CN109535372B

CN109535372B - Waterborne polyurethane and preparation method thereof

Info

Publication number: CN109535372B
Application number: CN201811289369.3A
Authority: CN
Inventors: 张建森; 郝伟; 郭金砚
Original assignee: Newmat Beijing Environmental Materials Technology Corp
Current assignee: Newmat Beijing Environmental Materials Technology Corp
Priority date: 2018-10-31
Filing date: 2018-10-31
Publication date: 2021-08-27
Anticipated expiration: 2038-10-31
Also published as: CN109535372A

Abstract

The invention relates to waterborne polyurethane, which is high-performance waterborne polyurethane chemically modified by functionalized polyhedral oligomeric silsesquioxane and a polyfunctional compound, has a network structure, and shows improved mechanical property and heat resistance, lower water absorption and good solvent resistance; the invention also relates to a preparation method of the high-performance waterborne polyurethane, which is prepared by introducing functionalized polyhedral oligomeric silsesquioxane for chemical side chain grafting and forming a network structure by using a multifunctional compound, and has the advantages of simple process and easily controlled process.

Description

Waterborne polyurethane and preparation method thereof

Technical Field

The invention relates to the field of high polymer materials, in particular to high-performance waterborne polyurethane chemically modified by functionalized polyhedral oligomeric silsesquioxane and a polyfunctional compound and a preparation method thereof.

Background

High-performance waterborne polyurethane has been known for a long time, takes water as a dispersion medium, and has the advantages of no toxicity, difficult combustion, no environmental pollution, energy conservation, safety, reliability and the like. In addition, the unique molecular structure of the polyurethane enables the polyurethane to have excellent hardness-softness adjustable characteristics, and the polyurethane can be used in the field of wide coating finishing.

Chinese patent CN 101265318B discloses a preparation method of a high-performance aqueous polyurethane dispersion, which is prepared by using polymer polyol containing 2-80% of cyclic structure as a main raw material and polyisocyanate. The water resistance, alcohol resistance, heat resistance and hardness of the high-performance aqueous polyurethane dispersion are improved, but the improvement on the mechanical properties such as flexibility, adhesion and the like of the high-performance aqueous polyurethane dispersion is not involved.

Chinese patent CN 1226323C discloses a method for preparing high performance waterborne polyurethane, which overcomes the problem of reducing effective chain extension due to a large amount of reaction between isocyanate functional groups and water when a prepolymer with an end group of aromatic isocyanate is dispersed in water by closely controlling the NCO content after the prepolymer is dispersed in water. The NCO content is accurately controlled by infrared spectroscopy to reduce side reactions of isocyanate. However, the operation method is complicated, which is not favorable for the wide popularization of technical products.

Chinese patent CN 100475874C discloses a preparation method of an efficient oxidation self-crosslinking high-performance aqueous polyurethane dispersion, alkyd resin is introduced in the chain structure design of polyurethane as an oxidation crosslinking unit, but the improvement of comprehensive properties such as mechanical property, heat resistance and the like is not involved.

Polyhedral oligomeric silsesquioxanes (POSS) are fairly popular organic-inorganic compounds with three-dimensional structures. The material has the advantages of low density, good thermal stability and good monodispersity, so that the thermal performance, the oxidation resistance and the like of the material can be improved by carrying out surface modification, grafting and polymerization reaction on the material through single or multiple reactive functional groups on the structure of the material. Patent CN 101250375B discloses a preparation method of POSS/polyurethane water-based composite coating, which comprises the steps of preparing non-terminated POSS by a hydrolysis method, then adopting silane coupling agent KH-550 to carry out termination on the POSS to prepare POSS containing amido, and finally carrying out chemical compounding on the POSS and high-performance water-based polyurethane dispersoid to prepare the POSS/polyurethane water-based composite coating. However, the POSS of the synthetic part has limited capping degree and unknown physical and mechanical properties, so that the wide application of the POSS is limited.

Patent CN 103467693B discloses a preparation method of high-performance waterborne polyurethane with good freeze-thaw stability, which is characterized in that amino-type cage-like silsesquioxane is introduced into the chain structure of the high-performance waterborne polyurethane, and the synthesized high-performance waterborne polyurethane has good wear resistance and bonding strength and good freeze-thaw stability. However, the amino cage type silsesquioxane has more active groups and complicated process control, and is not beneficial to industrial production.

The existing modified high-performance waterborne polyurethane still has the problems of poor comprehensive properties of products, such as mechanical property and water resistance, complex preparation method and the like.

Disclosure of Invention

The invention aims to provide high-performance aqueous polyurethane which is chemically modified by functionalized polyhedral oligomeric silsesquioxane (functionalized POSS) and a polyfunctional compound, has a network structure, improved mechanical properties and heat resistance, lower water absorption and good solvent resistance; the invention also provides a preparation method of the modified high-performance waterborne polyurethane, which is characterized in that the modified high-performance waterborne polyurethane is prepared by introducing functionalized POSS (polyhedral oligomeric silsesquioxane) to carry out chemical side chain grafting, and a network structure is formed by a polyfunctional compound, so that the process is simple and the process is easy to control.

The invention provides high-performance waterborne polyurethane which is characterized by being prepared by reacting the following components:

wherein the weight percentage of each component is based on the total weight of the waterborne polyurethane, and the sum of the weight percentage of each component is 100 weight percent.

