CA1044841A - Process for producing transparent block copolymer resins - Google Patents
Process for producing transparent block copolymer resinsInfo
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- CA1044841A CA1044841A CA210,254A CA210254A CA1044841A CA 1044841 A CA1044841 A CA 1044841A CA 210254 A CA210254 A CA 210254A CA 1044841 A CA1044841 A CA 1044841A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F297/00—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
- C08F297/02—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type
- C08F297/04—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type polymerising vinyl aromatic monomers and conjugated dienes
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- Health & Medical Sciences (AREA)
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- Organic Chemistry (AREA)
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Abstract
PROCESS FOR PRODUCING TRANSPARENT
BLOCK COPOLYMER RESINS
ABSTRACT OF THE DISCLOSURE
A block copolymer resin having at one or both ends a copolymer block of a vinyl aromatic compound and a conjugated diene is obtained by subjecting a vinyl aromatic compound and a conjugated diene to 2-or 3-stage block copolymerization in a hydrocarbon solvent in the presence of a definite amount of a Lewis base compound using an organolithium compound as an initiator.
The block copolymer resin is high in transparency and excellent in mechanical properties, and is successfully usable in the fields of sheets, films and various molded articles.
BLOCK COPOLYMER RESINS
ABSTRACT OF THE DISCLOSURE
A block copolymer resin having at one or both ends a copolymer block of a vinyl aromatic compound and a conjugated diene is obtained by subjecting a vinyl aromatic compound and a conjugated diene to 2-or 3-stage block copolymerization in a hydrocarbon solvent in the presence of a definite amount of a Lewis base compound using an organolithium compound as an initiator.
The block copolymer resin is high in transparency and excellent in mechanical properties, and is successfully usable in the fields of sheets, films and various molded articles.
Description
~l)4~
1 This inventlon relates to a proccss for pro-ducin~ n novcl blocl~ copolymer resln hi.gh in transparency an(~ excellcnt in mech<lllical properties. More particu]ar-ly, the invention is conccrned wi.th a process for pro-duclnl~ a transparent bl.ock copolymer rcsin exc~llent in mech~mical propcrties, par-ticularly in clongation and impact strength, by copolymeriz.ing at 2 or 3 stages in a speciflc order a vinyl aromatic compound monomer with a conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as an initiator.
It has heretofore been known that various block copolymers different in structure c~n be obtain-ed by copolymerizing vinyl aromatic compounds with conjugated dienes using as initiators alkali metals or organic alkali metal compounds. For example, Japanese Patent Publication Nos. 19,286/61 and 2,423/73 disclose processes for producing transparent resins by subjecting styrene, butadiene and the like monomers to 2-stage block copolymerization, and Japanese Patent Publication Nos. 3,252/72 and 28,915/72 disclose processes for pro-ducing transparent resins by subjecting the same monomers as above to 4- or 5-stage block copolymerization.
Further, Japanese Patent Publication No. 20,038/73, German Patent Application ~aid-Open No. 2,120,232 and Japanese Patent Application ~aid-Open (Kokai) No.7,597/71 propose processes for producing transparent resins by subjecting the same monomers as above to l-stage copoly-merization.
It is well known that a 3-blocked copolymer having at the center a block composed oi` a polymer of 10~
1 a conjug-te(l clicnc sllch as butadicnc (md having at cach of t-hc both tormillals a block composed of n polymer of a vi.nyl arom;tic compound SUC}l as styrcne, which copoly-mer is obtaincd by 2-stago bifunctionnl livi.ng copoly-merization accordi.ng to any of thc above-menkioned processes using as an initiator an aromatic compound having two litllil~ a-toms bonded thercto, for example, is practically insufficient in impact strength unless the feed weight ratio of styrene/butadiene is less th~n 75/25 (refer to Example 11 of the aforesai.d Japanese Patent Publieation No. 19,286/61). It is also weil known that according to a proeess in which the same monomers as above are subjected to 2-stage monofunctional living eopolymerization in an inert hydroearbon solvent free from polar eompound using an organo-monolithium eompound as an initiator (refer to the aforesaid Japanese Patent Publieation No. 2,423/73), the resulting eopolymer resin is not always suffieiently satisfaetory in meehanieal properties, in praetiee. ~urther, in a proeess for produeing a multi-bloek eopolymer having 5 to 7 bloeks by multi-stage eopolymerization in a hydrocarbon solvent using an org~nie alkali metal eom-pound as an initiator, not only the polymerization operation becomes complex but also the number of termi-nals inactivated at eaeh stage beeomes larger to makesmooth progress of the polymerization diffieult, with the result that bloek eopolymers having structures other ~;
than the desired strueture migrate undesirably into the resulting eopolymer to injure the transpareney and meehanieal properties of the resin. On the other hand, 1()4~
1 in a procc~s in w~l:ich, .in an attcmpt to carry out thc stngc-w:ise co~olymcrization at onc stage, a m.ixture of monomcrs s~lch as styrenc and bu1adionc is polymeriY,cd at one stc-gc using n~ an in:itiato~ the re<lction product of lithi~l metal wi~h a non-conderlsed polycyclic aromatic compound (refer to the aforesaid ~rerm~m Patent Appl.i.cation ~aid-Open (Kokai) No. 2,120,232), there are encountered such difficulties that the initiator is to be synthesizcd in a polar compound such as ether while the polymeri-zation reaction is to be conducted in an inert hydro-carbon solvent free from polar compound, with the result that marked commercial disadvantages are necessarily brought about.
With an aim to develop a process for producing with commercial advantages a transparent resin excellent in mechanical properties by using as starting materials a vinyl aromatic compound monomer and a conjugated diene monomer, the present inventors made extensive studies to find that a copolymer resin capable of satisfying the above-mentioned requirements can be obtained accord-ing to one- or both-terminal initiation type multi-stage polymerization using an organolithium compound as an initiator by controlling the feed ratio of the monomers added at each stage to a specific range and by making a definite amount of a ~ewis base compound present in the polymerization system. Based on this finiding, the inventors have accomplished the present invention.
An object of the present invention is to provide block copolymer resins which are high in trans-parency and excellent in mechanical properties 41consisting of 2 or 3 blocked copolymer and the process for pro-ducing same.
The accompanying drawing is a graph which diagramatically shows the ranges of feed weight proportions of the monomers used in the polymerization process of the present invention.
In the drawing, Sl represents the feed amount (parts by weight) of a vinyl aromatic compound added to form a polymer block of the vinyl aromatic compound; S2 the feed amount (parts by weight) of a vinyl aromatic compound added to form a copolymer block of the 0 vinyl aromatic compound and a conjugated diene; and B the feed amount (parts by weight) of a conjugated diene.
According to the present invention, a block copolymer resin consisting of 2 or 3 blocks can be obtained by subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated diene monomer to 2- or 3-stage block copolymerization in a hydrocarbon solvent using an organolithium compound as an initiator, thereby forming a 2-blocked copolymer having a block composed of a polymer of the vinyl aromatic compound and a copolymer block of the vinyl aromatic compound and 'O the conjugated diene, or a 3-blocked copolymer having at the center a block composed of a polymer of the vinyl aromatic compound and having at each of the both terminals a copolymer block of the vinyl aromatic compound and the , `O
lV'~ 41 1 conjug.ltcd di.cne.
In one mode, t;he prescnt invent:ion prov.idcs a proce~s for producing a tran~sp.lrent block copolymer resin excellent in mcchanical properties which compriscs subjecting 90 to 65 parts by wei.ght of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated d:iene monomcr to 2-stagc block copolymeriza-tion in an inert hydrocarbon solvent using an organo-monolithium compound as an initiator, characterized in that at the first stage of polymerization, Sl parts by weight of the vinyl aromatic compound monomer is added and substantially all of the monomer is polymerized, and then, at the second stage of polymerization, a mix-ture of S2 parts of the vinyl aromatic compound monomer and B parts by weight of the conjugated diene monomer is added and substantially all of the monomers are polymerized, or the order of addition of the monomers at the first and second stages is made reverse to the above-mentioned order, wherein the feed weight ratios of the individual monomers are controlled to the ranges of: .
Sl ~ S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) Sl/(Sl ~ S2) = 0.35 to O.go S2/B = 0.2 to 3.0 and the polymerization is effected in the presence of a Lewis base compound-in a proportion of 0.01 to 5 mole based on the total monomer.
In another mode, the present invention 1 provi~es .~ process for prodllcintr a novel block copo]y-mer resin Wh.i.C~l COlllpI`i.SeS subjocting 90 to 65 parts by weight of a vinyl ~romatlc compound monomcr and 10 to 35 parts by weight oi` a conjugclted dienc monomer to 3-stage bloch copolymerization in nn inert hydrocarbon solvcnt using an organo-monolithillm com~ound a~ an ini-tiator, characterizcd in that at thc first stage of polymerization, a mixture of Sl parts by wei~ht of the vinyl aromatic compound monomer and Bl parts by weight of the conjugated diene monomer is polymerized and substantially all of the monomers are polymerized; at the second stage of polymerization, S2 parts by weight of the vinyl aromatic compound monomer is added and the polymerization is continued to polymerize substantial-ly all of the monomers; and at the third stage ofpolymerization, a mixture of S3 parts by weight of the vinyl aromatic compound monomer and B3 parts by weight of the conjugated diene monomer is added and the poly-merization is continued to polymerize substantially all of the monomers, wherein the feed weight ratios of the individual monomers are controlled to satisfy the relation:
Sl + S2 + S3 = 90 to 65 (parts by weight) Bl + B3 = 10 to 35 (parts by weight) Sl/Bl = 0.2 to 3.0 S3/B3 = 0-2 to 3.0 S2/(Sl + S2 + S3) = 0.35 to O.go and the polymerization is effected in the presence of 1~ 4 ~
l a ~ew.is base compound in a propor-tion of 0.01 to 5 mole %
based on the total monom~r, there~y producing a block copolymer having at the cent;er n non-elastomeric block composed of a polymer of the vinyl aromatic compound and at each of the both terminals an ela5tomeric copo-lymer block composed mainly of the conjugated diene and the vinyl aromatic compound.
In still another mode~ the present invention provides a process for producing a novel block copolymer resin which comprises subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and lO to 35 parts by weight of a conjugated diene monomer to
1 This inventlon relates to a proccss for pro-ducin~ n novcl blocl~ copolymer resln hi.gh in transparency an(~ excellcnt in mech<lllical properties. More particu]ar-ly, the invention is conccrned wi.th a process for pro-duclnl~ a transparent bl.ock copolymer rcsin exc~llent in mech~mical propcrties, par-ticularly in clongation and impact strength, by copolymeriz.ing at 2 or 3 stages in a speciflc order a vinyl aromatic compound monomer with a conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as an initiator.
It has heretofore been known that various block copolymers different in structure c~n be obtain-ed by copolymerizing vinyl aromatic compounds with conjugated dienes using as initiators alkali metals or organic alkali metal compounds. For example, Japanese Patent Publication Nos. 19,286/61 and 2,423/73 disclose processes for producing transparent resins by subjecting styrene, butadiene and the like monomers to 2-stage block copolymerization, and Japanese Patent Publication Nos. 3,252/72 and 28,915/72 disclose processes for pro-ducing transparent resins by subjecting the same monomers as above to 4- or 5-stage block copolymerization.
Further, Japanese Patent Publication No. 20,038/73, German Patent Application ~aid-Open No. 2,120,232 and Japanese Patent Application ~aid-Open (Kokai) No.7,597/71 propose processes for producing transparent resins by subjecting the same monomers as above to l-stage copoly-merization.
