A water-based polyurethane dispersion for high-adhesion and low-gloss PVC artificial leather finishing agent, a preparation method and application thereof

Abstract

The application provides a high-adhesion low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion and a preparation method and application thereof, raw materials of the high-adhesion low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion include a polymerization modified water-based polyurethane dispersion and SiO2 extinction powder; the polymerization modified water-based polyurethane dispersion is prepared from raw materials including the following components in parts by weight: polyether polyol 12-14.2 parts, non-ionic dihydric alcohol 0.77-3 parts, diisocyanate 5.75-8 parts, small molecule chain extender 0.03-0.24 parts, hydrophilic chain extender 0.98-1.03 parts, a catalyst, a neutralizing agent, amino siloxane coupling agent 0.28-2.5 parts, hydroxy acrylate 4.14-7.36 parts, vinyl-containing sulfonate 4.14-7.36 parts, an initiator and deionized water; and the high-adhesion low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion has excellent extinction and stability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polyurethane, and particularly relates to a waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather surface treatment agent, a preparation method and application thereof. BACKGROUND

[0002] PVC artificial leather (referred to as artificial leather) is artificial leather prepared from PVC. Traditional artificial leather surface treatment agents are generally solvent-based resins, which contain dimethylformamide, toluene, butanone, ethyl acetate and butyl acetate, etc. These solvents can cause serious environmental pollution. According to the calculation, the amount of solvent discharged by each artificial leather production line is high, reaching more than 20 tons. Therefore, the artificial leather industry is faced with the problems of serious environmental pollution and serious resource waste, and the development of water-based resins to replace solvent-based resins has become the key to the further sustainable development of the artificial leather industry.

[0003] Waterborne polyurethane, as a common water-based resin, can be divided into polyester polyurethane and polyether polyurethane according to the types of polyols. The polyester polyurethane can effectively improve the adhesion of polyurethane to the PVC coating due to the presence of a large number of ester bonds, but the ester bonds are prone to hydrolysis in waterborne polyurethane; the polyether waterborne polyurethane has excellent hydrolysis resistance, but the adhesion between the polyether waterborne polyurethane and the PVC coating is poor.

[0004] Directly adding an extinction agent to a water-based resin is the most widely used method for preparing a water-based extinction treatment agent, but the extinction agent is prone to agglomeration in the system due to incompatibility between the extinction agent and the water-based resin, which results in poor stability and easy sedimentation of the coating, and uneven surface gloss. Inorganic extinction agents (such as silicon dioxide) have excellent extinction effect, but have the disadvantages of high brittleness, poor wear resistance and low adhesion strength. Therefore, it is difficult to balance the hydrolysis resistance and adhesion of the surface treatment agent, and there are relatively few stable low-gloss surface treatment agents.

[0005] Therefore, it is necessary to provide an improved technical solution to overcome the above-mentioned deficiencies of the prior art. SUMMARY

[0006] The present application aims to provide a waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather surface treatment agent, a preparation method and application thereof, to solve or improve the problem of poor emulsion stability or insufficient adhesion between the low-gloss surface treatment agent containing the waterborne polyurethane and the PVC coating in the prior art.

[0007] In order to achieve the above object, the present application provides the following technical scheme: a high-adhesion low-gloss PVC artificial leather finishing agent water-based polyurethane dispersion, raw materials of the high-adhesion low-gloss PVC artificial leather finishing agent water-based polyurethane dispersion include polymeric modified water-based polyurethane dispersion and SiO2 matt powder; the polymeric modified water-based polyurethane dispersion is prepared by using raw materials including the following weight parts: polyether polyol 12-14.2 parts, non-ionic dihydric alcohol 0.77-3 parts, diisocyanate 5.75-8 parts, small molecule chain extender 0.03-0.24 parts, hydrophilic chain extender 0.98-1.03 parts, catalyst 0.03-0.05 parts, neutralizing agent 0.74-0.78 parts, amino siloxane coupling agent 0.28-2.5 parts, hydroxy acrylate 4.14-7.36 parts, vinyl-containing sulfonate 4.14-7.36 parts, initiator 0.11-0.15 parts and deionized water 64-66 parts.

[0008] Preferably, the amino siloxane coupling agent is at least one of γ-aminopropyl triethoxysilane (KH550), γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, N-β(aminoethyl)-γ-aminopropyl triethoxysilane, phenylaminomethyl triethoxysilane and phenylaminomethyl trimethoxysilane; the non-ionic dihydric alcohol is linear polyethylene glycol difunctional methyl ether Ymer N120.

[0009] Preferably, the hydroxy acrylate is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate and 4-hydroxybutyl acrylate; the vinyl-containing sulfonate is sodium vinyl sulfonate and / or sodium styrene sulfonate.

[0010] Preferably, the polyether polyol is polyoxypropylene glycol and / or polytetrahydrofuran diol, the number average molecular weight of the polyether polyol is 1000-2000 g / mol; the diisocyanate is 4,4'-dicyclohexylmethane diisocyanate and / or isophorone diisocyanate; the small molecule chain extender is ethanolamine and / or 1,4-butanediol; the catalyst is organic bismuth; the neutralizing agent is triethylamine; the initiator is potassium persulfate.

[0011] Preferably, the mass ratio of the polymeric modified water-based polyurethane dispersion and SiO2 matt powder is (48-52):(0.5-1).

