A kind of preparation method of polyurethane aqueous dispersion and device thereof
One, technical field
The present invention relates to a kind of preparation method and device thereof of polyurethane aqueous dispersion.
Two, background technology
Polyurethane aqueous dispersion can be used for fields such as coating, tackiness agent, surface treatment agent, building materials.The high density polyurethane aqueous dispersion can be with the coating of various base materials.For example, be used as the paint film of timber, metal, plastics, paper, leather, textiles, felt, glass etc.So that its research and development are in the ascendant.
Polyurethane aqueous dispersion roughly is divided into three types of aqueous dispersions such as forced emulsification type, water-soluble sexual type and self-emulsifying type.
Forced emulsification type polyurethane aqueous dispersions is exactly by adding after emulsifying agent (tensio-active agent) carries out water-dispersion to the urethane resin of solution polymerization, behind the diamines chain extension, removing desolvates makes the performed polymer forced emulsification, thereby obtains the polyurethane aqueous dispersion of emulsified state.Its shortcoming is that the polyurethane particles diameter is big in the polyurethane aqueous dispersion, dispersion liquid storage tank poor stability, and cementability reduces.
Water-soluble type polyurethane aqueous dispersions just is to use the water soluble polyether polyvalent alcohol and can prepares the polyurethane aqueous dispersion of aqueous solution state with isocyanate reaction.But, the poor water resistance of this aqueous dispersions goods after crosslinking reaction, can be used for some special occasions.
The self-emulsifying type polyurethane aqueous dispersion imports ionic group exactly in urethane resin or the base polyurethane prepolymer for use as structure and makes urethane resin need not to add emulsifying agent just to form aqueous dispersions.The water-dispersion of self-emulsifying type urethane and other two kinds of aqueous dispersions compare, and its particle dia is little, the storage stability height, and the molecular designing amplitude is wide, and is better than other two kinds of aqueous dispersions.
Self-emulsifying type polyurethane aqueous dispersion and other two kinds of aqueous dispersions also interosculate, and carry out the intermittent type manufacturing with the reactor that is equipped with agitating vane usually.Promptly in reactor by isocyanic ester and polyol reaction, add the dimethylol propionic acid give hydrophilic group and wetting ability solubility promoter again and react and prepare base polyurethane prepolymer for use as, these solubility promoters are as acetone, butanone, glycol ether and N-Methyl pyrrolidone etc.After water-dispersion and by diamines, come further chain extension then, obtain the urethane of water-dispersion.Sometimes with the purposes difference of goods, lower boiling solubility promoter can be removed with the distillatory method; Sometimes then keep high boiling solubility promoter, omit distillation process.
In the intermittent type manufacturing process of self-emulsifying type polyurethane aqueous dispersion, be divided into three main phase such as performed polymer preparation, performed polymer water-dispersion and dispersion liquid chain extension.Performed polymer must add salt forming agents such as triethylamine before entering water-dispersion.Triethylamine be salt forming agent also be the catalyzer of polyurethane reaction, make to contain-viscosity of NCO group performed polymer sharply rises, must in certain hour (as 60 minutes), use up, otherwise can't emulsification, influence the quality of emulsion; When production contained the performed polymer of TDI, situation can be more serious, even the situation of serious blocking pipe can take place, the production-scale expansion of said circumstances restriction interrupter method, the emulsion that relatively more suitable batch production is 1000 kilograms.
The emulsifying stage of interrupter method production is to carry out in the chain extending reaction still of the band stirring of band emulsifier unit, the phenomenon that viscosity rises can take place when producing inversion of phases in interrupter method, the water-dispersion processing power is mixed with the performed polymer amount of putting into, reactor, stirring capacity and different, because stirring is insufficient and the dispersion of goods particle is inhomogeneous, the bad dispersibility of goods; A small amount of performed polymer can stick to reactor inwall and bottom after the polymerization, so each processing finishes all to get the cleaning reaction still once, carry out a series of processing with a reactor, big production is restricted, for example, makes 1 ton of goods polyurethane aqueous dispersion and will spend 1~2 day time.
In the dispersion liquid chain extension stage, select for use the mode of dropping above the dispersion liquid liquid level, to add chainextender quadrol (normally 20% the aqueous solution) usually.Based on quadrol and performed polymer end-the NCO radical reaction is rapid reaction, make chain extending reaction evenly must drip two amine aqueous solutions lentamente, if because the stirring shear ability at liquid level place is poor, if adding speed causes the quadrol of local emulsion excessive too soon easily, formed polyurethane molecular amount is low, degradation, the polyaminoester emulsion of formation primary amine end; The deficiency that causes other a part of emulsion quadrol amount simultaneously, the emulsion of formation NCO end finishes back emulsion of different nature together in reaction, and nature can reduce the stability in storage of dispersion liquid, the usability of goods and the glossiness after the goods film forming.The batch production mode will obtain the emulsion of good chain extension, must fully prolong the dropping time.When industrial scale enlarged, increase consuming time was just obvious especially.
