TWI657924B - Easy-to-use polyester film - Google Patents

Abstract

The invention is a polyester film that is easy to be used, and includes a substrate and a polyester film with a coating on the surface of the substrate. The coating is characterized in that the coating on the surface of the substrate contains 2-40 wt% mixed resin, 0.05- 30wt% surface-modified particle-filled particle solution, 0.05-10wt% additives, and 50-85wt% of the remaining water solvent, wherein the mixed resin component includes: a. 19-50wt% polyester resin; b. 30- 80 wt% acrylate grafted modified polyurethane resin, and c. 10-40 wt% cross-linking agent. The optical polyester film formed by coating on a polyester film has high transparency, low haze, excellent adhesiveness, and slip properties. It is suitable for optical substrates such as diffusion films for LCDs and substrates. Bright film and so on.

Description

Easy-to-use polyester film

The invention relates to a coating formula that can be applied to a polyester film (substrate), and after coating the formula, the polyester film (substrate) can have high transparency, low haze, and excellent adhesion. And slip properties, suitable for applications such as liquid crystal display (Liquid Crystal Disply, LCD) or cathode tube (Cathode Ray Tube, CRT) diffusion film, brightness enhancement film, anti-reflection film, protective film and other optical polyester film.

The optical film for flat panel display mainly includes a reflective film, a diffusion film, and a brightness enhancement film, and is used in a backlight module behind a liquid crystal display screen as a component to enhance the display effect. Biaxially stretched polyester films are widely used in various optical applications because of their high transparency, chemical resistance, and dimensional stability. In addition to the chemical resistance and dimensional stability of general polyester films, this type of optical polyester film In addition to physical properties, it must also have high transparency, low haze, excellent adhesion and slip properties. Generally, the coating liquid is applied to one or both sides of the polyester film to improve the physical properties described above. Previously related technologies such as European Patent No. 1,178,075 A1; US Patent No. 6,733,863 B1; US Patent No. 6,482,501 B2; Republic of China Patent No. I305216, etc. European Patent No. 1,178,075 A1 mentions a polyester film with high transparency, low haze and excellent adhesion. Its coating formula includes water-based polyester resin, acrylic resin, 0.01-0.3 μm fine particles and aliphatics. Amino compounds, etc., because these nano / micron fine particles have The surface energy is quite large. After coating and drying, the nano / sub-micron fine particles are very easy to agglomerate to form particles with a size of micrometers or tens of micrometers, which affects the transparency, haze and slip properties of the polyester film, especially the agglomeration If the particles are applied to a liquid crystal display panel, so-called optical defects may occur. U.S. Patent No. 6,733,863 B1 and U.S. Patent No. 6,482,501 B2 also mention a polyester film with low haze and a small amount of particles below 20 microns in size. Its coating formulation includes water-based copolyester resin, polyurethane resin, and Sliding function 0.01 ~ 1.0μm fine particles, etc. Similarly, these nano / micron fine particles with considerable surface energy in the formula are very easy to agglomerate to form micron-sized particles after coating and drying, which affects the polyester film. Optical properties. In addition, U.S. Patent No. 6,482,501 B2 particularly emphasizes that it uses a coating solution to filter out particles larger than 20 microns. It is obvious that the coating solution should be agglomerated. In addition, this patent also emphasizes that the optical polyester film has a good Dimensional stability of heat shrinkage, but the composition must contain a considerable amount of polyurethane component (10 ~ 90%). Its UV light resistance or heat resistance is generally inferior to conventional polyester or acrylate resin components, and it faces visual requirements. For a strict liquid crystal display panel, the performance of characteristics such as chromaticity and chromatic aberration is not an appropriate choice.

