Optical polyester film for dimming glass

Abstract

The invention relates to the technical field of high polymer materials, in particular to an optical polyester film for dimming glass. The invention relates to an optical polyester film for dimming glass, which is a biaxially oriented polyester film formed by co-extruding a polyester film base layer, a reinforcing layer, an anti-radiation layer and an antistatic layer, the polyester film base layer, the reinforcing layer, the anti-radiation layer and the anti-static layer respectively contain copolyester, enhanced acrylate emulsion, polyacrylonitrile fiber and anti-static modified polyester. Polyester is subjected to copolymerization modification through polycarbonate diol, polycarbonate diol is introduced into a main chain of polyester, regularity of a polyester chain segment is broken, crystallization time is prolonged so as to reduce the degree of crystallinity, flexibility of a polyester molecular chain can be effectively improved, the molecular structure of polycarbonate diol contains a large number of carbonate bonds, and therefore the polyester can be used for preparing a high-temperature-resistant polyester film. The heat resistance can be improved, so that the toughness and the heat resistance of the polyester are improved, and the strength of the optical polyester film is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to an optical polyester film for light-adjustable glass. BACKGROUND

[0002] The light-adjustable glass is installed with liquid crystal film between two layers of glass, and is processed into laminated glass under high temperature and high pressure, and has the characteristics of transparent when powered on and fogging when powered off, and the surface of the light-adjustable glass is usually protected by a polyester film. The polyester film is a film material made of polyethylene terephthalate as raw material, and is made by extrusion method and then by two-way stretching. The polyethylene terephthalate is mainly synthesized by esterification and polycondensation reaction of terephthalic acid and ethylene glycol, etc. under the action of a catalyst. The production technology of two-way stretching polyester film as a representative has been mature, but due to the regular arrangement of PET molecular chain and the fast crystallization speed, the crystallization area will affect the transmission of light, so the optical performance needs to be improved by changing the PET molecular structure and reducing the crystallization ability, and the copolymerization modification is to introduce different groups and segments into the main chain of the polymer from the molecular structure design level to change the physical and chemical properties of the polymer.

[0003] The most widely used is the copolymerization modification of polyester with alcohol monomers to introduce alcohol molecular groups and segments to reduce the crystallization rate and reduce the proportion of crystal area affecting the transmission of light, but the existing alcohol monomers have a small degree of reducing the crystallinity of the copolyester, so that the performance such as light transmittance and haze is difficult to improve, and other defects such as poor heat resistance and toughness are generated, resulting in the reduction of the strength of the optical polyester film. Therefore, an optical polyester film for light-adjustable glass is needed to solve the above problems. SUMMARY

[0004] In view of the shortcomings of the prior art, the purpose of the present application is to provide an optical polyester film for light-adjustable glass with good optical performance and high strength, to reduce the crystallization ability of the film, improve the light transmittance and haze, and improve the heat resistance and toughness of the polyester.

[0005] An optical polyester film for light-adjustable glass, the optical polyester film comprises a polyester film base layer, a reinforcing layer, a radiation protection layer and an antistatic layer, the reinforcing layer is arranged on the polyester film base layer, the radiation protection layer is arranged on the reinforcing layer, and the antistatic layer is arranged on the radiation protection layer.

[0006] The polyester film base layer contains copolyester, and the preparation steps of the copolyester are as follows: The polyester chip and the master batch are pre-crystallized in a blast drying oven at 90-100℃ for 2-4h, and then vacuum dried at 120-150℃ for 5-6h, the dried master batch and chip are mechanically mixed at 1:6-7, and then added into a double screw blending extruder to blend and extrude 350-450μm thick sheets, which are cooled, granulated, and dried to obtain the copolyester.

[0007] Further, the polyester chip is modified polyethylene terephthalate isophthalate, and the master batch is polysiloxane containing 45-55% polydimethylsiloxane soft segment.

[0008] The reinforcing layer contains a reinforced acrylate emulsion, and the preparation steps of the reinforced acrylate emulsion are as follows: ①Deionized water, non-ionic emulsifier and anionic emulsifier are mixed at a mass ratio of 40-50:0.04-0.045:0.013-0.022, and then 5-7 parts by mass of vinyl versatate, 0.15-0.3 parts by mass of isobornyl methacrylate, 35-40 parts by mass of n-butyl acrylate, 1-3 parts by mass of methacrylic acid, 0.02-0.04 parts by mass of N-methylol methacrylamide and 0.01-0.02 parts by mass of trimethylolpropane triacrylate are added to obtain a pre-emulsion; ②1-2% parts by mass of ammonium persulfate solution with a mass fraction of 10-15% is placed in a dropping tube, 25-30% of the pre-emulsion is added into a reaction bottle, 25-30% of the ammonium persulfate solution is added dropwise, and then polymerization is carried out at 30-35℃ for 30-40min, the temperature is increased to 70-75℃, the remaining pre-emulsion and ammonium persulfate solution are added dropwise in 2-3h, and then the reaction is carried out for 1-2h, the temperature is decreased to 30-50℃, the pH is adjusted to 7-9 with ammonia water, and then the product is filtered to obtain the reinforced acrylate emulsion.

