Water-dispersible blocked isocyanate prepolymer system as well as preparation method and application thereof

Abstract

The invention relates to a water-dispersible blocked isocyanate prepolymer system as well as a preparation method and application thereof. The blocked isocyanate prepolymer system is prepared by reacting isocyanate with two or more isocyanate groups, a sealing agent, a non-hydrophilic polyhydroxy compound and an active hydrogen compound containing a hydrophilic group. The blocked isocyanate prepolymer system disclosed by the invention is water-dispersible, can be processed into various products, and is wide in application field.

Description

Technical Field

[0001] The present invention belongs to the technical field of isocyanate, and specifically relates to a water-dispersible blocked isocyanate prepolymer system and a preparation method and application thereof. Background Art

[0002] Epoxy resins are widely used in machinery, home appliances, transportation, construction and other fields due to their good thermal stability, excellent bonding and adhesion, and chemical resistance. However, epoxy systems are brittle, especially at low temperatures. In order to improve and increase flexibility, good and permanent elasticization of epoxy resins can be achieved by combining polyurethane.

[0003] CN 115427472 discloses that a blocked isocyanate prepolymer obtained by using cardanol and cardol blocking agents can be used to enhance and improve the impact resistance, shock resistance and flexibility of epoxy resin systems.

[0004] Due to the structural characteristics of the epoxy resin itself, the highly cross-linked mesh rigid structure formed after curing of the water-based epoxy resin also leads to unsatisfactory impact resistance, shock resistance and flexibility of the finished product. CN109651922 discloses the improvement of the mechanical properties of water-based epoxy resin by introducing an aqueous polyurethane dispersion containing active hydrogen. CN110845938 discloses the use of a rubber-modified water-based polyurethane as a toughening agent for water-based epoxy resin. CN108949000 discloses a water-dispersible resin, which is obtained by reacting cardanol with epoxy vegetable oil, then reacting with diisocyanate, and finally reacting with hydrophilic diol to obtain a water-dispersible polyurethane-epoxy resin. The prior art mostly uses polyurethane containing active hydrogen or introduces polyurethane segments with inactive functional groups to achieve the purpose of toughening, and there is no report on water-based epoxy toughening agents containing potential isocyanate active functional groups. For example, the blocked isocyanate prepolymer disclosed in CN 115427472 cannot be dispersed into the water phase and thus cannot be applied to the waterborne epoxy resin system.

[0005] Therefore, there is a need in the art for water-dispersible blocked isocyanate prepolymer systems. Summary of the invention

[0006] It is an object of the present invention to provide a water dispersible blocked isocyanate prepolymer system.

[0007] Another object of the present invention is to provide a method for preparing a water-dispersible blocked isocyanate prepolymer system.

[0008] Therefore, according to the first aspect of the present invention, there is provided a water-dispersible blocked isocyanate prepolymer system, characterized in that it is prepared by reacting an isocyanate having two or more isocyanate groups, a blocking agent, a non-hydrophilic polyol compound and an active hydrogen compound containing a hydrophilic group, wherein the molar ratio of the non-hydrophilic polyol compound to the active hydrogen compound containing a hydrophilic group is in the range of 0.1-25.0, the molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol compound and the active hydrogen compound containing a hydrophilic group to all the isocyanate groups of the isocyanate is in the range of 0.30-0.80, and the molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol compound, the active hydrogen compound containing a hydrophilic group and the blocking agent to all the isocyanate groups of the isocyanate is in the range of 0.90-1.10.

[0009] According to a second aspect of the present invention, there is provided a method for preparing the above-mentioned water-dispersible blocked isocyanate prepolymer system, characterized in that it comprises the following steps:

[0010] A. reacting an isocyanate having two or more isocyanate groups with a blocking agent to obtain a partially blocked isocyanate intermediate; and

[0011] B. reacting the partially blocked isocyanate intermediate obtained with an active hydrogen compound containing a hydrophilic group and a non-hydrophilic polyol until the content of free isocyanate groups relative to the total weight of the entire reaction system is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

[0012] According to a third aspect of the present invention, there is provided a method for preparing the above-mentioned water-dispersible blocked isocyanate prepolymer system, characterized in that it comprises the following steps:

[0013] An isocyanate having two or more isocyanate groups is reacted with a non-hydrophilic polyol compound and an active hydrogen compound containing a hydrophilic group and then reacted with a blocking agent until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, and more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

[0014] According to a fourth aspect of the present invention, there is provided an aqueous dispersion of a blocked isocyanate prepolymer prepared from the above-mentioned water-dispersible blocked isocyanate prepolymer system.

[0015] According to a fifth aspect of the present invention, there is provided the use of the above-mentioned water-dispersible blocked isocyanate prepolymer system or blocked isocyanate prepolymer aqueous dispersion for preparing polyurethane plastics, adhesives, sealing materials, potting materials, fiber wetting agents or coatings.

[0016] According to a sixth aspect of the present invention, there is provided a polyurethane plastic, adhesive, sealant, potting material, fiber sizing or coating comprising a water-dispersible blocked isocyanate prepolymer system.

[0017] The blocked isocyanate prepolymer system of the present invention is water dispersible, can be processed into various products, and has a wide range of application fields. DETAILED DESCRIPTION

[0018] Certain specific embodiments of the invention will now be described for purposes of illustration and not limitation.

[0019] Water dispersible blocked isocyanate prepolymer system

[0020] According to a first aspect of the present invention, there is provided a water-dispersible blocked isocyanate prepolymer system, characterized in that it is prepared by reacting an isocyanate having two or more isocyanate groups, a blocking agent, a non-hydrophilic polyol and an active hydrogen compound containing a hydrophilic group.

[0021] The molar ratio of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group is in the range of 0.1-25.0, the molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group to all the isocyanate groups of isocyanate is in the range of 0.30-0.80, and the molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol, the active hydrogen compound containing a hydrophilic group and the blocking agent to all the isocyanate groups of isocyanate is in the range of 0.90-1.10.

[0022] The molar ratio of the non-hydrophilic polyhydroxy compound to the active hydrogen compound containing a hydrophilic group is preferably in the range of 0.1-23.0, more preferably 0.2-15.0.

[0023] The total isocyanate groups of the isocyanate refer to the total isocyanate groups contained before the isocyanate having two or more isocyanate groups reacts with the non-hydrophilic polyol or the active hydrogen compound containing a hydrophilic group or the blocking agent.

[0024] The molar ratio of all groups reactive with isocyanate of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group to all isocyanate groups of isocyanate is preferably in the range of 0.40-0.60, more preferably in the range of 0.45-0.55.

[0025] The molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol, the active hydrogen compound containing a hydrophilic group and the blocking agent to all the isocyanate groups of the isocyanate is in the range of 0.95-1.05.

[0026] The blocked isocyanate prepolymer of the present invention is water-dispersible and can be easily dispersed in water.

[0027] Isocyanate

[0028] The isocyanates used in the present invention may be any diisocyanates and / or polyisocyanates having aliphatically, cycloaliphatically, araliphatically and / or aromatically bonded isocyanate groups.