Preferably, the weight ratio of the functionalized POSS and the polyol can be from 1:10 to 30. Preferably, the ratio n of the amount of isocyanate used to polyol and functionalized POSS is_NCO:n_OH1.5-10:1, wherein n is_NCODenotes the molar amount of NCO groups in the isocyanate, n_OHIndicates the molar amount of OH groups in the polyol and functionalized POSS used. Preferably, the weight ratio of the polyfunctional compound to the polyol may be 1:50 to 150; and preferably, the weight ratio of the multifunctional compound to the high-performance aqueous polyurethane prepolymer is 0.5-2.0: 100. Preferably, the weight ratio of the hydrophilic chain extender to the high-performance aqueous polyurethane prepolymer can be 0.02-0.06:1, wherein the mass of the prepolymer refers to the sum of the masses of isocyanate, functionalized POSS, polyol, hydrophilic chain extender, micromolecular chain extender, polyfunctional compound and catalyst.

The invention also provides a preparation method of the high-performance waterborne polyurethane, which comprises the following steps:

a) adding a solvent into a reactor, adding functionalized POSS and a hydrophilic chain extender, controlling the temperature at 30-70 ℃, stirring for dissolving (preferably continuously for 0.5-2.0 hours), then dropwise adding (preferably slowly dropwise adding) isocyanate into the reactor, and reacting for 0.5-2.0 hours;

b) adding polyol, a micromolecular chain extender and a catalyst into a reactor, controlling the temperature to be 60-100 ℃, and reacting for 1.5-5.0 hours;

c) continuously adding the residual solvent into the mixture obtained in the step b), then adding a metered polyfunctional compound, controlling the temperature at 50-80 ℃, and reacting for 1.5-4.0 hours to obtain a high-performance waterborne polyurethane prepolymer;

d) controlling the temperature of the high-performance waterborne polyurethane prepolymer obtained in the step c) at 30-70 ℃, adding a salt forming agent, further cooling to 10-40 ℃, then adding water and emulsifying (preferably high-speed emulsifying) to obtain high-performance waterborne polyurethane containing a solvent; and

e) removing the solvent in the high-performance waterborne polyurethane obtained in the step d) to obtain the final high-performance waterborne polyurethane;

the preparation method comprises the following components:

The high-performance waterborne polyurethane of the invention has improved mechanical property, water resistance and ethanol resistance, and the preparation method is simple.

Drawings

FIG. 1 shows the network structure of the high performance aqueous polyurethane of the present invention, the network structure connecting points are multifunctional compounds, and functionalized POSS is grafted on the molecular chain of the aqueous polyurethane; in the figure, the squares represent functionalized POSS, the curves represent the molecular chain of the aqueous polyurethane, and the small dots represent polyfunctional compounds.

Detailed Description

In the present invention, all operations are carried out at room temperature under normal pressure unless otherwise specified. All polymers had molecular weights of weight average molecular weight.

The high-performance waterborne polyurethane disclosed by the invention has a network structure as shown in figure 1, wherein the connection point of the network structure is a multifunctional compound, and functionalized POSS is grafted on the molecular chain of the waterborne polyurethane. In FIG. 1, the squares represent functionalized POSS, the curves represent the molecular chains of the aqueous polyurethane, and the small dots represent polyfunctional compounds.

In the present invention, the high-performance aqueous polyurethane has a solid content of 20 to 50% by weight, preferably 25 to 40% by weight, more preferably 25 to 35% by weight, wherein the solid content is measured in accordance with GB/T1725-2007 determination of the nonvolatile content of paints, varnishes and plastics.

In the present invention, the high-performance aqueous polyurethane has a viscosity of 50 to 1000 mPas, preferably 50 to 800 mPas, more preferably 100 mPas to 500 mPas, as measured in accordance with GB/T2794-.

In a preferred embodiment of the present invention, the weight ratio of the functionalized POSS to the polyol may range from 1:10 to 30, preferably from 1:15 to 25, more preferably from 1:15 to 20.

In a preferred embodiment of the invention, the ratio of the amount of isocyanate used to polyol and functionalized POSS used, n, is such that_NCO:n_OHIs 1.5-10:1, preferably 1.5-8:1, more preferably 1.5-5:1, where n is_NCODenotes the molar amount of NCO groups in the isocyanate, n_OHIndicates the molar amount of OH groups in the polyol and functionalized POSS used.

In a preferred embodiment, the molar amount of NCO groups of the isocyanate is greater than the sum of the molar amounts of NCO-reactive groups in the polyol and other raw materials such as functionalized POSS, hydrophilic chain extenders, small molecule chain extenders, and the like, preferably, n_NCON' is 1.5-3.5:1.0, preferably 1.5-3.0:1.0, more preferably 1.5-2.5:1.0, wherein n_NCORepresenting the molar amount of NCO groups in the isocyanate and n' representing the sum of the molar amounts of NCO-reactive groups in the polyol and the chain extender.

In a preferred embodiment, the weight ratio of the hydrophilic chain extender to the prepolymer used may be 0.02-0.06:1, preferably 0.02-0.05:1, more preferably 0.03-0.05:1, where the mass of the prepolymer refers to the sum of the masses of the isocyanate, the functionalized POSS, the polyol, the hydrophilic chain extender, the small chain extender, the polyfunctional compound, and the catalyst.

The functionalized POSS has the structure of formula (I):

wherein R is₁Is H or C_1-8Alkyl, preferably H or C_1-6An alkyl group; r₂Is hydroxyl, amino, mercapto; m and n are selected from integers of 0-5. In a preferred embodiment, R₁Examples of (d) are H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl. The functionalized POSS are commercially available. In one embodiment, it is AM0275 (molecular weight Mw 917.65) available from Hybrid Plastics. The functionalized POSS is used in amounts of 0.2 to 4.0 weight percent, preferably 0.2 to 3.5 weight percent, more preferably 0.4 to 2.0 weight percent, more preferably 0.5 to 1.8 weight percent, and most preferably 0.6 to 1.5 weight percent, based on the total weight of the aqueous polyurethane.

The functionalized POSS has a weight average molecular weight of 600-.