In general, the transparency, haze, and slip of polyester films are in addition to the crystals of polyester film substrate (polyethylene terephthalate (PET) for short) and the type and size of micron-sized lubricants added to the PET film substrate. In addition to the content, another important factor is the coating layer coated on the polyester film substrate. In addition to the resin in the coating layer, fine particles are generally added to improve the slip of the polyester film. At the same time, the refractive index and surface flatness of the coating layer are related to the transparency of the PET polyester film. If the fine particles of the layer are aggregated, voids (Void) will be generated around the coating after the coating is extended. This aggregation phenomenon, Void and poor surface flatness will affect the light transmittance and haze of the PET polyester film. And slippery. In addition, the coating layer of PET polyester film In terms of adhesion, the coating layer must have excellent adhesion to both the polyester film of the substrate and the UV-curable high refractive index acrylate resin coating layer for LCD materials in order to meet the requirements for adhesion. Generally, if the coating on the surface of the polyester film is pure acrylate resin, although the weather resistance is good, the adhesion to the UV-curable high refractive index acrylate resin used for LCD materials and the substrate PET polyester film are not good; Similarly, if the coating layer on the surface of the polyester film is purely polyester resin, although it has good adhesion to the polyester film of the substrate PET, the adhesion to the acrylate coating layer for LCD materials is not good. If acrylate grafted and modified polyurethane resin is used, it can improve the shortcomings of low mechanical strength, UV light resistance, heat resistance, and poor water resistance of the polyurethane resin. It can also improve the adhesion of the coating layer for LCD materials (for optical adhesives). Adhesion).

The main object of the present invention is to provide a coating composition liquid which can simultaneously meet the quality requirements of high transparency, low haze, excellent adhesion and slipperiness, etc., through an in-line or Off-line coated on PET substrate.

The present invention uses an aqueous coating solution for polyester film to coat the surface of a polyester film substrate. The water-soluble coating solution includes (based on the total weight of the coating): (1) 2-40 wt% mixed Resin, (2) 0.05-30wt% mixed liquid containing filled particles treated with surface modification agent, (3) 0.05-10wt% additives and (4) the rest is water solvent 50-85wt%; of which (1) is mixed The resin composition contains (based on the total weight of the mixed resin):

a containing 10-60wt% polyester resin;

b. It contains 20-80wt% of urethane resin modified by acrylate grafting. The urethane resin modified by acrylate grafting can improve the low mechanical strength of the polyurethane resin, its resistance to UV light, heat resistance, and poor water resistance. Disadvantages can simultaneously improve the adhesion of the coating layer for LCD materials.

c. Containing 10-40 wt% of cross-linked resin, which can be one or more resins of melamine resin, melamine modified resin, carbodiimide-based cross-linking agent, and oxazoline-based cross-linking agent.

The polyester resin of the above mixed resin a. Is a resin having an ester chain in the main chain and the side chain, and contains a water-soluble group in the structure, such as -SO ₃ Na, -SO ₃ NH ₄ and the like. The polyester resin can be selected from water-soluble or water-dispersible polyester resins, which are polymerized from the following acids and alcohols. The acid component is selected from the group consisting of dicarboxylic acids containing sulfonic acid groups, including: One or more of 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, or sulfonic acid-free carboxylic acids include aromatic, fatty or cycloaliphatic dicarboxylic acids Or more than one functional acid; and the alcohol component is selected from, for example, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, 1,3-propylene glycol, polypropylene glycol, 1,4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, cyclohexane-1,2-diol, 1,3 cyclohexane-dimethanol, 1,4 cyclohexane-dimethanol, cyclohexane-1 One or more of 4-diols. The above polyester resin is preferably used in an amount of 10-60% by weight, more preferably 20-50% by weight.

The acrylic resin graft modified polyurethane resin dispersion of b. In the present invention, the main chain of the aqueous polyurethane acrylic graft modified resin has a group formed of polyisocyanate and polyol. Groups and nonionic groups, the side chain has anionic groups and nonionic groups containing sulfonic acid groups, and acrylate groups are dispersed therein.