[0029] As used herein, the term "polyisocyanate" refers to isocyanates having an isocyanate group functionality greater than 2.

[0030] Suitable diisocyanates are any diisocyanates which are obtainable in any manner, for example by phosgenation in the liquid or gas phase or by a phosgene-free route, for example by thermal cleavage of carbamates.

[0031] Preferred diisocyanates are those with aliphatically, cycloaliphatically, araliphatically and / or aromatically bonded isocyanate groups, with a molecular weight in the range from 140 to 400, for example 1,4-butane diisocyanate, 1,5-pentane diisocyanate (PDI), 1,6-hexane diisocyanate (HDI), 2-methyl-1,5-pentane diisocyanate, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-hexane diisocyanate, 1,10-decane diisocyanate, 1,3- and 1,4-cyclohexane diisocyanate, 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane, 1-isocyanato-3-diisocyanato-2,2-dimethylpentane. , 3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 4,4'-dicyclohexylmethane diisocyanate, 1-isocyanato-1-methyl-4(3)isocyanatomethylcyclohexane, bis(isocyanatomethyl)norbornane, 1,3- and 1,4-bis(2-isocyanatoprop-2-yl)benzene (TMXDI), toluene diisocyanate (toluene 2,4- and 2,6-diisocyanate, TDI), 2,4'- and 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), norbornane diisocyanate (NBDI) or any mixture of these diisocyanates.

[0032] Preferred diisocyanates are diisocyanates having isocyanate groups of different reactivities, for example 2-methyl-1,5-pentane diisocyanate, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-hexane diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1-isocyanato-1-methyl-4(3)isocyanatomethylcyclohexane, toluene diisocyanate (toluene 2,4- and 2,6-diisocyanate, TDI), 2,4′-diphenylmethane diisocyanate (MDI) or any mixtures of these diisocyanates.

[0033] Particularly suitable are 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), toluene diisocyanate (toluene 2,4- and 2,6-diisocyanate, TDI), 2,4'-diphenylmethane diisocyanate (MDI) or any mixtures of these diisocyanates. Preference is given to toluene diisocyanate (toluene 2,4- and 2,6-diisocyanate, TDI), in particular the 2,4- and 2,6-isomers and technical mixtures of these two isomers.

[0034] Very particularly suitable aromatic diisocyanates are toluene 2,4-diisocyanate and technical mixtures thereof consisting of 70 to 90% of toluene 2,4-diisocyanate and 30 to 10% of toluene 2,6-diisocyanate.

[0035] Suitable isocyanates are also any polyisocyanates having a uretdione, isocyanurate, allophanate, biuret, iminooxadiazinedione and / or oxadiazinetriaone structure which are prepared by modification of simple aliphatic, cycloaliphatic, araliphatic and / or aromatic diisocyanates and / or polyisocyanates, for example those of the type mentioned above, such as, for example, J. Prakt. Chem. 336 (1994) 185-200, DE-A 1 670 666, DE-A 1 954 093, DE-A 2 414 413, DE-A 2 452 532, DE-A 2 641 380, DE-A 3 700 209, DE-A 3 900 053 and DE-A 3 928 503 or EP-A 0 336 205, EP-A 0 339 396 and EP-A 0 798 299, or any mixtures of these isocyanates.

[0036] Sealing agent

[0037] The blocking agents that can be used in the present invention include, for example, pyrazoles, alcohols, oximes, lactams, β-dicarbonyl compounds, and phenolic compounds.

[0038] As an example of pyrazole compounds, 3,5-dimethylpyrazole may be mentioned.

[0039] As examples of alcohol compounds, mention may be made of methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol and 2-butoxyethanol.

[0040] As examples of oxime compounds, butanone oxime, acetone oxime, formaldehyde oxime, acetaldehyde oxime and cyclohexanone oxime may be mentioned.

[0041] As examples of lactam compounds, mention may be made of ε-caprolactam, δ-valerolactam and γ-butyrolactam.

[0042] As examples of β-dicarbonyl compounds, mention may be made of dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, di-n-propyl malonate, diisopropyl malonate, di-n-butyl malonate and diisobutyl malonate.

[0043] As examples of phenolic compounds, phenol, nonylphenol, cardanol, bisphenol A and bisphenol F may be mentioned.

[0044] Preferably, the blocking agent is selected from phenolic compounds. More preferably, the blocking agent is selected from phenolic compounds having an OH value of 184 to 206 mgKOH / g, preferably 184 to 200 mgKOH / g, more preferably 186 to 192 mgKOH / g.

[0045] Still more preferably, the blocking agent is selected from one of nonylphenol and cardanol or a mixture thereof, and cardanol is further preferred.

[0046] Cardanol has the following structure:

[0047]

[0048] Where R represents C 15 H 31-n , where n=0, 2, 4 and 6.

[0049] Active hydrogen compounds containing hydrophilic groups

[0050] As used in the present application, an active hydrogen compound containing a hydrophilic group refers to an organic compound containing both a hydrophilic group and an active hydrogen group that can react with an isocyanate group in its molecular structure.

[0051] Preferably, the active hydrogen compound containing a hydrophilic group has an average active hydrogen functionality of at least 1, more preferably an average active hydrogen functionality of at least 2.

[0052] Preferably, the hydrophilic group is on the side chain, so that the water dispersibility of the obtained water-dispersible prepolymer system is better.

[0053] Preferably, the active hydrogen compound containing a hydrophilic group is selected from organic alcohol compounds, organic amine compounds, mercapto compounds and mixtures thereof.

[0054] The hydrophilic group may be an ionic hydrophilic group, a nonionic hydrophilic group or a mixture thereof.

[0055] As used herein, an ionic hydrophilic group is understood to have a dissociation equilibrium that may be determined by the pH value when interacting with an aqueous medium, and thus may carry a negative charge, a positive charge, or a substantially neutral functional group, such as -COOY, -SO 3 Y, -PO(OY) 2 (where Y=H、NH 4 + or metal cation), -NR 2 、-NR 3 + (wherein R = H, alkyl or aryl).

[0056] Preferably, the ionic hydrophilic group is -COOY, -SO 3 Y, -PO(OY) 2 , which may be present in the form of inner salts (zwitterions, betaines, ylides) or metal or ammonium salts.

[0057] As used herein, nonionic hydrophilic groups refer to groups or molecular segments that do not contain ionic hydrophilic groups but achieve affinity with water by forming intermolecular H bonds with water. For example, the nonionic hydrophilic group can be a polyalkylene oxide polyether group, including pure polyethylene oxide polyether or mixed polyethylene oxide polyether, and the ethylene oxide unit content is not less than 30 mol%, preferably not less than 40 mol%.