The polyol may be a polyol including two or more OH groups, such as a polyester polyol, a polyether polyol, a polycaprolactone polyol, a polycarbonate polyol, an acrylate polyol, a polybutadiene polyol, or a modified compound thereof. Preferably polyester polyols such as polyethylene adipate polyols, polybutylene adipate polyols, polyethylene terephthalate polyols, polybutylene terephthalate polyols, polyhexamethylene terephthalate polyols or mixtures thereof, more preferably polybutylene adipate polyols, polyethylene terephthalate polyols; polyether polyols such as polyethylene oxide polyols, polypropylene oxide polyols, polytetrahydrofuran ether polyols or mixtures thereof, more preferably polypropylene oxide polyols, polytetrahydrofuran ether polyols or mixtures thereof. In the present invention, the polyol is used in an amount of 4 to 20% by weight, preferably 6 to 20% by weight, more preferably 8 to 19% by weight, more preferably 8.5 to 18% by weight, most preferably 9 to 15% by weight, based on the total weight of the aqueous polyurethane.

The weight average molecular weight of the polyol is 300-; the polyols have hydroxyl numbers of from 10 to 250mg KOH/g, preferably from 50 to 225mg KOH/g, more preferably from 50 to 200mg KOH/g, in the context of the present invention the hydroxyl numbers are in accordance with GB/T12008.3-2009, part 3 of Plastic polyether polyol: hydroxyl value determination adopts an acid-base titration method.

The isocyanate is an isocyanate having at least 2 isocyanate functional groups, preferably 2 to 3 and more preferably exactly 2 isocyanate functional groups. The isocyanate used is a monomeric diisocyanate which may be aromatic or aliphatic. Aromatic isocyanates are those isocyanates which comprise at least one aromatic ring system, i.e. both purely aromatic and araliphatic compounds. Aliphatic are those isocyanates which do not contain aromatic ring systems and which comprise linear aliphatic and cycloaliphatic compounds.

The isocyanates are preferably diisocyanates with only two isocyanate groups of the formula OCN-R₃-NCO, wherein R₃Aromatic, aliphatic, cycloaliphatic groups, groups commonly used in the art for isocyanate formation may be selected. The isocyanate may be Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), p-phenylene diisocyanate (PPDI), dimethylbiphenyl diisocyanate (TODI), Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), 1, 4-cyclohexane diisocyanate (CHDI), dicyclohexylmethane diisocyanate (H)₁₂MDI) or mixtures thereof.

Wherein isophorone diisocyanate is generally in the form of a mixture, especially a mixture of cis and trans isomers in a ratio generally from about 55:45 to 85:15 (w/w), preferably from about 60:40 to 80:20 (w/w), more preferably from about 70:30 to 75:25 (w/w), and more preferably in a ratio of about 75:25 (w/w). Dicyclohexylmethane diisocyanate may also be in the form of a mixture of different cis and trans isomers.

Preferably, the isocyanates generally have an NCO content of from 5 to 55% by weight, in particular from 30 to 45% by weight, and an average NCO functionality of from 1 to 4, preferably from 2 to 3, where the NCO content can be determined by methods known to the person skilled in the art, for example by the acetone-di-n-butylamine method. Preferably, the molecular weight of the diisocyanate used is 110-.

The isocyanates are used in an amount of from 8 to 30% by weight, preferably from 9 to 28% by weight, more preferably from 9.5 to 25% by weight, more preferably from 10 to 23% by weight, most preferably from 11 to 22% by weight, based on the total weight of the aqueous polyurethane.

The hydrophilic chain extender is a compound having at least two groups reactive with NCO and containing a hydrophilic group, and examples thereof are anionic hydrophilic chain extenders such as dimethylolpropionic acid, dimethylolbutyric acid, dihydroxy half ester, sodium ethylene diamino ethanesulfonate, sodium 1, 4-butanediol-2-sulfonate, preferably one or a mixture of two of dimethylolpropionic acid, dimethylolbutyric acid, sodium ethylene diamino ethanesulfonate, more preferably one or a mixture of two of dimethylolpropionic acid, dimethylolbutyric acid; cationic hydrophilic chain extenders such as dihydroxy compounds containing tertiary amine groups, for example N-methyldiethanolamine, the reaction product of diethylenetriamine with epichlorohydrin, benzyldimethyl (2-hydroxyethyl) ammonium chloride, mixtures of one or two of dodecyldimethyl (2-hydroxyethyl) ammonium bromide, preferably one or two of N-methyldiethanolamine, benzyldimethyl (2-hydroxyethyl) ammonium chloride, more preferably N-methyldiethanolamine. The hydrophilic chain extender is used in an amount of 0.4 to 6.0 wt%, preferably 0.8 to 4.0 wt%, more preferably 0.8 to 3.2 wt%, more preferably 1.0 to 3.0 wt%, most preferably 1.5 to 3.0 wt%, based on the weight of the aqueous polyurethane.

The small molecule chain extender is a chain extender having at least two groups reacting with NCO, is distinguished from a hydrophilic chain extender, does not contain a hydrophilic group in its structure, and has a molar mass of less than 200g/mol, and examples thereof may be polyethylene glycol, ethylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, diethylene glycol, 1, 4-cyclohexanedimethanol, methylpropanediol, ethylenediamine, ammonia, isophoronediamine, hydrazine hydrate or a mixture thereof, preferably 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, 1, 4-cyclohexanedimethanol, methylpropanediol, ethylenediamine, isophoronediamine, hydrazine hydrate or a mixture thereof, more preferably 1, 4-butanediol, neopentyl glycol, ethylenediamine, isophoronediamine, hydrazine hydrate or a mixture thereof. The small molecule chain extender is used in an amount of 0.1 to 4.0 wt%, preferably 0.2 to 3.5 wt%, more preferably 0.2 to 3.0 wt%, more preferably 0.3 to 2.8 wt%, most preferably 0.3 to 2.0 wt%, based on the weight of the aqueous polyurethane.

