CN1153180A - Vapor precipitation of polymers from solvent polymer blends by azeotropic spray drying - Google Patents

Abstract

A process for removing contaminating solvents from solutions containing solid solutes comprising contacting a co-solvent that forms an azeotrope with the contaminating solvent forming a mixture thereby and spray drying the contaminating solvent co-solvent mixture in the presence of the co-solvent at a temperature equal to or above the temperature where the azeotrope distills whereby the contaminating solvent has been azeotropically distilled away from the solute. The process is particularly useful for polymeric solutes, especially silicones.

Description

By the azeotropic spraying drying polymkeric substance steam from solvent-mixture of polymers is separated out

Invention field

The present invention relates to not wish to want by high-temperature steam, it is the method that the solvent of contaminative is removed from solvent-solute composition, the contaminative solvent that wherein exists in this steam and this solution forms azeotrope, when this solution carries out such processing, this azeotrope is steamed, so the solute that contains the contaminative solvent is purified.

Specifically, the present invention relates to the dispersion liquid in organic solvent at solvent vapo(u)r or polymkeric substance solute the solvent vapo(u)r azeotropic mixture in the presence of carry out spraying drying, form the free flowing powder do not contain the contaminative solvent.The better polymerization thing is a siloxane polymer.

Background of invention

A kind of method that is used to prepare the polysiloxane powder is disclosed in United States Patent (USP) 4,935, in 484 (' 484).The polysiloxane powder that the spray-dried generation median size of the moisture colloidal dispersion of siloxane polymer or multipolymer is 10-150nm.The powder of Sheng Chaning can be used for multiple use although it is so, but this powder still contains the emulsifying agent that uses when it prepares, and this is a kind of impurity.

According to the saying of ' 484 patent, adopt the polysiloxane powder that aqueous silicone polymkeric substance, the spray-dired method of multipolymer are produced to can be used in the plastics, as surrogate with hydrophobic white rouge.But, when through spray-dired like this polymkeric substance, multipolymer being a kind of polymkeric substance that constitutes jointly by three organic radical siloxy units and four siloxy units, multipolymer, incompatible with other polysiloxane fluids with the aqueous spray dried powder that the method for ' 484 patent is produced.

This shortcoming in view of ' 484 patent, if can produce granularity between the about 200 μ m of about 0.10-and aggregate size unrestricted flow organosilicon powder between the about 200 μ m of about 10 μ m-, and this powder again can be compatible with other siloxane polymers, thereby combination with it, then will be ideal very.What possess useful property in this class material after handling like this is that organic poly-polysiloxane and the hydrogenation that those and alkenyl replace gathers the class that polysiloxane fluid constitutes composition.

Summary of the invention

In a broad sense, the present invention utilizes the formation of azeotrope, and is used in combination spray drying process undesirable solvent is removed from solution, contains the solution of not wishing solvent thereby purify, perhaps this solvent is removed fully, produce and be substantially free of the solid of not wishing solvent.

Therefore, broadly say, a kind of following method of removing the contaminative solvent from the solution that contains one or more solutes be provided, comprising:

(a) allow described solution contact with cosolvent with certain boiling temperature, wherein said cosolvent and described solute unmixing, and the boiling temperature of described cosolvent is different with the boiling temperature of described contaminative solvent, and described cosolvent and described contaminative solvent form a kind of azeotrope simultaneously; And

(b) with described by the solution of solvent contamination spraying drying in the presence of described cosolvent, wherein said solvent and described cosolvent azeotropic steam,

Thereby described contaminative solvent just is removed from described solute.

As specific embodiment, method of the present invention can be applied to contain the solution of polymkeric substance, more specifically says and contains siloxane polymer, particularly contains the solution of the siloxane polymer of following general formula:

M _iD _jT _kQ _pWherein subscript j and k are zero, and subscript i and p are the positive numbers of non-zero.When method of the present invention is applied to preferably siloxane polymer, just generate the fines shape siloxane polymer that does not contain contaminative solvent (or mixture of contaminative solvent) substantially.