[0009] Further, the non-ionic emulsifier in the preparation steps of the reinforced acrylate emulsion is a fatty alcohol polyoxyethylene ether, and the anionic emulsifier is sodium dodecyl benzene sulfonate.

[0010] The radiation protection layer contains polyacrylonitrile fiber, and the preparation steps of the polyacrylonitrile fiber are as follows: ①Polyacrylonitrile and N,N-dimethylformamide solution are mixed at a mass ratio of 1:7-8, stirred at 400-500r / min for 10-12h, and then stood for 1-2h to remove bubbles, 1-1.5% parts by mass of ultraviolet absorber UV329 is added, and then stirred at 400-500r / min for 8-10h to remove bubbles, and then the product is obtained as polyacrylonitrile solution; ②The polyacrylonitrile solution is vacuum filtered for 10-15min at a vacuum degree of 0.0095-0.01MPa, the filter cake is dried at 50-60℃ for 1-2h, and then transferred into a melt spinning machine to perform spinning at a spinning temperature of 150-200℃ to obtain the polyacrylonitrile fiber.

[0011] The antistatic layer contains an antistatic modified polyester, and the preparation steps of the antistatic modified polyester are as follows: ①In a reaction kettle, terephthalic acid and ethylene glycol are added in a molar ratio of 1:1-1.2, and n-butyl titanate accounting for 0.5-0.8% of the mass of terephthalic acid is added, nitrogen is introduced, the temperature is raised to 200-220℃, esterification is carried out to remove the fraction, when no fraction is removed, polycarbonate dihydric alcohol accounting for 0.1-0.12% of the molar fraction of terephthalic acid is added, the temperature is raised to 250-270℃, and pre-polymerization is carried out for 1-2h, then vacuum is applied for polycondensation, the temperature is controlled at 280-285℃, the pressure is controlled at 50-100Pa, and the reaction is carried out for 2-3h to obtain a modified polyester; ②Polyvinyl alcohol and sodium alginate are mixed in a mass ratio of 4-5:1, 48-65 parts by mass of deionized water is added, and the mixture is heated in a water bath at 50-60℃ for 1-2h to obtain a spinning solution, the spinning solution is loaded into a feeding device, the solution flow rate is set to 2-3mL / h, the receiving distance is set to 8-10cm, and the spinning solution is uniformly coated on the surface of the modified polyester using an electrostatic spinning device to obtain an antistatic modified polyester.

[0012] Further, the feeding device in the preparation steps of the antistatic modified polyester comprises a syringe and a syringe pump, and the electrostatic spinning device comprises a high-voltage generator, the high-voltage generator is electrically connected to the syringe, the syringe pump is used to hold the syringe, and the high-voltage generator is used to stretch the spinning solution in the syringe into a jet.

[0013] The optical polyester film for light-adjustable glass is prepared by the following steps: ①The copolyester is added to the polyester film base layer of the optical polyester film, the reinforced acrylic emulsion is spin-coated onto the surface of the polyester film base layer using a film applicator, the coating is applied at 200-300r / min for 10-15s, then at 800-1000r / min for 10-15s, and the coating is heat-treated in an oven at 90-100℃ for 2-3h to form a reinforcing layer; ②The polyacrylonitrile fiber is added to the reinforcing layer to form a radiation protection layer, the modified polyester is added to the radiation protection layer to form an antistatic layer, and the four-layer structure is synchronously stretched in the longitudinal and transverse directions on a biaxial film stretching machine at a preheating temperature of 85-95℃ for 15-20s, a stretching speed of 100-120mm / s, and a stretching ratio of 4-5 to obtain an optical polyester film with a thickness of 30-120μm; ③The stretched film is shaped and cooled, the shaping temperature is 130-160℃, and the film is drawn and wound after cooling.