The polyfunctional compound is a compound containing three or more groups reactive with NCO, and examples thereof may be Trimethylolpropane (TMP), glycerol, castor oil, pentaerythritol, xylitol, sorbitol, sucrose, or a mixture thereof, preferably Trimethylolpropane (TMP), castor oil, pentaerythritol, or a mixture thereof, more preferably Trimethylolpropane (TMP), pentaerythritol, or a mixture thereof. The polyfunctional compound is used in an amount of 0.04 to 1.0 wt.%, preferably 0.08 to 1.0 wt.%, more preferably 0.10 to 1.0 wt.%, more preferably 0.11 to 1.0 wt.%, most preferably 0.12 to 0.8 wt.%, based on the weight of the aqueous polyurethane.

The catalyst is a reagent for catalyzing isocyanate to react with a group reacted with NCO, and can be triethylamine, diethylenetriamine, triethylenediamine, pyridine, N-dimethylpyridine, stannous octoate or dibutyl tin dilaurate or a mixture thereof, preferably dibutyl tin dilaurate, stannous octoate, triethylenediamine or pyridine or a mixture thereof, and more preferably dibutyl tin dilaurate, stannous octoate or a mixture thereof. The catalyst is used in an amount of 0.002 to 0.05 wt%, preferably 0.005 to 0.04 wt%, more preferably 0.01 to 0.03 wt%, more preferably 0.01 to 0.028 wt%, most preferably 0.012 to 0.025 wt%, based on the weight of the aqueous polyurethane.

The salt forming agent is a reagent for neutralizing the acid and the alkali of the high-performance waterborne polyurethane prepolymer. Under the condition that the obtained high-performance aqueous polyurethane prepolymer is acidic, the salt forming agent can be alkali metal hydroxide, such as potassium hydroxide, sodium hydroxide or a mixture thereof; amines such as triethylamine, ammonia, diethylenetriamine, triethylenetetramine, triethanolamine or mixtures thereof; preferably triethylamine, potassium hydroxide, aqueous ammonia or mixtures thereof, more preferably triethylamine, potassium hydroxide or mixtures thereof. Under the condition that the obtained high-performance aqueous polyurethane prepolymer is alkaline, the salt forming agent can be inorganic acid such as hydrochloric acid, sulfuric acid or a mixture thereof; organic acids such as formic acid, acetic acid or mixtures thereof. The salt former is used in an amount of 0.2 to 3.0 wt.%, preferably 0.4 to 3.0 wt.%, more preferably 0.6 to 3.0 wt.%, more preferably 0.8 to 2.8 wt.%, most preferably 0.8 to 2.5 wt.%, based on the weight of the aqueous polyurethane.

The amount of water is from 20 to 80% by weight, preferably from 25 to 80% by weight, more preferably from 30 to 80% by weight, more preferably from 40 to 75% by weight, most preferably from 45 to 70% by weight, based on the weight of the aqueous polyurethane.

The solvent is a solvent for adjusting the viscosity of the resulting mixture. Suitable solvents may be acetone, butanone, N-dimethylformamide, N-dimethylacetamide, toluene, xylene, ethyl acetate, butyl acetate or mixtures thereof, preferably acetone, butanone, N-dimethylformamide, toluene, xylene, ethyl acetate or mixtures thereof, more preferably acetone, butanone, N-dimethylformamide or mixtures thereof. The solvent is used in an amount of 2 to 12 wt.%, preferably 2 to 10 wt.%, more preferably 2.2 to 10.5 wt.%, more preferably 2.3 to 10 wt.%, most preferably 2.5 to 8 wt.%, based on the weight of the aqueous polyurethane.

In other embodiments, one or more additives selected from the group consisting of antifoaming agents, leveling agents, uv absorbers, antioxidants are optionally added to the high-performance aqueous polyurethane.

The features and preferred features broadly defined above in the description of the compounds of the components apply equally to the components in the preparation process hereinafter.

the preparation method comprises the following components:

Preferably, the weight ratio of the functionalized POSS and the polyol can be from 1:10 to 30. Preferably, the ratio n of the amount of isocyanate used to polyol and functionalized POSS is_NCO:n_OH1.5-10:1, wherein n is_NCODenotes the molar amount of NCO groups in the isocyanate, n_OHIndicates the molar amount of OH groups in the polyol and functionalized POSS used. Preferably, the weight ratio of the polyfunctional compound to the polyol may be 1:50 to 150; and preferably, the weight ratio of the multifunctional compound to the high-performance aqueous polyurethane prepolymer is 0.5-2.0: 100. Preferably, the hydrophilic membraneThe weight ratio of the chain agent to the high-performance water-based polyurethane prepolymer can be 0.02-0.06:1, wherein the mass of the prepolymer refers to the sum of the masses of isocyanate, functionalized POSS, polyol, hydrophilic chain extender, micromolecular chain extender, polyfunctional compound and catalyst.

It is noted that the components and amounts used in the preparation process may employ the features and preferred features broadly described in the description of the high performance aqueous polyurethane products above and the amounts thereof accordingly.

In step a), the reactor is a closed, dry reactor with temperature measurement and stirring. Preferably, it is carried out under an inert atmosphere, which is a gas that does not participate in the reaction of the polyol and the isocyanate, such as nitrogen, argon. In step a), the solvent is added in an amount of about 50 to 70 wt% based on the total amount of the solvent.