[0012] The application further provides a preparation method of the water-based polyurethane dispersion for the high-adhesion low-gloss PVC artificial leather surface treatment agent, which adopts the technical scheme: a preparation method of a water-based polyurethane dispersion for a high-adhesion low-gloss PVC artificial leather surface treatment agent, comprising the following steps: (1) synthesis of a polyurethane prepolymer: reflux stirring reaction of the polyether polyol, non-ionic dihydric alcohol, diisocyanate, small molecule chain extender, hydrophilic chain extender, catalyst and solvent a part at 60-70 DEG C until the percentage content of NCO reaches the theoretical value; then the amino siloxane coupling agent is added and reacted for 1-2 h; then the hydroxy acrylate is added until the NCO group in the system is completely reacted; the temperature is reduced to 45-55 DEG C, the vinyl-containing sulfonate is added and stirred to obtain the polyurethane prepolymer; (2) neutralization, emulsification and dispersion of the polyurethane: the polyurethane prepolymer obtained by step (1) is cooled to 30-40 DEG C, and the solvent b part is added to reduce the viscosity and stirred; then the neutralizer is added for neutralization to obtain the neutralized prepolymer; then the neutralized prepolymer is dispersed into the deionized water under stirring to obtain the modified water-based polyurethane dispersion; (3) preparation of the copolymerized modified water-based polyurethane dispersion: the modified water-based polyurethane dispersion obtained by step (2) is put into a reaction container, the initiator is added, the water bath is heated to 75-85 DEG C and stirred for 2.5-3.5 h, and then the solvent is removed by distillation under reduced pressure to obtain the polymerized modified water-based polyurethane dispersion; (4) the SiO2 matting powder is dispersed in the polymerized modified water-based polyurethane dispersion obtained by step (3) to obtain the water-based polyurethane dispersion for the high-adhesion low-gloss PVC artificial leather surface treatment agent.

[0013] Preferably, in step (1), the content of NCO is 2.35%-2.46% to reach the theoretical value; after the vinyl-containing sulfonate is added, the stirring time is 10-20 minutes.

[0014] Preferably, in step (2), the stirring speed of the deionized water under stirring is 1000-1500 rpm, and the modified water-based polyurethane dispersion is obtained after stirring for 10-20 minutes; after the solvent b part is added, the stirring time is 20-30 minutes; after the neutralizer is added, the stirring time is 20-300 minutes.

[0015] Preferably, in step (4), the dispersion of the SiO2 matting powder is carried out at room temperature, the dispersion speed is 800-1000 rpm, and the dispersion time is 1.5-2.5 h.

[0016] The application further provides a high-adhesion low-gloss PVC artificial leather surface treatment agent, which adopts the technical scheme: a high-adhesion low-gloss PVC artificial leather surface treatment agent, the raw materials and / or components of the surface treatment agent comprise the water-based polyurethane dispersion as described above.

[0017] Advantages:

[0018] Interface hydrogen bond and phase separation micro-nano structure can show strong adhesion to various surfaces. Inspired by its adhesion mechanism, a multifunctional modified waterborne polyurethane which can improve the adhesion to PVC artificial leather coating is designed and synthesized. By copolymerization modification method, hydroxyl acrylate and sodium vinyl sulfonate containing hydroxyl are introduced into the system at the same time. The hydroxyl-containing acrylate is selected as the monomer, and the copolymer coating has strong interface adhesion to PVC through hydrogen bond interaction. At the same time, the sulfonate containing vinyl is selected as the copolymer monomer, so that the coating has the required fireproof performance. In addition, the phase separation micro-nano structure formed by the strong polarity difference between the sulfonate containing vinyl and the hydroxyl acrylate further enhances the adhesion between the modified waterborne polyurethane and the PVC coating. The siloxane coupling agent introduced into the waterborne polyurethane can hydrolyze and condense with the silicon hydroxyl on the surface of the SiO2 matting powder to form a covalent bond, anchoring the matting powder on the polymer. The steric hindrance effect of the non-ionic dihydric alcohol introduced on the polymer can further promote the stability of the matting emulsion.

[0019] Combined with the excellent wear resistance, high strength and chemical corrosion resistance of polyurethane, the high adhesion and low gloss PVC artificial leather finishing agent of the present application has the functions of high adhesion, high extinction, stability, flame retardance and chemical corrosion resistance. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present application belong to the scope of protection of the present application.

[0021] The present application will be described in detail below with reference to the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0022] The present application provides a waterborne polyurethane dispersion for high adhesion and low gloss PVC artificial leather finishing agent to solve the problems of poor emulsion stability or insufficient adhesion between the coating and PVC of the low gloss finishing agent containing waterborne polyurethane.

[0023] The raw materials of the water-based polyurethane dispersion for the high-adhesion low-gloss PVC artificial leather finish of the embodiment of the application include a polymer-modified water-based polyurethane dispersion and SiO2 matt powder; wherein the polymer-modified water-based polyurethane dispersion is prepared from raw materials including the following weight parts: polyether polyol 12-14.2 parts (for example, 12 parts, 12.3 parts, 12.5 parts, 12.7 parts, 12.9 parts, 13.2 parts, 13.4 parts, 13.6 parts, 13.8 parts, 14 parts or 14.2 parts), non-ionic dihydric alcohol 0.77-3 parts (for example, 0.77 parts, 0.8 parts, 0.9 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts), diisocyanate 5.75-8 parts (for example, 5.75 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts or 8 parts), small molecule chain extender 0.03-0.24 parts (for example, 0.03 parts, 0.05 parts, 0.08 parts, 0.12 parts, 0.15 parts, 0.18 parts, 0.21 parts or 0.24 parts), hydrophilic chain extender 0.98-1.03 parts (for example, 0.98 parts, 0.99 parts, 1 part, 1.01 parts, 1.02 parts or 1.03 parts), catalyst 0.03-0.05 parts (for example, 0.03 parts, 0.04 parts or 0.05 parts), neutralizing agent 0.74-0.78 parts (for example, 0.74 parts, 0.75 parts, 0.76 parts, 0.77 parts or 0.78 parts), amino siloxane coupling agent 0.28-2.5 parts (for example, 0.28 parts, 0.3 parts, 0.5 parts, 0.8 parts, 1.5 parts, 1.8 parts, 2.1 parts or 2.5 parts), hydroxy acrylate 4.14-7.36 parts (for example, 4.14 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts or 7.36 parts), vinyl-containing sulfonate 4.14-7.36 parts (for example, 4.14 parts, 4.6 parts, 5.2 parts, 5.8 parts, 6.3 parts, 6.6 parts, 7.1 parts or 7.36 parts), initiator 0.11-0.15 parts (for example, 0.11 parts, 0.12 parts, 0.13 parts, 0.14 parts or 0.15 parts) and deionized water 64-66 parts (for example, 64 parts, 64.5 parts, 65 parts, 65.5 parts or 66 parts).