[0014] Further, the thickness ratio of the polyester film base layer, the reinforcing layer, the radiation protection layer, and the antistatic layer is 1-2:1-2:0.5-1:0.5-1. Advantages

[0015] 1、The poly carbonate diol is used for copolymerization modification of the polyester, the poly carbonate diol is introduced into the main chain of the polyester, the regularity of the polyester segment is broken, the crystallization time is prolonged to reduce the crystallinity, meanwhile, the flexibility of the polyester molecular chain can be effectively improved, the heat resistance can be improved due to the large amount of carbonate bonds in the molecular structure of the poly carbonate diol, so that the toughness and heat resistance of the polyester are improved, and the strength of the optical polyester film is improved.

[0016] 2、The polyvinyl alcohol and sodium alginate are used to configure the spinning solution, and the modified polyester surface is deposited through electrostatic spinning, so that the antistatic property of the polyester can be improved, the mixed solution of the polyvinyl alcohol and the sodium alginate contains more free hydroxyl and carboxyl groups, the structure for transporting charges is formed on the material surface, the charges formed on the material surface can be quickly drained to prevent the accumulation of static electricity, so that the antistatic effect is improved.

[0017] 3、The polyacrylonitrile and the ultraviolet absorber are selected as raw materials, the polyacrylonitrile fiber is prepared through melt spinning, and is introduced into the optical polyester film as a radiation protection layer, so that the ultraviolet resistance of the optical polyester film is improved, the prepared polyacrylonitrile fiber has good absorption to ultraviolet light, the transmittance of ultraviolet light can be reduced, and the ultraviolet protection performance is improved.

[0018] 4、The seed emulsion polymerization method is adopted to synthesize the acrylate latex, a composite system of anionic and non-ionic emulsifiers is selected, the acrylate polymer with high transparency is synthesized, the network structure of the polymer is formed by using the trifunctional crosslinking monomer trimethylolpropane triacrylate, the wear resistance of the polymer is improved, and the strength of the composite polyester film is improved.

[0019] 5、The self-crosslinking monomer N-methylol acrylamide is added, the adhesion of the polymer emulsion can be improved, the N-methylol acrylamide can introduce the methylol group and crosslink with other functional groups, the crosslinking density between the polymer molecules is improved, the combination firmness of the emulsion and the polyester is improved, and the performance of the emulsion after film formation is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The preparation flow chart of the optical polyester film for dimming glass used in the embodiment of the present application is shown in the figure. Figure 2 The experimental data graph of the crystallinity, light transmittance and haze test experiment of the comparative example of the present application is shown in the figure. DETAILED DESCRIPTION

[0021] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts are within the protection scope of the present application. Embodiment 1

[0022] An optical polyester film for dimming glass, as shown, comprises a polyester film base layer, a reinforcing layer, a radiation-proof layer and an antistatic layer, the polyester film base layer is provided with the reinforcing layer, the reinforcing layer is provided with the radiation-proof layer, the radiation-proof layer is provided with the antistatic layer, the polyester film base layer contains copolyester, the reinforcing layer contains reinforced acrylate emulsion, the radiation-proof layer contains polyacrylonitrile fiber, and the antistatic layer contains antistatic modified polyester. Figure 1

[0023] The preparation steps of the copolyester are as follows: Modified polyethylene terephthalate isophtalic acid and polysiloxane containing 50% polydimethylsiloxane soft segment are pre-crystallized in a blast drying oven at 90℃ for 2h, and then vacuum dried at 120℃ for 5h, the dried master batch and the chips are mechanically mixed at a ratio of 1:6, and then added into a double-screw blending extruder to blend and extrude 350μm thick sheets, which are cooled, granulated and dried to obtain the copolyester.

[0024] The preparation steps of the reinforced acrylate emulsion are as follows: Deionized water, non-ionic emulsifier fatty alcohol polyoxyethylene ether and anionic emulsifier sodium dodecyl benzene sulfonate are mixed at a mass ratio of 40:0.04:0.013, and then 5 parts of vinyl versatate, 0.15 parts of isobornyl methacrylate, 35 parts of n-butyl acrylate, 1 part of methacrylic acid, 0.02 parts of N-methylol methacrylamide and 0.01 parts of trimethylolpropane triacrylate are added to obtain a pre-emulsion; 1% of ammonium persulfate solution with a mass fraction of 10% is placed in a dropping tube, 25% of the pre-emulsion is added into a reaction bottle, 25% of the above ammonium persulfate solution is added dropwise, and then polymerization reaction is carried out at 30℃ for 30min, the temperature is raised to 70℃, the remaining pre-emulsion and ammonium persulfate solution are added, and the dropping is completed in 2h, and then the reaction is carried out for 1h, the temperature is lowered to 30℃, the pH is adjusted to 7 with ammonia water, and then the product is filtered out to obtain the reinforced acrylate emulsion.