Detailed Description Of The Invention

The polymkeric substance that synthetic or similar method synthetic by solution or process solution generates if therefrom removed organic solvent, usually can become a kind of reluctant solid.When the polymkeric substance after synthetic or the solvent in the multipolymer being removed can generate reluctant solid the time, generally solvent is not removed, and the product dispersion liquid in solvent or form use of solution when just preparing with it.This makes must develop highly filled synthetic method, perhaps removes the novel method of contaminative solvent.

Being applicable to the synthetic in organic solvent of the inventive method or adopting solvent polymkeric substance or oligopolymer auxiliary or that the mesomeric method is prepared is thermoplastic polymer, it includes but not limited to, polyethers, polysulfide, polyimide, polymeric amide, polyetherimide, polyetheramides, polysulfones, polyurethane, polyester, polycarbonate, polysiloxane, above-mentioned any alloy and composition thereof.Method of the present invention is particularly useful for polyester, polycarbonate and polysiloxane and so on.Under the situation of polysiloxane, can form by various with method exsiccant siloxane polymer of the present invention:

MDM、

TD、

MT、

MDT、

MDTQ、

MQ、

MDQ、

MTQ or the like.In these formulas each all is selected from the general formula of following polysiloxane:

M _iD _jT _kQ _pWherein subscript i, j, k and p can be zero or positive number independently, and precondition is when p is non-vanishing, and be also necessary non-vanishing one of among i, j, the k.For clarity sake, M is that general formula is R ₃SiO _1/2Simple function group, D is that general formula is R ₂SiO _2/2Bifunctional, T is that general formula is RSiO _3/2Trifunctional, be SiO and Q is a general formula _4/2Four-functional group.In these examples, substituent R can be any various organic group, certainly selects independently.Under the situation of M group, three all R groups can have nothing in common with each other, also can be wherein two identical, perhaps three whole identical.Similarly, for the D group, its R group both can be the same or different.In the process of preparation siloxane polymer,, then may generate multipolymer if in synthetic, use two or more different M, D or T group.Therefore, above-mentioned arrangement can infinitely be changed.Generally, these monovalent R substituting groups can be selected from hydrogen, contain the alkaryl of the alkyl of 1-40 carbon, the alkenyl that contains 2-40 carbon, the aryl that contains 6-40 carbon and 7-40 carbon.And, when these R substituting groups were not hydrogen, they can be by the partly halogenation of fluorine, chlorine, bromine, iodine, perhaps by the deriveding group of oxygen or sulphur, for example hydroxyl or thiohydroxy, ester group, thioester substrate, ether, thioether group etc., perhaps their any combination replaces.

Some solvents that are used for this class polymerization and oligomerisation process are the mixture of benzene,toluene,xylene, the paraffinic hydrocarbon solvent of mixing aromatic solvent, paraffinic hydrocarbon, a 5-20 carbon atom and the alcohol of 1-10 carbon atom.Recently this problem is according to United States Patent (USP) 5,319, and 040,5,324,806 and 5,357,007 disclosed method is resolved to remove to desolvate by spraying drying.The fine polymer powder that this method is produced no longer is difficult to handle, but is easy to handle, and can be dispersed in well in other siloxanes.This technology can be generalized to other and is gone in polymer composition of solvent contamination.For example, those are by with the solvent being polyreaction synthetic polyester, polycarbonate of medium and so on, can form unmanageable solid matter after desolvating removing when surpassing the molecular weight of certain numerical value.Therefore, this class spray drying technology newly developed can provide produces the higher polymkeric substance of molecular weight, and the means that make things convenient for of removing most of solvent from product easily, produce disperse very carefully, the easy to handle powder.

Though disclosed technology can be removed quite a few solvent by simple spraying drying measure in ' 040, ' 806 and ' 007 patent, can't remove whole solvents.This both may be an advantage, also may be disadvantage, and the existence that see this trace solvent is to help product is converted into useful form, or this solvent has been represented the pollutent that must remove and decided.Containing the trace aromatic solvent, for example under the situation of benzene or toluene, if this product is used for not relating to the occasion of human body, then special worry may and be unworthy in the pollution that causes of aromatic solvent.Otherwise, when being used for makeup and personal care formulations, perhaps will become under the occasion of parts of medical instruments at this resin or thermoplastics, it is more serious that then this solvent contamination just is considered to.

