CN101104666B - Improved polymerization process - Google Patents

Abstract

An emulsion polymerization process for the preparation of polybutadiene grafted with styrene and acrylonitrile monomers in a reaction system is provided. The resultant product has a low end content of unreacted residual monomers, low yellowness index, and improved impact strength. The diene rubber is prepared via a process wherein a chain transfer agent is added on a continuous basis to give a rubber substrate having a low crosslink density. In one embodiment of the invention, the process includes charging the reaction system with a pre-selected diene emulsion with a low crosslink density, adding a first portion of at least one of a styrene monomer and acrylonitrile monomer to the diene emulsion, adding to the reaction system, over a predetermined time, an initiator and a second portion of acrylonitrile and styrene monomer, and polymerizing the catalyzed reaction mixture of diene substrate, styrene and acrylonitrile to form ABS graft polymers. In another embodiment, a third monomer is added after the conversion rate of the monomers is greater than 98%.

Description

Improved polymerization process

The application is that priority date is that July 24 calendar year 2001, international filing date are July 24, original applying number in 2002 the dividing an application for the PCT application for a patent for invention that enters country's stage of " improved polymerization process " that be 02818646.X (2005101180765), invention exercise question.

This invention relates generally to a kind of method that has the polymkeric substance of low residual monomer content in the material property that keeps such as flowability, shock strength and color for preparing.

Background of invention

In prepare the two step embodiments of ABS with typical emulsion process, in the first step, prepare latex.EPA762693 discloses the first step of emulsion process, for the preparation of the Semi-batch Process of diene latex, wherein adds chain-transfer agent such as uncle's lauryl mercaptan (t-ddm) before the reaction beginning, with divinylic monomer and initiator.In order in latex, to obtain enough low cross-linking density, consider raw materials cost and by the reactor fouling of chain-transfer agent generation and the problem of the remaining smell in final ABS product, must add senior chain-transfer agent.

In the second step of emulsion process, can make vinyl cyanide and vinylbenzene and butadiene latex carry out letex polymerization, form acrylonitrile-butadiene-styrene (ABS) (ABS) graftomer.The polyreaction trend is finished.But, even sometimes when polymerization is finished substantially, the dissolving of a certain amount of undesirable acrylonitrile monemer and/or styrene monomer also arranged or be trapped in the polymkeric substance, and in reaction system remaining moisture still.Steam stripped general cell operation by vacuum or steam stripped reaction system content can not be removed all this undesirable remaining vinyl cyanide and/or styrene monomer.

Since it begins as Industrial materials, it has been recognized that the importance of monomer conversion in the ABS material.The hypertoxicity of vinyl cyanide is known, and divinyl is all relevant with health problem with styrene monomer.From the viewpoint of producing, with recovery, the recycle of residual monomer or process relevantly, utilizing fully of monomer helps to obtain higher productivity and lower cost.And the standard be applicable to their factory must be observed by manufacturers, and described standard limits the release of the volatile material of allowing.In market, more and more require to provide the ABS material with low volatility material (for example, chip component).

There are a lot of methods to be used for obtaining in the low residual monomer level of ABS product.In many cases, the polymeric material after separating is undertaken by drying in baking oven or fluidized-bed.This " pipe end (end-of-pipe) " method has been considered the very big reduction of residual monomer, but obtains desired reduction take risk capital and working cost as cost really.A kind of potential more effective method is to require to transform more completely in the polyreaction monomer.Even in this method, many different techniques have also been used.

During main reaction and graft reaction all taked the use at other monomer helpful aspect the transformation efficiency when finishing.For example, during reaction use vinyl carboxylates.Other patent disclosure when reaction finishes, use other monomer, comprise divinyl (US patent No.4,272,425), vinyl cyanide (US patent No.4,822,858), n-vinyl mercaptan (German Patent No.DE3,327,190) and methyl methacrylate (MMA) (US patent No.3,991,136-in polymerization at least about after 90% the monomer composition).The operation of the monomer that major part is other also comprises the initiator that some are other really.US patent No.4,301,264 disclose at last stage reaction and have used the second initiator.

The problem of existing method be not the level of residual monomer still than desirable height, be exactly that the loss of following at other physicals (for example, color or shock strength) aspect is so that final material has no magnetism as industrial goods.

As mentioned above, wish to reduce very much the discharging with volatile harmful organic constituent.When graft polymerization stops, rising along with ABS graftomer transformation efficiency in the polyreaction of such reduction residual monomer (it finally becomes harmful volatile organic compounds), the rubber cross density of graftomer also raises, so adversely affect shock strength, particularly under low (subzero) Fahrenheit temperature.

In order to improve low temperature impact strength, in the past, typically or improve the graftomer molecular weight, and/or use higher molecular weight matrix styrene acrylonitrile copolymer (SAN).But any one in these two kinds of methods all improved the melt viscosity of mixture, therefore adversely affected flowability and the processing characteristics of mixture.The another kind of method of using is the rubber level that improves in product forms, and has so also reduced flowability and modulus.

Summary of the invention

In one embodiment of the invention, provide Semi-batch Process to prepare lower crosslink density elastoprene matrix.The method comprises that said liquid batch of material comprises water, emulsifying agent and diene monomers to reaction system adding original liquid batch of material.Add to reaction system the liquid batch of material finish in or afterwards, the method further comprises to reaction system and adds the liquid feeding composition that comprises divinyl, initiator and chain-transfer agent.The continuous adding of chain-transfer agent can be used for preparing the crosslinked elastoprene matrix of low density.

In another embodiment, provide and optimized the flowability of ABS graftomer and the method for low temperature impact strength, the method comprises the rubber cross density for the preparation of the diene matrix of ABS graftomer connected with the ABS graftomer room temperature and the low temperature impact strength that make thus, and the diene matrix of the selection suitable cross-linking density relevant with low temperature impact strength with the desirable flowability of ABS graftomer.

In the 3rd embodiment, provide in the monomer quantity discharged that obtains higher conversion and reduction, in ABS graftomer product, keep the method for flowability-impact balance.The method comprises by selecting than the diene matrix compensation of lower crosslink density (%A) raising (because the transformation efficiency that improves) at ABS graftomer middle crosslink density (%A), with preparation ABS graftomer product.