[0025] The preparation steps of the polyacrylonitrile fiber are as follows: ​Polyacrylonitrile is mixed with N,N-dimethylformamide solution at a mass ratio of 1:7, stirred at 400 r / min for 10 h, defoamed for 1 h, 1% mass fraction of ultraviolet absorber UV329 is added, stirred at 400 r / min for 8 h, and defoamed for standby, to obtain a polyacrylonitrile solution; The polyacrylonitrile solution is vacuum filtered for 10 min at a vacuum degree of 0.0095 MPa, the filter cake is taken out and dried at 50℃ for 1 h, and then is transferred into a melt spinning machine for spinning at a spinning temperature of 150℃, to obtain polyacrylonitrile fibers.

[0026] The preparation steps of the antistatic modified polyester are as follows: In a reaction kettle, terephthalic acid and ethylene glycol are added at a molar ratio of 1:1, 0.5% of n-butyl titanate based on the mass of terephthalic acid is added, nitrogen is introduced, the temperature is raised to 200℃, esterification is carried out to remove the fraction, when no fraction is removed, 0.1% of the molar fraction of polycarbonate diol based on terephthalic acid is added, the temperature is raised to 250℃, and prepolymerization is carried out for 1 h, vacuum is applied for polycondensation, the temperature is controlled at 280℃, and the pressure is controlled at 50 Pa, and the reaction is carried out for 2 h, to obtain the modified polyester; Polyvinyl alcohol and sodium alginate are mixed at a mass ratio of 4:1, 48 mass parts of deionized water is added, and the mixture is heated in a water bath at 50℃ for 1 h to obtain a spinning solution, the spinning solution is loaded into a feeding device, in the specific implementation process, the feeding device includes a syringe and a syringe pump, the electrostatic spinning device includes a high-voltage generator, the syringe is clamped on the syringe pump, the needle of the syringe is connected with the positive electrode of the high-voltage generator, the high-voltage generator is turned on to apply voltage, the spinning solution is stretched into a jet, the flow rate of the solution is set to 2 mL / h, the receiving distance is set to 8 cm, and the spinning solution is uniformly coated on the surface of the modified polyester to obtain the antistatic modified polyester.

[0027] The optical polyester film for light-adjustable glass is prepared by the following steps: The copolyester is added to the polyester film base layer of the optical polyester film, the reinforced acrylate emulsion is spin-coated onto the surface of the polyester film base layer using a spin coater, the coating speed is 200 r / min for 10 s and 800 r / min for 10 s, and the polyester film is heated in an oven at 90℃ for 2 h for heat treatment to form a reinforcing layer; The polyacrylonitrile fibers are added to the reinforcing layer to form a radiation-proof layer, the modified polyester is added to the radiation-proof layer to form an antistatic layer, and the four-layer structure is preheated at a temperature of 85℃ for 15 s on a biaxial film stretching machine, and then is stretched in the longitudinal and transverse directions simultaneously at a stretching speed of 100 mm / s, and the stretching ratio is 4, to obtain an optical polyester film with a thickness of 48 μm; The stretched film is shaped, cooled, and then is drawn and wound after cooling.

[0028] The thickness ratio of the polyester film base layer, the reinforcing layer, the radiation-proof layer and the anti-static layer is 1:1:0.5:0.5. Example 2

[0029] An optical polyester film for light control glass, as shown in the drawings, comprises a polyester film base layer, a reinforcing layer, a radiation-proof layer and an anti-static layer. Figure 1 The polyester film base layer contains copolyester, the reinforcing layer contains reinforcing acrylic emulsion, the radiation-proof layer contains polyacrylonitrile fiber and the anti-static layer contains anti-static modified polyester.

[0030] The preparation steps of the copolyester are as follows: The modified polyethylene terephthalate isophtalic acid and polysiloxane containing 53% polysiloxane soft segment are pre-crystallized in a blast drying oven at 90℃ for 2h, and then vacuum dried at 120℃ for 5h. The dried master batch and the chips are mechanically mixed at a ratio of 1:7, and then added into a double screw blending extruder to blend and extrude 400μm thick sheets. After cooling, granulation and drying, the copolyester is obtained.