The present invention significantly is different from the prior art part and is, the spraying drying of solvent polymeric thing mixture is at plus solvent or solvent mixture, below is referred to as cosolvent, existence under carry out.By selecting cosolvent, so that this cosolvent forms azeotrope with solvent that is loaded with polymkeric substance, multipolymer, resin or thermoplastics or solvent mixture, spray-drying process also plays a part component distillation simultaneously, and polymkeric substance, multipolymer, resin or thermoplastics are separated out in spray drying device with the fines form.This novel method can be reduced to the solvent contamination of polymkeric substance, multipolymer, resin or thermoplastics the much lower level that can reach by the spray drying process of cosolvent than not.

The organic solvent of used solvent generally is that boiling point is lower than 250 ℃ solvent during as the synthetic intermediate medium or as synthetic polymer, multipolymer, resin or thermoplastics.For example, if a kind of polymer materials by solvent medium polymerization preparation, wherein solvent is a benzene, the spraying drying of the then resulting polymkeric substance that is polluted by benzene (solvent) then be water as cosolvent, form classical benzene-water azeotrope and finish.Carry out the azeotropic spraying drying under the benzene water azeotrope distillatory temperature and can make the azeotrope component distillation and leave polymkeric substance being equal to or higher than, thereby cause polymkeric substance to be separated out.Suitable cosolvent is water, ethylene glycol, propylene glycol, butanols, isopropylcarbinol, vinyl carbinol, acetic acid, ethylene chlorhydrin, quadrol, nitroethane, pyruvic acid, 1-chloro-2-acetone, Epicholorohydrin, propionic acid and 1,2-acetone glycol.

In order to remove the contaminative solvent, selected cosolvent is should be not miscible or be dissolved in wherein with solute or polymkeric substance.In the azeotropic spraying drying, use unmixing or undissolved cosolvent just can produce the low polymkeric substance of contaminative solvent (or solute), and can not cause the secondary pollution that causes because of cosolvent.What will consider in addition is that the selected spray-dired cosolvent of azeotropic that is used for must form the boiling point azeotrope lower than cosolvent itself with the contaminative solvent.This requirement has caused the formation of heterogeneous system, wherein has the liquid phase of a vapour phase and two requirements at least.Method requirement of the present invention, the cosolvent components selection of azeotropic mixture must make the contaminative solvent to steam from the lower liquid phase of spray-drying process mid-boiling point.Above-mentioned heterogenetic exists makes the contaminative solvent be dispensed in the lower liquid phase of boiling point, and this is excluded by component distillation in spray-drying process, thereby solute or polymkeric substance are purified.

The spraying drying of the solvent contamination polymkeric substance in the presence of cosolvent can adopt technology implementation known in the art, perhaps adopt spray-dryer that at least one eddy current atomization device nozzle is housed, the spray-dryer of two flow nozzles be housed or as United States Patent (USP) 5,248,087 disclosed a kind of spray-dryers that have little droplet generator are finished.

The temperature of spray-drying process can be low to moderate 50, and high range between 300 ℃ is decided according to the solvent and the selected cosolvent of preparation usefulness.This scope is preferably 90-300 ℃, more preferably 100-250 ℃, is preferably 150-200 ℃.When hope reduced the spray-dryer thermal load, these preferable range then became: better 60-250 ℃, and better 65-200 ℃, preferably 70-190 ℃.And when adopting high boiling solvent and cosolvent, above-mentioned preferable range becomes again: better 100-300 ℃, and better 150-300 ℃, preferably 200-300 ℃.

The invention provides a kind of method for preparing free-pouring polysiloxane powder.This free-pouring powder can form a kind of more stable batching with comparalive ease with other silicone materials blending.A specific embodiment of the inventive method comprises:

(1) hydrolyzed solution of a kind of organopolysiloxane of formation, it is regarded as being used for the polymkeric substance of the inventive method, comprise three organic radical siloxy units and four siloxy units, the ratio of its three organic radicals siloxy-and four siloxyies is about 0.65: about 3: 1 of 1-

(2) hydrolyzed solution that will contain the organic radical siloxy-comes out with the isolated in form of dispersion in organic solvent or solution from the mixture of step (1), and

(3) with the dispersion in organic solvent that generates in the step (2) or solution at steam, or carry out spraying drying under the existence of the azeotropic mixture of the solvent of use in steam and the step (2) or solvent mixture.