[0058] Advantageously, the active hydrogen compound having an ionic hydrophilic group is selected from dimethylolpropionic acid, dimethylolbutyric acid, dihydroxypropanesulfonic acid, dimercaptopropanesulfonic acid, sodium dihydroxypropanesulfonate, sodium dimercaptopropanesulfonate, sodium ethylenediamineethanesulfonate, sodium diaminobenzenesulfonate, hydroxypivalic acid, N-(2-aminoethyl)-β-alanine, 2-(2-aminoethylamino)ethanesulfonic acid, ethylenediaminepropanesulfonic acid or ethylenediaminebutanesulfonic acid, 1,2- or 1,3-propylenediamine-β-ethylsulfonic acid, lysine, 3,5-diaminobenzoic acid, and compounds containing structural units that can be converted into cationic groups (such as amine-based structural units) as hydrophilic structural components, such as N-methyldiethanolamine. In addition, cyclohexylaminoalkylsulfonic acid (such as cyclohexylaminopropanesulfonic acid, cyclohexylaminobutanesulfonic acid, etc.), N-(2-aminoethyl)-β-alanine, 2-(2-aminoethylamino)ethanesulfonic acid or hydrophilizing agents such as those in Example 1 of EP-A0916647 and their metal salts or ammonium salts can also be used. Preferably, the active hydrogen compound having an ionic hydrophilic group is selected from dimethylolpropionic acid, dimethylolbutanoic acid, dihydroxypropanesulfonic acid, dimercaptopropanesulfonic acid, sodium dihydroxypropanesulfonate, sodium dimercaptopropanesulfonate, sodium ethylenediamineethanesulfonate, sodium diaminobenzenesulfonate, cyclohexylaminoalkylsulfonic acid (such as cyclohexylaminopropanesulfonic acid, cyclohexylaminobutanesulfonic acid, etc.), N-(2-aminoethyl)-β-alanine and 2-(2-aminoethylamino)ethanesulfonic acid.

[0059] Preferably, the active hydrogen compound containing a nonionic hydrophilic group is selected from a monoalcohol containing a methyl-terminated polyethylene oxide polyether segment or a diol with a polyethylene oxide polyether segment on the side chain, wherein the polyethylene oxide polyether segment preferably has a number average molar mass of 300 to 4000 g / mol, preferably 300 to 2500 g / mol. Examples of the monoalcohol containing a methyl-terminated polyethylene oxide polyether segment are MPEG350, MPEG500, MPEG750 and MPEG 1000. Examples of the diol with a polyethylene oxide polyether segment on the side chain are YmerN90, YmerN1200 and YmerN180 from Perstorp.

[0060] Non-hydrophilic polyols

[0061] As used herein, non-hydrophilic polyols refer to those polyols that do not contain ionic hydrophilic groups or nonionic hydrophilic groups.

[0062] The non-hydrophilic polyols which can be used in the present invention may be, for example, polymer polyols known from polyurethane chemistry, such as polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols and / or polyacrylate polyols.

[0063] The non-hydrophilic polyols generally have an average functionality of 1.8 to 6.0, preferably 1.8 to 4.0, more preferably 1.9 to 2.2. The number average molecular weight of these polymer polyols (determined according to DIN 55672-I: 2016-03) is generally 1000 to 10000 g / mol, preferably 1000 to 8000 g / mol, more preferably 1000 to 4000 g / mol. Any mixture of these polymer polyols can also be used.

[0064] Preferably, the non-hydrophilic polyol is a polyether polyol or a mixture of polymer polyols comprising at least one polyether polyol.

[0065] More preferably, the non-hydrophilic polyol is selected from polyether polyols, provided that they meet the above descriptions regarding functionality and molecular weight.

[0066] Particular preference is given to using exclusively polyether polyols, in particular addition products of ethylene oxide and / or propylene oxide onto 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, diethylene glycol, glycerol, trimethylolpropane, triethanolamine, ethylenediamine and / or pentaerythritol, or polytetramethylene ether glycols in the abovementioned molecular weight range obtainable, for example, by polymerization of tetrahydrofuran according to Angew. Chem. 72, 927 (1960).

[0067] Very particular preference is given to addition products of ethylene oxide and / or propylene oxide with 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol and / or diethylene glycol, further particular preference is given to addition products of ethylene oxide and / or propylene oxide with 1,2-propylene glycol, wherein the polyether polyol contains 80% by weight of 1,2-propylene glycol, more preferably 90% by weight of 1,2-propylene glycol, most preferably 100% by weight of 1,2-propylene glycol.

[0068] Method for preparing blocked isocyanate prepolymer system

[0069] According to a second aspect of the present invention, there is provided a method for preparing the above-mentioned water-dispersible blocked isocyanate prepolymer system, characterized in that it comprises the following steps:

[0070] A. reacting an isocyanate having two or more isocyanate groups with a blocking agent to obtain a partially blocked isocyanate intermediate; and

[0071] B. reacting the partially blocked isocyanate intermediate obtained with an active hydrogen compound containing a hydrophilic group and a non-hydrophilic polyol until the content of free isocyanate groups relative to the total weight of the entire reaction system is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

[0072] The non-hydrophilic polyol compound and the active hydrogen compound containing a hydrophilic group can be reacted together with a partially blocked isocyanate intermediate to obtain a water-dispersible blocked isocyanate prepolymer system, or can be reacted with a partially blocked isocyanate intermediate separately, and the resulting products are mixed to obtain a water-dispersible blocked isocyanate prepolymer system.

[0073] In some embodiments, the method comprises the steps of:

[0074] reacting an isocyanate having two or more isocyanate groups with a blocking agent to obtain a partially blocked isocyanate intermediate;

[0075] reacting a portion of the partially blocked isocyanate intermediate with a non-hydrophilic polyol until the content of free isocyanate groups is less than 0.5 wt %, preferably less than 0.2 wt %, more preferably less than 0.1 wt %, to obtain a non-hydrophilic blocked isocyanate prepolymer,

[0076] reacting the remaining partially blocked isocyanate intermediate with an active hydrogen compound containing a hydrophilic group until the content of free isocyanate groups is less than 0.5 wt %, preferably less than 0.2 wt %, more preferably less than 0.1 wt %, to obtain a hydrophilic blocked isocyanate prepolymer, and

[0077] The non-hydrophilic blocked isocyanate prepolymer is mixed with the hydrophilic blocked isocyanate prepolymer to obtain a water-dispersible blocked isocyanate prepolymer system.

[0078] In some embodiments, the method comprises the steps of:

[0079] reacting an isocyanate having two or more isocyanate groups with a blocking agent to obtain a partially blocked isocyanate intermediate;

[0080] A partially blocked isocyanate intermediate, a non-hydrophilic polyol and an active hydrogen compound containing a hydrophilic group are reacted together until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

[0081] According to a third aspect of the present invention, there is provided a method for preparing the above-mentioned water-dispersible blocked isocyanate prepolymer system, characterized in that it comprises the following steps:

[0082] An isocyanate having two or more isocyanate groups is reacted with a non-hydrophilic polyol compound and an active hydrogen compound containing a hydrophilic group and then reacted with a blocking agent until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, and more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

[0083] The non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group can react with isocyanate together or successively to obtain a mixture of a non-hydrophilic isocyanate prepolymer and a hydrophilic isocyanate prepolymer, or react with isocyanate separately to obtain separate non-hydrophilic isocyanate prepolymer and hydrophilic isocyanate prepolymer.

[0084] The non-hydrophilic isocyanate prepolymer and the hydrophilic isocyanate prepolymer can be reacted with a blocking agent together to obtain a water-dispersible blocked isocyanate prepolymer system, or can be reacted with a blocking agent separately, and the resulting products are mixed to obtain a water-dispersible blocked isocyanate prepolymer system.