[0031] The preparation steps of the reinforcing acrylic emulsion are as follows: Deionized water, non-ionic emulsifier fatty alcohol polyoxyethylene ether and anionic emulsifier sodium dodecyl benzene sulfonate are mixed at a mass ratio of 45:0.042:0.018. Then, 6 parts of vinyl versatate, 0.2 parts of isobornyl methacrylate, 37 parts of n-butyl acrylate, 1.5 parts of methacrylic acid, 0.03 parts of N-methylol methacrylamide and 0.015 parts of trimethylolpropane triacrylate are added to obtain a pre-emulsion. 2% of ammonium persulfate solution with a mass fraction of 12% is placed in a dropping tube, 27% of the pre-emulsion is added into a reaction bottle, 27% of the above ammonium persulfate solution is added dropwise, and polymerization reaction is carried out at 30℃ for 35min. The temperature is raised to 70℃, the remaining pre-emulsion and ammonium persulfate solution are added dropwise in 2h, and the reaction is kept for 1h. The temperature is lowered to 30℃, ammonia water is added to adjust the pH to 8, and the product is filtered out to obtain the reinforcing acrylic emulsion.

[0032] The preparation steps of the polyacrylonitrile fiber are as follows: Polyacrylonitrile is mixed with N,N-dimethylformamide solution at a mass ratio of 1:8, stirred at 400r / min for 10h, and defoamed after standing for 1h. Then, 1.5% of ultraviolet absorber UV329 is added, and stirred at 400r / min for 8h. The product is defoamed and used, to obtain a polyacrylonitrile solution. The polyacrylonitrile solution is vacuum filtered for 10 minutes, the vacuum degree is 0.0095 MPa, the filter cake is dried at 50℃ for 1 hour, and then is transferred into a melt spinning machine to perform spinning, the spinning temperature is 150℃, and polyacrylonitrile fiber is obtained.

[0033] The preparation steps of the antistatic modified polyester are as follows: In a reaction kettle, terephthalic acid and ethylene glycol are added in a molar ratio of 1:1.2, 0.7% of the mass of terephthalic acid is added as n-butyl titanate, nitrogen is introduced, the temperature is raised to 200℃, esterification is performed to remove the fraction, when no fraction is removed, 0.12% of the molar fraction of terephthalic acid is added as polycarbonate diol, the temperature is raised to 250℃, and the prepolymerization is performed for 1 hour, then vacuum is applied for polycondensation, the temperature is controlled at 280℃, and the pressure is controlled at 50 Pa, and the reaction is performed for 2 hours to obtain the modified polyester. Polyvinyl alcohol and sodium alginate are mixed in a mass ratio of 5:1, 48 parts by mass of deionized water is added, and the mixture is heated in a water bath at 50℃ for 1 hour to obtain a spinning solution. In the specific implementation process, the feeding device includes a syringe and a syringe pump, and the electrospinning device includes a high-voltage generator. The syringe is clamped on the syringe pump, the needle of the syringe is connected to the positive electrode of the high-voltage generator, the high-voltage generator is turned on to apply a voltage, and the spinning solution is stretched into a jet. The solution flow rate is set to 2 mL / h, the receiving distance is set to 8 cm, the spinning solution is uniformly coated on the surface of the modified polyester, and the antistatic modified polyester is obtained.

[0034] The optical polyester film for light-adjustable glass is prepared by the following steps: The copolyester is added to the polyester film base layer of the optical polyester film, the reinforced acrylate emulsion is spin-coated onto the surface of the polyester film base layer using a spin coater, the coating speed is 200 r / min for 10 s and 800 r / min for 10 s, and the polyester film is heated in an oven at 90℃ for 2 hours to form a reinforcing layer. The polyacrylonitrile fiber is added to the reinforcing layer to form a radiation-proof layer, the modified polyester is added to the radiation-proof layer to form an antistatic layer, and the four-layer structure is preheated at 85℃ for 15 s on a biaxial film stretching machine, and then is stretched in the longitudinal and transverse directions simultaneously at a stretching speed of 100 mm / s, with a stretching ratio of 4, to obtain an optical polyester film with a thickness of 88 μm. The stretched film is shaped, cooled, and then is drawn and wound after cooling.

[0035] The thickness ratio of the polyester film base layer, the reinforcing layer, the radiation-proof layer, and the antistatic layer is 1.5:1.5:1:1. Example 3

[0036] An optical polyester film for light-adjustable glass is prepared by the following steps: Figure 1As shown, it comprises a polyester film base layer, a reinforcing layer, a radiation protection layer and an antistatic layer, the reinforcing layer is arranged on the polyester film base layer, the radiation protection layer is arranged on the reinforcing layer, and the antistatic layer is arranged on the radiation protection layer, the polyester film base layer contains copolyester, the reinforcing layer contains reinforced acrylate emulsion, the radiation protection layer contains polyacrylonitrile fiber, and the antistatic layer contains antistatic modified polyester.