In yet another embodiment of the present invention, provide the emulsion polymerization that in reaction system, prepares vinylbenzene and acrylonitrile monemer grafting polyhutadiene.Final product has the residual monomer of low final content.The method comprises: a) the diene latex is feeded to reaction system; B) within the predetermined time, add optional initiator, vinyl cyanide and styrene monomer to reaction system; C) make the reaction mixture polymerization of the catalysis of polyhutadiene, vinylbenzene and vinyl cyanide; And d) the transformation efficiency of monomer be about 98% or higher after, add the 3rd monomer and optional initiator to reaction system.

In another embodiment, provide preparation to have the emulsion polymerisation process of the ABS graftomer of low yellowness index.The method is included in the suitable ratio of keeping unreacted vinylbenzene and acrylonitrile monemer in the reaction system.

Brief Description Of Drawings

Fig. 1 represents the relation curve of rubber cross density (%A) with the rubber cross density (%A) of matrix of ABS graftomer.

Fig. 2 represents the at room temperature relation curve of the rubber cross density (%A) of breach Izod shock strength and ABS graftomer.

Fig. 3 is illustrated in the relation curve of the rubber cross density (%A) of breach Izod shock strength and ABS graftomer under the low temperature (20 ℃).

Fig. 4 is superimposed curves, when expression is satisfied low NAV and required, needs best rubber cross density (%A) in the matrix of low temperature (20 ℃) breach Izod shock strength.

Fig. 5 is the result's of experimental design (DOE) curve, the dependency of the continuously feeding of expression chain-transfer agent t-DDM and the cross-linking density of elastoprene matrix.

Detailed Description Of The Invention

Can prepare abs polymer by emulsion or mass polymerization.Emulsion polymerization is two-step approach, and the first step prepares latex, and second step is used at latex polymerizing styrene and vinyl cyanide to form the ABS emulsion.By adding stablizer, from the coagulum of ABS emulsion, reclaim abs polymer, slurry is filtered or centrifugation recovery ABS resin.

Prepare lower crosslink density latex by continuous adding chain-transfer agent.In an embodiment of emulsion polymerisation process of the present invention, obtain lower crosslink density latex.The applicant is surprised to find that, with in the former processing method chain-transfer agent charging by batches (adding all chain-transfer agents when the reaction beginning) is compared, during the feeding part of the Semi-batch Process for preparing latex, add continuously chain-transfer agent and can be used for preparing lower crosslink density latex.

In one embodiment of the invention, latex is diene latex.Suitable diene monomers charging comprises divinyl and isoprene and different comonomers, so just can prepare divinyl with less than comonomer such as vinylbenzene, vinyl cyanide, methyl methacrylate or the vinylformic acid C of 50 % by weight ₁-C ₆The multipolymer of-alkyl acrylate.In another embodiment, adding is less than the comonomer of 35 % by weight.

Based on the total amount of monomer, the comonomer that exists in the rubber is on the level that is less than 50 % by weight, and preferred 40 % by weight are more preferably less than about 25 % by weight.General because comonomer trends towards reducing the efficient of reflux cooling, most preferably do not use comonomer.Suitable comonomer comprises vinyl aromatic monomers and vinyl nitrile (unsaturated nitrile) monomer.

Spendable monovinylidene aromatic monomer (vinyl aromatic monomers) comprises vinylbenzene, alpha-methyl styrene, halogenated styrenes, such as Dowspray 9, at nuclear ring the monovinylidene aromatic monomer of single or two alkyl, alkoxyl group or hydroxyl substituent is arranged, such as Vinyl toluene, vinyl-dimethyl benzene, butylstyrene, 4-Vinyl phenol or methoxy styrene or its mixture.Employed monovinylidene aromatic monomer is generally by shown in the following formula:

Wherein X is selected from alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkoxyl group, aryloxy and the halogen of hydrogen, 1～5 carbon atom; R is selected from alkyl and the halogen of hydrogen, 1～5 carbon atom, such as bromine and chlorine.The vinyl aromatic compounds that replaces comprises vinylbenzene, 4-vinyl toluene, 3,5-diethylbenzene ethene, 4-n-propylbenzene ethene, alpha-methyl styrene, Alpha-Methyl Vinyl toluene, α-chloro-styrene, bromstyrol, dichlorostyrene, Dowspray 9, tetrachlorobenzene ethene and their mixture etc.The preferred monovinylidene aromatic monomer that uses is vinylbenzene and/or alpha-methyl styrene.

Suitable vinyl nitrile monomer comprises the vinyl nitrile of vinyl cyanide and replacement, such as methacrylonitrile.The vinyl cyanide of vinyl cyanide and replacement is generally by shown in the following formula:

R wherein ¹Can be selected from the identical group with the defined R in front.The example of this monomer comprises vinyl cyanide, ethyl acrylonitrile, methacrylonitrile, α-chloro-acrylonitrile and α-bromopropylene nitrile.Be noted that above cited monomer is useful during the first step polymerization divinyl is with preparation diene latex, and also is useful during the second step emulsion polymerization prepares the ABS graftomer.

In order to improve final polymer performance, in emulsion polymerization systems of the present invention, add chain-transfer agent.Chain-transfer agent is generally as molecular weight regulator.The polymer chain effect of chain-transfer agent and growth forms " non-activity " polymkeric substance, is formed for simultaneously the new center of polymer growth.For example, typical chain-transfer agent is organosulfur compound, such as C ₁-C ₁₅Alkyl sulfhydryl, preferably just-, different-and uncle-lauryl mercaptan.According to specific chain-transfer agent (" CTA "), employed monomer or the mixture of monomer, employed initiator, polymeric reaction condition etc., be recognized that the amount of employed chain-transfer agent can change.In one embodiment, the amount of adding CTA is about 0.1～3 weight part CTA/100 weight parts monomers.In second embodiment, this amount is about 0.1～2 weight part CTA/100 weight parts monomers.In other the 3rd embodiment, this amount is about 0.2～0.5 weight part.

In one embodiment, the chain-transfer agent of about 10-50% joins in the original liquid batch composition, and remaining chain-transfer agent is included in the continuously feeding composition.In an other embodiment, 100% chain-transfer agent adds with continuously feeding.

Stablizer and/or emulsifying agent also join in the letex polymerization by this way, so that the final size of control finished product latex.Emulsifying agent is known and usually employed in letex polymerization (D.C.Blackley, Emulsion Polymerization, Chapter7, Applied Science PublishersLtd, London, 1975).