The general formula of three organic radical siloxy-M is:

M=R ₃SiO _1/2, wherein the R group can be independently selected from the monovalence alkyl of hydrogen and 1-40 carbon atom.R better is selected from the alkyl of hydrogen, a 1-6 carbon atom, the aryl of a 6-20 carbon atom, the alkaryl of a 7-20 carbon atom, and R is more preferably methyl.Owing to only the R substituting group is defined, so can also there be other to make the functionalized substituting group of R substituting group with regard to carbon skeleton.Like this, R just comprises halogenated methyl, trifluoromethyl for example, trichloromethyl; Halo senior alkyl, for example trifluoro propyl; Halogenated aryl, for example chloro-phenyl-; Oxidation aryl, for example phenol substituent etc.Three organic radical siloxy units of other types, M ' and M ", can comprise the mixture that a part is hydrolyzed.The general formula of these class three organic radical siloxy groups is:

M '=R ₂R ¹SiO _1/2(or R ₂R ¹Si) and

M "=R ₂HSiO _1/2(or R ₂HSi) wherein R is as defined above, R ¹It is the alkenyl of 2-40 carbon atom.This three organic radicals siloxy units can further contain the following D unit of general formula:

R ²RSiO _2/2(perhaps R ²RSiO) and the following T unit of general formula:

RSiO _3/2(perhaps RSiO ₃) wherein R is with top definition, R ²Be selected from R, R ¹And H.The unitary quantity of D unit and T can be up to about 25% (mole) independently.

The unitary general formula of four siloxyies is:

SiO _4/2。

Organic hydrolyzed solution of mentioning in the explanation of the inventive method can be dispersed or dissolved in the aromatic solvent such as benzene,toluene,xylene, xylol.

Gross weight with organopolysiloxane is benchmark, and the organopolysiloxane hydrolyzed solution can contain about 5 weight percentage of the 0.02-that has an appointment, better about 0.1-3 weight percentage, the hydroxyl of preferably about 0.5-2.5 weight percentage.

The method of producing three organopolysiloxane hydrolyzed solutions can be referring to United States Patent (USP) 2,676,182 (' 182).In the patent of ' 182, silica hydrosol under acidic conditions with the source of three organic radical siloxy units, for example hexamethyldisiloxane or hydrolyzable three organopolysiloxanes, siloxane polymer or the multipolymer that obtains being dispersed in the organic solvent that resembles benzene and so on reclaimed in for example trimethylchloro-silicane oxygen alkane reaction subsequently.

Be applicable to that mainly general structural formula is MQ, MM ^ViQ, MD ^ViQ, MM ^HQ, MD ^HA particular of the present invention of the polysiloxane of Q, MDTQ, TD and various combinations thereof comprises:

(1) organic solution of polysiloxane is preheating to 50-300 ℃ temperature,

(2) pressed a two-phase spray nozzle to the pressurization of this solution and with it, make solution and a kind of polysiloxane only be slightly soluble in wherein, can contact with the steam of the cosolvent of this organic solvent formation azeotrope.And in order to form the azeotrope that works in the method for the invention, the volumetric molar concentration of organic solvent should be higher than the volumetric molar concentration of cosolvent or its mixture.The effect of these conditions is that polysiloxane is separated out with particulate state from solvent, and the effect in forming the azeotrope process is driven away solvent from polysiloxane by cosolvent simultaneously.Even residual have any liquid of following polysiloxane particle, also cosolvent normally.

Solvent system has the in fact whole solvents of removal and stays simultaneously by this ability of the wetting solid of cosolvent, has improved energy efficiency.Can be then dry in the indirect contact heat exchanger by the solid that cosolvent is wetting, can under the situation that does not increase the process steam consumption, carry out heat exchange like this.All compare to the process supply by the cosolvent that heated with whole input heats, the energy efficiency of indirect heat exchanger is higher.

