DE2120232A1 - Block copolymer and process for its preparation - Google Patents

Description

Case DKK-1 '2.4. April 1971

1 A - 253

DEUEI KAGAKÜ KOG-YO K.K. , Tokyo, Japan

Block copolyraeres and process for their preparation

The invention relates to a block copolyraeres made of one vinyl substituted aromatic hydrocarbon and a.] conjugated diene, and a process for its preparation.

It is known that various types of block copolyraeren can be produced by combining monomers, with an alkali metal or an organic alkali metal compound as a starter is used. The block copolymers obtained leave however in terms of optical clarity, impact resistance, and other physical factors Properties left to be desired.

Various types of processes have been described for the production of block copolymers which lead to self-vulcanizable elastomers. So describes z. B. Japanese published patent application IJr. 23 793/1965 the production of a block copolymer in a multistage reaction using a lithium compound as a starter. The Iiethode of "living" polymerization is used. Hau receives Llockcopolyraere in which a non-elastomer! " ¹ block from an unsaturated compound

109849/1631

binding, like ζ. B. a vinyl substituted aromatic Compound, an elastomeric block made of a conjugated diene, and the particular non-elastomeric block with each other linked.

From the Japanese patent application ITr. It is 19286/1961 known that block copolymers can be prepared which have a middle elastomeric block and two en.standi.re have non-elastomeric blocks. Even with this well-known In the process, the reaction is carried out in several stages. As a starter is an aromatic compound with two Iiithiuiaatoiaen used and the polymerization proceeds leading at both ends.

However, the compounds obtainable by the known multistage polymerization polymer products have several ITachteile which are based on _p undesirable Horaopolynere contained or two blocks Copolymers formed in erheblicr.en amounts in the resulting Blockcopolyneren "Bies is lead to an increase of the inactive Endgmppen zuTückzu which are increased in the respective stage by impurities in the solvent or in the Ilonoraeren allaäiilieh. An admixture of homopolymers or two-block copolymers in the three-block copolymer usually adversely affects the mechanical properties. of the block copolymer. Palis the three-block copolymer. If a two-block copolymer is mixed in, then the clarity, the elongation, and the tear strength are considerably reduced and, moreover, the impact resistance, which is the most important property, is reduced. So far it has not been possible to avoid this IT part in a polymerization process with several polymerization stages.

It is therefore the object of the present invention to provide a block copolymer of a vinyl-substituted aromatic

Hydrocarbon and a conjugated diene, which have excellent mechanical properties, in particular has high impact resistance and tear resistance and excellent clarity.

According to the invention, this object is achieved by means of a block copolymer solved, which is a three-block structure with an elastoraeren copolymeric middle block of the conjugated diene and a small amount of the vinyl-substituted aromatic colylene hydrogen having, the frequency of the τοπ conjugated diene Struktureiuheiten formed by the lutte des Hittelblockc su its ends gradually decreasing and with two terminal horaopolymeric blocks of the vinyl-substituted aromatic hydrocarbon are present.

The method according to the invention for producing this block copolymer consists in the fact that a mixture of a vinyl-substituted aromatic is produced in a one-step reaction Hydrocarbon and a conjugated diene into one non-polar solvent and polymerized in the presence of a starter, v / elcher by reacting lithium rait a non-condensed polycyclic aromatic hydrocarbon was produced.

It has been shown that for the production of clear thermoplastic Plastics of the above type having excellent impact resistance and excellent elasticity physical properties the block copolymer should have a three-block structure in which a elastomeric central block made of a conjugated diene on both sides with a non-elastic block made of a vinyl substituted aromatic hydrocarbon. There should preferably be a big difference between the glaze change point (Tg) of the two Blocks exist. The glass transition point of the non-elastic block (Tg) should preferably be above 100 ° G

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lie while the glass transition point of the elastomer Blocks (Tg) should be less than -40 ° G.

If a different from Lithiur.i is used to make the starter Alkali Metal Used- Is Used, Or If The Polymerization carried out in a polar solvent is, the content of tiny bonds in the increases resulting polybutadiene block and accordingly takes its Glass transition point (Tg) to. Hence, in such a Fall, the mechanical strength of the plastic as elastic plastic is reduced and the physical properties of the plastic at low temperatures are adversely affected.

The polymerization process according to the invention is it is a "living" polymerization at both ends. In a first reaction phase, the existing conjugated diene selectively polymerized, with only slight Hengen of the vinyl-substituted aromatic compound co-polymerized will. In the second reaction phase, the remainder of the vinyl-substituted aromatic Compound homopolymerized. This is due to a remarkable difference between the reaction rates of the two monomers in the non-polar solvent. In the one-stage polymerization according to the invention is, in the first reaction phase mainly that conjugated diene polymerizes with hit polymerization of only a small amount of the vinyl-substituted aromatic carbon hydrogen compound. At the same time, the ratio of vinyl-substituted aromatic hydrocarbon gradually becomes su conjugated diene increases »ITachdera the entire conjugated Diene along with the small amount of vinyl-substituted ones aromatic hydrocarbon compound is polymerized, only the polymerization of the vinyl substituted aromatic Hydrocarbon started in significant proportions, creating a horopolymer block.

The structure of the block copolyraeren according to the invention can be represented by the following general formula:

χ _ v _a - L Hittelblock -] - V _gt - X.

