An antifogging agent, a method for preparing the same, and use thereof

Abstract

The application discloses an antifogging agent and a preparation method and application thereof. The preparation raw material of the antifogging agent comprises, in weight parts, 2-10 parts of a non-ionic surfactant, 2-8 parts of a water-based resin, 70-90 parts of a hydrophilic solvent and 5-20 parts of water. The prepared antifogging agent has the advantages of high light transmittance and good antifogging performance, especially can still have durability under the condition that hot fog and cold fog exist simultaneously, does not affect the appearance effect of plastic packaging, greatly improves the commercial value of the packaging, and meanwhile, the preparation method has simple process formula, and remarkably reduces the influence on the packaging content and the environment.

Description

Technical Field

[0001] This invention belongs to the field of anti-fogging technology, with the classification number C09K3 / 18. Specifically, it relates to an anti-fogging agent, its preparation method, and its application. Background Technology

[0002] With the fast pace of life, more and more fast food and pre-prepared meals are appearing in people's lives, which requires a large amount of plastic packaging. Since the contents of the packaging are sometimes hot, sometimes need to be refrigerated, or sometimes both, the moisture in the contents will evaporate and condense under large temperature differences, causing serious fogging on the plastic sheet or plastic film cover of the packaging container. This makes it impossible to see the contents of the packaging, which seriously reduces the commercial value of the packaging. This problem exists in food boxes, side dish containers, pre-prepared food containers, and food sample containers in restaurants. There are two main solutions to the problem of fogging in plastic containers: One is to mix surfactants into the plastic particles during the manufacturing process, followed by injection molding / blow molding. This method requires a very large amount of surfactant, resulting in high costs, difficulty in widespread adoption, and less than ideal anti-fogging performance. The second method involves coating a plastic sheet or film cover with a superhydrophilic or superhydrophobic surfactant. However, this method has two problems: First, when a large amount of steam is generated inside the packaging, the steam accumulates and condenses into water droplets on the inner layer of the cover. As the water droplets flow, they gradually dissolve and wash away the surfactant, leading to a decrease or even complete failure of the anti-fogging effect. This is especially noticeable when packaging hot contents followed by refrigeration, directly causing the anti-fogging effect to worsen or disappear during subsequent refrigeration. Second, some surfactants have small molecular weights and low glass transition temperatures (T0). gThe low viscosity of PVA prevents it from forming a film on plastic substrates, making it impossible to roll up the film. Otherwise, it will stick to the back of the film, damaging the anti-fogging coating. To solve this problem, highly hydrophilic polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP) is usually added to the anti-fogging agent formulation (Chinese Patent CN111363425B). However, PVA is highly polar and has poor adhesion to non-polar substrates such as OPP and PE. At the same time, PVA is insoluble in alcohol solvents such as ethanol and can only be dissolved in water, resulting in a slow drying rate and low construction efficiency, which cannot meet production requirements. PVP is also highly polar and also has poor adhesion to non-polar substrates such as OPP and PE. Although PVP is soluble in ethanol, it is easily soluble in water, and there is also a risk of it being washed away by condensed water droplets, resulting in poor anti-fogging effect at high and low temperatures. Therefore, when antifogging agents are applied to polar PET substrates, non-polar PE, OPP and other substrates under conditions where hot fog and cold fog coexist, how to improve the high and low temperature antifogging performance of antifogging agents and maintain the durability of antifogging performance is an urgent technical problem that needs to be solved.

[0003] Chinese patent CN108441170B discloses an anti-fogging agent for new energy vehicles. The prepared anti-fogging agent mainly solves the problem of easy fogging of glass under low temperature conditions, but it does not solve the problem of poor anti-fogging effect of plastic packaging under high temperature conditions.

[0004] Chinese patent CN 112409987A discloses a hydrophilic antifogging agent. The prepared antifogging agent can maintain its durability over a wide temperature range (from -20°C to 10°C) and maintain good light transmittance. However, it does not solve the problem of poor antifogging effect of plastic packaging under high temperature conditions. Summary of the Invention

[0005] To address the aforementioned problems, a first aspect of the present invention provides an antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 0.1-10 parts of a nonionic surfactant, 0.1-8 parts of an aqueous resin, 70-90 parts of a hydrophilic solvent, and 5-20 parts of water.