[0024] The present application helps to make the polymeric modified waterborne polyurethane dispersion form covalent bonds with the silicon hydroxyl on the surface of the matting powder SiO2 by introducing amino siloxane coupling agent into the waterborne polyurethane, and anchor the matting powder on the polymer; by introducing non-ionic dihydric alcohol into the polymeric modified waterborne polyurethane dispersion, the steric hindrance effect brought by the non-ionic dihydric alcohol can further promote the stability of the matting emulsion (within a certain range, the more the amino siloxane coupling agent and the non-ionic dihydric alcohol reacted and polymerized into the waterborne polyurethane, the better the stability of the waterborne polyurethane dispersion of the present application; specifically, the more the amino siloxane coupling agent introduced into the polyurethane, the more covalent bonds formed by the hydrolysis of the silicon hydroxyl on the surface of the matting powder; and the more the non-ionic dihydric alcohol used, the more steric hindrance it brings; but if the amount of non-ionic dihydric alcohol is too much, it will damage the water resistance of the waterborne polyurethane prepared).

[0025] In addition, the interface hydrogen bond and the phase separation micro-nano structure can exhibit strong adhesion to various surfaces. Inspired by its adhesion mechanism, a multifunctional modified waterborne polyurethane which can improve the adhesion to the coating of PVC artificial leather is designed and synthesized. By introducing hydroxyl acrylate containing hydroxyl and sulfonate containing vinyl into the system through copolymerization modification, hydroxyl acrylate containing hydroxyl is selected as the monomer to make the copolymer coating have strong interface adhesion to PVC through hydrogen bond interaction. At the same time, sulfonate containing vinyl is selected as the copolymer monomer to make the coating have the required fireproof performance. In addition, the phase separation micro-nano structure formed by the strong polarity difference between the sulfonate containing vinyl and the hydroxyl acrylate further enhances the adhesion between the modified waterborne polyurethane and the PVC coating.

[0026] In the preferred embodiment of the high-adhesion low-gloss PVC artificial leather surface treatment agent waterborne polyurethane dispersion of the present application, the amino siloxane coupling agent is at least one of γ-aminopropyl triethoxysilane (KH550), γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, N-β(aminoethyl)-γ-aminopropyl triethoxysilane, phenylaminomethyl triethoxysilane and phenylaminomethyl trimethoxysilane; the non-ionic dihydric alcohol is linear polyethylene glycol di-functional methyl ether Ymer N120.

[0027] In the preferred embodiment of the high-adhesion low-gloss PVC artificial leather surface treatment agent waterborne polyurethane dispersion of the present application, the hydroxyl acrylate is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate and 4-hydroxybutyl acrylate; the sulfonate containing vinyl is sodium vinyl sulfonate and / or sodium styrene sulfonate.

[0028] In a preferred embodiment of the waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather finish of the present application, the polyether polyol is polyoxypropylene glycol and / or polytetrahydrofuran diol, the number average molecular weight of the polyether polyol is 1000-2000 g / mol (for example, 1000 g / mol, 1200 g / mol, 1400 g / mol, 1600 g / mol, 1800 g / mol, or 2000 g / mol); the diisocyanate is 4,4'-dicyclohexylmethane diisocyanate and / or isophorone diisocyanate; the small molecule chain extender is ethanolamine and / or 1,4-butanediol; the catalyst is organic bismuth; the neutralizing agent is triethylamine; and the initiator is potassium persulfate.

[0029] In a preferred embodiment of the waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather finish of the present application, the mass ratio of the polymer-modified waterborne polyurethane dispersion and the SiO2 matting powder is (48-52):(0.5-1) (for example, 48:0.5, 48:1, 52:0.5, 52:1, 50:0.5, or 50:1). If the mass ratio of the polymer-modified waterborne polyurethane dispersion and the SiO2 matting powder is too small (the amount of SiO2 matting powder is too large), the waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather finish prepared finally may be subject to sedimentation.

[0030] The application further provides a preparation method of the high-adhesion low-gloss PVC artificial leather finishing agent water-based polyurethane dispersion, and the preparation method comprises the following steps: (1) synthesis of a polyurethane prepolymer: reflux stirring of polyether polyol, non-ionic dihydric alcohol, diisocyanate, a small molecule chain extender, a hydrophilic chain extender, a catalyst and solvent a at 60-70 DEG C (for example, 60 DEG C, 62 DEG C, 64 DEG C, 66 DEG C, 68 DEG C or 70 DEG C) until the percentage content of NCO reaches a theoretical value (for example, the reaction process can be monitored by using di-n-butylamine titration until the percentage content of NCO reaches the theoretical value); then, amino siloxane coupling agent is added and reacted for 1-2 hours (for example, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours or 2 hours); then, hydroxy acrylate is added until the NCO groups in the system are completely reacted (which cannot be determined by FT-IR); the temperature is lowered to 45-55 DEG C (for example, 45 DEG C, 47 DEG C, 49 DEG C, 51 DEG C, 53 DEG C or 55 DEG C), and a vinyl-containing sulfonate is added and stirred to obtain the polyurethane prepolymer; (2) neutralization, emulsification and dispersion of the polyurethane: the polyurethane prepolymer obtained in step (1) is cooled to 30-40 DEG C (for example, 30 DEG C, 32 DEG C, 34 DEG C, 36 DEG C, 38 DEG C or 40 DEG C), and solvent b is added to reduce the viscosity and stir; then, a neutralizing agent is added to obtain a neutralized prepolymer; and then, the neutralized prepolymer is dispersed into deionized water under stirring to obtain a modified water-based polyurethane dispersion; (3) preparation of a copolymerized modified water-based polyurethane dispersion: the modified water-based polyurethane dispersion obtained in step (2) is put into a reaction container, an initiator is added, and the temperature is raised to 75-85 DEG C (for example, 75 DEG C, 77 DEG C, 79 DEG C, 81 DEG C, 83 DEG C or 85 DEG C) under stirring for 2.5-3.5 hours (for example, 2.5 hours, 2.7 hours, 2.9 hours, 3.1 hours, 3.3 hours or 3.5 hours), and then, the solvent is removed by distillation under reduced pressure to obtain a polymerized modified water-based polyurethane dispersion; and (4) dispersing SiO2 matting powder in the polymerized modified water-based polyurethane dispersion obtained in step (3) to obtain the high-adhesion low-gloss PVC artificial leather finishing agent water-based polyurethane dispersion.

