Background technology
Aqueous epoxy coating is a kind of Green Product, compares with solvent based coating, has characteristics such as less smell, safe in utilization and water cleaning, is widely used in decorating, field such as anticorrosion and extraordinary industrial coating.
At present, existing more to the research of the double-component aqueous epoxy coating product of normal temperature cured type, on market, have the various fields that are applied to, as: high performance trade sales coating, industrial premises hard floor paint, auto repair priming paint and industrial maintenance finish paint etc.Heating helps the effusion fully of moisture in the coating in the aqueous epoxy coating solidification process, thereby obtains high-quality coating.Fierce crosslinking reaction be owing to can take place down at high temperature (100-170 ℃) in the double-component aqueous epoxy coating of normal temperature cured type, causes moisture in the coating in time not volatilize and in coating, produces bubble, and then influence coating quality.
In the aqueous epoxy coating of hot setting type, the solidifying agent that especially is fit to single-component aqueous epoxy coating was limited especially during most of water soluble solid agent were difficult to be applicable to.In order to realize that aqueous epoxy coating forms high-quality coating under middle hot conditions; Need a kind of epoxy curing agent that possesses " hiding " property; This solidifying agent can keep secular stable performance down in storing temp (as: room temperature), and in solidification value (as: greater than 100 ℃) drying that curing reaction is accomplished coating takes place down.
Chinese invention patent application 200310110798.7 discloses a kind of method of manufacture of latent curing agent.This method is used earlier and is had the substituent imdazole derivatives of long-chain and low-molecular-weight epoxy resin (dihydroxyphenyl propane) after the YLENE addition reaction, reaction product is dissolved in again obtain latent curing agent in the epoxy resin.The solidifying agent that obtains not only has long working life (25 ℃ keep a week), but also has higher flexibility, is applicable to the encapsulation of electronic devices and components.
Chinese invention patent application 200410043655.3 discloses a kind of preparation method of intermediate temperature setting latent epoxy curing agent.Three (methyl aceto acetate) aluminium that this method will make earlier is with after toluene and alphanol mix, again with obtain after underpressure distillation and the cooling behind the solid recrystallization with bis-phenol s together as the intermediate temperature setting agent of cycloaliphatic epoxy resin.The solidification value of this solidifying agent is 110-120 ℃, can be applied to intermediate temperature setting epoxy resin.Following 65 days of room temperature condition, this solidifying agent proterties is constant basically.
Chinese invention patent application 200680024432.X discloses a kind of solvent-free single-component composition of Thermocurable with the storage at room temperature stability at least 2 weeks.This combination is by consisting of 5-90 weight part at least two functional (different) cyanate component; The 5-50 weight part is being the solid latent curing agent under at least 40 ℃ temperature based on what be fit to addition-crosslinked nitrogen compound; The 0-50 weight part contains the compound of epoxy and the properties-correcting agent of 0-50 weight part, and wherein all wt part sum is 100.This combination compsn solidifies in the several seconds under 120 ℃-150 ℃.
The latent epoxy resin curing agent of knowing also has boron amide complex compound, hydrazides, boron trifluoride and remodeling thing, novolac resin etc.Boron amide complex compound (as: 2-(dimethylamino ethyoxyl)-4-methyl isophthalic acid, 3,2-two dislikes assorted six rings of boron) form boron-nitrogen coordinate bond in the molecule, make the tertiary amine stabilisation.Though this compounds water soluble, because the partly hydrolysed of its dissolution process can make product viscosity increase and shelf lives very short.Mostly the solidifying agent of other kind is pressed powder, and fusing point is high, and is poor with epoxy resin compatibility property, and more can not mix with water-base epoxy forms single-component aqueous epoxy coating system steady in a long-term.
Summary of the invention
Problems such as one object of the present invention is to provide a kind of modification hydrazides solidifying agent, utilizes its solidification value relatively low, and the filming property of solution and epoxy resin compatibility property difference and formation is crisp.
Another object of the present invention is to provide a kind of latent curing agent that is used for aqueous epoxy coating, makes its curing that is applicable to middle high temperature aqueous epoxy coating and forms quality coating.
Another purpose of the present invention is to provide a kind of preparation method of hydrazide latency improving curing agent.
Hydrazide compound of the present invention is for having
The organic cpds of structure, its N-N singly-bound as :-NH-NH-,-NH-NH
2Or-N-N-.