[0006] More preferably, the raw materials for preparing the antifogging agent, by weight, include: 2-10 parts of nonionic surfactant, 2-8 parts of aqueous resin, 70-90 parts of hydrophilic solvent, and 5-20 parts of water.

[0007] More preferably, the raw materials for preparing the antifogging agent, by weight, include: 2-5 parts of nonionic surfactant, 2-4 parts of water-based resin, 75-85 parts of hydrophilic solvent, and 5-15 parts of water.

[0008] More preferably, the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 2.5 parts of water-based resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0009] More preferably, the hydrophilic solvent is ethanol.

[0010] Preferably, the nonionic surfactant has an HLB value of 10-20.

[0011] More preferably, the nonionic surfactant has an HLB value of 10-18.

[0012] Preferably, the nonionic surfactant comprises at least one of polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monopalmitate, polyoxyethylene sorbitol monooleate, polyoxyethylene sorbitol monostearate, diglyceride stearate, diglyceride laurate, tetraglyceride stearate, tetraglyceride laurate, hexaglyceride stearate, hexaglyceride laurate, decaglyceride stearate, decaglyceride laurate, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleate, polyoxyethylene stearate, and polyoxyethylene distearate.

[0013] Preferably, the nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of (1-4):(0.5-2).

[0014] The higher the HLB value of a surfactant, the stronger its anti-fogging effect. However, when the HLB value is greater than 20, water droplets will adhere to the surface coated with the anti-fogging agent, and the anti-fogging agent will be easily washed away. Therefore, this application selects a nonionic surfactant with an HLB value of 0 to 18. Based on this, polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol are further selected, and the mass ratio of the two is limited to (1-4):(0.5-2). While ensuring the hydrophilicity of the anti-fogging agent, the problem of the anti-fogging agent being easily ineffective due to the excessively high HLB value of the surfactant is avoided. At the same time, the long hydrocarbon chains of lauroyl polyoxyethylene glycerol and polyoxyethylene sorbitan monolaurate can also promote the compatibility between lauroyl polyoxyethylene glycerol and polyoxyethylene sorbitan monolaurate and waterborne polyurethane and rosin resin.

[0015] More preferably, the nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of (2-4):(0.5-1.5).

[0016] More preferably, the nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 3:1.

[0017] Preferably, the waterborne resin includes at least one of waterborne acrylic resin, waterborne polyurethane resin, waterborne polyester resin, waterborne alkyd resin, waterborne epoxy resin, and waterborne rosin resin.

[0018] Preferably, the waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of (1-4):(0.1-1). The waterborne polyurethane resin prepared by this invention has certain impact resistance and low-temperature resistance. The addition of rosin resin, which has high-temperature resistance, allows the two to interact effectively, not only encapsulating the nonionic surfactant and making it difficult for the nonionic surfactant to be washed away, but also ensuring the antifogging agent's durability under conditions of simultaneous hot and cold fog. Based on this, the mass ratio of the two is limited to 2:0.5.

[0019] More preferably, the waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of (1-3):(0.3-0.8).

[0020] More preferably, the waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 2:0.5.

[0021] Preferably, the solid content of the waterborne polyurethane resin is 20-40%.

[0022] More preferably, the solid content of the waterborne polyurethane resin is 25-38%.

[0023] More preferably, the solid content of the waterborne polyurethane resin is 30-35%.

[0024] Preferably, the raw materials for preparing the waterborne polyurethane resin, by weight, include 40-65 parts of polyethylene glycol, 45-70 parts of polydibutylene-1,4-butanediol diol, 1-5 parts of hexamethylene diisocyanate, 10-20 parts of isophorone diisocyanate, 6-12 parts of dimethylolpropionic acid, 2-7 parts of triethylamine, 1-5 parts of diethylenetriamine, 0.1-3 parts of ethylenediamine, 100-140 parts of acetone, and 200-400 parts of deionized water.