[0031] In the preferred embodiment of the preparation method of the high-adhesion low-gloss PVC artificial leather finishing agent water-based polyurethane dispersion, in step (1), the content of NCO is 2.35%-2.46% (for example, 2.35%, 2.37%, 2.39%, 2.41%, 2.43%, 2.45% or 2.46%) when reaching the theoretical value; and after adding the vinyl-containing sulfonate, the stirring time is 10-20 minutes (for example, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes).

[0032] In the preferred embodiment of the preparation method of the water-based polyurethane dispersion for high-adhesion low-gloss PVC artificial leather surface treatment agent of the present application, in step (2), the stirring speed of the deionized water is 1000-1500 rpm (for example, 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, or 1500 rpm), and the modified water-based polyurethane dispersion is obtained after stirring for 10-20 minutes (for example, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, or 20 minutes); after adding the acetone b portions, the stirring time is 20-30 minutes (for example, 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes, or 30 minutes); and after adding the neutralizing agent, the stirring time is 20-300 minutes (for example, 20 minutes, 60 minutes, 100 minutes, 120 minutes, 150 minutes, 200 minutes, 260 minutes, or 300 minutes). Preferably, the solvent (which mainly plays a dissolving role in the present application) is acetone.

[0033] In the preferred embodiment of the preparation method of the water-based polyurethane dispersion for high-adhesion low-gloss PVC artificial leather surface treatment agent of the present application, in step (4), the dispersion of the SiO2 extinction powder is carried out at room temperature, the dispersion speed is 800-1000 rpm (for example, 800 rpm, 850 rpm, 900 rpm, 950 rpm, or 1000 rpm), and the dispersion time is 1.5-2.5 h (for example, 1.5 h, 1.7 h, 1.9 h, 2.1 h, 2.3 h, or 2.5 h). The dispersion speed of the SiO2 extinction powder should not be too high or too low; if the speed is too high, the SiO2 extinction powder will be crushed, affecting the extinction performance; if the speed is too low, uniform dispersion of the SiO2 extinction powder cannot be achieved, which will adversely affect the extinction performance of the obtained product. The dispersion time is appropriately 1.5-2.5 h to achieve uniform dispersion of the SiO2 extinction powder.

[0034] The present application also provides a high-adhesion low-gloss PVC artificial leather surface treatment agent. The raw materials and / or components of the high-adhesion low-gloss PVC artificial leather surface treatment agent of the present application include the water-based polyurethane dispersion described above.

[0035] The high-adhesion low-gloss PVC artificial leather surface treatment agent of the present application contains the water-based polyurethane dispersion described above, and has high adhesion, high extinction, stability, flame retardancy, and chemical corrosion resistance, etc., due to the excellent wear resistance, high strength, and chemical corrosion resistance of polyurethane.

[0036] The water-based polyurethane dispersion for high-adhesion low-gloss PVC artificial leather surface treatment agent, the preparation method thereof, and the application thereof of the present application will be described in detail below through specific examples.

[0037] Example 1

[0038] The preparation method of the high-adhesion low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion of the present embodiment includes the following steps:

[0039] (1) Synthesis of polyurethane prepolymer: 13.35 parts of vacuum-dried polyoxypropylene glycol (2000 g / mol), 0.77 parts of polyethylene glycol difunctional methyl ether (Ymer N120), 6.49 parts of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts of 1,4-butanediol, 0.98 parts of hydrophilic chain extender dimethylol propionic acid, 0.03 parts of organic bismuth catalyst, and 5.54 parts of acetone (acetone a) were sequentially added to a reaction device equipped with a reflux tube, stirring device, and thermometer. The temperature of the reaction device was raised to 60°C, and the reaction process was monitored using di-n-butylamine titration method until the percentage content of NCO reached the theoretical value of 2.35%. After reaching the NCO theoretical value, 0.34 parts of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h, followed by the addition of 5.97 parts of hydroxyethyl acrylate and reaction at the same temperature for 1 h until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer;

[0040] (2) Neutralization, emulsification and dispersion of polyurethane: The temperature of the system was lowered to 30°C, 27.72 parts of acetone (acetone b) was added to reduce the viscosity, and stirred for 30 min. 0.74 parts of triethylamine was added and stirred for 20 min. The neutralized prepolymer was dispersed in 1000 rpm high-speed stirred 65 parts of deionized water, and the stirring was maintained for 30 min to obtain a modified water-based polyurethane dispersion.

[0041] (4) 50 parts of the polymeric modified water-based polyurethane dispersion from the above step was taken, and 0.75 parts of SiO2 matting powder was dispersed therein at a speed of 800 rpm for 2 h at room temperature to obtain the high-adhesion low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion containing SiO2 matting powder of the present embodiment.