In one embodiment, after addition of the functionalized POSS, hydrophilic chain extender, the temperature is controlled at about 30-70 ℃, preferably 35-65 ℃, more preferably 38-60 ℃ and dissolved with stirring for 0.5-2.0 hours, preferably 0.5-1.5 hours, more preferably 0.5-1.0 hours, until the mixture is in a clear and transparent state.

In one embodiment, the dropping time of the isocyanate is controlled to be 0.5 to 3 hours, preferably 0.5 to 2.5 hours, more preferably 0.5 to 2.0 hours. In one embodiment, after the isocyanate is added dropwise, the mixture is allowed to react for 0.2 to 2.5 hours, preferably 0.3 to 2.3 hours, more preferably 0.5 to 2 hours, most preferably 0.5 to 1.5 hours.

In the step b), after adding the polyalcohol and the micromolecular chain extender and the catalyst, controlling the temperature to be 60-100 ℃, preferably 65-95 ℃, and more preferably 60-90 ℃; in one embodiment, the reaction time is from 1.5 to 5.0 hours, preferably from 2.0 to 4.5 hours, more preferably from 2.0 to 4.0 hours.

In step c), a solvent is added to adjust the viscosity of the resulting mixture to 50 to 1000 mPas, preferably 50 to 800 mPas, more preferably 50 to 500 mPas. In one embodiment, in step c), the solvent is added in an amount of about 30 to about 50 wt% based on the total amount of solvent.

In one embodiment, the reaction temperature in step c) is controlled between 50 and 80 ℃, preferably between 55 and 75 ℃, more preferably between 60 and 70 ℃. In one embodiment, the reaction time is from 1 to 4.0 hours, preferably from 1.2 to 3.5 hours, more preferably from 1.5 to 3.0 hours.

In step d), the polyurethane prepolymer obtained in step c) is cooled to 30 to 70 ℃, preferably 30 to 65 ℃, more preferably 30 to 60 ℃ before the salt-forming agent is added. In one embodiment, the temperature is further reduced to 10-40 ℃, preferably 10-35 ℃, more preferably 10-30 ℃ after the addition of the salt forming agent. In one embodiment, the high speed emulsification is carried out in a high speed shear (available from Wenzhou Schwann light Industrial machines, Inc., model RHG) at a shear emulsification rate of 1000-.

In step e), the solvent introduced into the system is removed in a manner known to those skilled in the art, preferably by distillation under reduced pressure.

Preferably, the high performance aqueous polyurethane obtained by the process of the present invention is substantially free of solvent, in other words, the high performance aqueous polyurethane contains negligible solvent, for example, the high performance aqueous polyurethane contains less than 5 wt.%, preferably less than 2 wt.%, more preferably less than 0.5 wt.% solvent, based on the total weight of the aqueous polyurethane. In a preferred embodiment of the invention, the high-performance aqueous polyurethane is solvent-free.

The high-performance aqueous polyurethane is applied to the substrate in a conventional manner, for example by brushing, spraying, dipping, rolling or knife coating. In this case, the coating material may optionally also comprise further conventional additives, such as defoamers, levelling agents, uv absorbers, antioxidants.

Preferably, the high performance aqueous polyurethanes of the present invention are suitable for coating substrates such as wood, films, leather, and the like. Preferably, the coating of the substrate is performed by: firstly, coating a substrate with the high-performance waterborne polyurethane of the invention, and then drying the waterborne coating, more particularly, the temperature range of the drying step is more than or equal to-10 ℃ and less than or equal to 100 ℃, preferably more than or equal to 5 ℃ and less than or equal to 90 ℃, and particularly preferably more than or equal to 10 ℃ and less than or equal to 85 ℃. The specific drying temperature range should also be adjusted accordingly in conjunction with the characteristics of the substrate.

The high-performance waterborne polyurethane coating obtained by the invention has the characteristics of no toxicity, safety, high gloss uniformity, high and low temperature resistance, good transparency, good fullness and good hand feeling, and can be widely used in the fields of coatings, adhesives, printing inks, fabric treating agents and the like.

The present invention is more specifically illustrated by the following examples.

Examples

Example 1

In a dry reactor equipped with a stirrer and a temperature measuring instrument, 5g of Acetone (AC), 5g N, N-Dimethylformamide (DMF), 2g of isobutyl-substituted aminoethylaminopropyl-POSS (available from Hybrid Plastics, AM0275, Mw 917.65), 6g of dimethylolpropionic acid (DMPA) were charged, the temperature was controlled at 50 ℃, stirred and dissolved for 0.5 hour to a clear and transparent state, and then 45g of Toluene Diisocyanate (TDI) was slowly dropped into the reactor for 1 hour, followed by a reaction for 0.5 hour; 25g of polybutylene adipate diol (Mw 1000, hydroxyl value 110mgKOH/g), 1g of 1, 6-Hexanediol (HDO) and 0.05g of dibutyltin dilaurate were added to a reactor, and the mixture was stirred at 70 ℃ for reaction for 3 hours; adding 5g N, adjusting the viscosity to 400 mPas by N-Dimethylformamide (DMF), then adding 0.5g of Trimethylolpropane (TMP), stirring and reacting for 2 hours at 60 ℃ to obtain the high-performance waterborne polyurethane prepolymer. The obtained high-performance waterborne polyurethane prepolymer is cooled to 40 ℃, 4g of potassium hydroxide (KOH) is added, the mixture is further cooled to room temperature, and 150g of deionized water is added, and the mixture is sheared and emulsified in a high-speed shearing machine (purchased from Wenzhou Kong light industry Co., Ltd., model RHG) at the speed of 1800 rpm to obtain the solvent-containing high-performance waterborne polyurethane. A rotary evaporator (from Shanghai Tokyo instruments & Equipment Co., Ltd., model RE-201D) was used to remove the solvent from the high-performance aqueous polyurethane, to obtain 238.1g of high-performance aqueous polyurethane.