In view of the shortcoming of interrupter method production polyurethane aqueous dispersion length consuming time, develop the method for continuous production polyurethane aqueous dispersion gradually.Prior art US7,345,110B2, Mar, 18,2008 disclose the process of continuous production aqueous polyurethane, at first in proportion with base polyurethane prepolymer for use as and water, be provided with a spray orifice in by T type nozzle in 80 ℃, this injection diameter 2mm is ejected into performed polymer in the water with 0.2~50 bar pressure difference and produces pre-emulsion through mixing section, then by 6 injection dispersers; Be provided with two apertures in each injector, nine bore dia 0.8mm, become emulsion with pressure difference 17 crust homogenizing milk sap, continue it, temperature of charge be cooled to 29 ℃ put into Glass Containers with quadrol and hydrazine hydrate chain extension, filter and obtain polyurethane aqueous dispersion, its quality index is: mean ionic diameter 50nm, pH=8.0, solid content 38.6%.This method is with T type nozzle emulsification base polyurethane prepolymer for use as, and the device structure complexity is difficult to cleaning, and used pressure is bigger.Must add and give improvement.
Prior art JP2009-286892A, 2009.12.10 disclose the manufacture method and the device thereof of polyurethane aqueous dispersion, these method characteristics be with base polyurethane prepolymer for use as and water in the continuous decollator of CAVTRON CD1010, this decollator starting current is 26A, rotating speed 11,200min
-1Disperse continuously in 64 ℃, the dispersion liquid that continues enters storage tank, according to circumstances dispersion liquid can all or part ofly be circulated among the CAVTRON CD1010 and base polyurethane prepolymer for use as redispersion together, to polyurethane concentration be 40~50 quality %, just calculate and make polyurethane aqueous dispersion, the polyurethane aqueous dispersion quality index is: solid content 33.2~42.5%, average particle diameter 64~104nm, 63~65mPa.s during 25 ℃ of viscosity, it is big that the branch that this method is used spreads the device power consumption, dispersion liquid circulation dispersion results particle dia is inhomogeneous, and promptly the particle homogenization degree is poor.This method need add give improve perfect.It is thin to be necessary to prepare granularity, and the polyurethane dispersing liquid of assignment stability falls well in the look that is evenly distributed.Be necessary to provide manufacture method simple, emulsifying device is uncomplicated, and the process of processing ease has been the thing of enjoying popular confidence.
Three, summary of the invention
Prepare the performed polymer poor stability that self-emulsifying waterborne polyurethane dispersion liquid exists based on existing interrupter method, can be limited for emulsification times, enlarge the characteristics that emulsifying capacity is limited day by day and the chainextender time obviously prolongs with scale.Present inventors are through concentrating on studies, taken into full account the characteristics and the mutual relationship of stability, emulsifying capacity and chain extending reaction,, provide manufacture method simple from the polymerization engineering viewpoint, emulsifying device is uncomplicated, the preparation facilities of the semi-continuous polyurethane aqueous dispersion liquid of processing ease.Preparation polyurethane aqueous dispersion particle dia is little, is evenly distributed, and is coloury, the polyurethane aqueous dispersion of stable storing.Through particular study complete technical scheme has been proposed.
The preparation process of polyurethane aqueous dispersion comprises base polyurethane prepolymer for use as water-dispersion emulsion preparation and polyurethane aqueous dispersion preparation; Described base polyurethane prepolymer for use as comprises aromatic diisocyanate that uses tolylene diisocyanate (TDI) etc. and/or the prepared performed polymer of aliphatic diisocyanate that comprises isophorone diisocyanate (IPDI).Idiographic flow is: the base polyurethane prepolymer for use as that has carboxyl that 50~60 ℃ 100 weight parts contain stablizer is transported to the emulsor by volume pump from storage tank, meanwhile 60~95 weight parts waters are also carried the low pressure emulsor from storage tank by volume pump respectively from 90~105 parts of 5~6 weight % salt forming agent triethylamine aqueous solutions of storage tank and performed polymer carboxyl equivalent.Because triethylamine and performed polymer separated before emulsification, also added stablizer in the performed polymer simultaneously, the viscosity of performed polymer is very stable, does not also have the restriction of emulsification times, can guarantee the homogeneity of dispersion liquid particle
Needle-like agitator with 2000~3000 rev/mins of rotating speeds in emulsor is implemented powerful stirring and emulsifying in 50~60 ℃, constantly flowing into polyurethane aqueous dispersion through low-voltage high speed emulsive performed polymer dispersion liquid prepares in the still, polyurethane aqueous dispersion prepares still and is equipped with inclined paddle type agitator, and per minute stirs 150~170 to be changeed; After the whole emulsifications of performed polymer, based on 100 weight part base polyurethane prepolymer for use as, the aqueous solution 10~12 weight parts that from storage tank, add 20 weight % chainextender quadrols with semicontinuous form, the reinforced back that finishes continues to stir 0.5~1 hour in room temperature, puts into storage tank then; The device of preparation polyurethane aqueous dispersion comprises: base polyurethane prepolymer for use as storage tank, storage tank are equipped with anchor stirrer, water storage tank, base polyurethane prepolymer for use as emulsor; This still is equipped with pin type agitator, salt forming agent triethylamine solution storage tank, polyurethane aqueous dispersion and prepares still, this still is equipped with liquid pushing tube and polyurethane aqueous dispersion storage tank and performed polymer supply line, water supply line, triethylamine supply line, base polyurethane prepolymer for use as emulsion supply line and the polyurethane aqueous dispersion product line of inclined paddle type agitator and chainextender ethylenediamine solution storage tank, and first volume pump, second volume pump, the 3rd volume pump and chainextender ingress pipe.