[0042] Example 2

[0043] The preparation method of the high-adhesion low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion of the present embodiment includes the following steps:

[0044] (1) Synthesis of polyurethane prepolymer: 13.97 parts by weight of vacuum dehydrated polytetrahydrofuran diol, 0.81 parts by weight of polyethylene glycol difunctional methyl ether (Ymer N120), 5.75 parts by weight of isophorone diisocyanate, 0.21 parts by weight of 1,4-butanediol, 0.03 parts by weight of ethanolamine, 1.03 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, and 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, a stirring device, and a thermometer, the temperature of the reaction device was raised to 60°C, the reaction process was monitored using di-n-butylamine titration method until the percentage content of NCO reached the theoretical value of 2.46%, after reaching the theoretical value of NCO, 0.36 parts by weight of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h, then 4.14 parts by weight of hydroxyethyl acrylate was added and reacted for 1 h at the same temperature until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 4.14 parts by weight of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer;

[0045] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, stirred for 30 min, 0.78 parts by weight of triethylamine was added, and stirred for 20 min; the neutralized prepolymer was dispersed into 1000 rpm high-speed stirred 65 parts of deionized water, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0046] (3) Preparation of copolymer modified waterborne polyurethane dispersion: the modified waterborne polyurethane dispersion prepared in the above step was put into a four-necked flask, 0.12 parts by weight of K2S2O8 was added, the water bath was heated to 80°C, and the stirring reaction was carried out for 3 h. After the stirring was completed, the acetone was removed by distillation at 55°C under reduced pressure to obtain a polymer modified waterborne polyurethane dispersion.

[0047] (4) 50 parts of the polymer modified waterborne polyurethane dispersion in the above step was taken, 0.75 parts of SiO2 matting powder was dispersed therein, the dispersing machine was rotated at a speed of 800 rpm, and the dispersion was carried out at room temperature for 2 h to obtain a SiO2 matting powder containing waterborne polyurethane dispersion for high adhesion and low gloss PVC artificial leather surface finish agent of the present example.

[0048] Example 3

[0049] (1) Synthesis of polyurethane prepolymer: 12 parts of vacuum dewatered polyoxypropylene diol (2000 g / mol), 0.77 parts of polyethylene glycol difunctional methyl ether (Ymer N120), 6.49 parts of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts of 1,4-butanediol, 0.98 parts of hydrophilic chain extender dimethylol propionic acid, 0.03 parts of organic bismuth catalyst, and 5.54 parts of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, stirring device, and thermometer, the temperature of the reaction device was raised to 60°C, the reaction process was monitored using di-n-butylamine titration method until the percentage content of NCO reached the theoretical value of 2.35%; after reaching the NCO theoretical value, 0.34 parts of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h, then 7.36 parts of hydroxypropyl acrylate was added and reacted for 1 h at the same temperature until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 7.36 parts of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer;

[0050] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was lowered to 30°C, 27.72 parts of acetone (acetone b) was added to reduce the viscosity, stirred for 30 min, 0.74 parts of triethylamine was added, and stirred for 20 min; the neutralized prepolymer was dispersed into 65 parts of deionized water stirred at 1000 rpm, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0051] (4) 50 parts of the polymeric modified waterborne polyurethane dispersion in the above step was taken, 0.75 parts of SiO2 matting powder was dispersed therein, the disperser was rotated at 800 rpm, and the dispersion was carried out at room temperature for 2 h to obtain a SiO2 matting powder-containing waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather surface finish agent of the present example.

[0052] Example 4

[0053] (1) Synthesis of polyurethane prepolymer: 13.39 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 0.77 parts by weight of polyethylene glycol difunctional methyl ether (Ymer N120), 6.51 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.99 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, and 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, a stirring device, and a thermometer, the temperature of the reaction device was raised to 60°C, the reaction process was monitored using di-n-butylamine titration, until the percentage content of NCO reached the theoretical value of 2.35%; after reaching the theoretical value of NCO, 0.28 parts by weight of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h, then 5.97 parts by weight of hydroxyethyl acrylate was added and reacted for 1 h at the same temperature, until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer;

[0054] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, stirred for 30 min, 0.74 parts by weight of triethylamine was added and stirred for 20 min; the neutralized prepolymer was dispersed into 65 parts of deionized water stirred at 1000 rpm, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0055] (4) 50 parts of the polymeric modified waterborne polyurethane dispersion in the above step were taken, 0.75 parts of SiO2 matting powder was dispersed therein, the disperser was rotated at 800 rpm, and the dispersion was carried out at room temperature for 2 h to obtain the waterborne polyurethane dispersion containing SiO2 matting powder for high-adhesion low-gloss PVC artificial leather finish agent of the present example.

[0056] Comparative Example 1

[0057] The preparation method of the waterborne polyurethane dispersion for high-adhesion low-gloss PVC artificial leather finish agent of the present comparative example comprises the following steps:

[0058] (1) Synthesis of polyurethane prepolymer: 13.35 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 0.77 parts by weight of polyethylene glycol difunctional methyl ether (Ymer N120), 6.49 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.98 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, stirring device and thermometer, the temperature of the reaction device was raised to 60°C, the reaction process was monitored using di-n-butylamine titration method until the percentage content of NCO reached the theoretical value of 2.35%; after reaching the theoretical value of NCO, 0.34 parts by weight of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h, then 5.97 parts by weight of methyl methacrylate was added and reacted for 1 h at the same temperature until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of sodium vinyl sulfonate was added and stirred for 10 min to obtain a polyurethane prepolymer;

[0059] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, stirring for 30 min, 0.74 parts by weight of triethylamine was added and stirred for 20 min; the neutralized prepolymer was dispersed into 65 parts of deionized water stirred at 1000 rpm, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0060] (3) Preparation of copolymer modified waterborne polyurethane dispersion: the modified waterborne polyurethane dispersion prepared in the above step was put into a four-necked flask, 0.12 parts by weight of K2S2O8 was added, the water bath was heated to 80°C, and the stirring reaction was carried out for 3 h. After the stirring was completed, the acetone was removed by distillation at 55°C under reduced pressure to obtain a polymer modified waterborne polyurethane dispersion.

[0061] (4) 50 parts of the polymer modified waterborne polyurethane dispersion in the above step were taken, 0.75 parts of SiO2matte powder was dispersed therein, the dispersing machine was rotated at 800 rpm, and the dispersion was carried out at room temperature for 2 h to obtain a waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example.