Example 2

In a dry reactor equipped with a stirrer and a temperature measuring instrument, 12.5g of methyl ethyl ketone, 4g of phenyl-substituted hydroxyethyl hydroxypropyl-POSS (purchased from subunit Biotechnology Ltd., Hangzhou, P007, Mw: 1127.53) and 8g of dimethylolbutyric acid (DMBA) were added, the temperature was controlled at 60 ℃, stirred and dissolved for 1 hour until the mixture became clear and transparent, and then 35g of isophorone diisocyanate (IPDI) and 5g of Hexamethylene Diisocyanate (HDI) were uniformly mixed and slowly added dropwise into the reactor for 2 hours, followed by a reaction for 1 hour; adding 40g of polypropylene oxide glycol (Mw is 2000, hydroxyl value is 55mgKOH/g), 2g of neopentyl glycol (NPG) and 0.05g of stannous octoate into a reactor, and stirring and reacting at 80 ℃ for 2.5 hours; adding 5g N, adjusting the viscosity to 350 mPas by N-Dimethylformamide (DMF), then adding 1g of pentaerythritol, stirring and reacting for 2 hours at 80 ℃ to obtain the high-performance waterborne polyurethane prepolymer. The obtained high-performance waterborne polyurethane prepolymer is cooled to 35 ℃, then 5g of Triethylamine (TEA) is added, the mixture is further cooled to room temperature, and then 200g of deionized water is added, and the mixture is sheared and emulsified in a high-speed shearing machine (purchased from Wenzhou Kong light industry mechanical Co., Ltd., model RHG) at the speed of 1800 rpm to obtain the solvent-containing high-performance waterborne polyurethane. The solvent in the high-performance aqueous polyurethane was removed by a rotary evaporator (obtained from Shanghai Otsu instruments & Equipment Co., Ltd., model RE-201D) to obtain 301.7g of high-performance aqueous polyurethane.

Example 3

Adding 8g N, N-Dimethylformamide (DMF), 3g of isobutyl substituted mercaptoethyl mercaptopropyl-POSS (purchased from Hybrid Plastics, TH1550, Mw 949.65) and 5g N-methyldiethanolamine (DMEA) into a drying reactor provided with a stirrer and a temperature measuring instrument, controlling the temperature at 55 ℃, stirring and dissolving for 1 hour to be in a clear and transparent state, then uniformly mixing 28g of 4,4' -dicyclohexylmethane diisocyanate (HMDI) and 7g of 1, 4-cyclohexane diisocyanate (CHDI), slowly dropwise adding into the reactor, controlling the dropwise adding time to be 1 hour, and then reacting for 1.5 hours; 25g of polycarbonate diol (Mw: 1500, hydroxyl value 74mgKOH/g), 10g of acrylic polyol (Mw: 1000, hydroxyl value 110mgKOH/g), 3g of 1, 4-Butanediol (BDO) and 0.05g of dibutyltin dilaurate were put into a reactor, and stirred at 70 ℃ for 4 hours; adding 5g N, adjusting the viscosity to 500 mPas by N-Dimethylformamide (DMF), then adding 0.6g of pentaerythritol, stirring and reacting for 2 hours at 70 ℃ to obtain the high-performance aqueous polyurethane prepolymer. The obtained high-performance waterborne polyurethane prepolymer is cooled to 30 ℃, then 3g of formic acid is added, the mixture is further cooled to room temperature, and then 180g of deionized water is added, and the mixture is sheared and emulsified in a high-speed shearing machine (purchased from Wenzhou Kongwang light industry mechanical Co., Ltd., model RHG) at the speed of 1800 rpm to obtain the solvent-containing high-performance waterborne polyurethane. The solvent in the high-performance aqueous polyurethane was removed by a rotary evaporator (obtained from Shanghai Otsu instruments & Equipment Co., Ltd., model RE-201D) to obtain 269.7g of high-performance aqueous polyurethane.

Comparative example 1

Adding 10g of butanone and 7g of dimethylolpropionic acid (DMPA) into a drying reactor provided with a stirrer and a temperature measuring instrument, controlling the temperature at 50 ℃, stirring and dissolving for 0.5 hour to be in a clear and transparent state, then uniformly mixing 32g of isophorone diisocyanate (IPDI) and 5g of Hexamethylene Diisocyanate (HDI), slowly dropwise adding into the reactor, controlling the dropwise adding time to be 1.5 hours, and then reacting for 1 hour; adding 30g of polycaprolactone (Mw is 2000, hydroxyl value is 56mgKOH/g), 5g of 1, 4-cyclohexanedimethanol and 0.05g of stannous octoate into a reactor, and stirring for reaction at 70 ℃ for 3 hours; adding 5g of butanone to adjust the viscosity to 400 mPa.s, then adding 1g of Trimethylolpropane (TMP), stirring and reacting for 2.5 hours at 60 ℃ to obtain the aqueous polyurethane prepolymer. The obtained aqueous polyurethane prepolymer was cooled to 30 ℃, 4.5g of Triethylamine (TEA) was then added, the mixture was further cooled to room temperature, and 160g of deionized water was added and the mixture was sheared and emulsified at 1800 rpm in a high speed shearing machine (purchased from wazhou wang light industrial machinery, ltd., model RHG) to obtain an aqueous polyurethane containing a solvent. The solvent in the aqueous polyurethane was removed by using a rotary evaporator (available from Shanghai Tokyo instruments & Equipment Co., Ltd., model RE-201D) to obtain 249.1g of the aqueous polyurethane.

