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CN-122011329-A - High-resistance waterborne polyurethane resin as well as preparation method and application thereof

CN122011329ACN 122011329 ACN122011329 ACN 122011329ACN-122011329-A

Abstract

The invention discloses a high-resistance waterborne polyurethane resin, and a preparation method and application thereof, and belongs to the technical field of waterborne polyurethane resins. The resin comprises diisocyanate, polyalcohol and other components, and is characterized in that the surface migration agent is beta-cyclodextrin modified polydimethylsiloxane, and the response agent is adamantane modified nano silicon dioxide. The preparation method comprises the steps of pre-polymerizing, neutralizing, emulsifying and chain extension to obtain basic emulsion, sequentially adding a response agent and a surface migration agent, regulating pH and curing. The invention realizes the controllable construction of the hydrophobic layer by utilizing the recognition effect of the host and the guest, solves the bottleneck of poor water resistance of the existing waterborne polyurethane, avoids the problems of component aggregation and low migration efficiency, improves the protective performance and the service life of the coating, can be used for preparing the coating, and is suitable for decoration and protection of various base materials.

Inventors

  • TAN YOUHUA
  • MAI JIMIN
  • TAN YUAN
  • Feng Ruiheng

Assignees

  • 中山市明逸化工新材料有限公司

Dates

Publication Date
20260512
Application Date
20260305

Claims (10)

  1. 1. The high-resistance waterborne polyurethane resin is characterized by comprising diisocyanate, polyalcohol, a small molecule chain extender, a hydrophilic chain extender, a rear chain extender, a surface migration agent, a response agent, a neutralizer, a catalyst, a cosolvent, a pH regulator and deionized water; The surface migration agent is polydimethylsiloxane modified by beta-cyclodextrin; The response agent is adamantane modified nano silicon dioxide.
  2. 2. The high-resistance aqueous polyurethane resin according to claim 1, wherein the preparation method of the surface migration agent comprises the following steps: A1, reacting beta-cyclodextrin and 3-isocyanatopropyl triethoxysilane for 5-7 hours at 65-75 ℃ according to the mass ratio of 1:0.6-0.8 to obtain an intermediate; A2, reacting the hydroxyl-terminated polydimethylsiloxane with the intermediate for 10-14 hours at 75-85 ℃ according to the mass ratio of 1:0.4-0.6, and obtaining the beta-cyclodextrin modified polydimethylsiloxane.
  3. 3. The high-resistance aqueous polyurethane resin according to claim 1, wherein the preparation method of the responser comprises the following steps: B1, reacting nano silicon dioxide with an aminosilane coupling agent for 10-14 hours at 65-75 ℃ according to the mass ratio of 1:0.25-0.35 to obtain amino-modified nano silicon dioxide; And B2, reacting the amino modified nano silicon dioxide with adamantane formic acid for 22-26 hours at 25-35 ℃ according to the mass ratio of 1:0.15-0.25, thus obtaining the adamantane modified nano silicon dioxide.
  4. 4. A high-resistance aqueous polyurethane resin according to claim 1 or 3, wherein the nano silica has a particle diameter of 20 to 30nm.
  5. 5. The high-resistance aqueous polyurethane resin according to claim 1, which is characterized by comprising the following components, by weight, 35-50 parts of diisocyanate, 40-60 parts of polyol, 3-8 parts of small molecule chain extender, 3-6 parts of hydrophilic chain extender, 0.5-1.5 parts of rear chain extender, 2-4 parts of surface migration agent, 1-2.5 parts of response agent, 2-5 parts of neutralizer, 0.1-0.3 part of catalyst, 5-15 parts of cosolvent, 0.3-0.6 part of pH regulator and 150-300 parts of deionized water.
  6. 6. The high-resistance waterborne polyurethane resin according to claim 5, wherein the diisocyanate is isophorone diisocyanate, the polyol is polyester polyol, one or more selected from poly (1, 4-butylene adipate), poly (1, 6-hexanediol adipate) and polycaprolactone diol, the small molecule chain extender is 1, 4-butanediol, the hydrophilic chain extender is dimethylolpropionic acid, the post chain extender is ethylenediamine, the neutralizing agent is triethylamine, the catalyst is dibutyltin dilaurate, the cosolvent is N-methylpyrrolidone, and the pH regulator is triethylamine.
  7. 7. A method for producing a high-resistance aqueous polyurethane resin according to any one of claims 1 to 6, comprising the steps of: s1, mixing diisocyanate, polyalcohol, a small molecular chain extender, a hydrophilic chain extender, a catalyst and a cosolvent, and performing a prepolymerization reaction to obtain a prepolymer; S2, adding a neutralizing agent into the prepolymer obtained in the step S1 to perform a neutralization reaction; s3, adding the neutralized prepolymer into deionized water for emulsification, and then adding a rear chain extender for a rear chain extension reaction to obtain a waterborne polyurethane resin base emulsion; s4, adding a response agent into the basic emulsion obtained in the step S3, and uniformly dispersing; s5, after the surface migration agent is dissolved in the solvent, adding the solvent into the mixed solution obtained in the step S4; S6, adding a pH regulator to regulate the pH value, standing and curing to obtain the high-resistance aqueous polyurethane resin.
  8. 8. The method for preparing high-resistance aqueous polyurethane resin according to claim 7, wherein the responser in the step S4 is added by ultrasonic dispersion, the ultrasonic power is 200-400W, and the time is 10-20 min; In the step S5, the surface migration agent is dropwise added with ethanol as a solvent at the stirring speed of 200-300 rpm; and (3) regulating the pH in the step S6 to 7.3-7.8, and standing and curing for 20-28 hours.
  9. 9. The method for preparing a high-resistance aqueous polyurethane resin according to claim 7, wherein the prepolymerization reaction temperature in the step S1 is 75-85 ℃ until the NCO content is reduced to 6.5-7.5%; the emulsification temperature in the step S3 is 40-45 ℃, and the stirring speed is 1000-1500 rpm.
  10. 10. A coating comprising a high resistance aqueous polyurethane resin according to any one of claims 1 to 6.