The base polyurethane prepolymer for use as that contains stablizer, stablizer are to choose any one kind of them from trichoroacetic acid(TCA), aceticanhydride, Phenylsulfonic acid acyl chlorides; The add-on of stablizer is 0.5%~0.03% of a base polyurethane prepolymer for use as weight.It is stable for a long time for performed polymer adding stablizer, in production period band dispersive performed polymer viscosity obvious variation does not take place.The liquid pushing tube of chainextender quadrol storage tank extends to the terminal outer rim of agitating vane place, like this, the ethylenediamine solution that adds can THE ADIABATIC SHEAR IN and disperse, stir by oblique oar simultaneously and be assigned to the entire reaction still rapidly, when guaranteeing the chain extension quality, shorten the required time of chain extending reaction greatly, improved the efficient of chain extending reaction and the homogeneity of dispersion.
According to the polyurethane aqueous dispersion of the invention process preparation, its performance index are: particle dia 50~75nm, and solid content 40~100nm, pH 7.0~7.5, viscosity (25 ℃): 10-30mPa.s.
Four, description of drawings
Fig. 1 is a kind of schematic flow sheet of polyurethane aqueous dispersion preparation
Numeral number is described as follows:
1, the base polyurethane prepolymer for use as basin, 2, the water basin, 3, the triethylamine basin, 4, the base polyurethane prepolymer for use as emulsor, 5 pin type agitators, 6, the quadrol basin, 7, polyurethane aqueous dispersion prepares still, and 8, propeller stirrer, 9, the polyurethane aqueous dispersion basin, 10, anchor stirrer, 11, the ethylenediamine solution supply line, 12, the base polyurethane prepolymer for use as supply line, 13, the water supply line, 14 triethylamine supply lines, 15, base polyurethane prepolymer for use as emulsion supply line, 16, the polyurethane aqueous dispersion product line, 17, first volume pump, 18, second volume pump, 19, the 3rd volume pump, 20, the chainextender liquid-inlet pipe.
Five, embodiment
Especially exemplified by example it is described in order to implement the present invention better, but is not limitation of the present invention.
The base polyurethane prepolymer for use as preparation
The preparation of a type polyurethane performed polymer
40g polyneopentyl glycol adipate, 60g PTMG, 383g tolylene diisocyanate and 0.04g dibutyl tin laurate obtained performed polymer in 1 hour in 60~78 ℃ of reactions.Adding 12g dimethylol propionic acid that continues and 15g solubility promoter N-Methyl pyrrolidone, and 0.4g Phenylsulfonic acid acyl chlorides continues reaction 2 hours in 68 ℃, makes to be called a type polyurethane performed polymer.
The preparation of b type polyurethane performed polymer
Except that replacing the 383g tolylene diisocyanate with the 489g isophorone diisocyanate and adding the 1.0g trichoroacetic acid(TCA) replaces outside the 0.4g Phenylsulfonic acid acyl chlorides, other prescriptions are the same with the preparation of a type polyurethane performed polymer with operation steps.
Embodiment 1
A type polyurethane performed polymer is sent into base polyurethane prepolymer for use as emulsor 4 bottoms by first volume pump 17 from basin with 10Kg/min speed, meanwhile water is sent into base polyurethane prepolymer for use as emulsor 4 emulsification from basin 3 by the 3rd volume pump 19 with 10.2Kg/min speed by the triethylamine aqueous solution of second volume pump 18 and 5 weight % from basin 2 with 9.4Kg/min speed, stir lasting emulsification 65 minutes with 2000~3000 rev/mins of speed, the emulsification material is constantly sent into polyurethane aqueous dispersion from emulsor 4 tops and is prepared the still 7, inclined paddle type agitator 8 stirs with 160~170 rev/mins of speed, then, based on the 651.9Kg base polyurethane prepolymer for use as, from storage tank 6, be metered into behind the 20 weight % ethylenediamine solution 180Kg in stirring at room 0.5hr, put into storage tank 9 then and use for the user.This polyurethane aqueous dispersion particle dia 55nm, solid content 35%, pH7.0,25 ℃ of 10~30mPa.S of viscosity.
Embodiment 2
Remove b type polyurethane performed polymer 13.1Kg/min, water 9.37Kg/min, triethylamine 12.3Kg/min speed added 4,50 ℃ of lasting emulsify at a high speed of urethane emulsor 60 minutes, based on the 787Kg base polyurethane prepolymer for use as, the performed polymer dispersion liquid carries out chain extending reaction after adding the 81.9Kg ethylenediamine solution, and other operation prescriptions are the same with embodiment 1, as a result particle dia 45nm, solid content 42%, pH7.5,25 ℃ of viscosity, 30mPa.S.