According to the present invention, operable emulsifying agent comprises so-called anionic emulsifier, such as high fatty alcohol sulfuric ester, senior alkyl sulphonate, alkyl aryl sulfonate, aromatic yl sulphonate and they and the condensation product of formaldehyde, salt and the sulfuric ester ethylene oxide adduct of esters of sulfosuccinic acids; So-called nonionic emulsifying agent comprises oxyethane and Fatty Alcohol(C12-C14 and C12-C18), known response product, oxyethane and lipid acid such as lauryl alcohol, myristyl alcohol, hexadecanol, stearyl alcohol and oleyl alcohol, such as lauric acid, nutmeg acid, palmitinic acid, stearic acid and oleic acid and their amic known response product and oxyethane and alkylphenol, such as the known response product of isooctylphenol, different nonyl phenol and 4-dodecylphenol.

Based on the total amount of used monomer, the general consumption of emulsifying agent is 0.1～10wt.%, is in particular 0.2～8wt.%.

In emulsion process, also adopt radical initiator known in the art to improve speed of reaction.Initiator can be with the charging introducing so that the thermogenesis rate reaches maximum value at the emulsion process initial stage.The example of initiator comprises water soluble starter, such as peralcohol, and particularly inorganic peroxysulfate compound such as ammonium persulphate, Potassium Persulphate and Sodium Persulfate; Superoxide such as hydrogen peroxide; Organic hydroperoxide is such as isopropyl benzene hydroperoxide, tertbutyl peroxide, acetyl peroxide, lauroyl peroxide; Peracetic acid and peroxybenzoic acid; Redox initiator, wherein water-soluble reductive agent such as ferrous compound, has promoted the decomposition of superoxide, persulphate etc.; And other free-radical generating material, such as 2,2 '-Diisopropyl azodicarboxylate, 4,4 '-azo two (4-cyanovaleric acid) etc.In one embodiment, initiator is the combination of oxide of high activity reduction initiator such as cumene hydroperoxide hydrogen or other hydroperoxide and other compound such as reductive agent, heavy metallic salt and complexing agent.In one embodiment, the rate of initiation reaction of adding initiator generation is at least about and per hour has the diene that accounts for its total amount 10% to react.In another embodiment, rate of initiation reaction is 15～20%.

Semi-batch Process for the preparation of dialkylene latex comprises: a) add the original liquid batch composition that comprises water, emulsifying agent, diene monomers, optional chain-transfer agent, initiator and/or comonomer such as vinyl cyanide and vinylbenzene, optional inorganic and organic salt in the reaction system; B) inject in the container and comprise diene monomers and chain-transfer agent, optional comonomer such as the liquid feeding composition of vinyl cyanide and vinylbenzene and initiator, wherein initiator can be soluble in water; C) during continuously feeding, cool off; D) during continuously feeding and make afterwards diene monomers reaction.Feeding rate should make the level of unreacted diene monomers reach minimum value, and the peak value of heat generation results from the process initial stage.。

In one embodiment, the liquid batch composition also comprises ionogen, reductive agent, heavy metallic salt and complexing agent.The original liquid batch composition can comprise 10～30 % by weight of diene monomers total amount used in the method.12～28 % by weight that can comprise in one embodiment, the diene monomers total amount.15～25 % by weight that can comprise in another embodiment, the diene monomers total amount.This low-level initial diene monomers is used for the control than high reaction rate.

Charging is within the regular hour, adds remaining diene monomers and chain-transfer agent with controlled rate to reactor.Based on the cumulative volume of initial batch liquid phase compositions, continuously feeding be with 5～20 volume %/hour speed carry out, and finish charging in the method during initial 2～12 hours.During reaction by using agitator to mix.

In one embodiment of the invention, the continuously feeding composition comprises used chain-transfer agent in 100% the reaction of diene monomers and total amount.In second embodiment, continuously feeding comprises about 80% used chain-transfer agent of total amount.In one embodiment, the control charging to be obtaining in reactor final liquid volume as at least 80 volume % (based on the cumulative volume of reactor), and the transformation efficiency of diene monomers is 80wt.% (based on the total amount of diene used in the method) at least.In another embodiment, final liquid volume is that 84 volume % and diene monomers transformation efficiency are at least 90% (based on the total amount of diene used in the method).In another embodiment, the transformation efficiency of diene monomers is at least about 93%.

The original liquid batch composition that is fed to reactor is about 40%～about 80% of reactor volume.In one embodiment, for its 50%～70%.In another embodiment, be 50～60%.Volume of a container is defined as the internal volume that can be used for the container that taken by the liquid that contains diene reactant and steam.The cooling that relatively low original liquid level is used for the effective vapour space reaches maximum; And when using the high reactivity initiator in feed composition, relatively low and make the maximized while of effective steam cooling space in fluid level, speed of reaction and thermogenesis rate can reach peak value at the process initial stage.

The reaction times of Semi-batch Process typically is about 5-20 hour, and temperature of reaction is about 120 ℉～about 185 ℉, and is preferably 135 ℉～165 ℉.In one embodiment, the reaction times of Semi-batch Process of the present invention is about 5～15 hours.In the 3rd embodiment, be about 8～12 hours.Reactor pressure depends on temperature of reaction, typically is 20-150psig.When the vapour space was maximum in container, speed of reaction generally reached peak value at initial two hours of reaction, and maximum vapour space cooling makes vapour space cooling reach maximum, and vapour space cooling is generally more effective than the fluid space cooling.

In one embodiment of the invention, the viscosity of latex of latex is not higher than 200 centipoises (for example, use Automation Products, Lnc.Model#CL-10-10DV3 online viscometer measures).In another embodiment, the viscosity of latex in the whole reactor is 50～200 centipoises.

In one embodiment, the number average particle size diameter that the latex of generation has is 600 dusts～1200 dusts, and the granule number that diameter is lower than 500 dusts is less than 10%.The viscosity of reaction liquid is less than 200 centipoises in the preferred whole reactor.

In one embodiment of the invention, the final cross-linking density (%A) of polyhutadiene be about 10～about 60, and in another embodiment, be about 20～about 50%.In the 3rd embodiment.The final cross-linking density (%A) of polyhutadiene is about 24～44%.The cross-linking density of rubber represents with %A, its measuring method can be at " Pulsed NMR Analysis of Polybutadiene Emulsion PolymerizationReactions:Preliminary Evidence for Changes in Cross-Link Density; " Donald H.Ellington, GE Plastics, Bruker Minispec Application Note36 finds in 1991.