[0025] More preferably, the raw materials for preparing the waterborne polyurethane resin, by weight, include 40-60 parts of polyethylene glycol, 45-60 parts of polydibutylene-1,4-butanediol diol, 3-5 parts of hexamethylene diisocyanate, 10-15 parts of isophorone diisocyanate, 6-10 parts of dimethylolpropionic acid, 2-5 parts of triethylamine, 2-5 parts of diethylenetriamine, 1-3 parts of ethylenediamine, 100-130 parts of acetone, and 300-400 parts of deionized water.

[0026] More preferably, the raw materials for preparing the waterborne polyurethane resin, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.92 parts of triethylamine, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, and 326 parts of deionized water.

[0027] Further preferably, the method for preparing the waterborne polyurethane resin includes the following steps: (1) polyethylene glycol, polydibutylene-1,4-butanediol diol, and dimethylolpropionic acid are added to a reaction vessel by weight, heated and then dehydrated under vacuum, and then cooled to obtain the first reactant; (2) hexamethylene diisocyanate and isophorone diisocyanate are added to the first reactant by weight, and then 0.02% catalyst and acetone are added. The mixture is heated to 80-90℃ and reacted for 2-4 hours. Acetone is added to dilute the mixture, and then triethylamine is added to obtain a polyurethane prepolymer; (3) under a stirring speed of 1000-5000 rpm / min, deionized water is added to the polyurethane prepolymer by weight, and then ethylenediamine and diethylenetriamine are added. The mixture is stirred at the same stirring speed for 1-2 hours to obtain a dispersion emulsion; (4) the dispersion emulsion is heated to 50-70℃, acetone is removed under vacuum, and then cooled to room temperature. After filtration and packaging, waterborne polyurethane resin is obtained.

[0028] In step (2), the mass ratio of the first acetone added to the second acetone added is 10:110.

[0029] The waterborne polyurethane resin prepared in this invention includes polyethylene glycol, which is a hydrophilic group that promotes the compatibility between waterborne polyurethane and ethanol and has good hydrophilic properties. This solves the problem that existing antifogging agents can only use water as a diluent, resulting in slow drying rate and low construction efficiency. Polydimeric acid-1,4-butanediol and hexamethylene diisocyanate improve the adhesion to non-polar substrates such as OPP and PE, and promote the compatibility between waterborne polyurethane, lauroyl polyoxyethylene glycerol ester and polyoxyethylene sorbitan monolaurate. This can prevent the surfactant from being washed away by water vapor, which would reduce the antifogging effect.

[0030] The second aspect of the present invention provides a method for preparing an anti-fogging agent, comprising the following steps: mixing water, a hydrophilic solvent, and an aqueous resin, filtering, and packaging to obtain the finished anti-fogging agent.

[0031] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0032] Beneficial effects:

[0033] (1) The antifogging agent prepared by the present invention has the advantages of high light transmittance and good antifogging performance, and in particular, it can still have durability under the conditions of hot fog and cold fog at the same time.

[0034] (2) The antifogging agent prepared by the present invention has excellent adhesion to substrates such as glass and polar PET, as well as non-polar substrates such as OPP and PE. It solves the problem in the prior art that the adhesion of polyvinyl alcohol and polyvinylpyrrolidone with excessive polarity to non-polar substrates such as OPP and PE is poor. In addition, the antifogging agent can be dissolved in ethanol, which significantly improves the drying rate and application rate of the antifogging agent.

[0035] (3) The antifogging agent prepared by the present invention does not easily turn white after contact with steam; the coating does not turn white after bending, and will not affect the appearance of the plastic packaging, thus greatly enhancing the commercial value of the packaging. At the same time, the preparation method of the present invention has a simple process formula, significantly reducing the impact on the contents of the packaging and its environment, and has high food safety performance. Example

[0036] Example 1

[0037] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 2.5 parts of aqueous resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0038] The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 3:1. The polyoxyethylene sorbitan monolaurate (T-20) was purchased from Jiangsu Haian Petrochemical Plant, and the lauroyl polyoxyethylene (20) glycerol ester was purchased from Jiangsu Haian Petrochemical Plant.