The method for synthesizing the acrylate graft-modified polyurethane resin dispersion liquid includes the following steps (the following is based on the total amount of reaction raw materials containing deionized water): (1) Preparation of a prepolymer: a polyester (ether) polyol 15 ~ 25wt%, vacuum dehydration, add to the reactor equipped with stirrer, thermometer and condenser tube, when the oil bath temperature reaches 70-80 ℃, add 5-12wt% of aliphatic diisocyanate, Make it react. (2) Dilution and chain extension of the prepolymer: After the prepolymer is reacted for 2-3 hours, add 10 to 30% by weight of acrylate monomers to dilute the viscosity and maintain the temperature at 85-90 ° C until the theoretical NCO equivalent ratio (NCO / OH ) Is 1.1 to 2.3, and then 1.5 to 3.0 wt% of sodium ethylenediaminoethanesulfonate (AAS) is added, and the reaction is continued for 25-40 minutes. (3) Water dispersion: The polymer obtained in (2) is cooled to room temperature, and under the high-speed shearing speed of 500 rpm, an appropriate amount of deionized water is added to 35 to 55 wt%, and then a metered amount of ethylene diamine is added to 0.1 to 0.5 wt%. The chain extension reaction takes about 30 minutes to obtain a solvent-free sulfonate type aqueous polyurethane dispersion. (4) Synthesis of acrylates: Continued (3) Add 0.3 to 1.0% by weight of sodium lauryl sulfate (SLS) emulsifier to form an emulsion. After heating to 50-70 ° C, add ammonium persulfate aqueous solution (APS) dropwise. 0.01 ~ 0.10wt% of the initiator is used to polymerize the acrylate, and the temperature is continuously increased to 75-85 ° C, and the temperature is kept constant for 1-3 hours, and the temperature is reduced to 50-70 ° C, and the reducing agent is added to the range of 0.01 ~ 0.08wt% to obtain acrylate grafting. Modified polyurethane resin.

The above acrylate monomers include: (a) alkyl-containing (meth) acrylates 90 to 95 wt%; (b) hydroxyl-containing (meth) acrylates 4 to 9 wt%; (c) carboxyl-containing (formaldehyde) Based) acrylate 1 ~ 5wt%.

Alkyl-containing (meth) acrylates selected from methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, (meth) Isobutyl acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate One of the group consisting of an ester, cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate, and ethoxymethyl (meth) acrylate is used alone or in combination of one or more.

Hydroxyl-containing (meth) acrylates selected from the group consisting of 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl acrylate, and diethylene glycol mono (methyl) C) One of the groups of enoates.

The carboxyl group-containing (meth) acrylate is one selected from the group consisting of acrylic acid and methacrylic acid.

The crosslinked resin listed in c. In the present invention may be at least one of a melamine resin or a melamine modified resin, a carbodiimide-based crosslinking agent, and an oxazoline-based crosslinking agent. Such as melamine, a melamine modified melamine derivative of melamine and formaldehyde condensation, a reaction of a lower alcohol to locally or completely change to a hydroxymethyl modified melamine compound and a mixture thereof. Melamine can be a monomer or a condensate of a dimer or a polymer or a mixture thereof. As the lower alcohol used for the change, methanol, ethanol, isopropanol, n-butanol, or isobutanol, etc. can be used, but is not particularly limited by these alcohols. In the present invention, the preferred amount of the cross-linked resin as the main component is 5-40 wt%, and more preferably 10-30 wt%.

In the present invention (2) a surface treatment agent-containing modified overfilled particle mixed liquid, the modification treatment agent is selected from one or more compositions containing a silicon-containing compound, a surfactant, and a polymer; wherein the silicon-containing compound includes Silane compounds or polysilane compounds; surfactants include Sino-Japan's methylbenzene ammonium sulfate, polyethylene glycol nonyl ether sulfate, polyethylene glycol nonyl ether sulfate, polyethylene glycol octyl phenol Ether ammonium salts, condensed polyethylene glycol polycyclic nonyl ether methacrylate sulfate or Uniqema's Maxemul 6106, 6112 and other anionic surfactants; or polyethylene glycol nonanephenol ether and polyethylene glycol from Pan Asia Alkyl alkyl ethers, polyethylene glycol stearic acid ether, polyethylene glycol nonyl ether, polyethylene glycol octyl ether, polyethylene glycol decyl ether, polyethylene glycol tridecyl ether , Polyethylene glycol lauryl ether or Uniqema's Maxemul 5010, 5011 and other non-ionic surfactants); high-molecular polymers include: one or more combinations containing a polyester component, a polyacrylate component, and a polyurethane component; The filler particles are selected from one or more inorganic materials such as alumina, aluminum hydroxide, silicon oxide, titanium oxide, zirconia, calcium carbonate, magnesium carbonate, or barium sulfate, and the particle size is between 0.005 and 3 μm, depending on transparency, haze, and smoothness. Different physical properties such as physical properties can be selected and combined with inorganic particles of different sizes and particle sizes. The larger the particle size of the filler particles, the higher the anti-adhesion temperature can be. The preferred amount of the silicon-containing compound modification treatment agent is 0.001-0.05wt%, and more preferably 0.001-0.025wt%. The preferred amount of the surfactant-containing modification treatment agent is 0.02-1.0 wt%, and more preferably 0.05-0.5 wt%. The polymer polymer-containing modification treatment agent is preferably used in an amount of 0.01-15 wt%, and more preferably 0.1-10 wt%. The content of the filler particles is preferably 0.01 to 6 wt%, and more preferably 0.02 to 4 wt%.