One type of hydrazide compound, its structure is seen formula I
formula I
Wherein, R1 be selected from the C1-C20 alkyl, at least one
The substituted C1-C20 alkyl of group, C1-C20 thiazolinyl, at least one
The substituted C1-C20 thiazolinyl of group, phenyl and
X
1, X
2And X
3Be independently selected from hydrogen, carboxyl, nitro, hydroxyl
Base or C1-C6 alkyl.Like: succsinic acid hydrazides, Succinic Acid hydrazides, Regulox, hexanodioic acid hydrazides, sebacic acid hydrazides, Phthalocyclohydrazide, 3-nitro Phthalocyclohydrazide, m-phthalic acid hydrazides, to Para Hydroxy Benzoic Acid hydrazides and Whitfield's ointment hydrazides.
Hydrazide compound is selected from and can also be selected from dimethylcyclopropane hydrazides or phenyl amino propionic acid hydrazides, or above-mentioned any several kinds of hydrazide compounds, with the combination of arbitrary proportion.
Epoxy compounds of the present invention comprises the combination of mono-epoxy compounds, polyepoxy compound or mono-epoxy compounds and polyepoxy compound.
The structure of mono-epoxy compounds is seen formula I
formula II
Wherein, R2 be selected from H, C1-C6 alkyl or-the O-R3 base, R3 is selected from C1-C12 alkyl, C1-C6 thiazolinyl, phenyl or benzyl.Particular compound as: oxyethane, propylene oxide or, glycidyl allyl ether, butylglycidyl ether, octyl glycidyl ether, phenyl glycidyl ether or benzyl glycidyl ether etc.Mono-epoxy compounds can also be for above-mentioned any several kinds of mono-epoxy compounds, with the combination of arbitrary proportion.
Polyepoxy compound is selected from bisphenol A type epoxy resin, bisphenol f type epoxy resin or novolac epoxy.Polyepoxy compound can also be for above-mentioned any several kinds of polyepoxy compounds, with the combination of arbitrary proportion.
Epoxy compounds can be selected one or more in mono-epoxy compounds and the polyepoxy compound, with the mixing of arbitrary proportion.
A kind of latent curing agent comprises hydrazide compound and epoxy compounds, and the mol ratio of its hydrazide group and epoxy group(ing) is 1: 0.5-2.5.
Another kind of latent curing agent comprises hydrazide compound and epoxy compounds, and the mol ratio of its hydrazide group and epoxy group(ing) is 1: 1.
Above-mentioned latent curing agent can be the mixing of all cpds, or adopts the mode of addition reaction that monomer is formed polymkeric substance.During polymerization, the carbon of epoxy compounds-oxygen singly-bound is opened, with the amino formation carbon-nitrogen singly-bound on the hydrazide compound.Its reaction process example is seen formula III; Formula III is only as explaining the polymeric process; Not as limiting the present invention;
expression hydrazide compound wherein, R1 is corresponding with the group of concrete compound.These latent curing agents are processed directly or by the phase reversion method and are made an addition to aqueous epoxy coating (comprising single-component aqueous epoxy coating and bi-component aqueous epoxy coating) again after the emulsion and can make this coating under 100-150 ℃ of temperature, solidify and form coating.
Another kind of latent curing agent is formed by hydrazide compound and synthesis of epoxy compounds, and the mol ratio of its hydrazide group and epoxy group(ing) is 1: 0.5-2.5.
Another kind of latent curing agent is formed by hydrazide compound and synthesis of epoxy compounds, and the mol ratio of its hydrazide group and epoxy group(ing) is 1: 1.
Another kind of latent curing agent emulsion; Comprise alcoxyl phenol polyethenoxy ether surface active agent and the solidifying agent that forms by hydrazide compound and synthesis of epoxy compounds; The hydrazide group of this solidifying agent and the mol ratio of epoxy group(ing) are 1: 0.5-2.5, preferential 50% (w/w) that select of the content of solidifying agent in said latent curing agent emulsion.
The phase reversion method is a kind of method comparatively commonly used of preparation macromolecule resin emulsion, and can the overwhelming majority's macromolecule resin be got corresponding emulsion by means of the effect of outer emulsifying agent through physics emulsification.The detailed process that is equipped with curing agent emulsion with the phase reversion legal system is under the high speed shear effect, earlier outer emulsifying agent and solidifying agent to be mixed; Under certain shearing condition, in system, add zero(ppm) water subsequently lentamente; Progressively change to oil-in-water along with amount of water ground increases whole system, form uniform and stable water-dilutable system by water-in-oil.
A kind of preparation method of latent curing agent; Comprise the steps: organic hydrazide compound and epoxy compounds; In molar ratio 1: 0.5-2.5 is dissolved in the solvent, then in the presence of promotor in 60-150 ℃ of reaction 1-24 hour, removal of solvent under reduced pressure obtains latent curing agent.