It is well known that a 3-blocked copolymer having at the center a block composed oi` a polymer of 10~
1 a conjug-te(l clicnc sllch as butadicnc (md having at cach of t-hc both tormillals a block composed of n polymer of a vi.nyl arom;tic compound SUC}l as styrcne, which copoly-mer is obtaincd by 2-stago bifunctionnl livi.ng copoly-merization accordi.ng to any of thc above-menkioned processes using as an initiator an aromatic compound having two litllil~ a-toms bonded thercto, for example, is practically insufficient in impact strength unless the feed weight ratio of styrene/butadiene is less th~n 75/25 (refer to Example 11 of the aforesai.d Japanese Patent Publieation No. 19,286/61). It is also weil known that according to a proeess in which the same monomers as above are subjected to 2-stage monofunctional living eopolymerization in an inert hydroearbon solvent free from polar eompound using an organo-monolithium eompound as an initiator (refer to the aforesaid Japanese Patent Publieation No. 2,423/73), the resulting eopolymer resin is not always suffieiently satisfaetory in meehanieal properties, in praetiee. ~urther, in a proeess for produeing a multi-bloek eopolymer having 5 to 7 bloeks by multi-stage eopolymerization in a hydrocarbon solvent using an org~nie alkali metal eom-pound as an initiator, not only the polymerization operation becomes complex but also the number of termi-nals inactivated at eaeh stage beeomes larger to makesmooth progress of the polymerization diffieult, with the result that bloek eopolymers having structures other ~;
than the desired strueture migrate undesirably into the resulting eopolymer to injure the transpareney and meehanieal properties of the resin. On the other hand, 1()4~
1 in a procc~s in w~l:ich, .in an attcmpt to carry out thc stngc-w:ise co~olymcrization at onc stage, a m.ixture of monomcrs s~lch as styrenc and bu1adionc is polymeriY,cd at one stc-gc using n~ an in:itiato~ the re<lction product of lithi~l metal wi~h a non-conderlsed polycyclic aromatic compound (refer to the aforesaid ~rerm~m Patent Appl.i.cation ~aid-Open (Kokai) No. 2,120,232), there are encountered such difficulties that the initiator is to be synthesizcd in a polar compound such as ether while the polymeri-zation reaction is to be conducted in an inert hydro-carbon solvent free from polar compound, with the result that marked commercial disadvantages are necessarily brought about.
With an aim to develop a process for producing with commercial advantages a transparent resin excellent in mechanical properties by using as starting materials a vinyl aromatic compound monomer and a conjugated diene monomer, the present inventors made extensive studies to find that a copolymer resin capable of satisfying the above-mentioned requirements can be obtained accord-ing to one- or both-terminal initiation type multi-stage polymerization using an organolithium compound as an initiator by controlling the feed ratio of the monomers added at each stage to a specific range and by making a definite amount of a ~ewis base compound present in the polymerization system. Based on this finiding, the inventors have accomplished the present invention.
An object of the present invention is to provide block copolymer resins which are high in trans-parency and excellent in mechanical properties 41consisting of 2 or 3 blocked copolymer and the process for pro-ducing same.
The accompanying drawing is a graph which diagramatically shows the ranges of feed weight proportions of the monomers used in the polymerization process of the present invention.
In the drawing, Sl represents the feed amount (parts by weight) of a vinyl aromatic compound added to form a polymer block of the vinyl aromatic compound; S2 the feed amount (parts by weight) of a vinyl aromatic compound added to form a copolymer block of the 0 vinyl aromatic compound and a conjugated diene; and B the feed amount (parts by weight) of a conjugated diene.
According to the present invention, a block copolymer resin consisting of 2 or 3 blocks can be obtained by subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated diene monomer to 2- or 3-stage block copolymerization in a hydrocarbon solvent using an organolithium compound as an initiator, thereby forming a 2-blocked copolymer having a block composed of a polymer of the vinyl aromatic compound and a copolymer block of the vinyl aromatic compound and 'O the conjugated diene, or a 3-blocked copolymer having at the center a block composed of a polymer of the vinyl aromatic compound and having at each of the both terminals a copolymer block of the vinyl aromatic compound and the , `O
lV'~ 41 1 conjug.ltcd di.cne.
In one mode, t;he prescnt invent:ion prov.idcs a proce~s for producing a tran~sp.lrent block copolymer resin excellent in mcchanical properties which compriscs subjecting 90 to 65 parts by wei.ght of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated d:iene monomcr to 2-stagc block copolymeriza-tion in an inert hydrocarbon solvent using an organo-monolithium compound as an initiator, characterized in that at the first stage of polymerization, Sl parts by weight of the vinyl aromatic compound monomer is added and substantially all of the monomer is polymerized, and then, at the second stage of polymerization, a mix-ture of S2 parts of the vinyl aromatic compound monomer and B parts by weight of the conjugated diene monomer is added and substantially all of the monomers are polymerized, or the order of addition of the monomers at the first and second stages is made reverse to the above-mentioned order, wherein the feed weight ratios of the individual monomers are controlled to the ranges of: .
Sl ~ S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) Sl/(Sl ~ S2) = 0.35 to O.go S2/B = 0.2 to 3.0 and the polymerization is effected in the presence of a Lewis base compound-in a proportion of 0.01 to 5 mole based on the total monomer.
In another mode, the present invention 1 provi~es .~ process for prodllcintr a novel block copo]y-mer resin Wh.i.C~l COlllpI`i.SeS subjocting 90 to 65 parts by weight of a vinyl ~romatlc compound monomcr and 10 to 35 parts by weight oi` a conjugclted dienc monomer to 3-stage bloch copolymerization in nn inert hydrocarbon solvcnt using an organo-monolithillm com~ound a~ an ini-tiator, characterizcd in that at thc first stage of polymerization, a mixture of Sl parts by wei~ht of the vinyl aromatic compound monomer and Bl parts by weight of the conjugated diene monomer is polymerized and substantially all of the monomers are polymerized; at the second stage of polymerization, S2 parts by weight of the vinyl aromatic compound monomer is added and the polymerization is continued to polymerize substantial-ly all of the monomers; and at the third stage ofpolymerization, a mixture of S3 parts by weight of the vinyl aromatic compound monomer and B3 parts by weight of the conjugated diene monomer is added and the poly-merization is continued to polymerize substantially all of the monomers, wherein the feed weight ratios of the individual monomers are controlled to satisfy the relation:
Sl + S2 + S3 = 90 to 65 (parts by weight) Bl + B3 = 10 to 35 (parts by weight) Sl/Bl = 0.2 to 3.0 S3/B3 = 0-2 to 3.0 S2/(Sl + S2 + S3) = 0.35 to O.go and the polymerization is effected in the presence of 1~ 4 ~
l a ~ew.is base compound in a propor-tion of 0.01 to 5 mole %
based on the total monom~r, there~y producing a block copolymer having at the cent;er n non-elastomeric block composed of a polymer of the vinyl aromatic compound and at each of the both terminals an ela5tomeric copo-lymer block composed mainly of the conjugated diene and the vinyl aromatic compound.
In still another mode~ the present invention provides a process for producing a novel block copolymer resin which comprises subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and lO to 35 parts by weight of a conjugated diene monomer to
2-stage block copolymerization in an inert hydrocarbon solvent using an organo-dilithium compound as an initiator, characterized in that at the first stage of polymeri-zation, Sl parts by weight of the vinyl aromatic compound monomer is added and substantially all of the monomer is polymerized, and then, at the second stage of poly-merization, a mixture of S2 parts by weight of the vinyl aromatic compound monomer and B parts by weight of the conjugated diene monomer is added and the poly-merization is continued to polymerize substantially all of the monomers, wherein the feed weight ratios of the individual monomers are controlled to values within the ranges of:
Sl ~ S2 = 90 to 65 (parts by weight) B = lO to 35 (parts by weight) Sl/(Sl + S2) = 0.35 to O.go S2/B = 0.2 to 3.0 ~0 4 ~
1 and the polymerization i~ effectc~ in the prese~ce of a ~ewis base compound in a proportion of 0.01 to 5 mole %
based on the total monomer, thcreby producing a block copolymer resin havin~ at the center a non-elastomeric block composed of a polymer of the vinyl aromatic com-pound and having at each of the both terminals an elastomeric copolymer block composed mainly of the conjugated diene and the vinyl aromatic compound.
As mentioned above, the process of the present invention can be easily practiced on commercial scale.
Moreover, block copolymer resins obtained by the process of the present invention are character-istically high in transparency, excellent in mechanical properties and easily moldable, and can be widely applied to the fields in which resins are used.
The modes of practice of the present inven-tion are explained in detail below.
The vinyl aromatic compound used in the pre-sent invention includes styrene, ~-methylstyrene, vinylnaphthalene and nucleus-substituted styrene such as vinyltoluene, and mixtures thereof. Thè conjugated diene includes 1,3-butadiene, isoprene, piperylene, substituted butadienes such às 2,3-dimethyl-1,3-butadiene and l-phenyl-1,3-butadiene, and mixtures thereof.
Particularly, the use of styrene as the vinyl aromatic compound and butadiene as the conjugated diene is pre-ferable in view of the utilizability and effectiveness of the resulting copolymer resin.
The proportions of the monomers used in the process Or the present invention are 90 to 65 parts by iO4~
1 weight of the vinyl aromatic compound and 10 to 35 parts by weight of the conju~ated dienc. If the proportion of the vinyl aromatic compound is more than 90 parts by weight, the resulting resin is undesirably lo~Jered particularly in elongation and impact strength, while if the proportion thereof is less than 65 parts by weight, the resulting resin is undesirably lowered in tensile strength, stiffness and softenin~ point.
In the process of the present invention, there lQ is formed at one or both terminals an elastomeric block co~posed o~ a copolymer of the vinyl aromatic compound with the conjugated diene. The amount of the vinyl aromatic compound to be added at this stage should be in the range from 0.2 to 3.0 times the weight of the conjugated diene adaed at the same stage, and the amount of the vinyl aromatic compound, which is added to form a non-elastomeric block at the center or at one end, should be in a weight ratio in the range from 0.35 to 0.90 to the total feed amount of the vinyl aromatic compound. If the feed amounts of the monomers added at individual stages of polymerization exceed the ranges specified by the present invention, the resulting resin is undesirably deteriorated in mechanical proparties, partioularly in the balance between tensile strength and elongation, and in impact strength or moldability.
The inert hydrocarbon solvent used in the process of the present invention includes aromatic hydro-carbons such as benzene, toluene, xylene and ethylbenzene, aliphatic hydrocarbons such as pentane, hexane and heptane, and alicyclic hydrocarbons such as cyclopentane, _ 9 _ 1 cyclohexane and mcthylcyclohexan~. These may bc used either singly or in the form of a mixtùre of two or morc members. The amount of the hydrocarbon solvent to be used is ordinarily 1 to 20 parts by wei~ht per part by weight of the total monomer. The solvent and the aforesaid monomers should have sufficiently been freed prior to use from ~Jater, oxygen, carbon dioxide, certain sulfur compounds, acetylenes and the like substances which degrade the initiator used in the present invention or destroy the active terminals formed.
The organo-monolithium compound used in the process of the present invention is an alkyl, cyclo-alkyl or aryl lithium compound having 2 to 20 carbon atoms. Concrete examples of such compound include ethyllithium, propyllithium, butyllithium, amylli~hium, hexyllithium, 2-ethylhexyllithium, cyclohexyllithium~
decyllithium, dodecylli~hium, phenyllithium, tolyl-lithium, xylyllithium and naphthyllithium. These may be used either singly or in the form of a mixture of two or more members. The amount of the organo-monolit;hium compound to be used is 0.005 to 5 mole ~, preferably 0.01 to 1.5 mole %, based on the total monomer.
The organo-dilithium compound used in the process of the present invention is a so-called both-terminal initiation type organo-dilithium compound.
Concrete examples of such compound include alkylene dilithium compounds such as trimethylenedilithium, tetramethyl~nedilithi~un and pentamethylencdilithium, 1 and complexes formcd by rcactin~ a condensed or non-colldcns~d polycyclic aromatic compo-md with lithium metnl in a ~ewis base solvent such as an ether compound.
Exc~mples of said complexes are naphthalenelithium, stilbene-lithium and biphenyl-lithium complexes.
