of the obtained film surface are shown in Table 5. the

Example 18

Film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the polyester film base material raw material is polyethylene terephthalate (PET) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 6.0% water soluble polyurethane and 2.0% colloidal silicon dispersion. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking test of the obtained film surface are shown in Table 5. the

Example 19

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the raw material of the polyester film base material is polyethylene naphthalate (PEN) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 8 % water soluble sulfonated polyester and 2% colloidal silicon dispersion. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8μm. The results of the anti-blocking test of the obtained film surface are shown in Table 5. the

Example 20

Film is prepared according to the foregoing method, wherein the coating process is double-sided coating, and the polyester film base material raw material is polyethylene naphthalate (PEN) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 8 % water-soluble sulfonated polyester and 0.1% colloidal silicon dispersion. The thickness of the prepared film substrate is 4um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking test of the obtained film surface are shown in Table 5. the

table 5

the Example 17 Example 18 Example 19 Example 20 Single side or double side coating double sided single sided single sided double sided  Water-based resin solid content (%) 0.9 6.0 8.0 8.0 Colloidal silica solid content (%) 0.1 2.0 2.0 0.1 Static friction coefficient 0.55 0.41 0.41 0.57 Kinetic friction coefficient 0.55 0.38 0.40 0.55

Example 21

Film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the raw material of the polyester film base material is polyethylene terephthalate (PET) in the present embodiment, and the formula of the effective components of the coating solution used is: 1.5% water soluble polyacrylate and 0.5% colloidal silicon dispersion. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 6. the

Example 22

Film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the raw material of the polyester film base material is polybutylene terephthalate (PBT) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 6.0% water soluble sulfonated polyester and 1.5% colloidal silicon dispersion. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 6. the

Example 23

Prepare the film according to the aforementioned method, wherein the coating process is double-sided coating, the raw material of the polyester film base material is polybutylene terephthalate (PBT) copolymerized modified polyester in the present embodiment, and the coating solution used is effective Ingredients The formula is: 3.0% water soluble polyurethane and 1.0% colloidal silicon dispersion. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 6. the

Example 24

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the raw material of the polyester film base material is polyethylene naphthalate (PEN) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 6 % of water-soluble polyacrylate and 1.2% of colloidal silicon dispersion. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 6. the

Table 6

the Example 21 Example 22 Example 23 Example 24 Single side or double side coating double sided single sided double sided single sided  Water-based resin solid content (%) 1.5 6 3.0 6.0 Colloidal silica solid content (%) 0.5 1.5 1.0 1.2 Static friction coefficient 0.51 0.44 0.36 0.48 Kinetic friction coefficient 0.49 0.41 0.35 0.48

Example 25

The film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, the polyester raw material is polybutylene terephthalate (PBT), and the formula of the active ingredient of the coating solution used is: 3.0% water-soluble sulfonated Polyester and 0.8% colloidal silicon dispersion. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.6um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 7. the

Example 26

Film is prepared according to the foregoing method, wherein the coating process is single-sided coating, and the raw material of the polyester film base material is polyethylene terephthalate (PET) in the present embodiment, and the formula of the effective components of the coating solution used is: 5.0% water soluble polyacrylate and 1.2% colloidal silicon dispersion. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 7. the

Example 27

Film is prepared according to the aforementioned method, wherein the coating process is double-sided coating, and the raw material of the polyester film base material is polybutylene terephthalate (PBT) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 4.0% water soluble polyurethane and 1.0% colloidal silicon dispersion. The thickness of the prepared film substrate is 6um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 7. the

Example 28

The film is prepared according to the aforementioned method, wherein the coating process is single-sided coating, and the raw material of the polyester film base material is polyethylene naphthalate (PEN) in the present embodiment, and the formula of the active ingredient of the coating solution used is: 5.0 % water soluble sulfonated polyester and 0.8% colloidal silicon dispersion. The thickness of the prepared film substrate is 5um, and the particle diameter of the anti-adhesion particles is 0.2-0.8um. The results of the anti-blocking measurement of the obtained film surface are shown in Table 7. the

Table 7

the Example 25 Example 26 Example 27 Example 28 Single side or double side coating double sided single sided double sided single sided  Water-based resin solid content (%) 3.0 5.0 4.0 5.0 Colloidal silica solid content (%) 0.8 1.2 1.0 0.8 Static friction coefficient 0.35 0.47 0.34 0.53 Kinetic friction coefficient 0.32 0.44 0.31 0.53

Table 8 The commonly used production process parameters of the ultra-thin polyester film provided by the present invention

Table 9: Performance indicators and typical test results of the ultra-thin polyester film provided by the present invention

From the above examples and the performance parameters of the ultra-thin polyester film prepared by the examples, it can be concluded that the ultra-thin polyester film provided by the present invention has excellent physical and mechanical properties and anti-blocking properties. The preparation method of the ultra-thin polyester film provided by the invention has simple process, easy operation and low production cost. the

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. All equivalent changes and modifications made according to the contents of the present invention are covered within the patent scope of the present invention. the

Claims (10)

1. a ultra thin type polyester film comprises the polyester film base material, it is characterized in that, said polyester film base material outer surface is bonded with the antiblock particle through water-base resin.