Comparative example 2

4g N, N-Dimethylformamide (DMF), 2g of isobutyl-substituted aminoethylaminopropyl-POSS (obtained from Hybrid Plastics, AM0275, Mw 917.65) and 6g of dimethylolpropionic acid (DMPA) were added to a dry reactor equipped with a stirrer and a temperature measuring instrument, the temperature was controlled at 60 ℃, the mixture was dissolved with stirring for 0.5 hour until it became clear and transparent, 28g of 4,4' -dicyclohexylmethane diisocyanate (HMDI) and 5g of Hexamethylene Diisocyanate (HDI) were uniformly mixed and then slowly added dropwise to the reactor, the addition time was controlled at 1.5 hours, and then the reaction was carried out for 1.5 hours; 28g of polybutylene adipate diol (Mw 1000, hydroxyl value 110mgKOH/g), 2g of 1, 6-Hexanediol (HDO) and 0.05g of dibutyltin dilaurate were added to a reactor, and the mixture was stirred at 70 ℃ for reaction for 3 hours; adding 4g N, and adjusting the viscosity to 400 mPas by N-Dimethylformamide (DMF) to obtain the waterborne polyurethane prepolymer. The obtained waterborne polyurethane prepolymer is cooled to 30 ℃, 4g of Triethylamine (TEA) is added, the temperature is further cooled to room temperature, and 180g of deionized water is added, and the mixture is sheared and emulsified in a high-speed shearing machine (purchased from Wenzhouwang light industry mechanical Co., Ltd., model RHG) at the speed of 1800 rpm, so that the waterborne polyurethane containing the solvent is obtained. The solvent in the aqueous polyurethane was removed by using a rotary evaporator (available from Shanghai Tokyo instruments & Equipment Co., Ltd., model RE-201D) to obtain 258.6g of the aqueous polyurethane.

Comparative example 3

25g of polytetrahydrofuran ether diol (Mw 1400, hydroxyl value 78mgKOH/g), 2.5g of 1, 4-Butanediol (BDO), 2g of isobutyl-substituted aminoethylaminopropyl-POSS (available from Hybrid Plastics, AM0275, Mw 917.65), 6g of dimethylolbutyric acid (DMBA), 0.05g of dibutyltin dilaurate were charged into a dry reactor equipped with a stirrer and a temperature measuring instrument, and then 35g of Toluene Diisocyanate (TDI) was slowly added dropwise into the reactor, the dropping time was controlled at 0.5 hour, and the reaction was stirred at 60 ℃ for 2 hours; 10g N, N-Dimethylformamide (DMF) is added to adjust the viscosity to 300 mPas, then 0.3g of pentaerythritol is added, and the mixture is stirred and reacted for 1.5 hours at the temperature of 60 ℃ to obtain the waterborne polyurethane prepolymer. The obtained waterborne polyurethane prepolymer is cooled to 35 ℃, then 5g of potassium hydroxide (KOH) is added, the mixture is further cooled to room temperature, and then 160g of deionized water is added, and the mixture is sheared and emulsified in a high-speed shearing machine (purchased from Wenzhou Kongwang light industry mechanical Co., Ltd., model RHG) at the speed of 1800 rpm to obtain the waterborne polyurethane containing the solvent. The solvent in the aqueous polyurethane was removed by using a rotary evaporator (available from Shanghai Tokyo instruments & Equipment Co., Ltd., model RE-201D) to obtain 240.8g of the aqueous polyurethane.

The test method comprises the following steps:

solid content: measured according to GB/T1725-2007 determination of the content of non-volatile substances in paints, varnishes and plastics.

Surface tension: the determination is carried out according to the standard GB/T22237-2008 "determination of surface tension of surfactants".

Viscosity: measured according to standard GB/T2794-.

Particle size: measured by laser particle size method using a laser particle size distribution apparatus (trade name: Euramerican Kerr LS900)

The high-performance aqueous polyurethane prepared according to the method of the present invention was measured, and the results are shown in table 1.

TABLE 1

As can be seen from Table 1, the high-performance waterborne polyurethane of the present invention has moderate solid content, surface tension and viscosity, and has good particle size distribution.

Adhesive films were prepared using the aqueous polyurethanes of examples 1 to 3 and comparative examples 1 to 3, and the properties of the adhesive films were measured, and the results are shown in Table 2 below.

The preparation method of the adhesive film comprises the following steps: the platform was leveled with a leveling rod, and the cleaned template (tetrafluoroethylene indenter, specification 120mm × 120mm × 5mm) was placed on the leveling platform. Diluting the waterborne polyurethane with deionized water until the solid content is 24%, weighing 40g of sample, pouring the sample on a template, horizontally pushing the sample to the edge of the template by using a glass rod to enable the sample to be uniformly distributed, standing the template for 5 days at 25 ℃ and 55% relative humidity (R.H.), then placing the polyurethane film in an oven at 90 ℃ for fully drying for 3 hours, taking out the polyurethane film and placing the polyurethane film in a dryer. The adhesive film should be uniform and flat without defects such as bubbles and cracks.

Tensile strength and elongation at break of the adhesive film: the tensile stress strain properties of the vulcanizates or thermoplastics are determined in accordance with standard GB/T528-containing 2009 (determination of tensile stress strain Properties of vulcanizates or thermoplastics) (dumbbell test specimens).

Pencil hardness of the adhesive film: the test was carried out according to the standard GB/T6739-1996 pencil method for coating hardness (method A-tester method).