It is also possible to use a compound prepared by reacting any of the said complexes comprising a con-densed or non-condensed polycyclic aromatic compound and lithium with a small amount of a conju~ated diene to form a hydrocarbon dianion soluble in a hydrocarbon solvent in the form of a trimer or tetramer, and then removing by distillation or without removing the ~ewis base solvent such as ether compound used in preparation of the complex and substituting the said solvent with an inert hydrocarbon solvent. ~he use of this kind of initiator is particularly preferable. The above-men-tioned organo-dilithium compounds may be used either singly or in the form a mixture of two or more members.
The amount of the organo-dilithium compound to be used is 0.002 to 3 mole ~o, preferably 0.01 to 1.5 mole %, based on the total monomer mixture.
In the process of the present invention, a mixture of the vinyl aromatic compound and the conju-gated diene is added at either stage of polymerization to form an elastomeric copolymer block. For smooth formation of the elastomer-ic copolymer block, there is used a specific amount of a ~ewis base compound such as an ether compound or a tertiary amine compound.
Examples of the ether compound include cyclic ethers ~0 such as tetrahydrofuran and tetrahydropyran, aliphatic 1 monocthers such a~ diethyl cther and dibutyl ether, aliphatic polyethers such as diethyleneglycol-dimethyl-ether and diethyleneglycol-diethyl-ether, and mixtures thereof. Ex~mples of the tertiary amine compound include triethylamine, tripropylamine, tributylamine, N,N'-dimethylaniline, pyridine and mixtures thereof. The amount of the ~ewis base compound to be used is 0.01 to 5 mole %, preferably 0.05 to 2 mole %, based on the total monomer. If the amount of the ~ewis base compound is excessively more than the above-mentioned range, the ¢ontent of vinyl bond in the elastomeric copolymer block greatly increases to make the glass transition temperature Tg of the copolymer higher, whereby the resin is undesirably deteriorated in mechanical pro-perties and low temperature characteristics.Conversely, if the amount of the ~ewis base compound is excessively less than the above-mentioned range, copoly-merization of the vinyl aromatic compound with the conjugated diene cannot be effected smoothly to cause such phenomenon that at the initial stage, only the conjugated diene is chiefly polymerized, while at the latter stage, only the vinyl aromatic compound is chief-ly polymerized, with the result that the resulting block copolymer resin is deteriorated to a great extent in mechanical properties, particularly in elongation and impact strength.
The time of addition of the ~ewis base compound is not particularly limited, and may be any time prior to the stage at which the copolymer block is formed.
In one mode of the 2-stage polymerization 1 according to thc present invention, Sl parts by weight of the vinyl aromatic compound monomer is nddcd at the first stage of polymerization and substant.~ally all of the monomer is polymerized in the presence o an organo-monolithium compound to form a non-elastomeric block.
Subsequently, at the second stage of polymerization, a mixture of S2 parts by weight of the vinyl aromatic compound monomer and B parts by weight of the con-jugated diene monomer is added and the polymerization is continued to form an elastomeric block composed main-ly of a copolymer of the vinyl aromatic compound with the conjugated diene. In this case, it is needless to say that the proportions of the indivudual monomer added at the first and second stages of polymerization should satisfy, as mentioned previously, the following con-ditions:
Sl + S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) Sl/(Sl + S2) = 0.35 to O.9o S2/B = 0.2 to 3.0 It is undesirable to add and polymerize only the conjugated diene at the second stage of polymeri-zation to form as the elastomeric block a block composed of a polymer of only the conjugated diene, because the resulting block copolymer resin is greatly deteriorated in mechanical properties, particularly in elongation.
Alternatively, a mixture of the vinyl aromatic compound and the conjugated diene may be added and polymerized at the first stage of polymerization, and then the 1 remaining vinyl aromatic compound may be added and polymerizcd at the second stage of polymeriæation.
In this case also, it is of course necessary that the . weight proport.ions of the individual monomers should satisfy the above-mentioned conditi.ons.
In another mode of the 2-stage polymerization according to the present invention, Sl parts by weight of the vinyl aromatic compound monomer is added at the first stage of polymeri2ation and substantially all of the monomer is polymerized in the presence of a both terminal-initiation type organo-dilithium compound to form at the center a non-elastomeric block. Subsequent-ly, at the second stage of polymerization, a mixture of S2 parts by weight of the vinyl aromatic compound monomer and B parts by weight of the conjugated diene monomer is added and the polymerization is continued to form at each terminal an elastomeric block composed mainly of a copolymer of the conjugated diene with the vinyl aromatic compound. In this case, it is needless to say that the proportions of the monomers added at the first and second stages of polymerization should satisfy, as mentioned previously, the following condi- :
tions:
Sl ~ S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) Sl/(Sl ~ S2) = 0.35 to o.go S2/B = 0.2 to 3.0 ~:
It is undesirable to add and polymerize only 11 .
1 the conjugated dicnc at the second stage of polymeri-zation to form as the elastomeric block at each terminal a block composed of a polymer of only the conjugated . diene, because the resulting block copolymer resin is greatly deteriorated in mechanical properties, particular-ly in elongation.
In the 3-stage polymerization, which is still another mode o~ the present invention, a mixture of Sl parts by weight of the vinyl aromatic compound monomer and Bl parts by weight o~ the conjugated diene monomer is added at the first stage of polymerization and polymerized in the presence of an organo-monolithium compound and a ~ewis base compound to form an elastomeric copolymer block, and then at the second stage of poly-merization, S2 parts by weight of the vinyl aromaticcompound monomer is added and the polymerization is continued to form a non-elastomeric block. Subsequent-ly, at the third stage of polymerization, a mixture of S3 parts by weight of the vinyl aromatic compound monomer and ~3 parts by weight of the conjugated diene monomer is added and the polymerization is con-tinued to form an eiastomeric copolymer block. In this case, it is needless to say that the proportions of the individual monomers added at the first, second and third stages of polymerization should satisfy, as mentioned previously, the following conditions:
. Sl + S2 + S3 = 90 to 65 (parts by weight) Bl + B3 = 10 to 35 (parts by weight) Sl/Bl = O. 2 to 3 O
S3/B3 = O. 2 to 3. 0 S2/(Sl + S2 + S3) - 0.~5 to 0.90 It is undesirable to add and polymerize only the conjugated diene at the first and third stages of polymerization to form as the elastomeric block at each terminal a block composed of a polymer of only the conjugated diene, because the resulting resin is greatly deteriorated in mechanical properties, particularly in elongation.
In the multi-stage polymerization according to the present invention, the monomers added at the indi-vidual stages can be polymerized to substantially 100%, so that the yield of the resulting copolymer can be substantially lOO~o.
In the polymerization of the present inven-tion, the average molecular wèight of the resulting copolymer resin is controlled by the amount of the initiator used. The average molecular weight of the block copolymer according to the present invention should have a value in the range from 0.5 to 1.8 dl/g in terms of intrinsic viscosity (~) as measured in toluene solu-tion at 30C. If the molecular weight of the copolymer is so low as to show an intrinsic viscosity of less than 0.5 dl/g, the resin is undesirably deteriorated in mechanical properties, while if the molecular weight of the copolymer is so high as to show an intrinsic viscosity of more than 1.8 dl/g, the resin is undesirably deprived of transparency and becomes quite difficultly - lG -1 moldable.
The polymerization of the present invention is carried out at a temperature in the range from -20 to 150C., preferably from 20 to 120C. The pressure is selected from pressures sufficient to maintain the monomers and the solvent at the liquid phase at a tem-perature within the above-mentioned range. The poly-merization time varies depending on the polymerizatio~
conditions but is less than 48 hours, ordinarily less 10` than 24 hours. The time of addition of the monomers at each of the second and third stage is not particular-ly limited and may be any time after the conversion at the preceding step has reached substantially lOOpo.
After completion of the polymerization, the resulting copolymer may be precipitated and recovered by adding to the system water, methanol, isopropanol or the like compound in an amount sufficient to inacti-vate the active terminal, further adding, if necessary, a small amount of an antioxidant, e.g. 4-methyl-2,6-di-tert-butylphenol, and then adding excess methanol, ethanol, isopropanol or the like. Alternatively, the copolymer may be recovered by directly heating the polymerization liquid to dryness or by mixing the polymerization liquid with steam to remove the solvent.
The block copolymers according to the present invention may be processed by ordinary processing ope-ration and may be used in fields where conventional resins have been used. ~urther, the copolymers of the present invention may be incorporated by ordinary pro-~0 cedures with various additives such as stabilizers, 1 roinforcing agents, fillers, and various additives which have heretofore been employed.
As mentioned above, the present invention provides a process for producing novel block copolymer resins high in transparency and excellent in mechanical properties by subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated diene monomer to multi-stage polymerization using an organolithium compound as an initiator. The process of the present invention is easily practicable on commercial scale, and, moreover, the resins obtained by the process of the present inven-tion are high in transparency and excellent in mechani-cal properties, and hence can successfully be used not only the fields where the conventional resins have been used but also in the fields where the conventional resins have not successfully been usable. ~hus, the industrial value of the present invention is extremely high.
The modes of practice of the present inven-tion are illustrated in detail below with reference to examples, but the invention is not limited to the examples, and various modifications are possible within the scope of the invention.
Example 1 Into a 2.5-liters pressure glass autoclave, which had internally been flushed with argon gas, were charged 1.5 liters of purified, dried and degassed benzene and 300 g. of purified and dried styrene.
Subsequently, a hexane solution of n-butyllithium was ~ 4 ~
1 droppecl into thc ~utoclave until an orangc color of the active terminals of polystyryllithium was observed in the content o:~ the autoclave, and then ~.0 mmol. of n-butyllithium and 0.90 g. of tetrahydrofuran werc further added to the autoclave. Immediately thereafter, the autoclave was heated to 60C., and the mixture in the autoclave was continuously stirred at said temperature for 3 hours to carry out the first stage polymerization.
Subsequently, 100 g. of styrene and 100 g. of purified and dried butadiene were added to the reaction mixture inside the autoclave, and the resulting mixture was continuously reacted at 60C. for 3 hours to carry out the second stage polymerization. After 3 hours polymeri-zation, 50 ml. of methanol was added to the system to terminate the polymerization, and the polymerization liquid was charged into methanol incorporated with 4-methyl-2,6-di-tert-butylphenol as an antioxidant, where-- by polymer precipitates were deposited. The precipi-tates were collected by filtration, and then drled in vacuum to obtain a block copolymer in a yield of 99.4%.
The copolymer had an intrinsic viscosity of 0.80 dl/g as measured in toluene at 30C. 100 Parts by weight of the thus obtained copolymer was incorporated with 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl)-phosphite as antioxidants, and then pelletized by means of an extruder. The resulting pellets were subjected to injection molding to prepare a test piece for physical property measurement. The molded article ~las beautiful ~0 in appearance and high in transparency. The test piece 10~4~1 1 was me.l~ured in pllysicnl propcrties to obtain the result~
shown in Table 1.
Table Intrinsic viscosity (dl`/g) (Note 1) 0.80 Tensile strength (kg/cm2) (Note 2) 31~
Elongation (%) (Note 2) 212 .
Izod impact strength, with notch (kg.cm/cm2) (Note 3) 2.2 without notch (kg.cm/cm2) (Note 4) 16.8 Melt index (g/10 min.) (Note 5) 0.48 .
Haze value (%) (Note 6) 7.0 .
(Note 1) The copolymer before pelletization Nas measured in toluene at 30C. using Ubbelohde type viscometer.
(Note 2) Measured at 20C. with a tensile rate of 5 mm/min. according to JIS-K 6871.
(Note 3) The test piece with notch was measured at 20C. according to JIS-K 6871.
(Note 4) The test piece without notch was measured at 20C. according to JIS-K 6871.
(Note 5) Measured according to JIS-K 6760.
(Note 6) Measured according to ASTM-D 1003.
., .