The particle size of producing with method of the present invention is about 1, the 000 μ m of about 0.40-, better 10-200 μ m, preferably 20-100 μ m.

(3) Gu, make remaining cosolvent vaporizing liquid and make steam superheating with vapour/liquid/streams heating.

(4) by cyclonic separator, porous metal filter, weave or spin deep bed filter or candle filter is separated solid from superheated vapour.Cyclonic separator may be preferably, because this equipment can more effectively be caught fine granular materials by design.

(5) with the solid collection that is recovered in having the collection container of steaming out, preferably with air or nitrogen purging.The cosolvent steam displacement that steaming out will be entrained in the volume of solid free space is gone out, thereby has reduced the final solvent of solid.

(6) utilize directly contact or indirect contact heat exchanger with the vapour stream condensation.When as the solvent of preferred version and cosolvent unmixing, the direct contact type condenser connects a phase separator more especially effectively solvent cycle means just can be provided.

(7) for non-condensable gases provides low tension outlet, so that system operation is under pressure below atmospheric pressure, i.e. 2-760mmHg, better 25-700mmHg, better 50-300mmHg, the preferably pressure of 100-250mmHg.Because adopt decompression, the dividing potential drop of all components has all reduced.This is even more important for reducing the amount of carrying cosolvent in separating out solid free space volume secretly.A useful especially arrangement is to adopt a kind of spouting of liquid injector for appropriate low pressure occasion, and it provides the function of direct condenser, and the result also is provided as simultaneously and forms or keep the required energy of low pressure of injector upstream.Then, when adopting immiscible solvent and cosolvent, injector ejecta decantation can be cooled to a part below 27 ℃, be back to injector then as actuating fluid.

Any fusing point is higher than 25 ℃, better be higher than 35 ℃, better be higher than 43 ℃, preferably be higher than 50 ℃ and the polysiloxane that dissolves in organic solvent and all can adopt method of the present invention to remove solvent, its restricted condition is to have a kind of not miscible with this polysiloxane cosolvent, and, it has been arranged, and solvent and cosolvent form two liquid phases, and wherein solvent and cosolvent form lower boiling, are rich in the azeotrope of solvent.

Though relating to, this specific specific embodiments that removes solvent method forms free-pouring solid spraying drying,, method of the present invention equally also can be applicable to the dry material that is difficult to the thick liquid of purifying usually.If adopt the embodiment of this method, then will collect liquid in the bottom of spray-dryer, rather than solid-state free flowing powder.Cosolvent under the liquid dried process condition is selected, except that the restriction of the supplementary condition that will form the liquid phase immiscibility that also will be subjected to and be dried the azeotrope.

Method of the present invention is not limited to polymers soln, comprise from the solution of the product that contains needs or solute and remove the situation of not wishing solvent but can be generalized to, way be add therein can with do not wish or the contaminative solvent forms the cosolvent of azeotrope or the mixture of cosolvent, to contain the solution spray drying of solute, contaminative solvent and cosolvent then, thereby remove the contaminative solvent.

A favourable aspect that is even more important of the present invention is that it can be used for removing harmful (thereby being contaminative) aromatic solvent in the siloxane polymer.This point is why important to be because the synthetic method that is used for producing the most convenient of siloxane polymer often adopts aromatic solvent.Significant example is to contain as the application aspect main chain or the substituent polysiloxane of the substituent long chain hydrocarbon groups of end-blocking in production.This respect why have problems be because, the important use that various polysiloxane are arranged is to be used in the personal care product aspect, consider from the angle of health and safety, even it all is undesirable that the aromatic solvent of trace is arranged in the product, therefore the content of this class contaminative solvent is subjected to strict control in personal-care supplies.

All United States Patent (USP)s mentioned in this article are taken in this paper all as a reference.