[0062] Comparative Example 2

[0063] The preparation method of the waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example includes the following steps:

[0064] (1) Synthesis of polyurethane prepolymer: 13.35 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 0.77 parts by weight of polyethylene glycol difunctional methyl ether (Ymer N120), 6.49 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.98 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, stirring device and thermometer, the temperature of the reaction device was raised to 60°C, the reaction process was monitored using di-n-butylamine titration method until the percentage content of NCO reached the theoretical value of 2.35%; after reaching the theoretical value of NCO, 0.34 parts by weight of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h, then 5.97 parts by weight of hydroxyethyl acrylate was added and reacted for 1 h at the same temperature until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of methyl methacrylate was added and stirred for 10 min to obtain a polyurethane prepolymer;

[0065] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, stirring for 30 min, 0.74 parts by weight of triethylamine was added and stirred for 20 min; the neutralized prepolymer was dispersed into 1000 rpm high-speed stirred 65 parts of deionized water, and stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0066] (4) 50 parts of the polymeric modified waterborne polyurethane dispersion prepared in the above step were taken, 0.75 parts of SiO2 matting powder was dispersed therein, the disperser was rotated at 800 rpm, and the dispersion was carried out at room temperature for 2 h to obtain a waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example.

[0067] Comparative Example 3

[0068] The preparation method of the waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example includes the following steps:

[0069] (1) Synthesis of polyurethane prepolymer: 14.12 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 6.49 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.98 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, and 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, stirring device, and thermometer. The temperature of the reaction device was raised to 60°C, and the reaction process was monitored using di-n-butylamine titration method until the percentage content of NCO reached the theoretical value of 2.35%. After reaching the theoretical value of NCO, 0.34 parts by weight of γ-aminopropyl triethoxysilane (KH550) was added, and reacted for 1 h. Then, 5.97 parts by weight of hydroxyethyl acrylate was added, and reacted for 1 h at the same temperature until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of sodium vinyl sulfonate was added, and stirred for 10 min to obtain the polyurethane prepolymer.

[0070] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, and stirred for 30 min. Then, 0.74 parts by weight of triethylamine was added, and stirred for 20 min. The neutralized prepolymer was dispersed into 1000 rpm high-speed stirred 65 parts of deionized water, and the stirring was maintained for 30 min to obtain the modified waterborne polyurethane dispersion.

[0071] (3) Preparation of copolymer modified waterborne polyurethane dispersion: the modified waterborne polyurethane dispersion prepared in the above step was put into a four-necked flask, 0.12 parts by weight of K2S2O8 was added, the water bath was heated to 80°C, and the stirring was reacted for 3 h. After the stirring was completed, the acetone was removed by distillation at 55°C under reduced pressure to obtain the polymer modified waterborne polyurethane dispersion.

[0072] Comparative Example 4

[0073] The preparation method of the high-adhesion low-gloss waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example comprises the following steps:

[0074] (1) Synthesis of polyurethane prepolymer: 13.35 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 0.77 parts by weight of polyethylene glycol difunctional methyl ether (Ymer N120), 6.49 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.98 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, and 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, a stirring device, and a thermometer. The temperature of the reaction device was raised to 60°C, and the reaction process was monitored using di-n-butylamine titration until the percentage content of NCO reached the theoretical value of 2.35%. After reaching the theoretical value of NCO, 6.31 parts by weight of hydroxyethyl acrylate was added and reacted at the same temperature for 1 h until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer;

[0075] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, and stirred for 30 min. 0.74 parts by weight of triethylamine was added and stirred for 20 min. The neutralized prepolymer was dispersed in 1000 rpm high-speed stirred 65 parts of deionized water, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0076] (3) Preparation of copolymer modified waterborne polyurethane dispersion: the modified waterborne polyurethane dispersion prepared in the above step was put into a four-necked flask, 0.12 parts of K2S2O8 was added, the water bath was heated to 80°C, and the stirring reaction was carried out for 3 h. After the stirring was completed, the acetone was removed by distillation at 55°C under reduced pressure to obtain a polymer modified waterborne polyurethane dispersion.

[0077] Comparative Example 5

[0078] The preparation method of the high-adhesion low-gloss waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example comprises the following steps:

[0079] (1) Synthesis of polyurethane prepolymer: 14.12 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 6.49 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.98 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, and 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, stirring device, and thermometer. The temperature of the reaction device was raised to 60°C, and the reaction process was monitored using di-n-butylamine titration until the NCO% reached the theoretical value of 2.35. After reaching the NCO theoretical value, 6.31 parts by weight of hydroxyethyl acrylate was added and reacted at the same temperature for 1 h until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer;

[0080] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, and stirred for 30 min. 0.74 parts by weight of triethylamine was added and stirred for 20 min. The neutralized prepolymer was dispersed in 1000 rpm high-speed stirred 65 parts of deionized water, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0081] (3) Preparation of copolymer modified waterborne polyurethane dispersion: the modified waterborne polyurethane dispersion prepared in the above step was put into a four-necked flask, 0.12 parts of K2S2O8 was added, the water bath was heated to 80°C, and the stirring reaction was carried out for 3 h. After the stirring was completed, acetone was removed by distillation at 55°C under reduced pressure to obtain a polymer modified waterborne polyurethane dispersion.

[0082] Comparative Example 6

[0083] The preparation method of the high-adhesion low-gloss waterborne polyurethane dispersion for PVC artificial leather finishing agent of the present comparative example comprises the following steps:

[0084] (1) Synthesis of polyurethane prepolymer: 13.35 parts by weight of vacuum dewatered polyoxypropylene diol (2000 g / mol), 0.77 parts by weight of polyethylene glycol difunctional methyl ether (Ymer N120), 6.49 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 0.24 parts by weight of 1,4-butanediol, 0.98 parts by weight of hydrophilic chain extender dimethylol propionic acid, 0.03 parts by weight of organic bismuth catalyst, and 5.54 parts by weight of acetone (acetone a) were sequentially added into a reaction device equipped with a reflux tube, stirring device, and thermometer. The temperature of the reaction device was raised to 60°C, and the reaction process was monitored using di-n-butylamine titration until the percentage content of NCO reached the theoretical value of 2.35%. After reaching the theoretical value of NCO, 5.97 parts by weight of hydroxyethyl acrylate was added and reacted at the same temperature for 1 h. Then, 0.34 parts by weight of γ-aminopropyl triethoxysilane (KH550) was added and reacted for 1 h until the NCO groups in the system were completely reacted and could not be determined by FT-IR. The temperature was cooled to 45°C, 5.97 parts by weight of sodium vinyl sulfonate was added, and stirred for 10 min to obtain a polyurethane prepolymer.