[0085] In some embodiments, the method comprises the steps of:

[0086] reacting an isocyanate having two or more isocyanate groups with a non-hydrophilic polyol to obtain a non-hydrophilic isocyanate prepolymer,

[0087] An isocyanate having two or more isocyanate groups is reacted with an active hydrogen compound containing a hydrophilic group to obtain a hydrophilic isocyanate prepolymer,

[0088] The non-hydrophilic isocyanate prepolymer and the hydrophilic isocyanate prepolymer are reacted with a blocking agent respectively until the content of free isocyanate groups is less than 0.5 wt %, preferably less than 0.2 wt %, more preferably less than 0.1 wt %, to obtain a non-hydrophilic blocked isocyanate prepolymer and a hydrophilic blocked isocyanate prepolymer, and

[0089] A non-hydrophilic blocked isocyanate prepolymer and a hydrophilic blocked isocyanate prepolymer are mixed to obtain a water-dispersible blocked isocyanate prepolymer system.

[0090] In some embodiments, the method comprises the steps of:

[0091] reacting an isocyanate having two or more isocyanate groups with a non-hydrophilic polyol to obtain a non-hydrophilic isocyanate prepolymer,

[0092] reacting an isocyanate having two or more isocyanate groups with an active hydrogen compound containing a hydrophilic group to obtain a hydrophilic isocyanate prepolymer, and

[0093] The non-hydrophilic isocyanate prepolymer, the hydrophilic isocyanate prepolymer and the blocking agent are reacted together until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

[0094] In some embodiments, the method comprises the steps of:

[0095] reacting a non-hydrophilic polyol, an active hydrogen compound containing a hydrophilic group, and an isocyanate having two or more isocyanate groups to obtain a mixture of a non-hydrophilic isocyanate prepolymer and a hydrophilic isocyanate prepolymer, and

[0096] The mixture of the non-hydrophilic isocyanate prepolymer and the hydrophilic isocyanate prepolymer is reacted with a blocking agent until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer.

[0097] In some embodiments, the method comprises the steps of:

[0098] The non-hydrophilic polyol compound and the active hydrogen compound containing a hydrophilic group are reacted successively with an isocyanate having two or more isocyanate groups to obtain a mixture of a non-hydrophilic isocyanate prepolymer and a hydrophilic isocyanate prepolymer, and

[0099] The mixture of the non-hydrophilic isocyanate prepolymer and the hydrophilic isocyanate prepolymer is reacted with a blocking agent until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer.

[0100] In the method of the present invention, the isocyanate, blocking agent, non-hydrophilic polyol and active hydrogen compound containing a hydrophilic group are as defined above for the first aspect of the present invention.

[0101] In the method of the present invention, as described in relation to the first aspect of the present invention, the molar ratio of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group is in the range of 0.1-25.0, the molar ratio of all groups reactive with isocyanate of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group to all isocyanate groups of isocyanate is in the range of 0.3-0.8, and the molar ratio of all groups reactive with isocyanate of the non-hydrophilic polyol, the active hydrogen compound containing a hydrophilic group and the blocking agent to all isocyanate groups of isocyanate is in the range of 0.90-1.10.

[0102] The molar ratio of the non-hydrophilic polyhydroxy compound to the active hydrogen compound containing a hydrophilic group is preferably in the range of 0.1-23.0, more preferably 0.2-15.0.

[0103] The total isocyanate groups of the isocyanate refer to the total isocyanate groups contained before the isocyanate having two or more isocyanate groups reacts with the non-hydrophilic polyol or the active hydrogen compound containing a hydrophilic group or the blocking agent.

[0104] The molar ratio of all groups reactive with isocyanate of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group to all isocyanate groups of isocyanate is preferably in the range of 0.40-0.60, more preferably in the range of 0.45-0.55.

[0105] The molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol, the active hydrogen compound containing a hydrophilic group and the blocking agent to all the isocyanate groups of the isocyanate is in the range of 0.95-1.05.

[0106] The blocking reaction and the urethane reaction in the present application may be carried out at a temperature of 0 to 250°C, preferably 20 to 140°C, more preferably 40 to 100°C.

[0107] The reaction may also be carried out by adding a suitable reaction catalyst to accelerate the reaction and shorten the reaction time. The catalyst may be a catalyst known in polyurethane chemistry, for example, an organometallic compound, such as tin (II) octoate, dibutyltin (II) diacetate, dibutyltin (II) laurate, 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, a tertiary amine such as triethylamine, diazabicyclooctane, 1,8-diazabicyclo[5.4.0]undec-7-ene, and a mixture containing two or more of the above compounds.

[0108] The suitable amount of catalyst is 0.01% to 0.5%, preferably 0.02% to 0.3%, more preferably 0.02% to 0.2%.

[0109] The blocking reaction and / or the urethane reaction can also be carried out by using suitable solvents which are inert toward the reactive groups of the starting components.

[0110] Examples of suitable solvents include, but are not limited to, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether or monoethyl ether acetate, 1-methoxy-2-propyl acetate (MPA), 3-methoxy-n-butyl acetate, acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone, toluene, xylene, chlorobenzene, white spirit, more highly substituted aromatic hydrocarbons, such as those sold under the names solvent naphtha, Solvesso, Isopar, Nappar (ExxonMobil Chemical Central Europe, Cologne, Germany), and Shellsol (Shell Deutschland Oil GmbH, Hamburg, Germany), and solvents such as propylene glycol diacetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl ether and butyl ether acetate, N-methylpyrrolidone and N-methylcaprolactam, or any mixtures of these solvents.

[0111] Blocked isocyanate prepolymer aqueous dispersion

[0112] According to a fourth aspect of the present invention, there is provided an aqueous dispersion of a blocked isocyanate prepolymer prepared from the above-mentioned water-dispersible blocked isocyanate prepolymer system.

[0113] The blocked isocyanate prepolymer water dispersible is prepared by dispersing the blocked isocyanate prepolymer system of the present invention with water. A suitable dispersion method may be to gradually add distilled water under high-speed stirring of the blocked isocyanate prepolymer system, or to gradually add the blocked isocyanate prepolymer system under high-speed stirring of distilled water.

[0114] The dispersion process may also be carried out at 25-60°C, preferably at 30-50°C.

[0115] Prior to dispersion, the blocked isocyanate prepolymer system may also be diluted with a suitable solvent to reduce the viscosity and thus facilitate dispersion.

[0116] Examples of suitable solvents are the customary water-miscible solvents known per se, for example acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone, tetrahydrofuran, dimethyl ether, methanol, ethanol, ethyl acetate, ethylene glycol monomethyl ether or monoethyl ether acetate, 1-methoxy-2-propyl acetate (MPA), 3-methoxy-n-butyl acetate, and also solvents such as propylene glycol diacetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl ether and butyl ether acetate, N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide and N-methylcaprolactam, or any mixtures of these solvents. A solvent with a low boiling point and miscible with water is preferred, such as acetone, acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone, tetrahydrofuran, dimethyl ether, methanol, ethanol, ethyl acetate, ethylene glycol monomethyl ether or monoethyl ether acetate, 1-methoxy-2-propyl acetate (MPA), and particularly preferred are acetone, tetrahydrofuran, dimethyl ether, methanol, ethanol, ethyl acetate, ethylene glycol monomethyl ether or monoethyl ether acetate, 1-methoxy-2-propyl acetate (MPA). If a solvent is used to assist dispersion, the method for preparing the blocked isocyanate prepolymer aqueous dispersion may further include a step of removing the solvent, such as heating evaporation, vacuum extraction, or vacuum extraction under heating.