The time-delay of the 3rd monomer adds.In the second step of emulsion polymerization of preparation ABS, make monovinylidene aromatic hydrocarbon monomer (such as vinylbenzene) and vinyl unsaturated nitrile monomer (such as vinyl cyanide) in latex polymerization to prepare the ABS blendlatex.In the embodiment of Semi-batch Process, the first fuel loading that comprises the matrix of water, tensio-active agent and polyhutadiene adds reaction system, and finish in the end or afterwards at first fuel loading, carry out the preimpregnation operation, this operation comprises the mixture that adds at least a vinylbenzene, vinyl cyanide or vinylbenzene and vinyl cyanide.

The applicant has found that the delay adding of the 3rd monomer until monomer conversion is higher than 98%, has unexpectedly reduced the amount of residual monomer or the cinnamic NAV of unreacted.Transformation efficiency is that total transformation efficiency take monovinylidene aromatic hydrocarbon monomer and vinyl unsaturated nitrile monomer is as benchmark.The ABS that makes has the unreacted residual monomer of low levels.The adding of the delay of the 3rd monomer herein refers to " feeding intake afterwards " and adds.In another embodiment, the delay of initiator adding is carried out with the 3rd monomer.

Based on the monomer composition that comprises monovinylidene aromatic hydrocarbon monomer and vinyl unsaturated nitrile monomer reactivity highly being arranged, be chosen in the monomer conversion mark and reach the 3rd monomer that joins the emulsion graft polymerization reaction after 98%.In one embodiment, the 3rd monomer is to have the lower boiling monomer that is lower than 120 ℃ so that it can pass through coagulation, washing and dry easily volatilization from latex between the payback period of blend glue.

The 3rd monomer typically comprises methyl acrylate, ethyl propenoate, butyl acrylate, 2-ethylhexyl acrylate, the vinylformic acid cyclohexyl ester, the vinylformic acid benzyl ester, isopropyl acrylate, methyl methacrylate, β-dimethyl-aminoethylmethacrylate, butyl methacrylate, isopropyl methacrylate, methacrylic acid isodecyl ester, the methacrylic acid cyclohexyl ester, the methacrylic acid benzyl ester, acrylamide, Methacrylamide, vinylidene chloride, inclined to one side sym-dibromoethane, vinyl esters, for example vinyl acetate between to for plastic base ester and vinyl propionate base ester, the dialkyl of toxilic acid or fumaric acid is such as dimethyl maleate, ethyl maleate, dibutyl maleinate, dimethyl fumarate, DEF and dibutyl fumarate.In one embodiment, the 3rd monomer is selected from methyl acrylate and methyl methacrylate.

In an embodiment of the graft polymerization method for preparing ABS, the method comprises matrix, such as diene latex, feed to reaction system, at least a vinylbenzene and a kind of vinyl cyanide that add first part in the diene latex, then at least a vinyl cyanide and the styrene monomer that add in the given time catalyzer (or initiator) and second section make the catalyzed reaction polymerization of mixtures of diene latex, vinylbenzene and vinyl cyanide.Graft polymerization procedure can comprise emulsifying agent, and this emulsifying agent is the molecule with hydrophobic end and hydrophilic end.Term used herein " matrix " refers to the latex skeleton that makes vinylbenzene and acrylonitrile grafting thereon.In another embodiment, before initiator adds, do not have preimpregnation or do not add vinylbenzene and/or the vinyl cyanide of first part.

In one embodiment, matrix is the polyhutadiene emulsion, and this emulsion adopts emulsifying agent, makes it to be scattered in the water such as fatty acid soaps or high molecular weight alkyl or alkaryl sulfuric ester or sulphonate.In another embodiment, matrix can be homopolymer, divinyl and the isoprene of the homopolymer of polyhutadiene, styrene butadiene rubbers (SBR), acrylonitrile-butadiene rubber (NBR), chloroprene, isoprene or chloroprene, 2-methyl isophthalic acid, 3-divinyl, 2,3-dimethyl-1,3-divinyl, 1,2-propadiene, Isosorbide-5-Nitrae-pentadiene, 1,5-hexadiene, 1, the multipolymer of 2-pentadiene and ABS.Matrix can for equally distributed, non-uniform Distribution, directly increase or chemically or gluey cohesion ground.When graft reaction carries out with semi-batch, intermittence or continuous mode, require to use equally distributed matrix.Typically, the mean particle size of matrix is about 150 nanometers～about 500 nanometers.If use the matrix that directly increases, size-grade distribution is about 60 nanometers～about 500 nanometers.

The catalyzer that uses in graft reaction or initiator comprise superoxide and/or azo-compound, and they are activated in grafting and can resolve into free radical.Except redox initiator, also can use to have the peroxy initiator that the free radical ability is provided as reaction.Example comprises cumene hydroperoxide hydrogen (CHP), Sodium Persulfate, Potassium Persulphate, ammonium persulphate, diisopropyl benzene hydrogen peroxide, tert-butyl peroxide and 2,2 '-Diisopropyl azodicarboxylate (AIBN) is combined with other compound such as reductive agent, heavy metallic salt and complexing agent.In one embodiment, initiator is isopropyl benzene hydroperoxide and redox catalyst, such as the combination of iron (II) sugar or vanadium sugar.If can obtain enough rates of polymerization, thermal initiator should provide similar result.Can adopt at each time interval and add single initiator system or composite initiator.Can be at different time, be included in the 3rd monomer add at the beginning of, during the 3rd monomer adds, the 3rd monomer add finish in or afterwards, add initiator.If necessary, can use one or more rear monomers that adds.

In one embodiment, in reaction system, add and to make polyreaction continue the initiator of the q.s that carries out.In another embodiment, initiator or catalyzer are 0.01～2 % by weight of polymerization single polymerization monomer.In second embodiment, add initiator with the amount of about 0.1～0.5wt.% of polymerization single polymerization monomer.In another embodiment, during adding monomer component, add initiator to guarantee to help graft reaction.

In quadrature embodiment of the present invention, make the 3rd monomer and/or initiator after the interpolation that feeds intake postpone, until the transformation efficiency of vinylbenzene and acrylonitrile monemer (based on the original acrylonitrile monemer that is fed to the reactive polymeric system) is higher than about 98% in one embodiment, or be higher than in another embodiment 99%, or in another embodiment, be higher than 99.5%.

The emulsifying agent that can be used for graft polymerization procedure comprise the alkali metal soap of fatty acid soaps, high molecular weight alkyl or alkaryl sulfuric ester or sulphonate or ammonium soaps etc.By per 100 weight parts monomers compositions, the total amount of emulsifying agent is about 0.1～8 weight part.