[0039] The waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 2:0.5. The waterborne rosin resin is purchased from Shenzhen Yoshida Chemical Co., Ltd., with a softening point of 100-120℃, an acid value of 155-165, and a weight-average molecular weight of 1200.

[0040] The solid content of the waterborne polyurethane is 30%.

[0041] The raw materials for preparing the waterborne polyurethane, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0042] The method for preparing the waterborne polyurethane includes the following steps: (1) adding polyethylene glycol, polydibutylene diol-1,4-butanediol, and dimethylolpropionic acid into a reaction vessel according to the weight parts, heating to 120°C, vacuum dehydrating for 2 hours, and then cooling to 60°C to obtain the first reactant; (2) adding hexamethylene diisocyanate and isophorone diisocyanate to the first reactant according to the weight parts, then adding 0.02% stannous octoate and acetone, heating to 90°C, reacting for 3 hours, and waiting until NCO When the value reaches 3.8%, acetone is added for dilution, and then triethylamine is added to obtain a polyurethane prepolymer; (3) under the condition of stirring speed of 2000 rpm / min, deionized water is added to the polyurethane prepolymer by weight, and then ethylenediamine and diethylenetriamine are added. The mixture is stirred for 1.5 h at the same stirring speed to obtain a dispersion emulsion; (3) the dispersion emulsion is heated to 60°C, acetone is removed under vacuum, and then cooled to 25°C. After filtration and packaging, waterborne polyurethane resin is obtained. The polyethylene glycol was purchased from Jiangsu Haian Petrochemical Co., Ltd., with a relative molecular weight of 2000. The polydimer acid-1,4-butanediol diol was purchased from Croda Chemicals Ltd., UK, with a relative molecular weight of 2000.

[0043] In step (2), the mass ratio of the first acetone added to the second acetone added is 10:110.

[0044] The hydrophilic solvent is ethanol.

[0045] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water, ethanol, and rosin resin are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight parts; then polyoxyethylene sorbitan monolaurate, lauroyl polyoxyethylene glycerol ester, and waterborne polyurethane resin are added according to the weight parts; stirring is continued for 1 h; and then the mixture is filtered and packaged to obtain the product.

[0046] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0047] Example 2

[0048] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 2.5 parts of aqueous resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0049] The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 4:2.

[0050] The waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 2:0.5.

[0051] The solid content of the waterborne polyurethane is 38%.

[0052] The raw materials for preparing the waterborne polyurethane, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0053] The method for preparing the waterborne polyurethane includes the following steps: (1) adding polyethylene glycol, polydibutylene diol-1,4-butanediol, and dimethylolpropionic acid into a reaction vessel according to the weight parts, heating to 120°C, vacuum dehydrating for 2 hours, and then cooling to 60°C to obtain the first reactant; (2) adding hexamethylene diisocyanate and isophorone diisocyanate to the first reactant according to the weight parts, then adding 0.02% stannous octoate and acetone, heating to 90°C, and reacting for 3 hours until NC When the O value reaches 3.8%, acetone is added for dilution, and then triethylamine is added to obtain a polyurethane prepolymer; (3) under the condition of stirring speed of 2000 rpm / min, deionized water is added to the polyurethane prepolymer according to the weight, and then ethylenediamine and diethylenetriamine are added. The mixture is stirred for 1.5 h at the same stirring speed to obtain a dispersion emulsion; (3) the dispersion emulsion is heated to 60°C, acetone is removed under vacuum, and then the temperature is lowered by 25°C. After filtration and packaging, waterborne polyurethane resin is obtained.

[0054] In step (2), the mass ratio of the first acetone added to the second acetone added is 10:110.

[0055] The hydrophilic solvent is ethanol.