[0117] Use of water-dispersible blocked isocyanate prepolymer system and products containing same

[0118] According to a fifth aspect of the present invention, there is provided the use of the above-mentioned water-dispersible blocked isocyanate prepolymer system or blocked isocyanate prepolymer aqueous dispersion for preparing polyurethane plastics, adhesives, sealing materials, potting materials, fiber wetting agents or coatings.

[0119] The water-dispersible blocked isocyanate prepolymer system or blocked isocyanate prepolymer aqueous dispersion of the present invention can be processed into various products, such as polyurethane plastics, adhesives, sealing materials, potting materials, fiber sizing agents or coatings, and its application fields include but are not limited to water conservancy projects, shipbuilding (such as ballast tanks), transportation vehicles, green energy, pipes and floors, etc.

[0120] Therefore, according to the sixth aspect of the present invention, a polyurethane plastic, adhesive, sealing material, potting material, fiber sizing agent or coating containing the above-mentioned water-dispersible blocked isocyanate prepolymer system or blocked isocyanate prepolymer aqueous dispersion is provided.

[0121] In some embodiments, a blocked isocyanate prepolymer-epoxy reactive aqueous dispersion system is provided, which comprises the above-mentioned water-dispersible blocked isocyanate prepolymer system or blocked isocyanate prepolymer aqueous dispersion, polyamine and epoxy aqueous dispersion.

[0122] Preferably, the polyamines are polyamines having at least two primary and optionally also secondary amino groups per molecule and preferably having an average molecular weight of 60 to 500. Examples which may be mentioned include ethylenediamine, 1,2- and 1,3-diaminopropane, 1,4-diaminobutane, 2,2,4- and / or 2,4,4-trimethylhexanediamine, isomeric xylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, 1,4-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 1,3-diaminocyclopentane, 4,4′-diaminodicyclohexylsulfone, 4,4′-diaminodicyclohexylpropane, 1,3-diaminodicyclopentane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 1,4-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane, 4,4′-diaminodicyclohexylpropane. 2,2,3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3-aminomethyl-3,3,5-trimethylcyclohexylamine (isophoronediamine), 3(4)-aminomethyl-1-methylcyclohexylamine, technical grade bisaminomethyltricyclodecane, octahydro-4,7-methyleneindene-1,5-dimethylamine, and phenol-formaldehyde amine curing agents synthesized from phenol-formaldehyde resins and amine compounds, or polyamines having secondary amino groups in addition to at least two primary amino groups, such as diethylenetriamine or triethylenetetramine.

[0123] Particularly preferred are polyamines, especially diamines, within the abovementioned molecular weight range which contain one or more cycloaliphatic rings. Examples include, for example, 1,4-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-diaminocyclopentane, 4,4'-diaminodicyclohexylsulfone, 4,4'-diaminodicyclohexylpropane-1,3, 4,4'-diaminodicyclohexylpropane-2,2, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3-aminomethyl-3,3,5-trimethylcyclohexylamine (isophoronediamine), 3- and 4-aminomethyl-1-methylcyclohexylamine or technical-grade bisaminomethyltricyclodecane.

[0124] It is also possible to use, as a component of the amine component, an adduct prepared by reacting an excess of the polyamine described above with an epoxy resin of the type described below.

[0125] The polyamines may also comprise polyether polyols prepared by reacting polyether polyols with ammonia and available, for example, from Huntsman Polyetheramines sold under the trade name ANTIQUALINE®.

[0126] The epoxy resin aqueous dispersion is an aqueous dispersion of at least one epoxy resin having a functionality greater than 0.8 epoxy groups / molecule, prepared based on an external emulsifier or an internal emulsifier. The epoxy resin can be a saturated or unsaturated, linear or branched, aliphatic, cycloaliphatic, aromatic or heterocyclic epoxy resin.

[0127] The external emulsifier refers to compounds that can be added to the epoxy resin system by physical addition to help disperse the epoxy resin. Examples include but are not limited to nonylphenol ethoxylate, alkylphenol-initiated poly(ethylene oxide)ethanol, alkylphenol-initiated poly(propylene oxide)poly(ethylene oxide)ethanol, and a block copolymer comprising an internal poly(propylene oxide) block and two external poly(ethylene oxide)ethanol blocks, alkyl polyoxyethylene ether sodium sulfate, sodium dodecyl sulfate and sodium dodecylbenzene sulfonate, or a combination of two or more thereof.

[0128] The internal emulsifier refers to the groups contained in the epoxy resin structure itself that can help emulsify and disperse. The groups can be ionic hydrophilic groups, nonionic hydrophilic groups or mixtures thereof. Ionic hydrophilic groups can be understood as functional groups that can produce a dissociation equilibrium that may be determined by the pH value when interacting with aqueous media, and can therefore carry negative charges, positive charges or neutral functional groups, such as -COOY, -SO 3 Y, -PO(OY) 2 (where Y=H、NH4 + or metal cation), -NR 2 、-NR 3 + (wherein R=H, alkyl or aryl). Nonionic hydrophilic groups refer to those groups or molecular segments that do not contain ionic hydrophilic groups but achieve affinity with water by forming intermolecular H bonds with water. For example, the nonionic hydrophilic group can be a polyoxyalkylene polyether, including pure polyethylene oxide polyether or mixed polyethylene oxide polyether, and the ethylene oxide unit content is not less than 30 mol%, preferably not less than 40 mol%.

[0129] Examples of preferred aqueous epoxy resin dispersions are epoxy resins based on bisphenol A or bisphenol F, having a molecular weight of 350-10,000, dispersed in water in non-ionic form with or without glycol ether cosolvents.

[0130] Commercially available examples of aqueous epoxy resin dispersions include, for example, bisphenol A resins, such as EPI-REZ Resin 3510-W-60 (emulsion), EPI-REZ Resin 3520-WY-55, EPI-REZ Resin 3521-WY-53, EPI-REZ Resin 3523-WH-53, EPI-REZ Resin 6520-WH-53, EPI-REZ Resin 3540-WY-55, etc., all of which are available from Hexion Specialty Chemicals, Inc.

[0131] The blocked isocyanate prepolymer-epoxy reactive water dispersion system can be cured at room temperature and can be used as a coating. The coating made from these reactive systems has excellent impact resistance and shock resistance, and is flexible and elastic.

[0132] The descriptions of various features in this application can be combined with each other if they are not contradictory, and all fall within the scope of protection requested by this application.

[0133] The term "and / or" used in the present application means one or all of the mentioned elements.

[0134] All percentages in this application are by weight unless otherwise stated.