1 Example 2 ll)~ 4~
~ he polymcri~tion of Example 1 was repeated, except that the amount of tetrahydrofuran was varied to 2.0 g., the monomer added at the first stage was varied to 100 g. of styrene and 100 g. of butadiene, and the monomer added at the second stage was varied to 300 g.
of styrene, whereby a block copol~ner was obtained in a yield of 99.5%. ~he thus obtained copolymer was treated in the same manner as in Example 1 to prepare a test piece, which was then measured in physical properties to obtain the results shown in Table 2.
Table 2 Intrinsic viscosity (dl/g) 0.82 Melt index (g/10 min.) . 0.22 Tensile strength (kg/cm ) 333 Elongation (%) 190 Izod impact strength, with notch (kg.cm/cm2) 2.2 without notch (kg/cm/cm2) 14.5 Haze value (%) 8.5 Examples 3 - 6 The polymeri~.ation of Example 1 was repeated, except that the combination of the monomers and the - ~ewis base compound were varied to those shown in T~ble 3, in which were ~lso shown t;hc yields of the copol,ymers obt~ined.
iO~
.
~q ~ Fq O O O O
h b~o o c~ O O O O
~ r~ l l a) ~ o o o o r- Lr~ ~ ~
_ ._ _ ._ h ~ ~ ~ Lf~ 0 ~ ~ _, ~ a~ 0 ~
~o.~ ~ ~ C~
a) ~ ~ ~
''J h t~ h h h t~ o ~ ~ ~ ~ ~ ~
~:1 o ~h ~ O ~ ~h El E~ E~ E~
~1C ~ ~ ) ~:~0 ~0~0 O O O O O O O O
~ U~ ~o ~ ~0 ~0 . ~0 C~ ~0 ~ ~1 ~> ~.) O ~D O ~ O~ Q~
O ~0 ~t ~ ~ ~ ~ ~ ~
~ t3h ~ P~ h ~ h ~
. ~2 ~ ~ ~ ~ ~ ~
.._.
h ~ ~ bD ~ ~0 ~ ~0 a~ O a) o ~, o a~ o Oh Lt~ h u~ ~ O h ' ¢l ~1 ~ ~ ~ b~
. .
'~ 2; ~ ~t Lr~ ~o _ . ._ .__ .
lV~
1 The t}lUS obtained copolymcrs were treatcd in the same manner as in Example 1 to prcpare tcst pieces, which were then measurcd in physical properties to obtain the results shown in Table 4.
Table 4 Example Intrinsic Tensile Elon- strength Haze viscosity strength gation with notch value No. (dl/g) (kg/cm2) (%) (kg.cm/cm2) (~)
Sl ~ S2 = 90 to 65 (parts by weight) B = lO to 35 (parts by weight) Sl/(Sl + S2) = 0.35 to O.go S2/B = 0.2 to 3.0 ~0 4 ~
1 and the polymerization i~ effectc~ in the prese~ce of a ~ewis base compound in a proportion of 0.01 to 5 mole %
based on the total monomer, thcreby producing a block copolymer resin havin~ at the center a non-elastomeric block composed of a polymer of the vinyl aromatic com-pound and having at each of the both terminals an elastomeric copolymer block composed mainly of the conjugated diene and the vinyl aromatic compound.
As mentioned above, the process of the present invention can be easily practiced on commercial scale.
Moreover, block copolymer resins obtained by the process of the present invention are character-istically high in transparency, excellent in mechanical properties and easily moldable, and can be widely applied to the fields in which resins are used.
The modes of practice of the present inven-tion are explained in detail below.
The vinyl aromatic compound used in the pre-sent invention includes styrene, ~-methylstyrene, vinylnaphthalene and nucleus-substituted styrene such as vinyltoluene, and mixtures thereof. Thè conjugated diene includes 1,3-butadiene, isoprene, piperylene, substituted butadienes such às 2,3-dimethyl-1,3-butadiene and l-phenyl-1,3-butadiene, and mixtures thereof.
Particularly, the use of styrene as the vinyl aromatic compound and butadiene as the conjugated diene is pre-ferable in view of the utilizability and effectiveness of the resulting copolymer resin.
The proportions of the monomers used in the process Or the present invention are 90 to 65 parts by iO4~
1 weight of the vinyl aromatic compound and 10 to 35 parts by weight of the conju~ated dienc. If the proportion of the vinyl aromatic compound is more than 90 parts by weight, the resulting resin is undesirably lo~Jered particularly in elongation and impact strength, while if the proportion thereof is less than 65 parts by weight, the resulting resin is undesirably lowered in tensile strength, stiffness and softenin~ point.
In the process of the present invention, there lQ is formed at one or both terminals an elastomeric block co~posed o~ a copolymer of the vinyl aromatic compound with the conjugated diene. The amount of the vinyl aromatic compound to be added at this stage should be in the range from 0.2 to 3.0 times the weight of the conjugated diene adaed at the same stage, and the amount of the vinyl aromatic compound, which is added to form a non-elastomeric block at the center or at one end, should be in a weight ratio in the range from 0.35 to 0.90 to the total feed amount of the vinyl aromatic compound. If the feed amounts of the monomers added at individual stages of polymerization exceed the ranges specified by the present invention, the resulting resin is undesirably deteriorated in mechanical proparties, partioularly in the balance between tensile strength and elongation, and in impact strength or moldability.
The inert hydrocarbon solvent used in the process of the present invention includes aromatic hydro-carbons such as benzene, toluene, xylene and ethylbenzene, aliphatic hydrocarbons such as pentane, hexane and heptane, and alicyclic hydrocarbons such as cyclopentane, _ 9 _ 1 cyclohexane and mcthylcyclohexan~. These may bc used either singly or in the form of a mixtùre of two or morc members. The amount of the hydrocarbon solvent to be used is ordinarily 1 to 20 parts by wei~ht per part by weight of the total monomer. The solvent and the aforesaid monomers should have sufficiently been freed prior to use from ~Jater, oxygen, carbon dioxide, certain sulfur compounds, acetylenes and the like substances which degrade the initiator used in the present invention or destroy the active terminals formed.
The organo-monolithium compound used in the process of the present invention is an alkyl, cyclo-alkyl or aryl lithium compound having 2 to 20 carbon atoms. Concrete examples of such compound include ethyllithium, propyllithium, butyllithium, amylli~hium, hexyllithium, 2-ethylhexyllithium, cyclohexyllithium~
decyllithium, dodecylli~hium, phenyllithium, tolyl-lithium, xylyllithium and naphthyllithium. These may be used either singly or in the form of a mixture of two or more members. The amount of the organo-monolit;hium compound to be used is 0.005 to 5 mole ~, preferably 0.01 to 1.5 mole %, based on the total monomer.
The organo-dilithium compound used in the process of the present invention is a so-called both-terminal initiation type organo-dilithium compound.
Concrete examples of such compound include alkylene dilithium compounds such as trimethylenedilithium, tetramethyl~nedilithi~un and pentamethylencdilithium, 1 and complexes formcd by rcactin~ a condensed or non-colldcns~d polycyclic aromatic compo-md with lithium metnl in a ~ewis base solvent such as an ether compound.
Exc~mples of said complexes are naphthalenelithium, stilbene-lithium and biphenyl-lithium complexes.
It is also possible to use a compound prepared by reacting any of the said complexes comprising a con-densed or non-condensed polycyclic aromatic compound and lithium with a small amount of a conju~ated diene to form a hydrocarbon dianion soluble in a hydrocarbon solvent in the form of a trimer or tetramer, and then removing by distillation or without removing the ~ewis base solvent such as ether compound used in preparation of the complex and substituting the said solvent with an inert hydrocarbon solvent. ~he use of this kind of initiator is particularly preferable. The above-men-tioned organo-dilithium compounds may be used either singly or in the form a mixture of two or more members.
The amount of the organo-dilithium compound to be used is 0.002 to 3 mole ~o, preferably 0.01 to 1.5 mole %, based on the total monomer mixture.
In the process of the present invention, a mixture of the vinyl aromatic compound and the conju-gated diene is added at either stage of polymerization to form an elastomeric copolymer block. For smooth formation of the elastomer-ic copolymer block, there is used a specific amount of a ~ewis base compound such as an ether compound or a tertiary amine compound.
Examples of the ether compound include cyclic ethers ~0 such as tetrahydrofuran and tetrahydropyran, aliphatic 1 monocthers such a~ diethyl cther and dibutyl ether, aliphatic polyethers such as diethyleneglycol-dimethyl-ether and diethyleneglycol-diethyl-ether, and mixtures thereof. Ex~mples of the tertiary amine compound include triethylamine, tripropylamine, tributylamine, N,N'-dimethylaniline, pyridine and mixtures thereof. The amount of the ~ewis base compound to be used is 0.01 to 5 mole %, preferably 0.05 to 2 mole %, based on the total monomer. If the amount of the ~ewis base compound is excessively more than the above-mentioned range, the ¢ontent of vinyl bond in the elastomeric copolymer block greatly increases to make the glass transition temperature Tg of the copolymer higher, whereby the resin is undesirably deteriorated in mechanical pro-perties and low temperature characteristics.Conversely, if the amount of the ~ewis base compound is excessively less than the above-mentioned range, copoly-merization of the vinyl aromatic compound with the conjugated diene cannot be effected smoothly to cause such phenomenon that at the initial stage, only the conjugated diene is chiefly polymerized, while at the latter stage, only the vinyl aromatic compound is chief-ly polymerized, with the result that the resulting block copolymer resin is deteriorated to a great extent in mechanical properties, particularly in elongation and impact strength.
The time of addition of the ~ewis base compound is not particularly limited, and may be any time prior to the stage at which the copolymer block is formed.
In one mode of the 2-stage polymerization 1 according to thc present invention, Sl parts by weight of the vinyl aromatic compound monomer is nddcd at the first stage of polymerization and substant.~ally all of the monomer is polymerized in the presence o an organo-monolithium compound to form a non-elastomeric block.
Subsequently, at the second stage of polymerization, a mixture of S2 parts by weight of the vinyl aromatic compound monomer and B parts by weight of the con-jugated diene monomer is added and the polymerization is continued to form an elastomeric block composed main-ly of a copolymer of the vinyl aromatic compound with the conjugated diene. In this case, it is needless to say that the proportions of the indivudual monomer added at the first and second stages of polymerization should satisfy, as mentioned previously, the following con-ditions:
Sl + S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) Sl/(Sl + S2) = 0.35 to O.9o S2/B = 0.2 to 3.0 It is undesirable to add and polymerize only the conjugated diene at the second stage of polymeri-zation to form as the elastomeric block a block composed of a polymer of only the conjugated diene, because the resulting block copolymer resin is greatly deteriorated in mechanical properties, particularly in elongation.
Alternatively, a mixture of the vinyl aromatic compound and the conjugated diene may be added and polymerized at the first stage of polymerization, and then the 1 remaining vinyl aromatic compound may be added and polymerizcd at the second stage of polymeriæation.
In this case also, it is of course necessary that the . weight proport.ions of the individual monomers should satisfy the above-mentioned conditi.ons.
In another mode of the 2-stage polymerization according to the present invention, Sl parts by weight of the vinyl aromatic compound monomer is added at the first stage of polymeri2ation and substantially all of the monomer is polymerized in the presence of a both terminal-initiation type organo-dilithium compound to form at the center a non-elastomeric block. Subsequent-ly, at the second stage of polymerization, a mixture of S2 parts by weight of the vinyl aromatic compound monomer and B parts by weight of the conjugated diene monomer is added and the polymerization is continued to form at each terminal an elastomeric block composed mainly of a copolymer of the conjugated diene with the vinyl aromatic compound. In this case, it is needless to say that the proportions of the monomers added at the first and second stages of polymerization should satisfy, as mentioned previously, the following condi- :
tions:
Sl ~ S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) Sl/(Sl ~ S2) = 0.35 to o.go S2/B = 0.2 to 3.0 ~:
It is undesirable to add and polymerize only 11 .
1 the conjugated dicnc at the second stage of polymeri-zation to form as the elastomeric block at each terminal a block composed of a polymer of only the conjugated . diene, because the resulting block copolymer resin is greatly deteriorated in mechanical properties, particular-ly in elongation.