Measuring the ethanol swelling ratio of the adhesive film: the adhesive film was cut into square specimens of 50X 50mm, and the mass (m) thereof was accurately weighed₁) Soaking in ethanol for 24 hr, taking out, quickly wiping off the liquid on the surface with filter paper, and accurately weighing the mass (m) of the adhesive film₂) Ethanol swelling ratio (W) of the adhesive film_s) Is W_s＝(m₂–m₁)/m₁X 100%. Mass (m) after putting into oven and fully drying₃) Weight loss ratio (W) of the adhesive film_l) Comprises the following steps: w_l＝(m₁–m₃)/m₁×100％。

TABLE 2

Table 2 shows that the tensile strength, modulus, and elongation at break of the samples of examples 1-3 are all greatly improved compared to the comparative examples; the hardness is obviously improved; the ethanol swelling ratio and the weight loss ratio of the adhesive film are obviously reduced, which shows that the ethanol resistance of the samples of examples 1-3 is improved.

Selecting a test plate according to a standard GB/T9271-2008 standard test plate for color paint and varnish, and manufacturing the plate according to a standard GB/T1727-92 general preparation method for paint films.

And (3) testing the flexibility of the paint film: tested according to GB/T1731-93 paint film flexibility test.

And (3) water absorption of the paint film: tested according to HG/T3344-2012 "determination of water absorption of paint film".

Determination of the Water resistance of the paint film: tested according to GB/T1733 + 1993 'determination method for water resistance of paint film'.

Moisture and heat resistance measurement of the paint film: tested according to GB/T1740-2007 determination of humidity and heat resistance of paint film.

Determination of the tack-back of the paint film: tested according to GB/T1762-80 & lt determination of tack-back of paint film & gt.

TABLE 3

Table 3 shows that the samples of examples 1-3 have improved flexibility, reduced water absorption, improved water resistance, and improved wet heat and tack resistance ratings, as compared to the comparative examples.

Claims

1. The waterborne polyurethane is characterized by being prepared by reacting the following components:

wherein the weight percentage of each component is based on the total weight of the waterborne polyurethane, and the sum of the weight percentages of the components is 100 weight percent;

wherein the polyfunctional compound is a compound containing 3 or more groups reactive with NCO selected from trimethylolpropane, glycerol, castor oil, pentaerythritol, xylitol, sorbitol, sucrose or mixtures thereof;

wherein the functionalized polyhedral oligomeric silsesquioxane has the structure of formula (I):

wherein R is₁Is H or C_1-8An alkyl group; r₂Is hydroxyl, amino, mercapto; m and n are integers of 0-5;

and wherein the aqueous polyurethane is prepared by a process comprising the steps of:

a) adding a solvent into a reactor, adding functionalized polyhedral oligomeric silsesquioxane and a hydrophilic chain extender, controlling the temperature at 30-70 ℃, stirring for dissolving, then dropwise adding isocyanate into the reactor, and reacting for 0.5-2.0 hours;

d) controlling the temperature of the high-performance waterborne polyurethane prepolymer obtained in the step c) at 30-70 ℃, adding a salt forming agent, further cooling to 10-40 ℃, then adding water and emulsifying to obtain solvent-containing high-performance waterborne polyurethane; and

e) removing the solvent in the high-performance waterborne polyurethane obtained in the step d) to obtain the final high-performance waterborne polyurethane.

2. An aqueous polyurethane according to claim 1, wherein in the structure of formula (I) of the functionalized polyhedral oligomeric silsesquioxane, R is₁Is H or C_1-6An alkyl group.

3. The aqueous polyurethane of claim 1, wherein the weight ratio of the functionalized polyhedral oligomeric silsesquioxane to polyol is 1:10 to 30; the ratio of the amount of isocyanate to the amount of polyol and functionalized polyhedral oligomeric silsesquioxane n_NCO:n_OH1.5-10:1, wherein n is_NCODenotes the molar amount of NCO groups in the isocyanate, n_OHRepresents the molar amount of OH groups in the polyol and functionalized polyhedral oligomeric silsesquioxane used; the weight ratio of the polyfunctional compound to the polyhydric alcohol is 1: 50-150.

4. The aqueous polyurethane according to claim 1, wherein the polyol is selected from polyester polyol, polyether polyol, polycarbonate polyol, acrylate polyol, polybutadiene polyol or modified compounds thereof.

5. The aqueous polyurethane according to claim 1, wherein the polyol is selected from polycaprolactone polyols.

6. The aqueous polyurethane of claim 1, wherein the isocyanate is toluene diisocyanate, diphenylmethane diisocyanate, p-phenylene diisocyanate, dimethylbiphenyl diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1, 4-cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, or a mixture thereof.

7. A preparation method of waterborne polyurethane comprises the following steps:

the preparation method comprises the following components:

wherein the polyfunctional compound is a compound containing 3 or more groups reactive with NCO selected from trimethylolpropane, glycerol, castor oil, pentaerythritol, xylitol, sorbitol, sucrose or mixtures thereof; and is

wherein R is₁Is H or C_1-8An alkyl group; r₂Is hydroxyl, amino, mercapto; m and n are integers of 0-5.

8. The preparation method according to claim 7, wherein R is in the structure of formula (I) of the functionalized polyhedral oligomeric silsesquioxane₁Is H or C_1-6An alkyl group.

9. The production method according to claim 7 or 8, wherein the weight ratio of the functionalized polyhedral oligomeric silsesquioxane to the polyol is 1:10 to 30; the ratio of the amount of isocyanate to the amount of polyol and functionalized polyhedral oligomeric silsesquioxane n_NCO:n_OH1.5-10:1, wherein n is_NCODenotes the molar amount of NCO groups in the isocyanate, n_OHRepresents the molar amount of OH groups in the polyol and functionalized polyhedral oligomeric silsesquioxane used; the weight ratio of the polyfunctional compound to the polyhydric alcohol is 1: 50-150.

10. The production method according to claim 7 or 8, wherein in step a), the dropping is slow dropping for 0.5 to 3 hours, and the stirring dissolution is for 0.5 to 2.0 hours; in step d), the emulsification is high-speed emulsification, and the shearing emulsification rate is 1000-.