Can be intermittently, semi-batch or operate continuously carry out aforesaid method.If employing semi-batch operation, the initial charging that will comprise so the matrix of water, tensio-active agent and polyhutadiene adds reaction system, and initial charging finish in or afterwards, carry out the preimpregnation operation, this operation comprises the mixture that adds at least a vinylbenzene, vinyl cyanide or vinylbenzene and vinyl cyanide.In one embodiment, the temperature of reaction system is about 100 ℉～about 200 ℉.In second embodiment, be about 120 ℉～180 ℉.In the 3rd embodiment, be about 130 ℉～about 160 ℉.

By using heat exchanger to dispel the heat fully, so that polymerization system remains on satisfactory temperature so that satisfactory polyreaction to be provided.In reaction system, use and stir.The amount that stirs and stirring type want to make reactor content to produce good dispersion and produce desirable heat transfer capacity.

The suitable ratio applicant who keeps monovinylidene aromatic hydrocarbon monomer and vinyl unsaturated nitrile monomer also finds to be higher than about 1.5:1 when the ratio that makes unreacted benzene ethene and vinyl cyanide in emulsion polymerization process remains on, by keeping vinylbenzene abundance in the reaction, being characterized as of final composite prod has low yellowing.

In one embodiment, wherein add the 3rd monomer in the reaction later stage, the ratio of the total styrene monomer that adds and the acrylonitrile monemer of adding is about 1.5:1～about 4:1, and in another representative embodiment, this ratio is about 2:1～about 3.5:1.

In one embodiment, the ratio of total elastoprene of adding and the summation of styrene monomer and acrylonitrile monemer is about 0.1:1～3.0:1, and in another representative embodiment, this ratio is about 0.2:1～about 2:1.

In another embodiment, for obtaining the final product of low yellowing and low residual monomer amount, the rear material of the 3rd monomer is added postpones, until the transformation efficiency of vinyl cyanide be higher than 99% and the ratio of unreacted vinylbenzene and unreacted vinyl cyanide be approximately higher than 4.

In one embodiment, in about 30 minutes～about 200 minutes time range, with at least a reaction system that joins of vinyl cyanide and styrene monomer.In another embodiment, in about 45 minutes～about 160 minutes time range, be about 1:3～about 1:5 with at least a ratio that joins reaction system first part styrene monomer and second section styrene monomer of vinyl cyanide and styrene monomer, and the ratio of first part's acrylonitrile monemer and second section acrylonitrile monemer is about 1:3～about 1:5.In one embodiment, at least a styrene monomer of first part and acrylonitrile monemer or their mixture are joined in the polyhutadiene emulsion.In another embodiment, disposable interpolation styrene monomer and disposable interpolation acrylonitrile monemer.

In another embodiment, after the interpolation of initiator, acrylonitrile monemer and styrene monomer is finished, reaction was carried out about 40～90 minutes, then added about 0.5～about 5.0 part of the 3rd monomer/100 part total polymkeric substance and monomer and/or other initiator in the reaction mixture.

Optimize the rubber cross density of matrix: as previously mentioned, when when transformation efficiency is 90～95%, adding the 3rd monomer, in the grafted ABS polymkeric substance, realize good NAV reduction, and when reaching at transformation efficiency when adding the 3rd monomer after 98 and 99%, can be implemented in shockingly fabulous result of NAV reduction aspect.But along with the delay of the 3rd monomer is added, no matter transformation efficiency is more than 90% or more than 99%, and the impact property of ABS graftomer is all bad.In the present invention, the applicant has found to optimize by the rubber cross density of the optimizing diene matrix suitable rubber cross density relevant with the desirable room temperature of ABS graftomer and/or low temperature impact strength with selection (therefore compensation is added relevant low shock strength with the delay of the 3rd monomer) method of the impact property of ABS graftomer.

When using this embodiment, resulting product also has the unreacted residual monomer of low levels except the shock strength that improves uniquely with above-mentioned embodiment (interpolation of the 3rd monomer and reduction cross-linking density %A).

In the present invention, when realizing the monomer discharging of higher conversion and reduction by compensation ABS graftomer middle crosslink density (%A) rising (because the transformation efficiency that raises), obtain the balance of flowability-impact property in ABS graftomer product.Above-mentioned compensation is to realize by the diene matrix of selection than lower crosslink density (%A).

In one embodiment of the invention, the cross-linking density that has of diene matrix is 20-60%A.In second embodiment, cross-linking density is 25-45%A.In another embodiment, use cross-linking density to obtain best product performance as the diene matrix of 30-45%A.

Should be noted that emulsion polymerization of the present invention can interrupter method, Semi-batch Process or continuous processing carry out.

Embodiment

Further describe the present invention with reference to following examples, given embodiment only in order to illustrate not in order to limit scope of the present invention.

Embodiment 1-13 is fundamental test, and expression prepares high rubber ABS graftomer according to embodiment of the present invention by using vinylbenzene and acrylonitrile grafting polyhutadiene.According to following general process Preparation Example 1-13.In 3 liters of reactors, add the initial charging of polyhutadiene emulsion, and be heated to 57.2 ℃.Then in reactor, add 12.06 parts by weight of styrene as " preimpregnation "; After about 20 minutes of preimpregnation, begin to add 0.375 part of isopropyl benzene hydroperoxide initiator, within 70 minutes time, initiator is joined reactor; Begin to add 12.05 parts of vinyl cyanide after 5 minutes beginning to add initiator, within 65 minutes time, vinyl cyanide is joined reactor; Begin to add 24.09 parts of vinylbenzene after 10 minutes beginning to add initiator, within 60 minutes time, vinylbenzene is joined reactor.

In fundamental test, there is not the delay of the 3rd monomer to add, it should be noted that the NAV of product is high.

Embodiment 14 is comparative example, its preparation is similar to above-mentioned fundamental test embodiment 1-13, except before beginning to add initiator, in the polyhutadiene emulsion, not adding vinylbenzene, replace and beginning to add initiator after 10 minutes, the vinylbenzene that will all measure within 60 minutes time (36.15 parts) is fed in the reactor.When reaction is finished, the amount of residual styrene and acrylonitrile monemer and being shown in the following table 1 in the analytical reaction product.Experimental result is still the NAV height, and more than 3500 parts/1,000,000 parts (ppm) vinylbenzene.The result is as follows:

Table 1

Embodiment	The polyhutadiene emulsion	Residual styrene (ppm)	Remaining vinyl cyanide (ppm)
				1	A *	4938	1303
2	A *	2497	2561
				3	A *	4389	1031
4	A *	4683	1349
				5	B **	5098	1533
6	B **	4892	679
				7	B **	3388	1134
8	B **	3950	1046
				9	B **	4004	861
10	B **	3538	1415
				11	B **	3320	1305
12	B **	4285	1735
				13	B **	3800	775

14

B **

6900

575

^*Latex A is that to have cross-linking density be that 56%A, mean particle size are the equally distributed polyhutadiene emulsion of 290～320 nanometers.