The additive (3) referred to in the present invention includes one or more combinations of auxiliaries, catalysts, and co-solvents. Adding auxiliaries can improve the wettability of the coating film and the substrate and the flatness of the coating film; the catalyst can be controlled The reaction rate of the coating bridge; the co-solvent can control the volatilization rate of the liquid component. The above-mentioned auxiliary agents include silicon-containing or fluorine-containing or silicon-fluorine-containing mixed additives, silicon- or fluorine-containing additives, and silicon-containing additives can be selected from BYK307, BYK325, BYK331, BYK380N of BYK Company. One or more BYK381 or fluorine-containing additives can be selected from the group consisting of FC-4430 and FC-4432 from 3M, Zonyl FSN-100 from DuPont of the United States, and DSX from Daikin of Japan, or Silicon and fluorine-containing mixed ingredients can be selected from one or more of BYK346, BYK347, BYK348. The catalysts are inorganic substances, salts, organic substances, alkaline substances, acid substances, etc. The common solvents are methanol, ethanol, n-propyl Alcohol, isopropanol, isobutanol, butyl cellulose and other solvents.

The method for coating the composition coating liquid on the polyester film can be performed by a conventional off-line coating method, or a so-called in-line coating method. Coating processing, coated polyester film with high transparency, low haze, excellent adhesion and slip properties, suitable for substrates for optical applications such as diffusion films for LCDs and brightness enhancement Film, etc. Hereinafter, the present invention will be described more specifically with reference to the embodiments. Although the preferred embodiments will be described in detail, the technical scope and rights of the present invention are not limited by them.

In addition, the physical property evaluation of the present invention is performed by the following methods:

(1) Light transmittance and haze test: Tokyo Denshoku Co., Ltd. Haze Meter, model TC-HⅢ, was used to test the light transmittance and haze value of the optical films in the following examples. The method complies with JIS K7705. . The higher the light transmittance and the lower the haze value, the better the optical properties of the optical film.

(2) Adhesion test of optical adhesive: using Lianghong Company's exposure machine, Model F300S + AJ-6-UVL, test the adhesion of the acrylate UV adhesive applied to the diffuser film or brightness enhancement film in the embodiment The method conforms to ASTM D3359. Using a No. 12 coating rod, apply the optical glue for domestically produced diffusion film or brightness enhancement film to the coated surface of the optical film of the example, and then expose and dry it with a UV exposure machine. 3M 600 tape was affixed to the 100-gauge specimen, and the adhesive tape was peeled off for adhesiveness evaluation.

(3) Adhesion test of optical adhesive after UV light irradiation: The coated surface of the optical film of the example was first exposed with UV light, and after exposure energy of 500 mJ / cm2, the above-mentioned test method (2) was continued to evaluate the optical adhesive着 性。 Sex.

(4) Dispersion test of coating particles: Use Hitachi S5000 scanning electron microscope to test the dispersibility of the lubricant particles on the coating surface. First, fix the sample on carbon glue, and then use a gold plating machine to plate gold or platinum. The film was observed at a test magnification of 10,000 times.

(5) Anti-adhesive layer temperature: The temperature of the anti-adhesive layer in the test example is tested by using the heat-sealing tester of Hagi Corporation, model HST-H3. Test conditions: Take two samples, with the coating film surfaces facing each other, heat-sealing pressure of 2 MPa, and heat-sealing time of 2 minutes, and perform adhesion tests at different temperatures. After the heat seal test, the two samples can be easily separated without traces on the surface. Record this temperature as the temperature of the anti-adhesive layer.