In the 3-stage polymerization, which is still another mode o~ the present invention, a mixture of Sl parts by weight of the vinyl aromatic compound monomer and Bl parts by weight o~ the conjugated diene monomer is added at the first stage of polymerization and polymerized in the presence of an organo-monolithium compound and a ~ewis base compound to form an elastomeric copolymer block, and then at the second stage of poly-merization, S2 parts by weight of the vinyl aromaticcompound monomer is added and the polymerization is continued to form a non-elastomeric block. Subsequent-ly, at the third stage of polymerization, a mixture of S3 parts by weight of the vinyl aromatic compound monomer and ~3 parts by weight of the conjugated diene monomer is added and the polymerization is con-tinued to form an eiastomeric copolymer block. In this case, it is needless to say that the proportions of the individual monomers added at the first, second and third stages of polymerization should satisfy, as mentioned previously, the following conditions:
. Sl + S2 + S3 = 90 to 65 (parts by weight) Bl + B3 = 10 to 35 (parts by weight) Sl/Bl = O. 2 to 3 O
S3/B3 = O. 2 to 3. 0 S2/(Sl + S2 + S3) - 0.~5 to 0.90 It is undesirable to add and polymerize only the conjugated diene at the first and third stages of polymerization to form as the elastomeric block at each terminal a block composed of a polymer of only the conjugated diene, because the resulting resin is greatly deteriorated in mechanical properties, particularly in elongation.
In the multi-stage polymerization according to the present invention, the monomers added at the indi-vidual stages can be polymerized to substantially 100%, so that the yield of the resulting copolymer can be substantially lOO~o.
In the polymerization of the present inven-tion, the average molecular wèight of the resulting copolymer resin is controlled by the amount of the initiator used. The average molecular weight of the block copolymer according to the present invention should have a value in the range from 0.5 to 1.8 dl/g in terms of intrinsic viscosity (~) as measured in toluene solu-tion at 30C. If the molecular weight of the copolymer is so low as to show an intrinsic viscosity of less than 0.5 dl/g, the resin is undesirably deteriorated in mechanical properties, while if the molecular weight of the copolymer is so high as to show an intrinsic viscosity of more than 1.8 dl/g, the resin is undesirably deprived of transparency and becomes quite difficultly - lG -1 moldable.
The polymerization of the present invention is carried out at a temperature in the range from -20 to 150C., preferably from 20 to 120C. The pressure is selected from pressures sufficient to maintain the monomers and the solvent at the liquid phase at a tem-perature within the above-mentioned range. The poly-merization time varies depending on the polymerizatio~
conditions but is less than 48 hours, ordinarily less 10` than 24 hours. The time of addition of the monomers at each of the second and third stage is not particular-ly limited and may be any time after the conversion at the preceding step has reached substantially lOOpo.
After completion of the polymerization, the resulting copolymer may be precipitated and recovered by adding to the system water, methanol, isopropanol or the like compound in an amount sufficient to inacti-vate the active terminal, further adding, if necessary, a small amount of an antioxidant, e.g. 4-methyl-2,6-di-tert-butylphenol, and then adding excess methanol, ethanol, isopropanol or the like. Alternatively, the copolymer may be recovered by directly heating the polymerization liquid to dryness or by mixing the polymerization liquid with steam to remove the solvent.
The block copolymers according to the present invention may be processed by ordinary processing ope-ration and may be used in fields where conventional resins have been used. ~urther, the copolymers of the present invention may be incorporated by ordinary pro-~0 cedures with various additives such as stabilizers, 1 roinforcing agents, fillers, and various additives which have heretofore been employed.
As mentioned above, the present invention provides a process for producing novel block copolymer resins high in transparency and excellent in mechanical properties by subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated diene monomer to multi-stage polymerization using an organolithium compound as an initiator. The process of the present invention is easily practicable on commercial scale, and, moreover, the resins obtained by the process of the present inven-tion are high in transparency and excellent in mechani-cal properties, and hence can successfully be used not only the fields where the conventional resins have been used but also in the fields where the conventional resins have not successfully been usable. ~hus, the industrial value of the present invention is extremely high.
The modes of practice of the present inven-tion are illustrated in detail below with reference to examples, but the invention is not limited to the examples, and various modifications are possible within the scope of the invention.
Example 1 Into a 2.5-liters pressure glass autoclave, which had internally been flushed with argon gas, were charged 1.5 liters of purified, dried and degassed benzene and 300 g. of purified and dried styrene.
Subsequently, a hexane solution of n-butyllithium was ~ 4 ~
1 droppecl into thc ~utoclave until an orangc color of the active terminals of polystyryllithium was observed in the content o:~ the autoclave, and then ~.0 mmol. of n-butyllithium and 0.90 g. of tetrahydrofuran werc further added to the autoclave. Immediately thereafter, the autoclave was heated to 60C., and the mixture in the autoclave was continuously stirred at said temperature for 3 hours to carry out the first stage polymerization.
Subsequently, 100 g. of styrene and 100 g. of purified and dried butadiene were added to the reaction mixture inside the autoclave, and the resulting mixture was continuously reacted at 60C. for 3 hours to carry out the second stage polymerization. After 3 hours polymeri-zation, 50 ml. of methanol was added to the system to terminate the polymerization, and the polymerization liquid was charged into methanol incorporated with 4-methyl-2,6-di-tert-butylphenol as an antioxidant, where-- by polymer precipitates were deposited. The precipi-tates were collected by filtration, and then drled in vacuum to obtain a block copolymer in a yield of 99.4%.
The copolymer had an intrinsic viscosity of 0.80 dl/g as measured in toluene at 30C. 100 Parts by weight of the thus obtained copolymer was incorporated with 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl)-phosphite as antioxidants, and then pelletized by means of an extruder. The resulting pellets were subjected to injection molding to prepare a test piece for physical property measurement. The molded article ~las beautiful ~0 in appearance and high in transparency. The test piece 10~4~1 1 was me.l~ured in pllysicnl propcrties to obtain the result~
shown in Table 1.
Table Intrinsic viscosity (dl`/g) (Note 1) 0.80 Tensile strength (kg/cm2) (Note 2) 31~
Elongation (%) (Note 2) 212 .
Izod impact strength, with notch (kg.cm/cm2) (Note 3) 2.2 without notch (kg.cm/cm2) (Note 4) 16.8 Melt index (g/10 min.) (Note 5) 0.48 .
Haze value (%) (Note 6) 7.0 .
(Note 1) The copolymer before pelletization Nas measured in toluene at 30C. using Ubbelohde type viscometer.
(Note 2) Measured at 20C. with a tensile rate of 5 mm/min. according to JIS-K 6871.
(Note 3) The test piece with notch was measured at 20C. according to JIS-K 6871.
(Note 4) The test piece without notch was measured at 20C. according to JIS-K 6871.
(Note 5) Measured according to JIS-K 6760.
(Note 6) Measured according to ASTM-D 1003.
., .
1 Example 2 ll)~ 4~
~ he polymcri~tion of Example 1 was repeated, except that the amount of tetrahydrofuran was varied to 2.0 g., the monomer added at the first stage was varied to 100 g. of styrene and 100 g. of butadiene, and the monomer added at the second stage was varied to 300 g.
of styrene, whereby a block copol~ner was obtained in a yield of 99.5%. ~he thus obtained copolymer was treated in the same manner as in Example 1 to prepare a test piece, which was then measured in physical properties to obtain the results shown in Table 2.
Table 2 Intrinsic viscosity (dl/g) 0.82 Melt index (g/10 min.) . 0.22 Tensile strength (kg/cm ) 333 Elongation (%) 190 Izod impact strength, with notch (kg.cm/cm2) 2.2 without notch (kg/cm/cm2) 14.5 Haze value (%) 8.5 Examples 3 - 6 The polymeri~.ation of Example 1 was repeated, except that the combination of the monomers and the - ~ewis base compound were varied to those shown in T~ble 3, in which were ~lso shown t;hc yields of the copol,ymers obt~ined.
iO~
.
~q ~ Fq O O O O
h b~o o c~ O O O O
~ r~ l l a) ~ o o o o r- Lr~ ~ ~
_ ._ _ ._ h ~ ~ ~ Lf~ 0 ~ ~ _, ~ a~ 0 ~
~o.~ ~ ~ C~
a) ~ ~ ~
''J h t~ h h h t~ o ~ ~ ~ ~ ~ ~
~:1 o ~h ~ O ~ ~h El E~ E~ E~
~1C ~ ~ ) ~:~0 ~0~0 O O O O O O O O
~ U~ ~o ~ ~0 ~0 . ~0 C~ ~0 ~ ~1 ~> ~.) O ~D O ~ O~ Q~
O ~0 ~t ~ ~ ~ ~ ~ ~
~ t3h ~ P~ h ~ h ~
. ~2 ~ ~ ~ ~ ~ ~
.._.
h ~ ~ bD ~ ~0 ~ ~0 a~ O a) o ~, o a~ o Oh Lt~ h u~ ~ O h ' ¢l ~1 ~ ~ ~ b~
. .
'~ 2; ~ ~t Lr~ ~o _ . ._ .__ .
lV~
1 The t}lUS obtained copolymcrs were treatcd in the same manner as in Example 1 to prcpare tcst pieces, which were then measurcd in physical properties to obtain the results shown in Table 4.
Table 4 Example Intrinsic Tensile Elon- strength Haze viscosity strength gation with notch value No. (dl/g) (kg/cm2) (%) (kg.cm/cm2) (~)
3 ~ ~ 189 -- 2.2 ~~ 5-0
4 0.74 ~22 169 2.2 ~ 9.0 0.72 303 207 2.1 8.0 l 6 ¦ l,lB ¦ 340 ¦80 ¦ 2.4 ¦~
Examples 7 - 8 The polymerization of Example 1 was repeated, except that the combination of the monomers and the ~ewis base compound were varied to those shown in Table 5.
- 2~ -~ ~^ o ~ O ~ N (~J
S~ ~) O N O
cd ~ rl ~ I l Ll~
a) ~ o ~`--S~l~ ~ N
~ r-l ~ ~
~ ~ ~ ~ CJ~
O ~p, . . _ .
. ~ ~
. ~ .
~ ~ $0~ ~D $0~ ~D
~ ~ ~, ~ E~
L~
a) . . . .
a~ ~o ~o bD bD
~ o 8 u~ ~
~ C~l ~ ,, . - .
~0 i - N
a~
bD
~0 ~o ~, 8 ~ .
~ ~; C-- . 0 ~ .
1 The thus obtained copolymcrs were treated in the same manner as in Ex~mple 1 to prepare test pieces, which were then measured in physical properti.es to obtain . the results shown in Table 6.
Table 6 Example Intrinsic Tensile Elon- Izod impact Haze viscosity strength gation strength value No. with notch (dl/g)(kg/cm2) (%) (kg.cm/cm2) (%) . .
7 0.81 325 172 Z.2 11.5 ~ ~ 1~51 1 1 6 1 2.2 ~ 3 Comparative Example 1 The polymerization of Example 1 was repeated, except that 400 g. of styrene was used as the first stage monomer and 100 g. of butadiene was used as the second stage monomer, to obtain a block copolymer in a yield of 99.9%. The thus obtained copolymer was treated in the same manner as in Example 1 to prepare a test piece, which was then measured in physical properties to obtain the results shown in Table 7.
4~gl Table 7 . Intrinslc viscosity (dl/g)0.69 Tensile strength (kg/cm2) 352 Elongation (%) I~od impact strength, with notch (kg.cm/cm2) 1.8 without notch (kg.cm/cm2) 8.9 Haze value (%) LO O
1 ~om Table 7, it is clear that when only the conjugated diene is added as the second stage monomer, as seen in Comparative ~xample 1, to synthesize a 2-blocked copolymer consisting of (1) a polymer block of the vinyl aromatic compound and (2) a polymer block of the conjugated diene, the block copolymer is markedly inferior in mechanical properties, particularly in elongation.
Comparative Examples 2 - 3 The same polymerization as in Examples 7 and 8 was repeated, except that the Lewis base compound was not used as shown in Table 8.