Description

High-resistance waterborne polyurethane resin as well as preparation method and application thereof Technical Field The invention belongs to the technical field of waterborne polyurethane resin, and relates to a high-resistance waterborne polyurethane resin, a preparation method and application thereof. Background The aqueous polyurethane resin is an environment-friendly high polymer material, has the outstanding advantages of no VOC pollution, convenient construction, good film forming property, strong adhesive force and the like, is widely applied in the paint field, can be used in various scenes such as building paint, wood paint, industrial protective paint and the like, can provide decoration and protection effects for different base materials, and accords with the development trend of the current environment-friendly paint. However, poor water resistance is still a key technical bottleneck for restricting the further popularization and application of the waterborne polyurethane resin in the field of paint. In order to realize dispersibility or water solubility in water, the existing aqueous polyurethane resin must introduce hydrophilic groups (such as carboxyl, hydroxyl, carbamate groups and the like) into the molecular structure, and the existence of the hydrophilic groups ensures that a large number of hydrophilic sites remain on the surface after the resin is solidified to form a coating layer of the coating, so that the coating layer is easy to interact with water, the water contact angle of the coating layer is reduced, the water absorption rate is increased, and after the coating layer is in a humid environment or contacts with water for a long time, the coating layer is easy to generate quality problems such as foaming, whitening, light loss, falling, peeling and the like, thereby not only damaging the appearance decoration of the coating layer, but also reducing the protective performance and the service life of the coating layer, even causing the damage of a base material, and being incapable of meeting the practical application requirements of the coating. Disclosure of Invention The invention aims to provide a high-tolerance aqueous polyurethane resin, a preparation method and application thereof, and the in-situ construction of a hydrophobic layer in the later film forming stage is realized through a host-guest identification mechanism of a surface migration agent and a response agent, so that the water resistance and the long-term stability of a coating are obviously improved. The aim of the invention can be achieved by the following technical scheme: In a first aspect, the invention provides a high-resistance aqueous polyurethane resin, which comprises diisocyanate, polyalcohol, a small molecule chain extender, a hydrophilic chain extender, a post chain extender, a surface migration agent, a response agent, a neutralizing agent, a catalyst, a cosolvent, a pH regulator and deionized water; The surface migration agent is polydimethylsiloxane modified by beta-cyclodextrin; The response agent is adamantane modified nano silicon dioxide. Preferably, the preparation method of the surface migration agent comprises the following steps: A1, reacting beta-cyclodextrin and 3-isocyanatopropyl triethoxysilane for 5-7 hours at 65-75 ℃ according to the mass ratio of 1:0.6-0.8 to obtain an intermediate; A2, reacting the hydroxyl-terminated polydimethylsiloxane with the intermediate for 10-14 hours at 75-85 ℃ according to the mass ratio of 1:0.4-0.6, and obtaining the beta-cyclodextrin modified polydimethylsiloxane. Preferably, the preparation method of the response agent comprises the following steps: B1, reacting nano silicon dioxide with an aminosilane coupling agent for 10-14 hours at 65-75 ℃ according to the mass ratio of 1:0.25-0.35 to obtain amino-modified nano silicon dioxide; And B2, reacting the amino modified nano silicon dioxide with adamantane formic acid for 22-26 hours at 25-35 ℃ according to the mass ratio of 1:0.15-0.25, thus obtaining the adamantane modified nano silicon dioxide. Preferably, the adhesive comprises the following components, by weight, 35-50 parts of diisocyanate, 40-60 parts of polyol, 3-8 parts of small molecule chain extender, 3-6 parts of hydrophilic chain extender, 0.5-1.5 parts of rear chain extender, 2-4 parts of surface migration agent, 1-2.5 parts of response agent, 2-5 parts of neutralizer, 0.1-0.3 part of catalyst, 5-15 parts of cosolvent, 0.3-0.6 part of pH regulator and 150-300 parts of deionized water; Preferably, the diisocyanate is isophorone diisocyanate, the polyol is polyester polyol, the polyol is one or more selected from poly (1, 4-butylene adipate), poly (1, 6-hexanediol adipate) and poly (caprolactone) glycol, the small molecule chain extender is 1, 4-butanediol, the hydrophilic chain extender is dimethylolpropionic acid, the rear chain extender is ethylenediamine, the neutralizing agent is triethylamine, the catalyst is dibutyltin dilaurate, the c