^*Emulsion B is that to have cross-linking density be that 30-36%A, mean particle size are the equally distributed polyhutadiene emulsion of 290～320 nanometers.

Embodiment 15-31 represents to prepare ABS according to postponing to add the 3rd monomer.In these embodiments, do not comprise " preimpregnation " but comprise that the method with the monomer of vinylbenzene and acrylonitrile reactor " feeding intake afterwards " adopts vinylbenzene and acrylonitrile grafting polyhutadiene.Prepare these embodiment according to following general process.The initial charging of polyhutadiene emulsion B is joined in 3 liters of reactors, and be heated to 57.2 ℃.Then, add 0.475 part of CHP initiator.Within the time of 70 minutes (embodiment 15-27) or 85 minutes (embodiment 28-31), initiator is joined reactor.The starting point of initiator is counted T=0, when T=0, and charging and the cinnamic charging of beginning vinyl cyanide.Within the time of 70 minutes (embodiment 15-27) or 90 minutes (embodiment 28-31), vinyl cyanide is joined reactor.In the time of between T=110 minute and T=160 minute certain, with after the initiator that feeds intake and after the monomer that feeds intake within 5 minutes time, join reactor.In embodiment 28 and 30, after the initiator and the monomer that feed intake add in batch.For each embodiment, the monomer of add-on and initiator and adding sees Table 2.

Reaction one is finished, with regard to the amount of residual styrene and acrylonitrile monemer in the analytical reaction product.It is desirable containing in final product and being less than 3500 parts/1,000,000 (ppm) vinylbenzene.Should be noted that according to the present invention, (when T is 135 and 160 minutes then feed intake) added in the delay of the 3rd monomer, than the Zao interpolation of the 3rd monomer in the prior art (when T is 110 minutes then feed intake), can produce residual styrene and the vinyl cyanide of surprising more low levels.

Be noted that the time of origin (T) that feeds intake after slower produces the more residual monomer of low levels.For example, see embodiment 15 and 18, embodiment 27 and 16, embodiment 23 and 26 and embodiment 20 and 21.

Table 2

Embodiment	AN (part)	Vinylbenzene (part)	PB (part)	After the T=that feeds intake	After the Init that feeds intake	After the Init (part) that feeds intake	After the Mon. that feeds intake	After the Mon. (part) that feeds intake	Residual styrene (ppm)	Remaining AN (ppm)
											15	11.800	35400	51.800	110	CHP	0.150	MMA	1.000	4214	168
16	11.300	33.900	51.800	160	CHP	0.250	MMA	3.000	1162	163
											17	11.550	34.650	51.800	135	CHP	0.200	MMA	2.000	1809	519
18	11.800	35.400	51.800	160	CHP	0.150	MMA	1.000	2957	139
											19	11.300	33.900	51.800	110	CHP	0.075	MMA	3.000	1337	204
20	11.300	33.900	51.800	110	CHP	0.150	MMA	3.000	1862	131
											21	11.300	33.900	51.800	160	CHP	0.150	MMA	3.000	974	97
22	11.550	34.650	51.800	135	CHP	0.200	MMA	2.000	1806	120
											23	11.800	35.400	51.800	110	CHP	0.250	MMA	1.000	3566	119
24	11.550	34.650	51.800	135	CHP	0.200	MMA	2.000	1168	147
											25	11.800	35.400	51.800	160	CHP	0.250	MMA	1.000	5543	267
26	11.800	35.400	51.800	160	CHP	0.250	MMA	1.000	2596	48
											27	11.300	33.900	51.800	110	CHP	0.250	MMA	3.000	1504	220
28	11.687	35.060	50.244	110	PPS	0.200	BA	3.000	660	693
											29	11.687	35.060	50.244	110	CHP	0.200	BA	3.000	686	527
30	11.687	35.060	50.244	135	PPS	0.200	BA	3.000	756	527
											31	11.687	35.060	50.244	160	CHP	0.200	BA	3.000	738	417

The AN=vinyl cyanide; The PB=polyhutadiene; The CHP=isopropyl benzene hydroperoxide; The PPS=Potassium Persulphate; The MMA=methyl methacrylate; With the BA=butyl acrylate, the Init.=initiator; The Mon.=monomer.T is the time (by minute mensuration) from the initiator initial charge begins to calculate.

In the comparing embodiment 32 of basic test, 50 parts vinylbenzene and vinyl cyanide (ratio is 3:1) are joined in the emulsion that contains 50 parts of polyhutadiene.Cause letex polymerization by the CHP redox system that adopts iron (II) sugar.Except before injecting initiator and residual monomer, adding 12 parts of vinylbenzene, monomer was fed in the emulsion within 70 minutes time.When 70 minutes finish, total solid content be 36% and the level of vinylbenzene and vinyl cyanide be respectively 3800 and 1500ppm.

In embodiments of the invention 33-38, there is not cinnamic preimpregnation.React in the mode of semi-batch Conditions of Emulsion Polymerization in addition.40 or 90 minutes delay (be used in the time of 110 or 160 minutes then feed intake) is arranged when adding methyl methacrylate monomer (MMA) together with other CHP initiator.Can point out to compare with basic test, for using 1 part or 3 parts of MMA, each situation of 0.15 or 0.25 part, adopt to postpone the interpolation time, low surprising of the amount of total residual monomer.

Table 3

Embodiment	Rear charging time	Part MM	Part CHP	Residual styrene (ppm)	Remaining AN (ppm)	Remaining MMA (ppm)	Total remaining (ppm)
								33	110	1	0.15	4214	168	248	4630
34	160	1	0.15	2957	139	451	3548
								35	110	1	0.25	3566	119	288	3973
36	160	1	0.25	2596	48	458	3102
								37	110	3	0.15	1862	131	788	2782
38	160	3	0.15	974	97	745	1816
								39	110	3	0.25	1504	220	1246	2970
40	160	3	0.25	1162	163	953	2278

In embodiment 41-47, polyhutadiene is that 50 parts, vinylbenzene are that 37 parts and vinyl cyanide are 13 parts.Some vinylbenzene are preimpregnation, that is, joined in the polyhutadiene before beginning and acrylonitrile polymerization.