[0037] The preparation steps of the copolyester are as follows: The modified polyethylene terephthalate and the polysiloxane containing 50% polydimethylsiloxane soft segment are pre-crystallized in a blast drying oven at 95℃ for 3h, and then vacuum dried at 130℃ for 5.5h, the dried master batch and the chips are mechanically mixed at a ratio of 1:6, added into a twin-screw blending extruder, and then blended and extruded into a 350μm thick sheet, cooled, granulated and dried to obtain the copolyester.

[0038] The preparation steps of the reinforced acrylate emulsion are as follows: The deionized water, non-ionic emulsifier fatty alcohol polyoxyethylene ether and anionic emulsifier sodium dodecylbenzenesulfonate are mixed at a mass ratio of 40:0.04:0.013, and then 5 parts of vinyl versatate, 0.15 parts of isobornyl methacrylate, 35 parts of n-butyl acrylate, 1 part of methacrylic acid, 0.02 parts of N-hydroxymethyl methacrylamide and 0.01 parts of trimethylolpropane triacrylate are added to obtain a pre-emulsion; 1% of a 10% mass fraction ammonium persulfate solution is placed in a dropping tube, 25% of the pre-emulsion is added into a reaction bottle, 25% of the above ammonium persulfate solution is added dropwise, polymerization is carried out at 35℃ for 35min, the temperature is raised to 75℃, the remaining pre-emulsion and ammonium persulfate solution are added, and the dropping is completed in 2.5h, the reaction is maintained for 1.5h, the temperature is lowered to 40℃, the pH is adjusted to 7 with ammonia water, and the product is filtered out to obtain the reinforced acrylate emulsion.

[0039] The preparation steps of the polyacrylonitrile fiber are as follows: The polyacrylonitrile and the N,N-dimethylformamide solution are mixed at a mass ratio of 1:7, stirred at 420r / min for 11h, and then stood for 1.5h to remove bubbles, 1% of the ultraviolet absorber UV329 is added, and stirred at 450r / min for 9h to remove bubbles, and then used, to obtain a polyacrylonitrile solution. The polyacrylonitrile solution is vacuum filtered for 12min at a vacuum degree of 0.01MPa, the filter cake is dried at 55℃ for 1.5h, and then transferred into a melt spinning machine to perform spinning at a spinning temperature of 170℃, to obtain the polyacrylonitrile fiber.

[0040] The preparation steps of the antistatic modified polyester are as follows: In a reaction kettle, terephthalic acid and ethylene glycol were added in a molar ratio of 1:1, 0.5% of the mass of terephthalic acid was added as n-butyl titanate, nitrogen was introduced, the temperature was raised to 210°C, esterification was carried out to remove the fraction, when no fraction was removed, 0.1% of the molar fraction of terephthalic acid was added as a polycarbonate diol, the temperature was raised to 260°C, and the prepolymerization reaction was carried out for 1.5h, and the temperature was controlled at 285°C and the pressure was 70Pa, and the polycondensation reaction was carried out for 2.5h, to obtain a modified polyester; Polyvinyl alcohol and sodium alginate were mixed in a mass ratio of 4:1, 48 parts by mass of deionized water was added, and heated in a water bath at 55°C for 1.5h to obtain a spinning solution. In the specific implementation process, the feeding device includes a syringe and a syringe pump, and the electrospinning device includes a high-voltage generator. The syringe is clamped on the syringe pump, the needle of the syringe is connected to the positive electrode of the high-voltage generator, the high-voltage generator is turned on to apply voltage, and the spinning solution is stretched into a jet. The solution flow rate is set to 2.5mL / h, the receiving distance is 10cm, the spinning solution is uniformly coated on the surface of the modified polyester, and the antistatic modified polyester is obtained.

[0041] The light control glass optical polyester film is prepared by the following steps: The copolyester is added to the polyester film base layer of the optical polyester film, and the reinforced acrylic emulsion is spin-coated onto the surface of the polyester film base layer using a spin coater, coated at 250r / min for 12s, coated at 820r / min for 12s, and heat treated in a 95°C oven for 3h to form a reinforcing layer; The polyacrylonitrile fiber is added to the reinforcing layer to form a radiation protection layer, the modified polyester is added to the radiation protection layer to form an antistatic layer, and the four-layer structure is preheated at 90°C for 18s on a biaxial film stretching machine, and stretched longitudinally and transversely at a stretching speed of 110mm / s, with a stretching ratio of 5, to obtain an optical polyester film with a thickness of 48μm; The stretched film is shaped, cooled, shaped at 150°C, and then drawn and wound after cooling.

[0042] The thickness ratio of the polyester film base layer, the reinforcing layer, the radiation protection layer, and the antistatic layer is 1:1:0.5:0.5.