[0056] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water, ethanol, and rosin resin are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight parts; then polyoxyethylene sorbitan monolaurate, lauroyl polyoxyethylene glycerol ester, and waterborne polyurethane resin are added according to the weight parts; stirring is continued for 1 h; and then the mixture is filtered and packaged to obtain the product.

[0057] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0058] Example 3

[0059] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 2.5 parts of aqueous resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0060] The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 3:1.

[0061] The waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 3:0.7.

[0062] The solid content of the waterborne polyurethane is 35%.

[0063] The raw materials for preparing the waterborne polyurethane, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0064] The method for preparing the waterborne polyurethane includes the following steps: (1) adding polyethylene glycol, polydibutylene diol-1,4-butanediol, and dimethylolpropionic acid into a reaction vessel according to the weight parts, heating to 120°C, vacuum dehydrating for 2 hours, and then cooling to 60°C to obtain the first reactant; (2) adding hexamethylene diisocyanate and isophorone diisocyanate to the first reactant according to the weight parts, then adding 0.02% stannous octoate and acetone, heating to 90°C, reacting for 3 hours, and waiting until NCO When the value reaches 3.8%, acetone is added for dilution, and then triethylamine is added to obtain polyurethane prepolymer; (3) under the condition of stirring speed of 2000 rpm / min, deionized water is added to polyurethane prepolymer by weight, and then ethylenediamine and diethylenetriamine are added. Stirring is carried out at the same stirring speed for 1.5 h to obtain dispersion emulsion; (3) The dispersion emulsion is heated to 60°C, acetone is removed under vacuum, and then the temperature is lowered by 25°C. After filtration and packaging, waterborne polyurethane resin is obtained.

[0065] In step (2), the mass ratio of the first and second additions of acetone is 10:110.

[0066] The hydrophilic solvent is ethanol.

[0067] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water, ethanol, and rosin resin are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight parts; then polyoxyethylene sorbitan monolaurate, lauroyl polyoxyethylene glycerol ester, and waterborne polyurethane resin are added according to the weight parts; stirring is continued for 1 h; and then the mixture is filtered and packaged to obtain the product.

[0068] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0069] Comparative Example 1

[0070] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 4 parts of water-based resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0071] The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 3:1.

[0072] The waterborne resin is a waterborne polyurethane resin.

[0073] The solid content of the waterborne polyurethane is 38%.

[0074] The raw materials for preparing the waterborne polyurethane, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0075] The method for preparing the waterborne polyurethane includes the following steps: (1) adding polyethylene glycol, polydibutylene diol-1,4-butanediol, and dimethylolpropionic acid into a reaction vessel according to the weight parts, heating to 120°C, vacuum dehydrating for 2 hours, and then cooling to 60°C to obtain the first reactant; (2) adding hexamethylene diisocyanate and isophorone diisocyanate to the first reactant according to the weight parts, then adding 0.02% stannous octoate and acetone, heating to 90°C, reacting for 3 hours, and waiting until NCO When the value reaches 3.8%, acetone is added for dilution, and then triethylamine is added to obtain polyurethane prepolymer; (3) under the condition of stirring speed of 2000 rpm / min, deionized water is added to polyurethane prepolymer by weight, and then ethylenediamine and diethylenetriamine are added. Stirring is carried out at the same stirring speed for 1.5 h to obtain dispersion emulsion; (3) The dispersion emulsion is heated to 60°C, acetone is removed under vacuum, and then the temperature is lowered by 25°C. After filtration and packaging, waterborne polyurethane resin is obtained.

[0076] In step (2), the mass ratio of the first and second additions of acetone is 10:110.

[0077] The hydrophilic solvent is ethanol.

[0078] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water and ethanol are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight parts, and then polyoxyethylene sorbitan monolaurate, lauroyl polyoxyethylene glycerol ester and waterborne polyurethane resin are added according to the weight parts, and the mixture is stirred for 1 h, filtered and packaged to obtain the product.

[0079] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0080] Comparative Example 2

[0081] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 7 parts of nonionic surfactant, 2.5 parts of aqueous resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0082] The nonionic surfactant is lauroyl polyoxyethylene glycerol ester.