The applicant has found in preimpregnation and has prolonged under the condition of supplying with the initiator time, it is the highest to obtain best transformation efficiency and the material of minimum color and luster (the most desirable aspect low yellowness index) the unreacted vinylbenzene that has and the ratio of vinyl cyanide, and most of colored materials is when containing most of vinyl cyanide.These data declarations add vinylbenzene in preimpregnation can obtain higher conversion, but coloured as cost take material height.

Table 4

Embodiment	Vinylbenzene preimpregnation amount	CHP part	CHP injection/the time	Styrene charge/time	PpmAN	Ppm vinylbenzene	YI@400F	YI@450F	YI@500F
										41	0	0.375	130	110	0	7633	24.8	25.7	26.2
42	0	0.375	100	90	373	5719	254	27.4	28.6
										43	0	0.475	100	110	0	6849	25.8	26.3	26.8
44	7.5	0.425	115	100	412	4715	282	29.0	29.8
										45	15	0.375	100	110	705	8314	28.4	28.9	29.9
46	15	0.375	130	90	1467	1693	29.8	30.8	31.5
										47	15	0.475	100	90	930	2255	33.1	34.3	354

Embodiment 48. in this embodiment, carry out experimental design (DOE), 5 factors (CHP initial level, styrene/acrylonitrile feed time, after feed intake middle CHP level, after feed intake middle methyl methacrylate level, after time of feeding intake), totally 19 tests.The statistical study explanation YI of yellowness index (YI) is not added by the delay of the 3rd monomer to be affected, as follows:

Term Coef StDev T P

Constant 25.7837 0.1800 143.241 0.000

CHP feeds intake 0.2800 0.1962 1.427 0.174

The monomer feed time 0.3887 0.1962 1.982 0.066

MMA charging-0.2450 0.1962-1.249 0.231

As implied above, with regard to YI, statistical significant factor is from the monomer feed time, that is, and and from the suitable ratio of keeping unreacted benzene ethene and vinyl cyanide.

Embodiment 49. in this embodiment, by operating weight than be the interrupter method preparation of 85/15 Butadiene/Styrene in the divinyl matrix of the different horizontal %A of cross-linking density, then make its even distribution with pressure.Carry out graft reaction in equally distributed matrix (51.3 parts of rubber), 34 parts of styrene monomers, 11.7 parts of vinyl cyanide and 3 parts of MMA are used for grafting.After finishing 30 minutes, vinylbenzene and vinyl cyanide charging add MMA.Measure the %A ' on the ABS graftomer.

The result relevant with the cross-linking density of divinyl rubber and product A BS graftomer is as follows:

The %A of matrix	The %A of HRG
		21.630.342.151.8	56.960.464.169.4

Embodiment 50. with the ABS graftomer among the embodiment 49 mix with SAN, compound, then be molded as the measurement that rod is used for breach Izod impact property under the room temperature.The result is as follows:

The %A of HRG	Izod shock strength (kJ/m2)
		56.960.464.669.4	17.016.013.612.3

Fig. 1 and Fig. 2 illustrate the data plot of rubber cross density role aspect the room temperature that defines the ABS graftomer and low temperature impact strength of elastoprene.As shown in Figure 1, found that polyhutadiene matrix provides baseline for the cross-linking density of rubber in the ABS graftomer.In Fig. 2, when the matrix cross-linking density of ABS graftomer hanged down, room temperature breach Izod shock strength improved.Because their mutual relationship, breach Izod shock strength depends on the rubber cross density of matrix.

Following Fig. 3 has shown the relation curve of the cross-linking density %A of rubber in-20 ℃ of breach Izod shock strengths and the ABS graftomer that comprises 70% polybutadiene rubber.

Embodiment 51. (amounting to 30 tests) 2 levels of experimental design, 4 factors according to the factor shown in the following table and setting, are carried out completely factor response surface central composite design (alpha of 1).The test of the central point that comprises 6 repetitions that the applicant does illustrates the impact of transformation efficiency and rubber cross density and has optimized flowability and low temperature impact properties.

The DOE factor and the setting of table 5-graft reaction

^*The umber of part=per 100 parts of ABS graftomer to be formed

The polyhutadiene matrix (according to the needed rubber level in the ABS graftomer that produces that arranges of selecting among the DOE) of water and requirement is feeded to reactor.According to the setting among the DOE, change the cross-linking density of the polyhutadiene matrix of reaction.After under the initial temperature (according to the setting of DOE, change temperature of reaction) batch of material being shifted out, add FeSO ₄The solution of the redox system of/tetrasodium pyrophosphate/fructose.Reactor is maintained the initial temperature of defined among the DOE, start the fresh feed pump of initiator (CHP), styrene monomer, acrylonitrile monemer and chain-transfer agent (t-DDM).Make the ratio of vinylbenzene and vinyl cyanide maintain about 3:1.Consumption between reaction and the reaction changes, so that the umber of polyhutadiene, vinylbenzene, vinyl cyanide and methyl methacrylate adds up to 100 parts.In about 45 minutes, finish the monomer charging.After the beginning monomer adds, through 50 minutes, within 5 minutes time, add " feeding intake afterwards " that 3 parts of methyl methacrylates also begin another part CHP simultaneously, and charging within 30 minutes time.Once you begin monomer charging makes temperature of reaction 8 ℉ that progressively raise in 40 minutes of beginning, then again rose to 160 ℉ in ensuing 20 minutes, in afterwards 60 minutes this temperature is remained unchanged.With about 5 hours of the ABS graftomer emulsion ageing that obtains, then add the oxidation inhibitor emulsion of appropriate amount, ageing is about 3 hours again.Then with acid emulsion is condensed, and the ABS graftomer is separated and drying.Just before condensing, emulsion is carried out the test of residual monomer content (NAVs).Make dry polymkeric substance and styrene-acrylonitrile (SAN) blend by melting mixing, be molded as proof stick, test breach Izod shock strength.

Fig. 4 represents DOE result, has shown in the volatile while that shows low non-water, for the best cross-linking density (%A) of rubber in the needed divinyl matrix of low temperature (20 ℃) breach Izod shock strength.As shown in the figure, by selecting to satisfy the matrix with suitable cross-linking density of shock strength needs, the non-water volatility of ABS graftomer can be designed in desirable level.Therefore, by reduce NAV and thereby reduce the polymerization process of monomer discharging, it is possible keeping the balance of flowability-shock strength in the ABS graftomer, and still can obtain higher conversion in the ABS graftomer.By selecting the polyhutadiene matrix than lower crosslink density (%A), the rising (because the transformation efficiency that improves) of %A can realize in the compensation ABS graftomer.