Experiment

Example 1:

The M/Q mol ratio of 60wt% is that about 0.65, number-average molecular weight is about 3,000 gram/mole and silanol content are about MQ resin-toluene solution of 2.0wt%, under atmospheric pressure carry out steam and separate out, feed the bag type filtering separator, to capture the micro-solid particle that generates with water vapour.Vapor phase is condensation in shell-and tube condenser.Amount that the solid materials that just has been recovered to contains wet (promptly moisture) for 14wt/%, size-grade distribution from 0.40 μ m to about 100 μ m, median size is 14 μ m.The solid particulate resin that is reclaimed by deep bed filter is through super-dry, to remove residual water-content.Adopt the polydimethyl polysiloxane fluid of 20 centipoises, just only mix by hand and the granular resin for preparing like this can be disperseed, generate transparent mixture.This shows that the granular polysiloxane that generates with the technology of the present invention is easy to be dispersed in the low-molecular-weight polysiloxane fluid.

The wet granular polysiloxane sample of portion 3.518 grams that reclaims from deep bed filter is heated to 150 ℃ the sealed septum phial, adopts Hewlett-Packard's headspace analysis instrument of model 19395A to take out 105 meters RTX-1 capillary tube gas chromatographic columns of 3ml gas sample injection from polysiloxane liquid level top then.Through contrast space on every 20ml liquid contain 0.0009 gram toluene with reference to mixture, in sample, do not detect toluene.Limit of detection is 7 (weight) ppm.Therefore, the polysiloxane sample that method of the present invention is produced, the aromatic solvent that contains in its product is below 7ppm.Obviously, this method may operate under the more strict condition, to reach higher contaminative removal of solvents degree.Therefore, better that contaminative removal of solvents to 3 (weight) ppm is following level, better 1 (weight) be below the ppm, the level that best 0.5 (weight) ppm is following.

Example 2

In order to compare, adopt the light HT spray-dryer of Niro that two flow nozzles are housed that the MQ resin toluene solution identical with example 1 carried out spraying drying.Spray-dired operational condition is, employing nitrogen is siccative, and its flow is 85 kilograms/hour, and the import and export temperature is respectively 200 and 110 ℃.Nitrogen dry gas and MQ resin (the solution form of 60wt% in toluene) weight ratio is 0.72.The mean particle size of the MQ toner that obtains is 68 μ m, contains the residual toluene solvent of 1.5wt%.

This example adopts the cosolvent that forms azeotrope can significantly reduce the degree of the contaminated property of the powder solvent contamination of generation in the spray-drying process of polysiloxane solution by the contrast proof.

Definition

Capping group M also can be defined as:

M=R ₃Si, a) common definition then is:

M＝R ₃SiO _1/2。B) if do not note the habitual rule of existing stoichiometric calculation, these two kinds of definition are used interchangeably, then they all can cause about existing, and still do not exist divalence oxygen to connect the form structure problem of planting.When adopting definition a), must insert an extra Sauerstoffatom on the left side such as the such structural formula of MDM, i.e. MODM, suppose that simultaneously the definition of D is:

When adopting definition b) time, for the purpose of accurately, structural formula MDM must be write becomes MD (SiR ₂) M, so that an extra Sauerstoffatom in the cancellation structural formula.Be generally popular (or habitual) literary style supposition that the polysiloxane chemistry is accepted, the professional who is familiar with this area general knowledge is (for specialty chemical, regulation according to American Chemical Society, possess Sc. M.'s degree) know that when using this need when writing a Chinese character in simplified form structural formula according to what adopt be which kind of definition increases or deletes bivalent oxygen atom, this point is even more important when using these structural formulas interchangeably when the stoichiometric calculation details as above-mentioned definition basis is paid no heed to, because typical simplified style is MDM rather than MODM or MD (SiR ₂) M, although from context, back two formulas are correct according to the definition of M, but the former may be generically or be correct traditionally, also may be incorrect, and this will see whether definition is confused and decides.

When using timestamp under the mark, in concept, the atom of mark is shared coequally by two centers like this.Habitually practising in the polysiloxane chemistry, this is meant the shared coequally Sauerstoffatom of two Siliciumatoms.Therefore, subscript 1/2 is illustrated in the oxygen of a link in the link structure that silicon and Sauerstoffatom alternately occur, the oxygen of two links of 2/2 expression, the oxygen of three links of 3/2 expression, 4/2 oxygen of four links of expression then.