[0083] The waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 2:0.5.

[0084] The solid content of the waterborne polyurethane is 30%.

[0085] The raw materials for preparing the waterborne polyurethane, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0086] The method for preparing the waterborne polyurethane includes the following steps: (1) adding polyethylene glycol, polydibutylene diol-1,4-butanediol, and dimethylolpropionic acid into a reaction vessel according to the weight parts, heating to 120°C, vacuum dehydrating for 2 hours, and then cooling to 60°C to obtain the first reactant; (2) adding hexamethylene diisocyanate and isophorone diisocyanate to the first reactant according to the weight parts, then adding 0.02% stannous octoate and acetone, heating to 90°C, reacting for 3 hours, and waiting until NCO When the value reaches 3.8%, acetone is added for dilution, and then triethylamine is added to obtain polyurethane prepolymer; (3) under the condition of stirring speed of 2000 rpm / min, deionized water is added to polyurethane prepolymer by weight, and then ethylenediamine and diethylenetriamine are added. Stirring is carried out at the same stirring speed for 1.5 h to obtain dispersion emulsion; (3) The dispersion emulsion is heated to 60°C, acetone is removed under vacuum, and then the temperature is lowered by 25°C. After filtration and packaging, waterborne polyurethane resin is obtained.

[0087] In step (2), the mass ratio of the first and second additions of acetone is 10:110.

[0088] The hydrophilic solvent is ethanol.

[0089] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water, ethanol, and rosin resin are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight ratio, and then lauroyl polyoxyethylene glycerol ester and waterborne polyurethane resin are added according to the weight ratio, and the mixture is stirred for 1 h before being filtered and packaged to obtain the antifogging agent.

[0090] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0091] Comparative Example 3

[0092] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 2.5 parts of aqueous resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0093] The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 3:1.

[0094] The waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 2:0.5.

[0095] The solid content of the waterborne polyurethane is 30%.

[0096] The raw materials for preparing the waterborne polyurethane, by weight, include 100 parts of polydimeric acid-1,4-butanediol diol, 4.2 parts of hexamethylene diisocyanate, 12 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0097] The method for preparing the waterborne polyurethane includes the following steps: (1) Polydimethylol diol and dimethylolpropionic acid are added to a reaction vessel according to the weight parts, heated to 120°C and then dehydrated under vacuum for 2 hours, and then cooled to 60°C to obtain the first reactant; (2) Hexamethylene diisocyanate and isophorone diisocyanate are added to the first reactant according to the weight parts, and then 0.02% stannous octoate and acetone are added. The mixture is heated to 90°C and reacted for 3 hours. When the NCO value reaches 3.8%, acetone is added to dilute it, and then triethylamine is added to obtain the polyurethane prepolymer; (3) Under the condition of stirring speed of 2000 rpm / min, deionized water is added to the polyurethane prepolymer according to the weight parts, and then ethylenediamine and diethylenetriamine are added. The mixture is stirred for 1.5 hours at the same stirring speed to obtain the dispersion emulsion; (4) The dispersion emulsion is heated to 60°C, and acetone is removed under vacuum conditions. Then the mixture is cooled to 25°C, filtered and packaged to obtain the waterborne polyurethane resin.

[0098] In step (2), the mass ratio of the first and second additions of acetone is 10:110.

[0099] The hydrophilic solvent is ethanol.

[0100] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water, ethanol, and rosin resin are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight parts; then polyoxyethylene sorbitan monolaurate, lauroyl polyoxyethylene glycerol ester, and waterborne polyurethane resin are added according to the weight parts; stirring is continued for 1 h; and then the mixture is filtered and packaged to obtain the product.

[0101] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0102] Comparative Example 4

[0103] An antifogging agent, wherein the raw materials for preparing the antifogging agent, by weight, include: 4 parts of nonionic surfactant, 2.5 parts of aqueous resin, 83 parts of hydrophilic solvent, and 10 parts of water.

[0104] The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of 3:1.

[0105] The waterborne resin is a waterborne polyurethane resin and a waterborne rosin resin, with a mass ratio of 2:0.5.