[Precast Acrylate Graft Modified Polyurethane Resin]

First, an acrylate graft-modified polyurethane resin is preformed, as described below.

(1) Preparation of prepolymer: 100g of PTMG2000 (polyether diol, molecular weight 2000) and 6.5g of 1,4-BG (1,4-butanediol, molecular weight 90) are sequentially added to the reactor, and stirred at a uniform speed The temperature was raised to 80 ° C, and then 43 g of isophorone diisocyanate was added. The temperature was raised to 85-90 ° C, and the reaction was performed at this temperature for 2-3 hours. (2) Prepolymer dilution and chain extension: batches can be approved at this time. Add 140g of methyl methacrylate (MMA), 8g of 2-hydroxyethyl acrylate (2-HEA), and 4.8g of ethyl acrylate (EA) to dilute the viscosity, and add 10g of sodium ethylenediamine ethanesulfonate ( AAS), after 25-40 minutes of continuous reaction, (3) water dispersion: cool the prepolymer obtained in (2) to room temperature, add 300 g of deionized water at 500 rpm, and add 1 g of ethylenediamine for chain extension reaction In about 30 minutes, a sulfonate-based aqueous polyurethane emulsion can be obtained. (4) Acrylate synthesis: Continued (3). Add 4.8 g of emulsifier sodium lauryl sulfate (SLS) to the above sulfonic acid under rapid stirring. The salt-type water-based polyurethane emulsion was heated to 50-70 ° C, and then 0.40 g of an ammonium persulfate aqueous solution (APS) was added dropwise, and the temperature was further increased to 75-85 ° C. The temperature was maintained at this temperature for 1-3 hours, and the temperature was reduced to 50-70 ° C Add restore 0.12 g of t-butyl hydroperoxide aqueous solution (TBHP) and 0.12 g of sodium formaldehyde sulfoxylate (SFS) were reacted for 30 minutes to obtain acrylate graft-modified polyurethane resin.

[Example 1]

After the PET pellets are sufficiently dried, they are fed to the extruder for melting and extrusion, and the surface temperature is 25 ° C. The cooling cylinder is cooled and solidified to obtain an unstretched PET sheet. After heating, it is stretched longitudinally at a draw ratio of 4 times, and then subjected to single-sided coating treatment. The coating solution contains 1 g of polyester resin. 7.5 grams of acrylate graft-modified polyurethane resin, 1.0 grams of melamine resin, another 0.05 grams of anionic surfactant A, 0.5 grams of non-ionic surfactant B, 0.05 grams of silicon-containing compounds and 1.1 grams of polymer ( Polyester resin) as the treatment agent, the treated particles are 80nm silica particles A 0.20g and 30nm silica particles B0.12g as filling particles, after adding 81.97g of water for surface treatment, and finally 0.1g Catalyst, 5 g of isopropyl alcohol, 1.4 g of butyl cellulose, and 0.01 g of silicon or fluorine-containing compound, etc., mix and stir to make a coating solution, and evenly coat the PET substrate, and then use a fixing clip to The coated uniaxially stretched PET film is introduced into a 105 ° C heating zone. After drying to remove the moisture of the coating layer, it is sent to a 125 ° C heating zone for 3.5 times lateral stretching. Then the biaxially stretched PET film is subjected to 235 ℃ treated 8 Bell, to obtain a coating thickness of the polyester film is 50μm. The physical property measurement results are shown in Table 1.

[Example 2]

Its formula composition is that the PET pellets are fully dried, then fed to an extruder for melting and extrusion, and cooled and solidified by a cooling drum with a surface temperature of 25 ° C, so as to obtain an unstretched PET Sheet. After heating, the stretch ratio is 4 It is extended longitudinally and then coated on one side. The coating solution contains 2.75 g of polyester resin, 5.5 g of acrylate grafted modified polyurethane resin, 0.4 g of melamine resin, and 1 g of oxazoline resin. Mix as resin, take 0.5g of anionic surfactant A, 0.05g of nonionic surfactant B, 0.05g of silicon-containing compound and 1g of polymer (polyester resin) as the treatment agent, the treated particles are 80nm Silica particles A 0.1 g and 30 nm silica particles B 0.3 g are considered as filled particles. After adding 81.84 g of water for surface treatment, finally 0.1 g of catalyst, 5 g of isopropanol, and 1.4 g of butyl cellulose are added. And 0.01 g of silicon or fluorine-containing additives Compounds and the like are mixed and stirred evenly to form a coating liquid, which is evenly coated on the PET substrate. Except that the coating formulation is different from that of Example 1, other steps similar to those of Example 1 are used to obtain a single-sided coating polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1.