[0085] (2) Neutralization, emulsification and dispersion of polyurethane: the temperature of the system was reduced to 30°C, 27.72 parts by weight of acetone (acetone b) was added to reduce the viscosity, and stirred for 30 min. Then, 0.74 parts by weight of triethylamine was added and stirred for 20 min. The neutralized prepolymer was dispersed into 65 parts by weight of deionized water under high-speed stirring at 1000 rpm, and the stirring was maintained for 30 min to obtain a modified waterborne polyurethane dispersion.

[0086] (4) 50 parts of the polymeric modified waterborne polyurethane dispersion obtained in the above step was taken, and 0.75 parts of SiO2 matting powder was dispersed therein at a rotation speed of 800 rpm of a dispersing machine for 2 h at room temperature to obtain a SiO2 matting powder-containing waterborne polyurethane dispersion for high-adhesion and low-gloss PVC artificial leather finishing agent of the present example.

[0087] Experimental Example

[0088] 1. The SiO2 matting powder-containing waterborne polyurethane dispersion for artificial leather finishing agent obtained in each of the above examples and comparative examples was compounded with 1 part of a nitrogen pyridine curing agent, an appropriate amount of an associative thickener, and 0.3 parts of a leveling agent, and then coated on a PVC substrate, which was then dried at 100°C. The adhesion was tested according to the GB / T9286-1988 standard, and the results are shown in Table 1. The adhesion was best at level 0 and worst at level 5. For general purposes, the adhesion was acceptable at levels 1-3.

[0089] 2. The SiO2-containing flatting powder-containing artificial leather finishing agent water-based polyurethane dispersion obtained in each of the above examples and comparative examples was left to stand at room temperature for a certain period of time, and the sedimentation was observed.

[0090] 3. The SiO2-containing flatting powder-containing artificial leather finishing agent water-based polyurethane dispersion obtained in each of the above examples and comparative examples was diluted with deionized water to an emulsion having a solid content of 0.5%, and then an appropriate amount of the emulsion was taken with a disposable dropper and added to a quartz dish, which was then placed in a particle size analyzer for testing. The testing angle was 90°, the dispersion medium was water, and the testing was performed at room temperature.

[0091] 4. The SiO2-containing flatting powder-containing artificial leather finishing agent water-based polyurethane dispersion obtained in each of the above examples and comparative examples was compounded with a nitrogen pyridine curing agent, a thickening agent, and a leveling agent, and then coated on synthetic leather, which was then baked at 120°C for 3 minutes, and the gloss was tested using a gloss meter.

[0092] 5. The SiO2-containing flatting powder-containing artificial leather finishing agent water-based polyurethane dispersion obtained in each of the above examples and comparative examples was compounded with a nitrogen pyridine curing agent, a thickening agent, and a leveling agent, and then placed in a mold, which was then slowly cured and air-dried at room temperature, and then placed in a 60°C oven until the mass no longer changed, to obtain a transparent, bubble-free, and flat solid sample having a thickness of 2 cm, which was subjected to a combustion test in accordance with GB / T 2408-2008.

[0093] The test results are shown in Table 1 below.

[0094] Table 1

[0095]

[0096]

[0097] As can be seen from Table 1 above, each of Examples 1 to 4 has good adhesion, stability, flame retardancy, and flatting (the 60° gloss index is a way of testing gloss, and tests the reflection of light at an angle of 60°; the smaller the 60° gloss, the stronger the flatting; the larger the particle size of the water-based resin, the better the flatting); and as can be seen from the examples and comparative examples in the table above, the polyurethane modified with the sodium sulfonate containing a vinyl group and the hydroxy acrylate has certain adhesion, the polyurethane modified with the sulfonic group has certain flame retardancy, and the water-based polyurethane modified with the amino siloxane coupling agent and the non-ionic dihydric alcohol has good emulsion stability.

[0098] Comparative Example 1 is compared with Example 1, the only difference is that the same amount of hydroxyethyl acrylate is replaced by the same amount of methyl methacrylate; due to the replacement of hydroxyethyl acrylate containing hydroxyl components, the adhesion of the modified waterborne polyurethane material in Comparative Example 1 is reduced, and at the same time the sulfonic acid group contained therein imparts certain flame retardancy to the modified waterborne polyurethane material.

[0099] Comparative Example 2 is compared with Example 1, the only difference is that the same amount of sodium vinyl sulfonate is replaced by the same amount of methyl methacrylate; due to the replacement of hydroxyethyl acrylate containing hydroxyl components, the modified waterborne polyurethane material in Comparative Example 2 has certain adhesion.

[0100] Comparative Example 3 is compared with Example 1, the only difference is that the same amount of Ymer N120 is replaced by the same amount of polyoxypropylene glycol; the modified waterborne polyurethane material in Comparative Example 3 does not have the solvation effect and steric effect provided by polyethylene glycol bifunctional methyl ether, so the stability of the emulsion is poor.

[0101] Comparative Example 4 is compared with Example 1, the only difference is that the same amount of KH550 is replaced by the same amount of hydroxyethyl acrylate, the modified waterborne polyurethane material in Comparative Example 4 cannot form a covalent bond with the silicon hydroxyl on the surface of the matting powder SiO2 by hydrolysis and condensation, and cannot anchor the matting powder on the polymer, so the stability of the emulsion is poor.

[0102] Comparative Example 5 is compared with Example 1, the only difference is that the same amount of KH550 is replaced by the same amount of hydroxyethyl acrylate, and the same amount of Ymer N120 is replaced by the same amount of polyoxypropylene glycol, the modified waterborne polyurethane material in Comparative Example 5 has poor emulsion stability.