[0106] The solid content of the waterborne polyurethane is 30%.

[0107] The raw materials for preparing the waterborne polyurethane, by weight, include 50 parts of polyethylene glycol, 50 parts of polydibutylene-1,4-butanediol diol, 16.2 parts of isophorone diisocyanate, 6 parts of dimethylolpropionic acid, 3.5 parts of diethylenetriamine, 1.5 parts of ethylenediamine, 120 parts of acetone, 3.92 parts of triethylamine, and 326 parts of deionized water.

[0108] The method for preparing the waterborne polyurethane includes the following steps: (1) Polyethylene glycol, polydibutylene diol-1,4-butanediol, and dimethylolpropionic acid are added to a reaction vessel according to the weight parts, heated to 120°C, and then dehydrated under vacuum for 2 hours, and then cooled to 60°C to obtain the first reactant; (2) Isophorone diisocyanate is added to the first reactant according to the weight parts, and then 0.02% stannous octoate and acetone are added. The mixture is heated to 90°C and reacted for 3 hours. When the NCO value reaches 3.8%, acetone is added to dilute the mixture, and then triethylamine is added to obtain the polyurethane prepolymer; (3) Under the condition of a stirring speed of 2000 rpm / min, deionized water is added to the polyurethane prepolymer according to the weight parts, and then ethylenediamine and diethylenetriamine are added. The mixture is stirred at the same stirring speed for 1.5 hours to obtain the dispersion emulsion; (4) The dispersion emulsion is heated to 60°C, and acetone is removed under vacuum. The mixture is then cooled to 25°C, filtered, and packaged to obtain the waterborne polyurethane resin.

[0109] In step (2), the mass ratio of the first acetone added to the second acetone added is 10:110.

[0110] The hydrophilic solvent is ethanol.

[0111] The second aspect of the present invention provides a method for preparing an antifogging agent, comprising the following steps: water, ethanol, and rosin resin are stirred at a stirring speed of 400 rpm / min for 15 min according to the weight parts; then polyoxyethylene sorbitan monolaurate, lauroyl polyoxyethylene glycerol ester, and waterborne polyurethane resin are added according to the weight parts; stirring is continued for 1 h; and then the mixture is filtered and packaged to obtain the product.

[0112] A third aspect of the present invention provides an application of an anti-fogging agent in plastic packaging.

[0113] Performance Evaluation

[0114] 1. Anti-fog effect test:

[0115] (1) Dilute the antifogging agent prepared in the examples and comparative examples with anhydrous ethanol at a mass ratio of antifogging agent:ethanol = 1:4, then use 5 # RDS linear bar coating is applied to PE or CPP films, with a coating amount of 10 g / m². 2 Dry and store for later use;

[0116] (2) Pour 100ml of deionized water at 80℃ into a 200ml open glass bottle, cover the bottle opening with the PE film or CPP film coated with anti-fogging agent, with the coated side facing the water vapor side in the glass bottle, and tie the bottle opening securely with a rubber band.

[0117] (3) Place it at room temperature until the water cools to room temperature, about 30 minutes. During this process, observe the water mist on the film at the bottle mouth.

[0118] (4) Place the glass bottle in the refrigerator for 72 hours; observe the water mist on the film at the bottle opening regularly.

[0119] 2. Anti-fog rating standards are as follows:

[0120] Level 1: Completely transparent, no water droplets.

[0121] Level 2: Good transparency, with a small number of unevenly distributed large water droplets.

[0122] Level 3: Basically transparent, with many water droplets.

[0123] Level 4: Semi-transparent, with many small water droplets.

[0124] Level 5: Completely foggy and opaque.

[0125] 3. Heat-sealing performance test: The PE and PP plastic films coated with anti-fogging agent were heat-sealed together with the uncoated PE and PP plastic films using a heat sealer (Jinan Chenchi Test Instrument Co., Ltd., model STH-3). The heat was applied at 180 degrees Celsius and 0.4 MPa using a 20mm wide sealing strip for 1 second. After natural cooling, a 15mm wide test strip was accurately cut from the heat-sealed sample and tested at 25 degrees Celsius.