[0135] The analytical measurements described in this application were all performed at 23°C unless otherwise stated.

[0136] The weight average molecular weight and number average molecular weight of the isocyanate described in the present application (including fully blocked isocyanate) are measured according to DIN 55672-1:2016-03 by TOSOH HLC-8320EcoSEC type gel chromatograph using polystyrene standards, high-performance general chromatographic columns 4-fold column set (TSKgel G2000HXL, TSKgel G2500HXL, TSKgel G3000HXL and TSKgel G4000HXL, chromatographic column filler is styrene-divinylbenzene copolymer) and differential refractive index detector, the eluent is tetrahydrofuran, the flow rate is 1.0 ml / min, the pressure is 6.4 MPa, and the column temperature is 40 ° C.

[0137] The isocyanate group (NCO) content is determined by titration according to DIN-EN ISO 11909: 2007-05, and the determined data include the content of free and potentially free NCO groups.

[0138] The latent free NCO groups can become free NCO groups under conditions such as heating.

[0139] The average particle size of the dispersion was measured by laser correlation spectroscopy at 23° C. according to ISO 13321-1996 after diluting the sample with deionized water (instrument: Malvern Zetasizer Nano ZS 3600, Malvern Inst. Limited).

[0140] The solid content is determined by heating the weighed sample to 120° C. The solid content is calculated by reweighing the sample at constant weight.

[0141] Viscosity measurements were performed using a HAAKE VT550 viscometer according to DIN EN ISO 3219:1994-10.

[0142] Impact resistance is tested according to ASTM 2794-1993. A 120 μm wet film is applied on a tinplate substrate. After sufficient curing and maintenance, the film is subjected to a reverse impact test with the film facing downward. The test data is represented by the maximum drop height (cm) that the film can withstand without cracking.

[0143] The flexibility test is carried out according to ISO 1519-2011. A 120 μm wet film is applied on a tinplate substrate. After sufficient curing and maintenance, a bending test is performed using a flexibility tester. The test data is represented by the minimum bending diameter (mm) that the paint film can withstand without cracking.

[0144] The pendulum hardness test method is carried out according to DIN EN ISO 1522-2007. After a 120 μm wet film is applied to a glass plate substrate and fully cured and maintained, the pendulum swing time (in seconds) is measured on a pendulum tester. The pendulum time in the pendulum test result can represent the hardness of the paint film. The longer the pendulum time, the higher the hardness of the paint film. Other tests not described are carried out according to the commonly used methods in the art.

[0145] The terms “comprising” and “including” described in the present application encompass a case where the component is further comprised or includes other elements not explicitly mentioned as well as a case where the component is composed of the mentioned elements.

[0146] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention belongs. When the definition of a term in this specification conflicts with the meaning commonly understood by those skilled in the art to which the invention belongs, the definition described in this article shall prevail.

[0147] Unless otherwise indicated, all numerical values ​​expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that can vary depending upon the desired properties desired to be obtained.

[0148] Example

[0149] The following will further illustrate the concept, specific structure and technical effects of the present invention in combination with the embodiments, so that those skilled in the art can fully understand the purpose, characteristics and effects of the present invention. It is not difficult for those skilled in the art to understand that the embodiments herein are only for illustrative purposes, and the scope of the present invention is not limited thereto.

[0150] The main raw materials used in the following examples are as follows:

[0151] T 80: contains about 80 wt% 2,4-toluene diisocyanate and 20 wt% 2,6-toluene diisocyanate, from Covestro Polymers (China) Co., Ltd.

[0152] NX 2026: Cardanol, from Cardolite Specialty Chemicals Europe NV.

[0153] EG 1000: polyether diol, OH value 110-114 mg KOH / g, from Shandong Bluestar Dongda Co., Ltd.

[0154] DP 1000E: polyether diol, OH value 110-114 mg KOH / g, from Guodu Chemical Co., Ltd.

[0155] DP 2000E: polyether diol, OH value 54-58 mg KOH / g, from Guodu Chemical Co., Ltd.

[0156] DP 2000: polyether diol, OH value 54-58 mg KOH / g, from Guodu Chemical Co., Ltd.

[0157] YmerN120: polyether diol, OH value 100-120 mgKOH / g, from Perstorp Ltd.

[0158] MPEG 500: methoxy polyethylene glycol, OH value of about 112 mgKOH / g, purchased from Ineos NV.

[0159] Sumiphen 1468: Polyether diol, OH value about 28mgKOH / g, from Covestro Japan.

[0160] PEG 1000: polyether glycol, OH value 110-114 mg KOH / g, from Shandong Bluestar Dongda Co., Ltd.

[0161] Tin(II) octanoate: from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0162] 2,2-Dihydroxymethylbutyric acid: from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0163] Triethylamine: from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0164] EPIKOTE TMResin 6529-WH-57A: Non-ionic aqueous dispersion of solid bisphenol A epoxy resin, epoxy equivalent 480-600 g / mol (based on solid content), solid content 55%-59%, from Hexion Chemical Co., Ltd.

[0165] EPIKURE TM 6870-W-53: A non-ionic aqueous dispersion modified by amine adduct, with an amine value of 235-265 mgKOH / g and a solid content of 51%-54%, from Hexion Chemical Co., Ltd.

[0166] Example 1: Preparation of Cardanol-blocked Toluene Diisocyanate

[0167] 420.0 g of toluene diisocyanate ( T 80, containing about 80 wt% of 2,4-toluene diisocyanate and 20 wt% of 2,6-toluene diisocyanate) was added to the reaction bottle, heated to 90°C with stirring, 766.8 g of cardanol (NX 2026) was slowly added dropwise to the reaction solution through a dropping funnel over about 4 hours, and after the addition was completed, the reaction was continued to be stirred at 90°C until the NCO content was 8.6%, and cooled to obtain cardanol-blocked toluene diisocyanate.

[0168] Example 2: Non-hydrophilic blocked isocyanate prepolymer 1

[0169] 600.0 g of polyether diol (Sumiphen 1468, OH value of 28 mgKOH / g) was placed in a reaction bottle, heated to 60°C under stirring, 1.6 g of tin (II) octoate catalyst was added, and then 150.0 g of cardanol-blocked toluene diisocyanate obtained in Example 1 was slowly added dropwise to the reaction bottle through a dropping funnel. After the addition, the reaction was continued until NCO% < 0.3%. Then 2.1 g of benzoyl chloride was added and stirred for another 30 minutes. After cooling, a non-hydrophilic blocked isocyanate prepolymer was obtained, and the measured viscosity was 12860 mPas. An appropriate amount of acetone was added to dilute the solution to 80% by weight to obtain a non-hydrophilic blocked isocyanate prepolymer 1.

[0170] Example 3: Non-hydrophilic blocked isocyanate prepolymer 2

[0171] 30.0 g of isophorone diisocyanate (IPDI) was placed in a reaction bottle, heated to 65°C under stirring, 0.1 g of catalyst tin (II) octoate was added, 48.6 g of cardanol was slowly added through a dropping funnel and reacted for about 1 hour, then 135.2 g of polyether diol DP2000E was added and the reaction continued until the infrared display NCO absorption peak basically disappeared. Then 0.2 g of benzoyl chloride was added and stirred for another 30 minutes, and after cooling, a non-hydrophilic blocked isocyanate prepolymer 2 was obtained, and the measured viscosity was 8830 mPas.