[Example 3]

Its formula composition is that the PET pellets are fully dried, then fed to an extruder for melting and extrusion, and cooled and solidified by a cooling drum with a surface temperature of 25 ° C, so as to obtain an unstretched PET Sheet. After heating, the stretch ratio is 4 It is extended longitudinally, and its coating solution contains 4 g of polyester resin, 4 g of acrylate graft-modified polyurethane resin, 1 g of melamine resin, and 0.5 g of oxazoline-based resin. Anionic surfactant A, 0.25 grams of non-ionic surfactant B, 0.05 grams of silicon-containing compounds and 1 gram of high molecular polymer (polyester resin) are treated as the treating agent, and the treated particles are 0.25 grams of 80 nm silica particles A And 30nm silica particles B0.15g are considered as filled particles. After adding 82.04g of water for treatment, finally 0.1g of catalyst, 5g of isopropyl alcohol, 1.4g of butyl cellulose and 0.01g of silicon or fluorine Auxiliary compounds and the like are mixed and stirred evenly to form a coating liquid, which is evenly coated on the PET substrate. Except that the coating formulation is different from that of Example 1, other steps similar to those of Example 1 are used to obtain a single-sided coating polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1.

[Example 4]

Its formula composition is that the PET pellets are fully dried, then fed to an extruder for melting and extrusion, and cooled and solidified by a cooling drum with a surface temperature of 25 ° C, so as to obtain an unstretched PET Sheet. After heating, the stretch ratio is 4 The coating solution contains 5.45 grams of polyester resin, 2.8 grams of acrylate graft-modified polyurethane resin, 0.5 grams of melamine resin, and 0.5 grams of oxazoline-based resin. Mix as resin, take another 0.25g of anionic interface activity Agent A, 0.25 grams of non-ionic surfactant B, 0.01 grams of silicon-containing compounds and 1 gram of high molecular polymer (polyester resin) as processing agents, the treated particles are 80nm silica particles A0.15g and 30nm 0.1 g of silicon oxide particles B are considered as filled particles. After adding 82.48 g of water for treatment, finally 0.1 g of catalyst, 5 g of isopropyl alcohol, 1.4 g of butyl cellulose and 0.01 g of silicon or fluorine-containing compounds Etc., uniformly coated on a PET substrate. Except that the coating formulation is different from that of Example 1, other steps similar to those of Example 1 are used to obtain a double-sided coating polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1.

[Example 5]

Its formula consists of fully drying the PET pellets, feeding them to the extruder for melting and extruding, and cooling and solidifying through a cooling drum with a surface temperature of 25 ° C. After heating, longitudinal stretching is performed at a draw ratio of 4 times, and then For single-sided coating, the coating solution contains 5.5 g of polyester resin, 2.2 g of acrylate graft-modified polyurethane resin, 1 g of melamine resin, and 0.7 g of oxazoline-based resin. Anionic surfactant A, 0.5 g of non-ionic surfactant B, 0.05 g of silicon-containing compound and 1 g of high molecular polymer (polyester resin) are treated as the treating agent, and the treated particles are 80 nm silica particles A 0.5 g And 30nm silica particles B0.1g as filling particles, after adding 81.89g of water for treatment, then add 0.1g of catalyst, 5g of isopropanol, 1.4g of butyl cellulose and 0.01g of silicon or fluorine The compound and the like are mixed and stirred to be a coating liquid, and the PET substrate is evenly coated. Except that the coating formulation is different from that of Example 1, other steps similar to those of Example 1 are used to obtain a single-sided coating polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1.