[0126] In a constant temperature room with 85% RH, the peel strength of the heat-sealed area was tested using a universal tensile testing machine (C610M intelligent electronic tensile testing machine, Jinan Langguang Electromechanical Technology Co., Ltd.) at a tensile speed of 100 mm / min in a 180-degree direction. The test was considered qualified when the peel strength was >8 N / 15 mm.

[0127] 4. Transparency Test: By visual inspection, if the anti-fogging agent applied to PE film or CPP film does not affect the transparency of the original PP film or CPP film, it is considered qualified; otherwise, it is considered unqualified.

[0128] 5. Bending resistance: Fold and press the PE film or CPP film coated with anti-fogging agent in half repeatedly 50 times. If there is no peeling or whitening at the crease, it is qualified; otherwise, it is unqualified.

[0129] Table 1. Anti-fog test results for comparative and example cases.

[0130]

[0131]

[0132] Table 2. Results of transparency and heat-sealing tests for comparative examples and embodiments.

[0133] Test Project transparency heat sealing performance Bending resistance Example 1 qualified qualified qualified Example 2 qualified qualified qualified Example 3 qualified qualified qualified Comparative Example 1 qualified qualified qualified Comparative Example 2 qualified Unqualified qualified Comparative Example 3 Unqualified qualified Unqualified Comparative Example 4 qualified qualified Unqualified

Claims

1. An anti-fogging agent, characterized in that, The raw materials for preparing the antifogging agent, by weight, include: 0.1-10 parts of nonionic surfactant, 0.1-8 parts of aqueous resin, 70-90 parts of hydrophilic solvent, and 5-20 parts of water. The nonionic surfactant is polyoxyethylene sorbitan monolaurate and lauroyl polyoxyethylene glycerol ester, with a mass ratio of (1-4):(0.5-2). The aqueous resin is an aqueous polyurethane resin and an aqueous rosin resin, with a mass ratio of (1-4):(0.1-1); the nonionic surfactant has an HLB value of 10-20. The solid content of the waterborne polyurethane resin is 20-40%; The raw materials for preparing the waterborne polyurethane resin, by weight, include 40-65 parts of polyethylene glycol, 45-70 parts of polydibutylene-1,4-butanediol diol, 1-5 parts of hexamethylene diisocyanate, 10-20 parts of isophorone diisocyanate, 6-12 parts of dimethylolpropionic acid, 2-7 parts of triethylamine, 1-5 parts of diethylenetriamine, 0.1-3 parts of ethylenediamine, 100-140 parts of acetone, and 200-400 parts of deionized water. The method for preparing the waterborne polyurethane resin includes the following steps: (1) Polyethylene glycol, polydibutylene-1,4-butanediol diol, and dimethylolpropionic acid are added to a reaction vessel by weight, heated and dehydrated under vacuum, and then cooled to obtain the first reactant; (2) Hexamethylene diisocyanate and isophorone diisocyanate are added to the first reactant by weight, and then 0.02% catalyst and acetone are added. The mixture is heated to 80-90℃ and reacted for 2-4 hours. Acetone is added to dilute the mixture, and then triethylamine is added to obtain a polyurethane prepolymer; (3) Under the condition of a stirring speed of 1000-5000 rpm / min, deionized water is added to the polyurethane prepolymer by weight, and then ethylenediamine and diethylenetriamine are added. The mixture is stirred at the same stirring speed for 1-2 hours to obtain a dispersion emulsion; (4) The dispersion emulsion is heated to 50-70℃, and acetone is removed under vacuum. The mixture is then cooled to room temperature, filtered, and packaged to obtain the waterborne polyurethane resin.

2. A method for preparing the antifogging agent according to claim 1, characterized in that, The steps include: mixing water, hydrophilic solvent, and water-based resin, filtering, and packaging to obtain the finished anti-fogging agent.

3. The application of the antifogging agent according to claim 1 in plastic packaging.

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