[0172] Example 4: Non-hydrophilic blocked isocyanate prepolymer 3

[0173] 31.0 g of toluene diisocyanate was placed in a reaction bottle, heated to 80°C under stirring, 0.2 g of catalyst tin (II) octoate was added, 89.0 g of polyether diol DP1000 was slowly added through a dropping funnel to react for about 2 hours, then cooled to 65°C, 59.4 g of cardanol was added to continue the reaction until the infrared display NCO absorption peak basically disappeared. Then 0.2 g of benzoyl chloride was added and stirred for another 30 minutes. After cooling, a water-dispersible blocked isocyanate prepolymer 3 was obtained, and the measured viscosity was 70880 mPas.

[0174] Example 5: Hydrophilic blocked isocyanate prepolymer 4

[0175] 375.0 g of polyether diol (YmerN120, OH value of 100-120 mgKOH / g) was placed in a reaction bottle and heated to 60°C with stirring. Then 360.0 g of the cardanol-blocked toluene diisocyanate obtained in Example 1 was slowly added dropwise to the reaction bottle through a dropping funnel. After the addition, the reaction was continued until NCO% <0.5%. About 184 g of acetone was added, and after stirring and cooling, a hydrophilic blocked isocyanate prepolymer 4 was obtained. The measured viscosity was 865 mPas.

[0176] Example 6: Hydrophilic blocked isocyanate prepolymer 5

[0177] 89.0 g of the cardanol-blocked toluene diisocyanate obtained in Example 1 was placed in a reaction bottle and heated to 50° C. with stirring. Then, 13.8 g of 2,2-dihydroxymethylbutyric acid and 30 g of acetone were slowly added. After the addition, the reaction was continued until NCO% < 0.5%. About 7.2 g of triethylamine was added and the reaction was continued with stirring for one hour. After cooling, a hydrophilic blocked isocyanate prepolymer 5 was obtained.

[0178] Example 7: Hydrophilic blocked isocyanate prepolymer 6

[0179] 100.0 g of the cardanol-blocked toluene diisocyanate obtained in Example 1 was placed in a reaction bottle and heated to 60° C. with stirring. Then, 96.1 g of MPEG 500 was slowly added dropwise through a dropping funnel. After the addition, the reaction was continued until NCO% <0.5%. After cooling, a hydrophilic blocked isocyanate prepolymer 6 was obtained, and the measured viscosity was 2030 mPas.

[0180] Example 8: Preparation of blocked isocyanate prepolymer aqueous dispersion 1

[0181] 20 g of blocked isocyanate prepolymer 1 and 80 g of hydrophilic blocked isocyanate prepolymer 4 were mixed evenly, and about 120 g of deionized water was slowly added under stirring to form a white emulsion. The emulsion was stirred and heated to 40° C., and acetone was removed under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 1.

[0182] Example 9: Preparation of blocked isocyanate prepolymer aqueous dispersion 2

[0183] 30 g of blocked isocyanate prepolymer 1 and 70 g of hydrophilic blocked isocyanate prepolymer 4 were mixed evenly, and about 120 g of deionized water was slowly added under stirring to form a white emulsion. The emulsion was stirred and heated to 40° C., and acetone was removed under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 2.

[0184] Example 10: Preparation of blocked isocyanate prepolymer aqueous dispersion 3

[0185] 70 g of blocked isocyanate prepolymer 1 and 30 g of hydrophilic blocked isocyanate prepolymer 4 were mixed evenly, and about 120 g of deionized water was slowly added under stirring to form a white emulsion. The emulsion was stirred and heated to 40° C., and acetone was removed under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 3.

[0186] Example 11: Preparation of blocked isocyanate prepolymer aqueous dispersion 4

[0187] 90 g of blocked isocyanate prepolymer 1 and 10 g of hydrophilic blocked isocyanate prepolymer 5 were mixed evenly, and about 120 g of deionized water was slowly added under stirring to form a white emulsion. The emulsion was stirred and heated to 40° C., and acetone was removed under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 4.

[0188] Example 12: Preparation of blocked isocyanate prepolymer aqueous dispersion 5

[0189] 95 g of blocked isocyanate prepolymer 2 and 5 g of hydrophilic blocked isocyanate prepolymer 4 were mixed evenly, and about 75 g of deionized water was slowly added under stirring to form a white emulsion. The emulsion was stirred and heated to 40° C., and acetone was removed under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 5.

[0190] Example 13: Preparation of blocked isocyanate prepolymer aqueous dispersion 6

[0191] 90 g of blocked isocyanate prepolymer 2 and 10 g of hydrophilic blocked isocyanate prepolymer 6 were mixed evenly, and about 300 g of deionized water was slowly added under stirring to form a white emulsion, thereby obtaining the preparation of blocked isocyanate prepolymer aqueous dispersion 6.

[0192] Example 14: Preparation of blocked isocyanate prepolymer aqueous dispersion 7

[0193] 95 g of blocked isocyanate prepolymer 3 and 5 g of hydrophilic blocked isocyanate prepolymer 4 were mixed evenly, and about 149 g of deionized water was slowly added under stirring to form a white emulsion. The emulsion was stirred and heated to 40° C., and acetone was removed under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 7.

[0194] Table 1 summarizes the molar ratio of the non-hydrophilic polyhydroxy compound to the active hydrogen compound containing a hydrophilic group in the aqueous dispersion obtained above, as well as the particle size and solid content thereof.

[0195] Example 15: Blocked isocyanate prepolymer 7

[0196] 18.3 g of toluene diisocyanate was placed in a reaction bottle, heated to 80°C under stirring, 52.6 g of polyether diol DP1000E was slowly added dropwise to the reaction bottle for reaction, cooled to 50°C after about 2 hours, 37.5 g of acetone was added to dilute the reaction solution, 0.3 g of catalyst tin (II) octoate was added, 26.8 g of YmerN120 (DP1000E / YmerN120 molar ratio was about 2.0) was added dropwise under stirring, and the reaction continued for 2 hours, and then 17.4 g of cardanol was slowly added dropwise through a dropping funnel to continue the reaction until the infrared display NCO absorption peak basically disappeared. Then 0.5 g of benzoyl chloride was added and stirred for another 30 minutes, and after cooling, a water-dispersible blocked isocyanate prepolymer 7 was obtained. The solid content was about 78% and the viscosity was about 2725 mPas.

[0197] Take 100 g of the blocked isocyanate prepolymer 7, add 95 g of water under high-speed stirring, and heat the milky white filtrate after filtration to 40° C. under stirring. Remove acetone under reduced pressure to obtain a blocked isocyanate prepolymer aqueous dispersion 8 with a solid content of 43% and a particle size of 146 nm.