2r~
10~4~i . :
~ o ~
m ~ o ~ o N
~ O C\i S~
~ '~
~d ~
~ a~ ~zi ~;
.~
~ a~ ~D ~D bD ~0 bD O O
o o .
S~ c~l ~ ~ a~
~: ~ ~
~3 ~ ~ ~ ~. . . . .
cd S~ ~ ~D a~
O
a ~ R b ~ . .
. . ~ .
~ 0;
~0 ~ ~ ., lU~
1 The thus obtained copolymers were trcated in the same manner as in ~xample 1 to prepare test pieces, which were then measured in physical properties to obtain the results shown in Table 9.
Table 9 . ..
Compa- Intrinsic Tensile Elon- strength Haze rative viscosity strength gation with notch value Example (dl/g) (kg/cm2) (%) (kg.cm/cm2) (%) ........ _ ...
2 0.87 335 15 1.8 10.5 3 0.68 390 12 1.8 8.0 Erom comparison of Comparative Examples 2 and 3 with Examples 7 and 8, it is clear that when the ~ewis base compound is used in an amoùnt within the specified range, like in the present invention,-the resulting resin is greatly increased in mechanical properties, particularly in elongation.
Example 9 ~ he polymerization of Example 2 was repeated, except that the solvent was relaced by 300 ml. of n-hexane and the second stage monomer, i.e. 300 g. of styrene, was continuously added over a period of about 1.5 hours by use of a plunger pump, whereby a block copolymer in the form of a slurry suspended in n-hexane was obtained. The thus obtained copolymer was treated in the same manner as in Example 1 to prepare a test iU~4~41 1 piece, which was then measured in physical properties to obtain the results sho~m in Table 10.
Table 10 ..
Intrinsic viscosity ~dl/g) 0.74 .. . _ .
Melt index (g/10 min.) 1.86 _ ... _ ~ensile strength (kg/cm2) 292 . _ __ _ Blongation (%) 126 :
.. _ ............... ._ Izod impact strength without notch (kg.cm/cm2) 50.0 . .
Haze value (%) 8.0 1 Example 10 A 2.5-liters pressure glass autoclave was internally flushed with argon gas, and then charged with 1.5 liters of purified and dried benzene, 50 g.
of purified and dried styrene, 50 g. of purified and dried butadiene, 0.9 g. of tetrahydrofuran and 5.0 mmol.
of a hexane solution of n-butyllithium as an initiator.
Subsequently, the autoclave was heated to 60C. and the mixture in the autoclave was polymerized at said temperature for 2 hours to carry out the first stage polymerization. Thereafter, 300 g. of styrene was added as the second stage monomer, and the polymeri-zation was continued for 2 hours to carry out the second stage polymerization. Subsequently, a mixture of 50 g.
1 of ~tyrene and 50 g. of butadienc was added as thc third stage monomer, and the polymerization was further con-tinued for addltional 2 hours to carry out the third stage polymerization. Finally, 50 ml. of methanol was added to the system to terminate the polymerization, and the resulting viscous polymerization liquid was charged into a large amount of methanol to deposit poly-mer precipitates. The precipitates were collected by ~iltration, and then dried in vacuum to obtain a block copolymer in a yield of 99.1%. The copolymer had an intrinsic viscosity of 0.74 dl/g as measured in toluene at 30C. 100 Parts by weight of the thus obtained copolymer was incorporated with 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl)-phosphite as antioxidants, and then pelletized by means of an extruder. The resulting pellets were subjected to injection molding to prepare a test piece for physical property measurement. The molded article was beautiful in appearance and high in transparency. ~he test piece was measured in physical properties to obtain the results shown in Table 11.
'~
Table 11 . Intrinsic viscosity (dl/g) O. 74 Melt index (g/10 mln.) 0.2 Tensile strength (kg/cm2 ) 305 ~ 190 Izod impact strength, with notch (kg.cm/cm2) 2.2 without notch (kg.cm/cm2) 18.5 .
Haze value (%) ..
.
1 Examples 11 - 15 ~ he polymerization of Example 10 was repeated, except that the combination of the monomers and the amount of the ~ewis base compound were varied to those shown in Table 12. ~he resulting copolymers were treated .
in the same manner as in Example 10 to prepare test pieces, which were then measured in physical properties to obtain the results shown in ~able 13. All the molded articles were transpàrent and were beautiful in appear-ance.
iv~
~q~ o o o o o ~ ~ ~ o NO o ~1 6q I N 11~ l l l N l O O O O
~ r- l ~ ~
~ l O l O O O If~
~ ; , O ~ O O O
~ If ~ N N ~I ~J
~ ~ ~ ~ ~ 0~ ~
~ C~ ~ ~ ~ c~
~0 ~ ~ ~ C~ Ci~ C~ .
~q ~ ~ q~
td ~ O . O . O . O . O
,Q ~ ~ ~D h ~0 h bD ~ bD S~ bD
t~ O ~ ~ ~ 0 ~ O P, ~ ~
;~ ~ ~ O ~ ~: ~ .s: o ~ ~ h ~ E~ ~ h . . . . . .
E~ S~ ~D ~D ~D bD . ~D bD ~0 ~0 ~d 0 ~ Q> 1~ 0 O O g O O 15~ O
~ o ~l ~l E~ ~ E-l ~ ~ M ~ M ~ M ~
.. .__ S~ r~ bO . ~ bD ~0 ~D
O 0 g U~ $
0 ~3 ~ O C~ N N r-l N
~ ~ O ~Z; 1~1 ~1 E-l E-l E-l bQ Q~ ~ 0:2 ~n M ~
S~ ~0 ~0 ~D ~0 ~D bD ~D bD bD bD
~ L~ O O O O O O O O ~
~ t O N 15~ ~ ~ O 11~ O 1~ O r--h m E~ ~; ~ ~ E~ ~ E~
. , . .
~1 ' .
.~l 0 r-l N ~1 ~1 ~1 1~ ~ 4 ~ 4 1 1 (Note 1) ST = Styrene, BD = Bu-tadiene ( ) Sl, S2, S3, Bl and B2 are weight pro-portions of the monomers added at each stage of polymerization.
Table 13 Izod impact Example Intrinsic Tensile Elon- strength Haze No. viscosity strength gation (kg.cm/cm2) value (dl/g) (kg/cm2) (%) With with- (%) notch out . notch . __ . ._ _ 11 .7 - ----- 330 155 2.2 15.5 5.5 12 0.74 305 173 2.2 16.2 9.0 13 0.72 - 298 191 2.1 16.7 8.0 14 0.84 300 `202 2.2 17.5 7.5 0.70 285 2Z0 ` 2.3 20.5 8.5 Comparative Example 4 The polymerization of Example 10 was repeated, except that the combination of the monomers added at individual stages was varied to the below-mentioned combination, to obtain a block`copolymer in a yield of 99-4~-~ irst stage monomer: Butadiene 50 g.
Second stage monomer: Styrene 400 g.
Third stage monomer: Butadiene 50 g, - 3It -1 The thus obt~ined copolymcr was treated in the same manner as in Example 10 to prepare a test piece, which was then measured in physical properties to obtain th~ results shown in Table 14.
Table 14 Intrinsic viscosity (dl/g) 0.75 .. . . ...... __ . ..
Tensile strength (kg/cm2) 335 . ~
Elongation (%) 12 .
Izod impact strength, with notch (kg.cm/cm2) 1.8 without notch (kg.cm/cm2) 8.0 . .. _ , Haze value (%) 5.0 As is clear from Table 14, it is understood that the 3-blocked copolymer having at each terminal a polymer block of the conjugated diene (butadiene) and having at the center a polymer block of the vinyl aromatic compound (styrene) is far inferior in mechanical properties to the block copolymer according to the present invention.
Example 16 The oligoisoprenyl-dilithium initiator employed in this Example was synthesized in the following manner:
A 300 ml, four-necked flask was internally 1 flushcd with argon gas, and then charged with a dis-persion of 0.35 g. (0.05 mole) of lithium metal in 50 ml. of purified and dried tetrahydrofuran. Sub-se~uently, a solution of 6.4 g. (0.05 mole) of naphthalene in 150 ml. of tetrahydrofuran was added through a dropping funnel to the dispersion in the flask with stirring, and the resulting mixture was reacted ~or 24 hours to synthesize a naphthalene-lithium complex. ~he reaction liquid was cooled, and 40 ml. of purified isoprene was gradually added thereto while maintaining the temperature at -40 to -50C. Thè
resulting mixture was reacted at said temperature for about 6 hours, and then the temperature was gradually elevated to room temperature to form a solution of oligoisoprenyl-dilithium. This solution was heated under reduced pressure to remove tetrahydrofuran, and the residue was freshly charged with 400 ml. of purified and dried benzene to obtain a homogeneous solution.
The thus obtained benzene solution was subdividèd and sealed in ampoules and used as a polymerization ini-tiator.
Using the initiator synthesized in the above manner, the following polymerization according to the present invention was conducted:
A 2.5-liter pressure glass autoclave equipped with a stirrer was internally flushed with argon gas, and then charged with a mixture of 1.5 liters of de-hydrated and degassed dry benzene, 240 g. of purified and dried styrene, and 0.72 g. (10 mmol.) of tetrahydro-furan. Subsequently, 100 ml. of the benzene solution .
1 of oli~oi~oprenyl-(lilithium initiator synthesized above was injected into thc mixture inside the autoclave to initiate the polymerization. Thc mixture was polymerized at 60C. for 3 hours to carry out the first stage poly-meriæation. Thereafter, a mixture of 80 g. o~ styreneand 80 g. of purified and dried butadiene was added as the second stage monomer, and the resulting mixture was reacted at 60C. for 3 hours to carry out the second stage polymerization. After completion of the second stage polymerization, 50 ml. of methanol was added as a polymerization terminator, and the resulting poly-merization liquid was charged into methanol incorporated with 4-methyl-2,6-di-tert-butylphenol as an anitoxidant to deposit polymer precipitates. The precipitates were collected by filtration and then dried in vacuum to obtain a block copolymer in a yield of 99.1%. The copolymer had an intrinsic viscosity (~) of 0.64 dl/g as measured in toluene at 30~. 100 Parts by weight of the thus obtained copolymer was incorporated with 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl)-phosphite as antioxidants, and then pelletized by means of an extruder. The resulting pellets were subjected to injection molding to prepare a test piece for physical property measurement. The molded article was beautiful in appearance and high in transparency. The test piece was measured in physical properties to obtain the results sho~ in Table 15.
1()~4~1 Table 15 .
Intrinsic ViSCOSlty (dl/g) 0.64 Tensile strength (kg/cm2) 298 . ...._ Elongation (%) 173 . , Izod impact strength, with notch (kg.cm/cm2) 2.2 without notch (kg.cm/cm2) 17~5 . .__ Haze value (%) 6.0 1 Examples 17 - 20 The polymerization of Example 16 was repeated, except that the combination o~ the monomers and initiator was varied to the combination shown in Table 16, to obtain copolymers. The thus obtained copolymers were treated in the same manner as in Example 16 to prepare test pieces, which were then measured in physical properties to obtain the results shown in Table 17.
Ali the molded articles were high in transparency and beautiful in appearance.
- 3~ -h N _ ~ O~
P~ ~ ' O~ ~ CO O~
h .( ~ _ o ~ ~D O O O O
~1 ~_ ~ ~1 ~ 0 .
h -- O N
h g bD
~ o ~o o~ 8 C~ h C~J . ~ (~J cu h h .,~
:d ~ ~ h ~ o ~ h ~ ~0 ~ 0 ~ rl ,5: 0 ~
H ~_1 ~_1 H r-l r-l 0~ 0~ 0~1 0 ~1 ~ ~1 0:) ~1 O ' :~
1()44t~
o _ _ o N ~1 ~ . . .
1~ ' I ~ 0 c- r-~ ~0 . ' ~ ~ ~ O O O
a) ~ ~D ~I ~D C-~O ~3 S~ ~ N _ _ O O N ~ O N
H . C~J N N C~J
r-l 1 _ , .