[0043] Comparative Example 1 The difference from Example 1 is that in the preparation step of the antistatic modified polyester, this comparative example uses 1,6-hexanediol instead of polycarbonate diol to prepare the modified polyester. The specific steps are: terephthalic acid and ethylene glycol are added in a molar ratio of 1:1 in a reactor, n-butyl titanate accounting for 0.5% by mass of terephthalic acid is added, nitrogen is introduced, the temperature is raised to 200°C, esterification is carried out to remove the fraction, and when no fraction is removed, 1,6-hexanediol accounting for 0.1% by mole fraction of terephthalic acid is added, the temperature is raised to 250°C, prepolymerization reaction is carried out for 1 hour, vacuumization is carried out for condensation, the temperature is controlled at 280°C, the pressure is 50 Pa, and the reaction is carried out for 2 hours to obtain a modified polyester, which is recorded as Comparative Example 1. The modified polyester prepared in Example 1 is recorded as Example 1, and crystallinity test experiments are carried out respectively.

[0044] The crystallinity test experiment adopts the X-ray diffraction method, and the specific steps are: drying the modified polyester at 160°C for 4h, using a slicer to slice the dried modified polyester, and using an injection molding machine for injection molding. The preheating time of the injection molding machine is 5s, the pre-pressing pressure is 2.5MPa, the pre-pressing time is 10min, the melt temperature is 145°C, the full pressing pressure is 5MPa, the full pressing time is 30min, the injection molded sheet is 2mm thick, the injection molded sheet is placed on the XRD sample table, and X-ray diffractometer analysis is performed. The crystallinity of Comparative Example 1 and Example 1 is obtained after computer processing.

[0045] like Figure 2 As shown, the crystallinity data of Example 1 and Comparative Example 1 are compared, from which it can be seen that the copolymerization modification effect of polycarbonate diol on polyester is better.

[0046] Comparative Example 2 Compared with Example 1, this comparative example uses 1,6-hexanediol instead of polycarbonate diol to prepare modified polyester. The other steps refer to Example 1. Finally, an optical polyester film is prepared, which is recorded as Comparative Example 2. The transmittance and haze test experiments are carried out separately with Example 1.

[0047] The light transmittance and haze test experiments were conducted according to GB / T 2410-2008. The optical polyester film was cut into 100 mm × 100 mm pieces. The light transmittance and haze of the optical polyester film were tested using a colorimeter. The results are recorded as Comparative Example 2 and Example 1.

[0048] like Figure 2 As shown, the transmittance and haze data of Example 1 and Comparative Example 2 are compared. It can be seen that the optical properties of the modified polyester prepared by polycarbonate diol are better.

[0049] The above embodiments are only illustrative of the principles of the present application and its efficacy, and are not intended to limit the present application. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. An optical polyester film for dimming glass, characterized in that: It includes a polyester film base, a reinforcement layer, an anti-radiation layer and an antistatic layer. The reinforcement layer is arranged on the polyester film base, the anti-radiation layer is arranged on the reinforcement layer, and the anti-radiation layer is arranged on the antistatic layer.

2. The optical polyester film for dimming glass according to claim 1, characterized in that: The polyester film base layer contains copolyester, and the preparation steps of the copolyester are as follows: The polyester chips and masterbatch are pre-crystallized in a blast drying oven at 90-100°C for 2-4 hours, and then vacuum dried at 120-150°C for 5-6 hours. The dried masterbatch and chips are mechanically mixed at a ratio of 1:6-7, added to a twin-screw blending extruder, and blended and extruded into 350-450μm thick sheets. After cooling, granulation and drying, copolyester is obtained.

3. The optical polyester film for dimming glass according to claim 2, characterized in that: The polyester chips are polyethylene terephthalate modified with isophthalic acid, and the masterbatch is polysiloxane containing 45-55% of polydimethylsiloxane soft segments.

4. The optical polyester film for switchable glass according to claim 1, characterized in that: The reinforcing layer contains a reinforced acrylic emulsion, and the preparation steps of the reinforced acrylic emulsion are as follows: ① Deionized water, a nonionic emulsifier (fatty alcohol polyoxyethylene ether), and an anionic emulsifier (sodium dodecylbenzene sulfonate) are mixed in a mass ratio of 40-50:0.04-0.045:0.013-0.022, and 5-7 parts by mass of versatate, 0.15-0.3 parts by mass of isobornyl methacrylate, 35-40 parts by mass of n-butyl acrylate, 1-3 parts by mass of methacrylic acid, 0.02-0.04 parts by mass of N-hydroxymethyl methacrylamide, and 0.01-0.02 parts by mass of trimethylolpropane triacrylate are added to obtain a pre-emulsion; ② Place 1-2% by mass of a 10-15% ammonium persulfate solution in a drip tube, add 25-30% of the pre-emulsion into the reaction bottle, add 25-30% of the above ammonium persulfate solution dropwise, and polymerize at 30-35°C for 30-40 minutes. Raise the temperature to 70-75°C, add the remaining pre-emulsion and ammonium persulfate solution, and add them dropwise over 2-3 hours. Keep the temperature for 1-2 hours, cool to 30-50°C, adjust the pH to 7-9 with aqueous ammonia, and filter the material to obtain a reinforced acrylic emulsion.