[0198] Table 1

[0199]

[0200]

[0201] Example 16

[0202] 57.14 Water-based epoxy emulsion EPIKOTE TM Add 17.14g of blocked isocyanate prepolymer aqueous body 3 to Resin 6529-WH-57A, stir until a uniform mixture is formed, and then add 25.71g of EPIKURE TM 6870-W-53 water-based epoxy resin curing agent was stirred and mixed again, and the mixed emulsion was molded on a glass plate and tinplate, baked at 60°C for half an hour, and cured at room temperature for 7 days to obtain a paint film with the mechanical characteristics shown in Table 2:

[0203] Comparative Example 17

[0204] Add 68.97g of water-based epoxy emulsion EPIKOTE TM Add 31.03g EPIKURE to Resin 6529-WH-57A TM 6870-W-53 water-based epoxy resin curing agent, after stirring until a uniform mixture is formed, molds are made on glass plates and tinplate, baked at 60°C for half an hour, and cured at room temperature for 7 days to obtain a paint film with the mechanical characteristics of Table 2:

[0205] Table 2

[0206] Pendulum hardness Impact resistance Flexibility Example 16 166s >100cm <1mm Comparative Example 17 218s <5cm >15mm

[0207] The above only describes exemplary embodiments or embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention are included in the scope of the claims of this application.

Claims

1. A water-dispersible blocked isocyanate prepolymer system, It is characterized in that It is prepared by reacting an isocyanate having two or more isocyanate groups, a blocking agent, a non-hydrophilic polyol and an active hydrogen compound containing a hydrophilic group. The molar ratio of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group is in the range of 0.1-25.0, the molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group to all the isocyanate groups of isocyanate is in the range of 0.30-0.80, and the molar ratio of all the groups reactive with isocyanate of the non-hydrophilic polyol, the active hydrogen compound containing a hydrophilic group and the blocking agent to all the isocyanate groups of isocyanate is in the range of 0.90-1.

10.

2. The blocked isocyanate prepolymer system according to claim 1, It is characterized in that The molar ratio of the non-hydrophilic polyhydroxy compound to the active hydrogen compound containing a hydrophilic group is in the range of 0.1-23.0, more preferably 0.2-15.

0.

3. The blocked isocyanate prepolymer system according to claim 1 or 2, It is characterized in that The molar ratio of all groups reactive with isocyanate of the non-hydrophilic polyol and the active hydrogen compound containing a hydrophilic group to all isocyanate groups of isocyanate is in the range of 0.40-0.60, preferably in the range of 0.45-0.

55.

4. The blocked isocyanate prepolymer system according to any one of claims 1 to 3, It is characterized in that The isocyanate is selected from diisocyanates and / or polyisocyanates having aliphatically, cycloaliphatically, araliphatically and / or aromatically bonded isocyanate groups, preferably the isocyanate is selected from diisocyanates having aliphatically, cycloaliphatically, araliphatically and / or aromatically bonded isocyanate groups.

5. The blocked isocyanate prepolymer system according to any one of claims 1 to 4, It is characterized in that The blocking agent is selected from pyrazoles, alcohols, oximes, lactams, β-dicarbonyl compounds and phenolic compounds. Preferably, the blocking agent is selected from phenolic compounds; more preferably, it is selected from phenolic compounds with an OH value of 184 to 206KOH / g, preferably 184 to 200KOH / g, more preferably 186 to 192KOH / g; more preferably, it is selected from phenol, nonylphenol, cardanol, bisphenol A and bisphenol F; and even more preferably, it is selected from nonylphenol and cardanol.

6. The blocked isocyanate prepolymer system according to any one of claims 1 to 5, It is characterized in that The non-hydrophilic polyhydroxy compound is selected from polymer polyols having an average functionality of 1.8 to 6.0, preferably 1.8 to 4.0, more preferably 1.9 to 2.2 and a number average molecular weight of 1000 to 10000 g / mol, preferably 1000 to 8000 g / mol, more preferably 1000 to 4000 g / mol; preferably, the non-hydrophilic polyhydroxy compound is selected from addition products of ethylene oxide and / or propylene oxide under polymerization initiated by 1,2-propylene glycol, 1,3-propylene glycol, glycerol, trimethylolpropane, ethylenediamine and / or pentaerythritol, and more preferably, the non-hydrophilic polyhydroxy compound is selected from addition products of ethylene oxide and / or propylene oxide under polymerization initiated by 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol and / or diethylene glycol.

7. The blocked isocyanate prepolymer system according to any one of claims 1 to 6, It is characterized in that The active hydrogen compound containing a hydrophilic group has an average active hydrogen functionality of at least 1, preferably an average active hydrogen functionality of at least 2.

8. The blocked isocyanate prepolymer system according to any one of claims 1 to 7, It is characterized in that The active hydrogen compound containing a hydrophilic group is selected from organic alcohol compounds, organic amine compounds, thiol compounds and mixtures thereof. Preferably, the hydrophilic group of the active hydrogen compound containing a hydrophilic group is on the side chain. More preferably, the active hydrogen compound containing a hydrophilic group is selected from dimethylolpropionic acid, dimethylolbutanoic acid, dihydroxypropanesulfonic acid, dimercaptopropanesulfonic acid, sodium dihydroxypropanesulfonate, sodium dimercaptopropanesulfonate, sodium ethylenediamineethanesulfonate, sodium diaminobenzenesulfonate, cyclohexylaminoalkylsulfonic acid (such as cyclohexylaminopropanesulfonic acid, cyclohexylaminobutanesulfonic acid, etc.), N-(2-aminoethyl)-β-alanine, 2-(2-aminoethylamino)ethanesulfonic acid, monoalcohols containing methyl-terminated polyethylene oxide polyether segments, and diols with polyethylene oxide polyether segments on the side chains.

9. A method for preparing a blocked isocyanate prepolymer system according to any one of claims 1 to 8, It is characterized in that It includes the following steps: A. reacting the isocyanate having two or more isocyanate groups with the blocking agent to obtain a partially blocked isocyanate intermediate; and B. reacting the partially blocked isocyanate intermediate obtained with an active hydrogen compound containing a hydrophilic group and a non-hydrophilic polyol until the content of free isocyanate groups relative to the total weight of the entire reaction system is less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

10. A method for preparing a blocked isocyanate prepolymer system according to any one of claims 1 to 8, It is characterized in that It includes the following steps: An isocyanate having two or more isocyanate groups is reacted with a non-hydrophilic polyol compound and an active hydrogen compound containing a hydrophilic group and then reacted with a blocking agent until the content of free isocyanate groups is less than 0.5% by weight, preferably less than 0.2% by weight, and more preferably less than 0.1% by weight, to obtain a water-dispersible blocked isocyanate prepolymer system.

11. A blocked isocyanate prepolymer aqueous dispersion prepared from the blocked isocyanate prepolymer system according to any one of claims 1 to 8.

12. Use of the blocked isocyanate prepolymer system according to any one of claims 1 to 8 or the blocked isocyanate prepolymer aqueous dispersion according to claim 11 for preparing polyurethane plastics, adhesives, sealing materials, potting materials, fiber sizings or coatings.

13. A polyurethane, adhesive, sealing material, potting material, fiber sizing or coating comprising the blocked isocyanate prepolymer system according to any one of claims 1 to 8 or the blocked isocyanate prepolymer aqueous dispersion according to claim 11.

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