_~ C~l ~ ~ O
El h ~1 N _ r I
O ~N~4 1~ O C~ rt ~Q ~D ~ ~ ~O ~ 0~) E~ C~ ~ C~l C~l .~0~-~' _ _ _ ~0~ O ~ O O
H p r~l __ _--F~ 7~j ~ ~1 N
-- 1~o --1 Compar~tive Example 5 The polymerization of Example 16 was repeated, except that the combination of the monomers used at the individual stages of polymerization was varied to a combination of 320 g. of styrene as the first stage monomer wi-th 80 g. of butadiene as the second stage monomer, to obtain a black copolymer in a yield of 98~ 8~o~ The thus obtained copolymer was treated in the' same manner as in Example 16 to prepare a test piece, which was then measured in physical properties to obtain the results shown in Table 18.
Table 18 . .
Intrinsic viscosity (dl/g) 0.65 .
Tensile strength (kg/cm2) 330 ~longation (%) 11 , Izod impact strength, with notch (kg.cm/cm2) 1.7 without notch (kg.cm/cm2) 8.5 . .~ . . 7 Haze value (~) 9.0 As is clear from Table 18, it is understood that the 3-blocked copolymer ha~-ing at the center a polymer block of the vinyl aromatic compound (styrene) and having at each terminal a polymer block of the conjugated diene (butadiene) is far interior in lU~4~4~
mech~nical properties to the block copolymer according to the present invention.
Examples 7 - 8 The polymerization of Example 1 was repeated, except that the combination of the monomers and the ~ewis base compound were varied to those shown in Table 5.
- 2~ -~ ~^ o ~ O ~ N (~J
S~ ~) O N O
cd ~ rl ~ I l Ll~
a) ~ o ~`--S~l~ ~ N
~ r-l ~ ~
~ ~ ~ ~ CJ~
O ~p, . . _ .
. ~ ~
. ~ .
~ ~ $0~ ~D $0~ ~D
~ ~ ~, ~ E~
L~
a) . . . .
a~ ~o ~o bD bD
~ o 8 u~ ~
~ C~l ~ ,, . - .
~0 i - N
a~
bD
~0 ~o ~, 8 ~ .
~ ~; C-- . 0 ~ .
1 The thus obtained copolymcrs were treated in the same manner as in Ex~mple 1 to prepare test pieces, which were then measured in physical properti.es to obtain . the results shown in Table 6.
Table 6 Example Intrinsic Tensile Elon- Izod impact Haze viscosity strength gation strength value No. with notch (dl/g)(kg/cm2) (%) (kg.cm/cm2) (%) . .
7 0.81 325 172 Z.2 11.5 ~ ~ 1~51 1 1 6 1 2.2 ~ 3 Comparative Example 1 The polymerization of Example 1 was repeated, except that 400 g. of styrene was used as the first stage monomer and 100 g. of butadiene was used as the second stage monomer, to obtain a block copolymer in a yield of 99.9%. The thus obtained copolymer was treated in the same manner as in Example 1 to prepare a test piece, which was then measured in physical properties to obtain the results shown in Table 7.
4~gl Table 7 . Intrinslc viscosity (dl/g)0.69 Tensile strength (kg/cm2) 352 Elongation (%) I~od impact strength, with notch (kg.cm/cm2) 1.8 without notch (kg.cm/cm2) 8.9 Haze value (%) LO O
1 ~om Table 7, it is clear that when only the conjugated diene is added as the second stage monomer, as seen in Comparative ~xample 1, to synthesize a 2-blocked copolymer consisting of (1) a polymer block of the vinyl aromatic compound and (2) a polymer block of the conjugated diene, the block copolymer is markedly inferior in mechanical properties, particularly in elongation.
Comparative Examples 2 - 3 The same polymerization as in Examples 7 and 8 was repeated, except that the Lewis base compound was not used as shown in Table 8.
2r~
10~4~i . :
~ o ~
m ~ o ~ o N
~ O C\i S~
~ '~
~d ~
~ a~ ~zi ~;
.~
~ a~ ~D ~D bD ~0 bD O O
o o .
S~ c~l ~ ~ a~
~: ~ ~
~3 ~ ~ ~ ~. . . . .
cd S~ ~ ~D a~
O
a ~ R b ~ . .
. . ~ .
~ 0;
~0 ~ ~ ., lU~
1 The thus obtained copolymers were trcated in the same manner as in ~xample 1 to prepare test pieces, which were then measured in physical properties to obtain the results shown in Table 9.
Table 9 . ..
Compa- Intrinsic Tensile Elon- strength Haze rative viscosity strength gation with notch value Example (dl/g) (kg/cm2) (%) (kg.cm/cm2) (%) ........ _ ...
2 0.87 335 15 1.8 10.5 3 0.68 390 12 1.8 8.0 Erom comparison of Comparative Examples 2 and 3 with Examples 7 and 8, it is clear that when the ~ewis base compound is used in an amoùnt within the specified range, like in the present invention,-the resulting resin is greatly increased in mechanical properties, particularly in elongation.
Example 9 ~ he polymerization of Example 2 was repeated, except that the solvent was relaced by 300 ml. of n-hexane and the second stage monomer, i.e. 300 g. of styrene, was continuously added over a period of about 1.5 hours by use of a plunger pump, whereby a block copolymer in the form of a slurry suspended in n-hexane was obtained. The thus obtained copolymer was treated in the same manner as in Example 1 to prepare a test iU~4~41 1 piece, which was then measured in physical properties to obtain the results sho~m in Table 10.
Table 10 ..
Intrinsic viscosity ~dl/g) 0.74 .. . _ .
Melt index (g/10 min.) 1.86 _ ... _ ~ensile strength (kg/cm2) 292 . _ __ _ Blongation (%) 126 :
.. _ ............... ._ Izod impact strength without notch (kg.cm/cm2) 50.0 . .
Haze value (%) 8.0 1 Example 10 A 2.5-liters pressure glass autoclave was internally flushed with argon gas, and then charged with 1.5 liters of purified and dried benzene, 50 g.
of purified and dried styrene, 50 g. of purified and dried butadiene, 0.9 g. of tetrahydrofuran and 5.0 mmol.
of a hexane solution of n-butyllithium as an initiator.
Subsequently, the autoclave was heated to 60C. and the mixture in the autoclave was polymerized at said temperature for 2 hours to carry out the first stage polymerization. Thereafter, 300 g. of styrene was added as the second stage monomer, and the polymeri-zation was continued for 2 hours to carry out the second stage polymerization. Subsequently, a mixture of 50 g.
1 of ~tyrene and 50 g. of butadienc was added as thc third stage monomer, and the polymerization was further con-tinued for addltional 2 hours to carry out the third stage polymerization. Finally, 50 ml. of methanol was added to the system to terminate the polymerization, and the resulting viscous polymerization liquid was charged into a large amount of methanol to deposit poly-mer precipitates. The precipitates were collected by ~iltration, and then dried in vacuum to obtain a block copolymer in a yield of 99.1%. The copolymer had an intrinsic viscosity of 0.74 dl/g as measured in toluene at 30C. 100 Parts by weight of the thus obtained copolymer was incorporated with 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl)-phosphite as antioxidants, and then pelletized by means of an extruder. The resulting pellets were subjected to injection molding to prepare a test piece for physical property measurement. The molded article was beautiful in appearance and high in transparency. ~he test piece was measured in physical properties to obtain the results shown in Table 11.
'~
Table 11 . Intrinsic viscosity (dl/g) O. 74 Melt index (g/10 mln.) 0.2 Tensile strength (kg/cm2 ) 305 ~ 190 Izod impact strength, with notch (kg.cm/cm2) 2.2 without notch (kg.cm/cm2) 18.5 .
Haze value (%) ..
.
1 Examples 11 - 15 ~ he polymerization of Example 10 was repeated, except that the combination of the monomers and the amount of the ~ewis base compound were varied to those shown in Table 12. ~he resulting copolymers were treated .
in the same manner as in Example 10 to prepare test pieces, which were then measured in physical properties to obtain the results shown in ~able 13. All the molded articles were transpàrent and were beautiful in appear-ance.
iv~
~q~ o o o o o ~ ~ ~ o NO o ~1 6q I N 11~ l l l N l O O O O
~ r- l ~ ~
~ l O l O O O If~
~ ; , O ~ O O O
~ If ~ N N ~I ~J
~ ~ ~ ~ ~ 0~ ~
~ C~ ~ ~ ~ c~
~0 ~ ~ ~ C~ Ci~ C~ .
~q ~ ~ q~
td ~ O . O . O . O . O
,Q ~ ~ ~D h ~0 h bD ~ bD S~ bD
t~ O ~ ~ ~ 0 ~ O P, ~ ~
;~ ~ ~ O ~ ~: ~ .s: o ~ ~ h ~ E~ ~ h . . . . . .
E~ S~ ~D ~D ~D bD . ~D bD ~0 ~0 ~d 0 ~ Q> 1~ 0 O O g O O 15~ O
~ o ~l ~l E~ ~ E-l ~ ~ M ~ M ~ M ~
.. .__ S~ r~ bO . ~ bD ~0 ~D
O 0 g U~ $
0 ~3 ~ O C~ N N r-l N
~ ~ O ~Z; 1~1 ~1 E-l E-l E-l bQ Q~ ~ 0:2 ~n M ~
S~ ~0 ~0 ~D ~0 ~D bD ~D bD bD bD
~ L~ O O O O O O O O ~
~ t O N 15~ ~ ~ O 11~ O 1~ O r--h m E~ ~; ~ ~ E~ ~ E~
. , . .
~1 ' .
.~l 0 r-l N ~1 ~1 ~1 1~ ~ 4 ~ 4 1 1 (Note 1) ST = Styrene, BD = Bu-tadiene ( ) Sl, S2, S3, Bl and B2 are weight pro-portions of the monomers added at each stage of polymerization.
Table 13 Izod impact Example Intrinsic Tensile Elon- strength Haze No. viscosity strength gation (kg.cm/cm2) value (dl/g) (kg/cm2) (%) With with- (%) notch out . notch . __ . ._ _ 11 .7 - ----- 330 155 2.2 15.5 5.5 12 0.74 305 173 2.2 16.2 9.0 13 0.72 - 298 191 2.1 16.7 8.0 14 0.84 300 `202 2.2 17.5 7.5 0.70 285 2Z0 ` 2.3 20.5 8.5 Comparative Example 4 The polymerization of Example 10 was repeated, except that the combination of the monomers added at individual stages was varied to the below-mentioned combination, to obtain a block`copolymer in a yield of 99-4~-~ irst stage monomer: Butadiene 50 g.
Second stage monomer: Styrene 400 g.
Third stage monomer: Butadiene 50 g, - 3It -1 The thus obt~ined copolymcr was treated in the same manner as in Example 10 to prepare a test piece, which was then measured in physical properties to obtain th~ results shown in Table 14.
Table 14 Intrinsic viscosity (dl/g) 0.75 .. . . ...... __ . ..
Tensile strength (kg/cm2) 335 . ~
Elongation (%) 12 .
Izod impact strength, with notch (kg.cm/cm2) 1.8 without notch (kg.cm/cm2) 8.0 . .. _ , Haze value (%) 5.0 As is clear from Table 14, it is understood that the 3-blocked copolymer having at each terminal a polymer block of the conjugated diene (butadiene) and having at the center a polymer block of the vinyl aromatic compound (styrene) is far inferior in mechanical properties to the block copolymer according to the present invention.