[Example 6]

Its formula consists of fully drying the PET pellets, feeding them to the extruder for melting and extruding, and cooling and solidifying through a cooling drum with a surface temperature of 25 ° C. After heating, longitudinal stretching is performed at a draw ratio of 4 times, and then Double-sided coating treatment, the coating solution contains 1 g of polyester resin, 6 g of acrylate graft-modified polyurethane resin, 2.5 g of oxazoline-based resin, etc. mixed as resin, and another 0.05 g of anionic surfactant A 0.5 grams of non-ionic surfactant B, 0.05 grams of silicon-containing compounds and 1 gram of high molecular polymer (polyester resin) as processing agents, the treated particles are 80 nm silica particles A 0.1 g and 30 nm silica Particle B 0.3 g is considered to be filled particles. After adding 81.99 g of water for treatment, add 0.1 g of catalyst, 5 g of isopropyl alcohol, 1.4 g of butyl cellulose, and 0.01 g of silicon or fluorine-containing compound, etc., and mix well. It is assumed that the coating liquid is uniformly coated on the PET substrate. Except that the coating formulation is different from that of Example 1, other steps similar to those of Example 1 are used to obtain a double-sided coating polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1.

[Comparative Example 1]

Its formula composition is that the PET pellets are fully dried, then fed to an extruder for melting and extrusion, and cooled and solidified by a cooling drum with a surface temperature of 25 ° C, so as to obtain an unstretched PET Sheet. After heating, the stretch ratio is 4 It is extended longitudinally and then subjected to single-sided coating treatment. The composition of the coating solution is as follows: 8.5 g of polyester resin and 1 g of melamine resin are mixed to be the resin, and then 83.59 g of water and 80 nm silica particles A are added. Amount of 0.1g, 30nm silica particles B, 0.3g of mixed solution, finally add 0.1g of catalyst, 5g of isopropanol, 1.4g of butyl cellulose and 0.01g of silicon or fluorine-containing compound, etc. It is assumed that the coating liquid is uniformly coated on the PET substrate. Except that the composition of the aqueous coating solution (as shown in Table 1) for coating is different from that shown in Example 1, other steps similar to those in Example 1 were used to obtain a single-sided coating type polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1, which shows that its physical properties are poor.

[Comparative Example 2]

Its formula composition is that the PET pellets are fully dried, then fed to an extruder for melting and extrusion, and cooled and solidified by a cooling drum with a surface temperature of 25 ° C, so as to obtain an unstretched PET Sheet. After heating, the stretch ratio is 4 It is extended longitudinally and then subjected to single-sided coating treatment. The composition of the coating solution is as follows: 1.5 g of polyester resin, 5 g of acrylate resin, 1 g of melamine resin, etc. are mixed as a resin, and then 85.59 g of water, A mixed solution of 0.1 g of 80 nm silica particles A and 0.3 g of 30 nm silica particles B, and finally add 0.1 g of catalyst, 5 g of isopropanol, 1.4 g of butyl cellulose, and 0.01 g of silicon or fluorine-containing additives Compounds and the like are mixed and stirred evenly to form a coating liquid, which is uniformly coated on a PET substrate. Except that the film thickness and the coating formulation are different from those of Comparative Example 1, other steps similar to those of Example 1 were used to obtain a single-sided coated polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1, which shows that its physical properties are poor.

[Comparative example three]

Its formula composition is that the PET pellets are fully dried, then fed to an extruder for melting and extrusion, and cooled and solidified by a cooling drum with a surface temperature of 25 ° C, so as to obtain an unstretched PET Sheet. After heating, the stretch ratio is 4 It is stretched twice and then subjected to single-side coating treatment. The composition of the coating solution is as follows: 8.5 g of acrylate graft-modified polyurethane resin and 1 g of oxazoline-based resin are mixed to be a resin. Then add a mixed solution containing 83.59 grams of water, 0.1 grams of 80nm silica particles A, 0.3 grams of 30nm silica particles B, and finally add 0.1 grams of catalyst, 5 grams of isopropanol, 1.4 grams of butyl cellulose, and 0.01 Grams of silicon-containing or fluorine-containing auxiliary compounds are mixed and stirred evenly to be a coating liquid, which is evenly coated on the PET substrate. Except that the film thickness and the coating formulation are different from those of Comparative Example 1, other steps similar to those of Example 1 were used to obtain a single-sided coated polyester film with a film thickness of 50 μm. The physical property measurement results are shown in Table 1, which shows that its physical properties are poor.