Embodiment 50 (21 tests)

In the present embodiment, carry out the DOE (2 of the partial factors of 21 tests ^(6-2)Individual additional central point) to determine the best way of control cross-linking density.The DOE factor that changes as shown in the following Table 6.

The factor	Explanation	Unit	Low-level	Central point	High level
						A	TFA soap charging level	pphm	1.50	2.00	2.50
B	The divinyl BD level of feeding	pphm	15.0	20.00	25.0
						C	Initial CHP feeding rate	pphm/hr	0.0028	0.0098	0.0168
D	Starting temperature	℉	142	145	148
						E	The t-DDM level of feeding	pphm	0.20	0.60	0.80
F	The t-DDM feed level	pphm/hr	0	0.06	0.12

Pphm: umber/100 part BD monomer

The initial charging that is used for the reactor of test comprises: 150 parts of water, 0.01 part of ferrous sulfate FeSO4,0.0039 part of EDTA, 0.4 part of tetrasodium pyrophosphate or TSPP, " E " part t-DDM (as shown in the DOE factor table), " B " part butadiene feed level (as above shown in the table) and 0.050 part of sodium sulfoxylate formaldehyde (sodiumformaldehyde sulfoxalate dyhydrate) SFS that dewaters.

The charging that is used for experiment is as follows: the 1st hour " C " part initial CHP; 0.0882 part CHP, with the speed of 0.0126pphm (part/100 parts of monomers) until react and finish; Divinylic monomer adds within 5 hours reaction times with the speed charging of 100-" B " (in upper table); " F " part t-DDM added within 5 hours reaction times.

Polish temperature is 160 ℉ (after the BD charging stops), and starting temperature is " D ".

Reaction process comprises at first making and is vacuum in the reactor, then adds initial charging water, FeSO4, ETDA, TFA soap, TSPP, initial TDDM and initial divinylic monomer.Reaction mixture is heated to starting temperature, then adds SFS.With reaction mixture 5 minutes, then carry out the CHP charging.The charging of beginning divinyl and t-DDM after the CHP charging begins 10 minutes.When divinyl and t-DDM charging are finished, the temperature of reaction mixture is risen to polish temperature.Continue the charging of CHP, until obtain 93%～96% transformation efficiency, then reaction mixture is cooled to 150 ℉.By vacuum any unreacted divinyl is removed, then the emulsion that obtains is evenly distributed to desirable granularity.The result is as shown in table 7.

DOE presentation of results shown in Fig. 5 during the butadiene feed part of reaction, can obtain lower crosslink density polyhutadiene matrix with the Semi-batch Process preparation by continuous interpolation t-DDM.The charging by batches of t-DDM is not effective aspect cross-linking density being reduced to be lower than 49%.Aspect the reduction cross-linking density, when adding the t-DDM replacement in beginning during the feeding part, add about effective 4 times.Therefore, use the t-DDM of low amount can obtain similar cross-linking density.When being used for the ABS graftomer when obtaining preferably low temperature impact strength (at high conversion time), lower cross-linking density is favourable.

Be somebody's turn to do invention although described with various specific embodiments, those skilled in the art can recognize that the change that utilizes in the spirit and scope of claim can realize the present invention.

Claims (6)

1. preparation has the method for the ABS graftomer of the unreacted residual monomer that hangs down final content, and the method comprises:

The diene emulsion is feeded to reaction system;

In the given time, vinyl cyanide and styrene monomer are joined reaction system with optional initiator;

Make the reaction mixture polymerization of diene, vinylbenzene and vinyl cyanide; With

After having reacted greater than 98% described vinylbenzene and acrylonitrile monemer, in reaction mixture, add the 3rd monomer, the 3rd monomer and vinylbenzene and acrylonitrile monemer all have reactivity highly,

Wherein the 3rd monomer comprises at least a in methyl acrylate, ethyl propenoate, butyl acrylate, 2-ethylhexyl acrylate, vinylformic acid cyclohexyl ester, vinylformic acid benzyl ester, isobornyl acrylate, methyl methacrylate, β-dimethyl-aminoethylmethacrylate, butyl methacrylate, IBOMA, methacrylic acid isodecyl ester, methacrylic acid cyclohexyl ester, the methacrylic acid benzyl ester.

2. the method for claim 1 further is included in when adding the 3rd monomer to reaction mixture, adds at least a initiator.

3. the method for claim 2, wherein initiator comprises at least a in isopropyl benzene hydroperoxide, Sodium Persulfate, Potassium Persulphate, ammonium persulphate, diisopropylbenzenehydroperoxide and the tert-butyl peroxide.

4. preparation has the emulsion polymerisation process of grafted ABS polymkeric substance of the shock strength of the unreacted residual monomer that hangs down final content and raising with formation with the diene of vinylbenzene and acrylonitrile grafting in reaction system, and described method comprises:

To comprise and having based on the ABS graftomer product of desirable shock strength and the emulsion of the diene of the cross-linking density %A that selects is feeded to reaction system;

At least a styrene monomer and the acrylonitrile monemer that add first part in the emulsion;

Make the reaction mixture polymerization of diene, vinylbenzene and vinyl cyanide; With

After described vinylbenzene at least 98% and acrylonitrile monemer have reacted, add the 3rd monomer in reaction mixture, the 3rd monomer and vinylbenzene and acrylonitrile monemer all have the reactivity of height,

Wherein the 3rd monomer comprises at least a in methyl acrylate, ethyl propenoate, butyl acrylate, 2-ethylhexyl acrylate, vinylformic acid cyclohexyl ester, vinylformic acid benzyl ester, isobornyl acrylate, methyl methacrylate, β-dimethyl-aminoethylmethacrylate, butyl methacrylate, IBOMA, methacrylic acid isodecyl ester, methacrylic acid cyclohexyl ester, the methacrylic acid benzyl ester.

5. the method for claim 4, wherein the 3rd monomer is to join in the reaction mixture after at least 98% described vinylbenzene and acrylonitrile monemer have reacted.

6. the method for claim 4, wherein the add-on of the 3rd monomer is 0.5～5.0 part of the 3rd monomer/100 part polymkeric substance and monomer.

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