Example 16 The oligoisoprenyl-dilithium initiator employed in this Example was synthesized in the following manner:
A 300 ml, four-necked flask was internally 1 flushcd with argon gas, and then charged with a dis-persion of 0.35 g. (0.05 mole) of lithium metal in 50 ml. of purified and dried tetrahydrofuran. Sub-se~uently, a solution of 6.4 g. (0.05 mole) of naphthalene in 150 ml. of tetrahydrofuran was added through a dropping funnel to the dispersion in the flask with stirring, and the resulting mixture was reacted ~or 24 hours to synthesize a naphthalene-lithium complex. ~he reaction liquid was cooled, and 40 ml. of purified isoprene was gradually added thereto while maintaining the temperature at -40 to -50C. Thè
resulting mixture was reacted at said temperature for about 6 hours, and then the temperature was gradually elevated to room temperature to form a solution of oligoisoprenyl-dilithium. This solution was heated under reduced pressure to remove tetrahydrofuran, and the residue was freshly charged with 400 ml. of purified and dried benzene to obtain a homogeneous solution.
The thus obtained benzene solution was subdividèd and sealed in ampoules and used as a polymerization ini-tiator.
Using the initiator synthesized in the above manner, the following polymerization according to the present invention was conducted:
A 2.5-liter pressure glass autoclave equipped with a stirrer was internally flushed with argon gas, and then charged with a mixture of 1.5 liters of de-hydrated and degassed dry benzene, 240 g. of purified and dried styrene, and 0.72 g. (10 mmol.) of tetrahydro-furan. Subsequently, 100 ml. of the benzene solution .
1 of oli~oi~oprenyl-(lilithium initiator synthesized above was injected into thc mixture inside the autoclave to initiate the polymerization. Thc mixture was polymerized at 60C. for 3 hours to carry out the first stage poly-meriæation. Thereafter, a mixture of 80 g. o~ styreneand 80 g. of purified and dried butadiene was added as the second stage monomer, and the resulting mixture was reacted at 60C. for 3 hours to carry out the second stage polymerization. After completion of the second stage polymerization, 50 ml. of methanol was added as a polymerization terminator, and the resulting poly-merization liquid was charged into methanol incorporated with 4-methyl-2,6-di-tert-butylphenol as an anitoxidant to deposit polymer precipitates. The precipitates were collected by filtration and then dried in vacuum to obtain a block copolymer in a yield of 99.1%. The copolymer had an intrinsic viscosity (~) of 0.64 dl/g as measured in toluene at 30~. 100 Parts by weight of the thus obtained copolymer was incorporated with 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl)-phosphite as antioxidants, and then pelletized by means of an extruder. The resulting pellets were subjected to injection molding to prepare a test piece for physical property measurement. The molded article was beautiful in appearance and high in transparency. The test piece was measured in physical properties to obtain the results sho~ in Table 15.
1()~4~1 Table 15 .
Intrinsic ViSCOSlty (dl/g) 0.64 Tensile strength (kg/cm2) 298 . ...._ Elongation (%) 173 . , Izod impact strength, with notch (kg.cm/cm2) 2.2 without notch (kg.cm/cm2) 17~5 . .__ Haze value (%) 6.0 1 Examples 17 - 20 The polymerization of Example 16 was repeated, except that the combination o~ the monomers and initiator was varied to the combination shown in Table 16, to obtain copolymers. The thus obtained copolymers were treated in the same manner as in Example 16 to prepare test pieces, which were then measured in physical properties to obtain the results shown in Table 17.
Ali the molded articles were high in transparency and beautiful in appearance.
- 3~ -h N _ ~ O~
P~ ~ ' O~ ~ CO O~
h .( ~ _ o ~ ~D O O O O
~1 ~_ ~ ~1 ~ 0 .
h -- O N
h g bD
~ o ~o o~ 8 C~ h C~J . ~ (~J cu h h .,~
:d ~ ~ h ~ o ~ h ~ ~0 ~ 0 ~ rl ,5: 0 ~
H ~_1 ~_1 H r-l r-l 0~ 0~ 0~1 0 ~1 ~ ~1 0:) ~1 O ' :~
1()44t~
o _ _ o N ~1 ~ . . .
1~ ' I ~ 0 c- r-~ ~0 . ' ~ ~ ~ O O O
a) ~ ~D ~I ~D C-~O ~3 S~ ~ N _ _ O O N ~ O N
H . C~J N N C~J
r-l 1 _ , .
_~ C~l ~ ~ O
El h ~1 N _ r I
O ~N~4 1~ O C~ rt ~Q ~D ~ ~ ~O ~ 0~) E~ C~ ~ C~l C~l .~0~-~' _ _ _ ~0~ O ~ O O
H p r~l __ _--F~ 7~j ~ ~1 N
-- 1~o --1 Compar~tive Example 5 The polymerization of Example 16 was repeated, except that the combination of the monomers used at the individual stages of polymerization was varied to a combination of 320 g. of styrene as the first stage monomer wi-th 80 g. of butadiene as the second stage monomer, to obtain a black copolymer in a yield of 98~ 8~o~ The thus obtained copolymer was treated in the' same manner as in Example 16 to prepare a test piece, which was then measured in physical properties to obtain the results shown in Table 18.
Table 18 . .
Intrinsic viscosity (dl/g) 0.65 .
Tensile strength (kg/cm2) 330 ~longation (%) 11 , Izod impact strength, with notch (kg.cm/cm2) 1.7 without notch (kg.cm/cm2) 8.5 . .~ . . 7 Haze value (~) 9.0 As is clear from Table 18, it is understood that the 3-blocked copolymer ha~-ing at the center a polymer block of the vinyl aromatic compound (styrene) and having at each terminal a polymer block of the conjugated diene (butadiene) is far interior in lU~4~4~
mech~nical properties to the block copolymer according to the present invention.
Claims (21)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for producing a transparent block copoly-mer resin which comprises subjecting 90 to 65 parts by weight of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated diene monomer to 2-stage block copolymerization in an inert hydrocarbon solvent using an organo-mono lithium compound in amount of 0.005 to 5 mole % or oryano-dilithium compound in amount of 0.002 to 3 mole % based on the total monomer as an initiator, characterized in that at the first stage of polymerization, S1 parts by weight of the vinyl aromatic compound monomer is added and substantially all of the monomer is poly-merized, and then, at the second stage of polymerization, a mixture of S2 parts by weight of the vinyl aromatic compound monomer and B parts by weight of the conjugated diene monomer is added and the polymerization is continued to polymerized sub-stantially all of the monomers, wherein the feed weight ratios of the individual monomers are controlled to values within the ranges of:
S1 + S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) S1/(S1 + S2) = 0.35 to 0.90 S2/B = 0.2 to 3.0 and the polymerization is effected in the presence of 0.01 to 5 mole % of a Lewis base compound based on the total monomer, to produce a block copolymer resin having an average molecular weight in the range from 0.5 to 1.8 dl/g in terms of intrinsic viscosity as measured in toluene at 30°C.
S1 + S2 = 90 to 65 (parts by weight) B = 10 to 35 (parts by weight) S1/(S1 + S2) = 0.35 to 0.90 S2/B = 0.2 to 3.0 and the polymerization is effected in the presence of 0.01 to 5 mole % of a Lewis base compound based on the total monomer, to produce a block copolymer resin having an average molecular weight in the range from 0.5 to 1.8 dl/g in terms of intrinsic viscosity as measured in toluene at 30°C.
2. A process according to claim 1, wherein the vinyl aromatic compound monomer is one member selected from the group consisting of styrene, .alpha.-methyl-styrene and vinyltoluene.
3. A process according to claim 2, wherein the vinyl aromatic compound monomer is styrene.
4. A process according to claim 1, wherein the con-jugated diene monomer is one member selected from the group consisting of 1,3-butadiene, isoprene and piperylene.
5. A process according to claim 4, wherein the con-jugated diene monomer is 1,3-butadiene.
6. A process according to claim 1, wherein the inert hydrocarbon solvent is a paraffinic, naphthenic or aromatic inert hydrocarbon having 5 to 20 carbon atoms.
7. A process according to claim 6, wherein the inert hydrocarbon solvent is one member selected from the group consisting of hexane, heptane, cyclohexane, methylcyclohexane, benzene and toluene.
8. A process according to claim 1, wherein the inert hydrocarbon solvent is used in a proportion of 1 to 20 parts by weight per part by weight of the total monomer.
9. A process according to claim 1, wherein the Lewis base compound is an ether compound or a tertiary amine compound.
10. A process according to claim 9, wherein the ether compound is one member selected from the group consisting of cyclic ethers, aliphatic monoethers and aliphatic polyethers.
11. A process according to claim 10, wherein the ether compound is one member selected from the group consisting of tetrahydrofuran, tetrahydropyran, diethyl ether, dibutyl ether, ethyleneglycol-dimethyl-ether and diethyleneglycol-diethyl-ether.
12. A process according to claim 9, wherein the tertiary amine compound is one member selected from the group consisting of triethylamine, tripropylamine, tributylamine, N,N'-dimethylaniline and pyridine.
13. A process according to claim 1, wherein the Lewis base compound is used in a proportion of 0.05 to 2 mole-% based on the total monomer.
14. A process according to claim 1, wherein the organo-monolithium compound is one member selected from the group consisting of ethyllithium, propyllithium, butyllithium, amyl-lithium, hexyllithium, 2-ethylhexyllithium, cyclohexyllithium, decyllithium, dodecyllithium, phenyllithium, tolyllithium, xylyllithium and naphthyllithium.
15. A process according to claim 14, wherein the organo-monolithium compound is butyllithium.
16. A process according to claim 1, wherein the organo-dilithium compound is one member selected from the group consisting of trimethylene-dilithium, tetramethylene-dilithium, pentamethylene dilithium, naphthalene-lithium complex, stilbene-lithium complex, diphenyl-lithium complex, oligobutadienyl-dilithium and oligo-isoprenyl-dilithium.
17. A process according to claim 16, wherein the organo-dilithium compound is one member selected from the group consist-ing of oligobutadienyl-dilithium and oligoisoprenyl-dilithium.
18. A process according to claim 1, wherein the organo-monolithium compound is used in a proportion of 0.01 to 1.5 mole-%
based on the total monomer.
based on the total monomer.
19. A process according to claim 1, wherein the organo-dilithium compound is used in a proportion of 0.01 to 1.5 mole %
based on the total monomer.
based on the total monomer.
20. A process according to claim 1, wherein the poly-merization is effected at a temperature in the range from 20°
to 120°C.
to 120°C.
21. A process according to claim 1, wherein after completion of the polymerization, the polymerization liquid is contacted with excess of a lower alcohol, or directly heated to dryness, or mixed with steam, thereby removing the solvent to recover the polymer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10994673A JPS5748571B2 (en) | 1973-09-29 | 1973-09-29 | |
| JP11259373A JPS5748572B2 (en) | 1973-10-05 | 1973-10-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1044841A true CA1044841A (en) | 1978-12-19 |
Family
ID=26449654
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA210,254A Expired CA1044841A (en) | 1973-09-29 | 1974-09-27 | Process for producing transparent block copolymer resins |
Country Status (6)
| Country | Link |
|---|---|
| CA (1) | CA1044841A (en) |
| DE (1) | DE2446255C3 (en) |
| FR (1) | FR2272110B1 (en) |
| GB (1) | GB1477344A (en) |
| IT (1) | IT1019430B (en) |
| NL (1) | NL157025B (en) |
-
1974
- 1974-09-26 NL NL7412706A patent/NL157025B/en not_active IP Right Cessation
- 1974-09-27 DE DE19742446255 patent/DE2446255C3/en not_active Expired
- 1974-09-27 FR FR7432678A patent/FR2272110B1/fr not_active Expired
- 1974-09-27 CA CA210,254A patent/CA1044841A/en not_active Expired
- 1974-09-27 IT IT5326274A patent/IT1019430B/en active
- 1974-09-30 GB GB4229774A patent/GB1477344A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2446255A1 (en) | 1975-04-03 |
| FR2272110B1 (en) | 1978-07-21 |
| NL157025B (en) | 1978-06-15 |
| DE2446255B2 (en) | 1979-12-20 |
| DE2446255C3 (en) | 1980-08-21 |
| IT1019430B (en) | 1977-11-10 |
| NL7412706A (en) | 1975-04-02 |
| FR2272110A1 (en) | 1975-12-19 |
| GB1477344A (en) | 1977-06-22 |
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