A kind of preparation method of latent curing agent emulsion; Comprise the steps: organic hydrazide compound and epoxy compounds; In molar ratio 1: 0.5-2.5 is dissolved in the solvent; Then in the presence of promotor in 60-150 ℃ of reaction 1-24 hour, the solidifying agent that obtains mixed again getting the latent curing agent emulsion through the phase reversion legal system with tensio-active agent alcoxyl phenol polyethenoxy ether (as: Nonidet P40 (NP-40)).
Among the above-mentioned various preparation method, solvent is selected from a kind of of Pyranton, glycol ethers solvent, propylene glycol kind solvent and zero(ppm) water or the mixture of these solvents arbitrarily.
Among the above-mentioned various preparation method; Promotor is selected from dimethyl benzyl amine, 2; 4,6-three (dimethylamino methyl) phenol, triethylamine, dimethylethanolamine, imidazoles, glyoxal ethyline, 2-ethyl-4-methylimidazole, 1 benzyl 2 methyl imidazole, boron trifluoride ethyl ether complex.
In the prepared curing agent emulsion, preferential 50% (w/w) that select of the content of solidifying agent in said latent curing agent emulsion.
The beneficial effect that technical scheme of the present invention realizes:
Latent curing agent of the present invention; Especially earlier the latent curing agent emulsion that makes via the phase reversion method makes an addition to aqueous epoxy coating (comprising single-component aqueous epoxy coating and bi-component aqueous epoxy coating), can make coating under 100-150 ℃ of temperature, solidify and form coating.For single-component aqueous epoxy coating, these solidifying agent can keep stable down at 40 ℃.
Resulting modification hydrazides of the present invention and liquid-state epoxy resin have good consistency; The single-component aqueous epoxy coating that is made into not only has long working life; And solidification value is moderate; The coating surface smooth that obtains, snappiness is good, is applicable to the insulating coating of electronic devices and components and the insulating coating of electricinstallation coil.
Term involved in the present invention is identical with notion as the one of which.
Described " C1-C6 alkyl ", " C1-C12 alkyl " and " C1-C20 alkyl ", refer to the straight or branched alkyl.The carbonatoms that the numeral group is contained, the positive integer of " 1 ", " 6 " and " 12 " expression 1-6 or 1-12.As: methyl, ethyl, propyl group, sec.-propyl, normal-butyl, isobutyl-, the tertiary butyl and n-octyl etc.
" C1-C6 thiazolinyl " and " C1-C20 thiazolinyl " refers to the straight or branched thiazolinyl, the carbonatoms that the numeral group is contained, the positive integer of " 1 ", " 6 " and " 20 " expression 1-6 or 1-20.As: propenyl, crotonyl and 1,3-butadiene base etc.
Embodiment
Below describe technical scheme of the present invention in detail.The cited embodiment of the present invention is only unrestricted in order to technical scheme of the present invention to be described; Although the present invention is specified with reference to preferred embodiment; Those of ordinary skill in the art is to be understood that; Can make amendment or be equal to replacement the technical scheme of invention, and not break away from the spirit and the scope of technical scheme of the present invention, it all should be encompassed in the claim scope of the present invention.
The reagent that the present invention is used is not if clearly indicate, then all available from Sigma-aldrich (Sigma-Aldrich).
Embodiment 1
In the there-necked flask of the 500ml that electric mixer, spherical condensation tube and TM are housed; The butyl glycol ether that adds m-phthalic acid hydrazides 250g, glyoxal ethyline 0.15g and 150ml; After 120 ℃ of heating for dissolving, add the 150g butylglycidyl ether in batches, continuously stirring was reacted 8-10 hour under this temperature then; Vacuumize to remove and desolvate, the colourless or faint yellow thick thing that obtains is latent curing agent.
Add alcoxyl phenol polyethenoxy ether surface active agent (NP-40) 10 grams, utilize the phase reversion method to be mixed with the latent curing agent emulsion that solid content is 50% (w/w).
Getting marque is epoxy resin latex 100 grams and this curing agent emulsion 95 gram uniform mixing of IE-7008W (UPPC Company products); Add 1.5 gram flow agent BYK381 (German Munzing company); 1.3 the single-component aqueous epoxy coating following shelf lives of room temperature that gram skimmer EGTAN760 (German Munzing company) is made into reaches not gelling more than 4 months, solidifies 2h/130 ℃+2/150 ℃ and is solidified into the transparent paint film of the good yellowish brown of elasticity.