5. The optical polyester film for switchable glass according to claim 4, characterized in that: In the preparation step of the enhanced acrylic ester emulsion, the nonionic emulsifier is fatty alcohol polyoxyethylene ether, and the anionic emulsifier is sodium dodecylbenzene sulfonate.

6. The optical polyester film for switchable glass according to claim 1, characterized in that: The radiation protection layer contains polyacrylonitrile fiber, and the preparation steps of the polyacrylonitrile fiber are as follows: ① Mix polyacrylonitrile and N,N-dimethylformamide solution in a mass ratio of 1:7-8, stir at 400-500 r / min for 10-12 hours, let stand for 1-2 hours to defoam, add 1-1.5% by mass of ultraviolet absorber UV329, stir at 400-500 r / min for 8-10 hours, defoam and set aside to obtain polyacrylonitrile solution; ② The polyacrylonitrile solution was vacuum filtered for 10-15 minutes at a vacuum degree of 0.0095-0.01 MPa, the filter cake was dried at 50-60°C for 1-2 hours, and then transferred to a melt spinning machine for spinning at a spinning temperature of 150-200°C to obtain polyacrylonitrile fiber.

7. The optical polyester film for switchable glass according to claim 1, characterized in that: The antistatic layer contains antistatic modified polyester, and the preparation steps of the antistatic modified polyester are: ① Add terephthalic acid and ethylene glycol in a molar ratio of 1:1-1.2 into a reactor, add n-butyl titanate accounting for 0.5-0.8% of the mass of terephthalic acid, introduce nitrogen, heat to 200-220°C, carry out esterification and remove fractions, and when no fraction is removed, add polycarbonate diol accounting for 0.1-0.12% of the molar fraction of terephthalic acid, heat to 250-270°C, carry out prepolymerization for 1-2 hours, vacuumize for polycondensation, control the temperature at 280-285°C, and the pressure at 50-100 Pa, and react for 2-3 hours to obtain modified polyester; ② Mix polyvinyl alcohol and sodium alginate in a mass ratio of 4-5:1, add 48-65 parts by mass of deionized water, and heat in a water bath at 50-60°C for 1-2 hours to obtain a spinning solution. Load the spinning solution into a feeding device, set the solution flow rate to 2-3 mL / h, and the receiving distance to 8-10 cm. Use an electrospinning device to evenly coat the spinning solution on the surface of the modified polyester to obtain an antistatic modified polyester.

8. The optical polyester film for switchable glass according to claim 7, characterized in that: The feeding device in the preparation step of the antistatic modified polyester includes a syringe and a syringe pump, and the electrospinning device includes a high-voltage generator, which is electrically connected to the syringe. The syringe pump is used to clamp the syringe, and the high-voltage generator is used to stretch the spinning solution in the syringe into a jet.

9. The optical polyester film for switchable glass according to claim 8, characterized in that: The optical polyester film for dimming glass is prepared by the following steps: ① Add the copolyester to the polyester film base of the optical polyester film, use a spin coater to spin-coat the enhanced acrylic emulsion onto the surface of the polyester film base, apply at 200-300 r / min for 10-15s, apply at 800-1000 r / min for 10-15s, and place in a 90-100°C oven for heat treatment for 2-3 hours to form a reinforcement layer; ② Adding polyacrylonitrile fiber to the reinforcement layer to form an anti-radiation layer, adding modified polyester to the anti-radiation layer to form an antistatic layer, and preheating the four-layer structure to 85-95°C on a biaxial film stretching machine for 15-20 seconds, and simultaneously stretching the longitudinal and transverse structures at a stretching speed of 100-120 mm / s, with a stretching multiple of 4-5, to obtain an optical polyester film with a thickness of 30-120 μm; ③ The stretched film is shaped and cooled at a temperature of 130-160°C. After cooling, it is pulled and rolled up.

10. The optical polyester film for switchable glass according to claim 9, characterized in that: The thickness ratio of the polyester film base layer, the reinforcement layer, the radiation protection layer and the antistatic layer is 1-2:1-2:0.5-1:0.5-1.

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