Similarly, a constituent is write a Chinese character in simplified form the subscript H of M, D or T top, for example M ^HOr DH, represent that a hydrogen atom has replaced a R substituting group, represents that this chemical seed has changed so-called hydride or hydrogen polysiloxanes into.In addition, subscript vi represents a vinyl substituted base particularly, is often referred to alkenyl substitutents; General alkenyl substitutents is selected from the kiki alkenyl group of 2-40 carbon atom.

The applicant is defined as the contaminative solvent exist in the product any in this article and does not wish the solvent wanted.

Claims (10)

1. method of removing the contaminative solvent with certain boiling temperature from the solution that contains the polymkeric substance solute comprises:

(a) allow described solution contact with a kind of cosolvent with certain boiling temperature, wherein said cosolvent and described solute unmixing, the boiling temperature of described cosolvent is different from the boiling temperature of described contaminative solvent, and described cosolvent and described contaminative solvent form a kind of azeotrope; And

(b) will be by the described polymkeric substance of described contaminative solvent contamination spraying drying in the presence of described cosolvent, wherein said solvent and described cosolvent azeotropic steam,

Thereby described contaminative solvent just removes from described polymkeric substance.

2. the process of claim 1 wherein that described polymkeric substance is selected from polyester, polycarbonate and polysiloxane.

3. the method for claim 2, wherein said solvent is selected from benzene,toluene,xylene, contains the paraffinic hydrocarbon solvent of 1-20 carbon atom, contains alcoholic solvent of 1-10 carbon atom and composition thereof.

4. the method for claim 3, wherein said cosolvent is selected from water, ethylene glycol, propylene glycol, butanols, isopropylcarbinol, vinyl carbinol, acetic acid, ethylene chlorhydrin, quadrol, nitroethane, pyruvic acid, 1-chloro-2-acetone, Epicholorohydrin, propionic acid and 1,2-acetone glycol.

5. the method for claim 4, wherein said polysiloxane has following general formula:

M _iD _jT _kQ _pWherein subscript j and k are zero, and subscript i and p are the positive numbers of non-zero, and the general formula of M is:

R ₃SiO _1/2, wherein R is independently selected from the alkyl of hydrogen, a 1-40 carbon atom, the alkenyl of a 2-40 carbon atom, the aryl of a 6-40 carbon atom and the alkaryl of 7-40 carbon atom; The general formula of Q is:

SiO _4/2。

6. use the spraying drying siloxane polymer of the method production of claim 5, wherein the concentration of the contaminative solvent in the spraying drying siloxane polymer is below about 7ppm.

7. method that is used for removing from the solution that contains solute the contaminative solvent with certain boiling temperature comprises:

(a) allow described solution contact with a kind of cosolvent with certain boiling temperature, wherein said cosolvent and described solute unmixing, the boiling temperature of described cosolvent is different with the boiling temperature of described contaminative solvent, and described cosolvent and described contaminative solvent form a kind of azeotrope; And

(b) with described by the solution of solvent contamination spraying drying in the presence of described cosolvent, wherein said solvent and described cosolvent azeotropic steam, thus described contaminative solvent is just disposed from described solute.

8. the method for claim 7, wherein said spraying drying are carried out not being higher than under the atmospheric pressure.

9. method that is used for removing contaminative solvent with certain boiling temperature from the solution that contains the polymkeric substance solute, this method is made of following steps basically:

(a) allow described solution contact with a kind of cosolvent with certain boiling temperature, wherein said cosolvent and described solute unmixing, the boiling temperature of described cosolvent is different with the boiling temperature of described contaminative solvent, and described cosolvent and described contaminative solvent form a kind of azeotrope; And

(b) with polymkeric substance spraying drying in the presence of described cosolvent of described contaminated property solvent contamination, wherein said solvent and described cosolvent azeotropic steam,

Thereby described contaminative solvent just removes from described polymkeric substance.

10. spray-dired siloxane polymer of the method with claim 1, wherein in the spraying drying siloxane polymer content of contaminative solvent below about 7ppm.