Embodiment 2
In the there-necked flask of the 500ml that electric mixer, spherical condensation tube and TM are housed, add sebacic acid hydrazides 230g, 2,4; The Pyranton of 6-three (dimethylamino methyl) phenol 0.2g and 100ml; After 120 ℃ of heating for dissolving, add the 180g phenyl glycidyl ether in batches, continuously stirring was reacted 8-10 hour under this temperature then; Vacuumize to remove and desolvate, the colourless or faint yellow thick thing that obtains is latent curing agent.
Add alcoxyl phenol polyethenoxy ether surface active agent (NP-40) 15 grams, utilize the phase reversion method to be mixed with the latent curing agent emulsion that solid content is 50% (w/w).
Getting marque is epoxy resin latex 100 grams and this curing agent emulsion 95 gram uniform mixing of IE-7008W (UPPC company); Add 1.5 gram flow agent BYK381 (German Munzing company); 1.3 gram skimmer EGTAN 760 (German Munzing company), the single-component aqueous epoxy coating that is made into are with distilled water diluting to solid content 50%.Store not gelling more than 4 months under this coating room temperature, solidify 2h/130 ℃+2/150 ℃ and be solidified into the transparent paint film of the good yellowish brown of elasticity.
Embodiment 3
In the there-necked flask of the 500ml that electric mixer, spherical condensation tube and TM are housed; Add sebacic acid hydrazides 230g, 2,4, the ethylene glycol ether acetate of 6-three (dimethylamino methyl) phenol 0.05g and 100ml; After 120 ℃ of heating for dissolving; Add DER332 epoxy resin (Dow company) 100 grams in batches, butylglycidyl ether 100 grams, continuously stirring was reacted 8-10 hour under this temperature then; Vacuumize to remove and desolvate, the colourless or faint yellow thick thing that obtains is latent curing agent.
Add alcoxyl phenol polyethenoxy ether surface active agent (NP-40) 20 grams, utilize the phase reversion method to be mixed with the latent curing agent emulsion that solid content is 50% (w/w).
Getting marque is epoxy resin latex 100 grams and this curing agent emulsion 130 gram uniform mixing of IE-7008W (UPPC company); Add 1.5 gram flow agent BYK348 (German Munzing company); 1 gram skimmer EGTAN760 (German Munzing company); The single-component aqueous epoxy coating that is made into is with distilled water diluting to solid content 50%.Store not gelling more than 4 months under this coating room temperature, solidify 2h/130 ℃+2/150 ℃ and be solidified into the transparent paint film of the good yellowish brown of elasticity.
Embodiment 4
In the there-necked flask of the 500ml that electric mixer, spherical condensation tube and TM are housed; The ethylene glycol ether acetate that adds Whitfield's ointment hydrazides 100 grams, 3-nitro Phthalocyclohydrazide 150g, 1 benzyl 2 methyl imidazole 0.25g and 100ml; After 120 ℃ of heating for dissolving; Add CY-281 epoxy resin (Ciba-geigy company) 200 grams in batches; Continuously stirring was reacted 8-10 hour under this temperature then, vacuumized to remove to desolvate, and the colourless or faint yellow thick thing that obtains is latent curing agent.
Add alcoxyl phenol polyethenoxy ether surface active agent (NP-40) 20 grams, utilize the phase reversion method to be mixed with the latent curing agent emulsion that solid content is 50% (w/w).
Getting marque is epoxy resin latex 100 grams and this curing agent emulsion 130 gram uniform mixing of IE-7008W (UPPC Company products); Add 1.5 gram flow agent BYK348 (German Munzing company); 1 gram skimmer EGTAN760 (German Munzing company); The single-component aqueous epoxy coating that is made into is with distilled water diluting to solid content 50%.Store not gelling more than 4 months under this coating room temperature, solidify 2h/130 ℃+2/150 ℃ and be solidified into the transparent paint film of the good yellowish brown of elasticity.
Comparative example
With 2-(dimethylamino ethyoxyl)-the 4-methyl isophthalic acid, 3,2-two dislikes assorted six rings of boron 40 grams, is dissolved in the 60 gram distilled water, this solution after 24 hours, is got 10 grams and 100 gram IE-7008W(UPPC Company products 30 ℃ of held) epoxy resin latex mix.The room temperature held after 24 hours viscosity be 330mPa.S, part gelling after 96 hours.
Other performances of the coating of embodiment 1-4 and comparative example see the following form
Annotate: viscosity is measured after coating sample is made into 24 hours.