[0103] Comparative Example 6 is compared with Example 1, the only difference is that the feeding order of KH550 and hydroxyethyl acrylate is changed, since the last KH550 is not reacted onto the polymer, there is no connecting medium between the matting powder and the waterborne polyurethane, and the modified waterborne polyurethane material in Comparative Example 6 has poor emulsion stability.

[0104] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the preparation of a waterborne polyurethane dispersion for high adhesion and low gloss PVC leather finish, characterized by, The raw materials of the high-attachment low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion include a polymer modified water-based polyurethane dispersion and SiO2 matt powder; The polymer modified water-based polyurethane dispersion is prepared from the following raw materials by weight: 12-14.2 parts of polyether polyol, 0.77-3 parts of non-ionic dihydric alcohol, 5.75-8 parts of diisocyanate, 0.03-0.24 parts of small molecule chain extender, 0.98-1.03 parts of hydrophilic chain extender, 0.03-0.05 parts of catalyst, 0.74-0.78 parts of neutralizing agent, 0.28-2.5 parts of amino siloxane coupling agent, 4.14-7.36 parts of hydroxy acrylate, 4.14-7.36 parts of vinyl-containing sulfonate, 0.11-0.15 parts of initiator, and 64-66 parts of deionized water. The preparation method comprises the following steps: (1) synthesis of polyurethane prepolymer: reflux stirring reaction of the polyether polyol, non-ionic dihydric alcohol, diisocyanate, small molecule chain extender, hydrophilic chain extender, catalyst and solvent a parts at 60-70℃ until the percentage content of NCO reaches the theoretical value; then adding the amino siloxane coupling agent for 1-2 h; then adding the hydroxy acrylate until the NCO group in the system is completely reacted; reducing the temperature to 45-55℃, adding the vinyl-containing sulfonate, and stirring to obtain the polyurethane prepolymer; (2) neutralization, emulsification and dispersion of polyurethane: cooling the polyurethane prepolymer obtained in step (1) to 30-40℃, adding solvent b parts to reduce the viscosity, and stirring; then adding a neutralizing agent to neutralize to obtain a neutralized prepolymer; then dispersing the neutralized prepolymer into deionized water under stirring to obtain a modified water-based polyurethane dispersion; (3) preparation of copolymer modified water-based polyurethane dispersion: putting the modified water-based polyurethane dispersion obtained in step (2) into a reaction container, adding the initiator, and stirring under water bath heating to 75-85℃ for 2.5-3.5 h; after the reaction is completed, the solvent is removed by distillation under reduced pressure to obtain a polymer modified water-based polyurethane dispersion; (4) dispersing the SiO2 matt powder in the polymer modified water-based polyurethane dispersion obtained in step (3) to obtain the high-attachment low-gloss PVC artificial leather surface treatment agent water-based polyurethane dispersion; The non-ionic dihydric alcohol is linear polyethylene glycol bifunctional methyl ether Ymer N120.

2. The method of preparing a water-based polyurethane dispersion for high adhesion and low gloss PVC artificial leather finish according to claim 1, characterized in that, The amino siloxane coupling agent is at least one of γ-aminopropyl triethoxysilane, γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, N-β(aminoethyl)-γ-aminopropyl triethoxysilane, anilino methyl triethoxysilane and anilino methyl trimethoxysilane.

3. The method of preparing a water-based polyurethane dispersion for high adhesion and low gloss PVC artificial leather finish according to claim 1, characterized in that, The hydroxy acrylate is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate and 4-hydroxybutyl acrylate; The vinyl-containing sulfonate is sodium vinyl sulfonate and / or sodium styrene sulfonate.

4. The method of preparing a water-based polyurethane dispersion for high adhesion and low gloss PVC artificial leather finish according to claim 1, characterized in that, The polyether polyol is polyoxypropylene glycol and / or polytetrahydrofuran diol, the number average molecular weight of the polyether polyol is 1000-2000 g / mol; The diisocyanate is 4,4'-dicyclohexylmethane diisocyanate and / or isophorone diisocyanate; The small molecule chain extender is ethanolamine and / or 1,4-butanediol; The catalyst is organic bismuth; The neutralizing agent is triethylamine; The initiator is potassium persulfate.

5. The method for preparing a water-based polyurethane dispersion for high- adhesion low-gloss PVC artificial leather finish according to any one of claims 1 to 4, characterized in that, The mass ratio of the polymeric modified waterborne polyurethane dispersion and SiO2 matting powder is (48-52):(0.5-1).

6. The method of preparing a water-based polyurethane dispersion for high adhesion and low gloss PVC artificial leather finish as claimed in claim 1, characterized by, In step (1), the content of NCO is 2.35%-2.46% to reach the theoretical value; After adding the vinyl-containing sulfonate, the stirring time is 10-20 minutes.

7. The preparation method of the high-adhesion low-gloss PVC artificial leather finishing agent waterborne polyurethane dispersion according to claim 1, characterized in that, In step (2), the stirring speed of the deionized water is 1000-1500 rpm, and the modified waterborne polyurethane dispersion is obtained after stirring for 10-20 minutes; After adding the solvent b parts, the stirring time is 20-30 minutes; After adding the neutralizing agent, the stirring time is 20-300 minutes.

8. The method of preparing a water-based polyurethane dispersion for high adhesion and low gloss PVC artificial leather finish as claimed in claim 1, characterized by, In step (4), the dispersion of SiO2 matting powder is carried out at room temperature, the dispersion speed is 800-1000 rpm, and the dispersion time is 1.5-2.5 h.

9. A waterborne polyurethane dispersion for high adhesion and low gloss PVC artificial leather finish, characterized by, The high-adhesion low-gloss PVC artificial leather finishing agent waterborne polyurethane dispersion is prepared by the method according to any one of claims 1-8.

10. A high adhesion low gloss PVC artificial leather finish, characterized in that, The raw materials and / or ingredients of the finishing agent include the waterborne polyurethane dispersion according to claim 9. The raw materials and / or ingredients of the finishing agent include the waterborne polyurethane dispersion according to claim 9.

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