2. ultra thin type polyester film according to claim 1; It is characterized in that the used polyester raw material of said polyester film base material comprises PETG (PET), polybutylene terephthalate (PBT) (PBT), PEN (PEN) or its co-polymerization modified polyester; Said water-base resin comprises water-soluble polyacrylate, soluble polyurethane, water soluble sulfonated polyester; Said antiblock particle is an inorganic matter; Said water-base resin and antiblock particle form tack coat.

3. one kind like ultra thin type polyester film as described in the claim 2, it is characterized in that said antiblock particle is a silica dioxide granule.

4. one kind like ultra thin type polyester film as described in one of claim 1 to 3; It is characterized in that; Said water-base resin and antiblock particle are before being bonded in said polyester film substrate surface; Be mixed with coating fluid earlier; Be applied to said polyester film substrate surface through coating technique; After the drying, the antiblock particle is bonded in said polyester film substrate surface through water-base resin; The composition of said coating fluid is (following percentage composition is a weight percentage) as follows:

Water-base resin 0.9-8%

Colloid silicon 0.1-2%

All the other are pure water; Said water-base resin is meant the solid active ingredient in the resin aqueous solution; Said colloid silicon is meant the solid active ingredient in the colloid silicon aqueous solution.

5. one kind like ultra thin type polyester film as described in the claim 4, it is characterized in that the composition of said coating fluid is (following percentage composition is a weight percentage) as follows:

Water-base resin 1.5-6%

Colloid silicon 0.5-1.5%

All the other are pure water; Said water-base resin is meant the solid active ingredient in the resin aqueous solution; Said colloid silicon is meant the solid active ingredient in the colloid silicon aqueous solution.

6. one kind like ultra thin type polyester film as described in the claim 4, it is characterized in that the composition of said coating fluid is (following percentage composition is a weight percentage) as follows:

Water-base resin 3-5%

Colloid silicon 0.8-1.2%

All the other are pure water; Said water-base resin is meant the solid active ingredient in the resin aqueous solution; Said colloid silicon is meant the solid active ingredient in the colloid silicon aqueous solution.

7. the preparation method of a ultra thin type polyester film; It is characterized in that; Said ultra thin type polyester film comprises the polyester film base material; Said polyester film base material thickness is 4-6 μ m; Said polyester film base material outer surface is bonded with antiblock particle or particle through water-base resin; Said ultra thin type polyester film preparation method is following: said polyester film base material adopts the stretch processes preparation; Said stretch processes comprises: raw material drying melt extrudes the casting sheet; Longitudinal stretching; Cross directional stretch, thermal finalization, cooling; Traction, winding process; Between said longitudinal stretching and cross directional stretch operation, increased painting process; After said longitudinal stretching operation is accomplished; In said painting process; The coating fluid that will contain said water-base resin and antiblock particle is applied to the polyester film substrate surface, and the composition of said coating fluid is (following percentage composition is a weight percentage) as follows:

Water-base resin 0.9-8%

Colloid silicon 0.1-2%

All the other are pure water; Said water-base resin is meant the solid active ingredient in the resin aqueous solution; Said colloid silicon is meant the solid active ingredient in the colloid silicon aqueous solution; Said coating fluid is accomplished dry at the preheating section of cross directional stretch.

8. preparation method like ultra thin type polyester film as described in the claim 7 is characterized in that the composition of said coating fluid is (following percentage composition is a weight percentage) as follows:

Water-base resin 1.5-6%

Colloid silicon 0.5-1.5%

All the other are pure water; Said water-base resin is meant the solid active ingredient in the resin aqueous solution; Said colloid silicon is meant the solid active ingredient in the colloid silicon aqueous solution.

9. the preparation method like ultra thin type polyester film as described in the claim 7 is characterized in that, the coating method that adopts in the said painting process is intaglio plate coating or bar type coating.

10. one kind like the described ultra thin type polyester film of claim 1-6, it is characterized in that said polyester film is used for the insulating materials of capacitor.

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