Discussion of results:

As mentioned above, the present invention is an aqueous mixed solution composed of a polyester resin, an urethane graft-modified polyurethane resin, a crosslinked resin, a filler particle solution modified with a surface treatment agent, and other additives. The coating layer formed after being applied to a substrate has characteristics that significantly improve the substrate's transparency, haze, adhesion, and slipperiness. The results of the above examples and comparative examples are described below.

1. The polyester resin and acrylate-grafted polyurethane resin are mixed in the coating solution of Examples 1-6, which can improve the adhesiveness to the optical adhesive, and the adhesiveness to the optical adhesive after UV light resistance, and improve the stability of the optical adhesive product. And yield, Comparative Example 1-2 did not add acrylate-grafted polyurethane resin, and all had poor adhesiveness to optical adhesives. Even if more acrylate was added in Comparative Example 2, the adhesive properties to optical adhesives were also poor.

2. In Examples 1-6, a particle solution modified by a surface treatment agent is additionally added, which has good dispersibility in the coating layer, good light transmittance (transparency) and haze of the product, and can achieve the effect of increasing the temperature of the anti-adhesive layer. In Comparative Example 1-2, no treatment agent was added, and the product had poor light transmittance and poor haze.

3. Comparative Example 3 Excessive acrylate-grafted urethane resin has good adhesiveness to optical adhesives and good adhesiveness to optical adhesives after UV light irradiation, but has poor dispersion of filler particles in the coating layer.

4. The larger the particle diameter of the filler particles, the higher the anti-adhesion temperature can be. The anti-adhesion temperature of Examples 3 and 5 is as high as 100 ° C or more.

5. Comparative Example 2 A mixed solution of a polyester resin, a melamine resin, and an acrylate resin was used, but there was still insufficient adhesion to the optical adhesive coating layer, which is the main improvement item of the present invention.

Claims (6)

An easy-to-use polyester film comprising a substrate and a coating on one or both sides of the substrate, characterized in that, according to the JIS K7705 test standard, its light transmittance is between 90.80 ~ 92.80% and haze range from 0.65 to 0.80%, and the anti-adhesion layer temperature of the coating reaches 90 ° C or above under the conditions of heat sealing pressure of 2 MPa and heat sealing time of 2 minutes, among which the coating It is composed of the following components based on the total weight of the coating: (1) 2-40wt% mixed resin; (2) 0.05-30wt% filled particle solution treated with surface modifier; (3) 0.05-10wt% additive, choose self-service One or more of an agent, a catalyst or a co-solvent; and (4) a 50-85wt% water solvent; wherein the mixed resin (1) based on the total weight of the mixed resin comprises: a. 10-60wt% polyester resin ; B. 20-80wt% acrylate graft modified polyurethane resin dispersion; c. 10-40wt% cross-linked resin, selected from melamine resin, melamine modified resin, carbodiimide-based cross-linking agent or One or more of oxazoline-based crosslinking agents. The easy-to-use polyester film according to item 1 of the scope of the patent application, wherein the surface modifier used in the filling particle solution (2) is selected from the group consisting of a silicon-containing compound, a surfactant, and a polymer. the above. The easy-to-use polyester film as described in item 2 of the patent application range, wherein the amount of the silicon-containing compound modifier is 0.001-0.05wt%, and the amount of the surfactant modifier is 0.02-1.0 wt%, the amount of the polymer polymer modifier is 0.01-15 wt%. The easy-to-adhere polyester film as described in item 1 of the scope of the patent application, wherein the filler particles in the filler particle solution (2) have a particle diameter of 0.005 to 3 μm and are selected from alumina, aluminum hydroxide, One or more of silicon oxide, titanium oxide, zirconia, calcium carbonate, magnesium carbonate, or barium sulfate. The easy-to-adhere polyester film described in item 1 of the scope of the patent application, wherein the filler particle concentration of the coating layer accounts for 0.01% to 6% of the solid content of the coating layer. The easy-to-use polyester film as described in item 1 of the scope of the patent application, wherein the auxiliary agent is selected from a silicon-containing auxiliary agent, a fluorine-containing auxiliary agent, or an auxiliary agent containing a silicon-fluorine mixed component.