Y denotes a structural unit resulting from the vinyl-substituted aromatic hydrocarbon and a and a ¹ denote numbers determining the number of structural units in the end blocks. X means an end group which is determined by the chain termination reaction and z. B. is a oxygenatora.

The middle block has the following composition:

Here, D denotes the structural unit resulting from the conjugated diene and η and m are missing and denote e the look! of groups V and D in the middle block. The sequence of the structural units 7 and D im Ilittelblock can be represented by the following general formula:

- "ray ^v nx" · ^J m2 ^v n1 ^ mI ^v n1 »· ^υ η2 *"' ^v nx ^f ^ my «

The following applies to the average values of the index numbers α and η where the following relationship:

mT> rä? (ΈΤΤ) ..... ^ By "
nT (nf) ^ ή?

The order of the average index numbers m and η along the chain of the middle block is through the

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different reaction speeds of the ionizers set under the respective reaction conditions and can be calculated or estimated with sufficient accuracy will.

Animals the molecular weight of the block polyester according to the invention is preferably 50,000 to 200,000, in particular 70 to 140,000.

According to the invention, a method SWR producing a Bloekcopolyraeren the following to sarasens et to ng created (non-elastomeric block of vinylsufestituierteni aromatic hydrocarbon) - (elastoaerer block oit a predominant amount of konjugja ^ tem diene, which gradually abnit to the ends] at) ~ (non-elastomeric block of vinyl-substituted aromatic hydrocarbons} «The reaction is carried out in one stage. This is an active" living "polymerization. The vinyl-substituted aromatic hydrocarbon and the conjugated diene are dissolved in a non-polar solvent in the presence of the reaction agent. Product of lithium and a niclitcondensed polycyclic arotsatis before η hydrocarbon converted, there being a difference between the reaction rates of the two monomers, namely the vinyl-substituted aromatic hydrocarbons and the conjugated diene.

It was already known that a dilithiura adduct, i.e. H. one organic dilithium compound can be used as a starter for the preparation of three-block copolymers. Such conventional organic dilithium compounds have ira however, generally poor solubility in non-polar solvents such as hydrocarbons, so that a heterogeneous catalyst system with a low effectiveness for starting the polymerization arises «

The starter according to the invention is made by reacting

Litlion made with a non-condensed aromatic hydrocarbon in a polar medium. The polar hediura can be a silicone ether or an aliphatic polyether. The resulting reaction complex becomes a small amount of conjugate. T? Wi given, whereby the Bianion of an oligo-core of the hydrocarbon is formed. The polar iodine is then exchanged for a non-polar solvent by distilling off the polar iodine. add niclitpolares solvent. After all, a homogeneous starter was produced.

It vrde. already disclosed in the published Japanese patent 11t, 11090/1964 that the reaction product of lithium and a condensed aromatic compound in a polar agent as a starter ends up in the published Japanese patent Mr. 26 592/1 g53 discloses that the reaction product of lithium and certain accelerators, e.g., a condensed aromatic hydrocarbon in an aliphatic carbon ether, can be used as a starter. .

The starter used for the method according to the invention However, compared to the known starters, it has a considerable increased activity.

The Eur production of the starter according to the invention used nielrfckondensierten poly sy kl is before η aroraa-Nazi hydrocarbons include s. B. Biphenylkohlenwasserstoffe New York Convention O herpheny! Hydrocarbons. But no ¹ =; condensed aromatic hydrocarbons such as E. Maphtslin, anthracene, phenanthrene or alkyl derivatives thereof are used.

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ORIGINAL INSPECTH)

120232

When making the starter, at least one Graran Atom Liΐΐιium with a Hol of the iiichtkondensierten a-romatisclien Hydrocarbon implemented. Preferably should not less than 1 gr a min A to α lithium and 1 col of nicitconoensated aromatic hydrocarbon is used v / ground, otherwise the starter obtained will have less activity on v / e. On the other hand, it is also not preferred using too large an excess of lithium to complete the process to keep economically. Preferably there should be 1 to 10 grams of lithium atoms per 1 pint of the non-condensed aromatic Hydrocarbon come.

When preparing the starter, the reaction temperature should be generally between -78 ° G and +30 ° C, preferably between -40 ° C and 0 ° G. At more than 30 ° C polymerizes the conjugated diene. The reaction time can be selected depending on the reaction temperature. she however, it is not subject to any restrictions.

The one used to produce the starter according to the invention polar medium includes ζ. B. cyclic ethers such. 3. tetrahydrofuran and tetrahydropyran; aliphatic ^ polyether, such as B. Ethylene glycol diethyl ether, ethylene glycol dimethyl ether, Diethylene glycol dimethyl ether.

It is not beneficial to have an aliphatic lionoether too because the reaction speed in this pail would be quite slow. In contrast, the reaction speed is remarkably high when an aliphatic / ollyether or a cyclic ether is used. In the latter All there is a secondary advantage in that the ratio of uncondensed α aromatic hydrocarbon can be reduced to lithium so that the purity of the final product can be increased.

The amount of polar.] I Ie el i υ π is not limited, it is however, a substantial amount of this polar required Medium after the reaction of lithium and the non-condensed to remove aromatic hydrocarbons and. against a non-polar solvent such as a hydrocarbon to exchange. In the event that the polar medium remains in the starter and in an amount of Dit the monomers are ashed which exceeds the value of 2 percent by weight, nan only receives a statistical Gopyrneres irregularly distributed fees and it is impossible to obtain a block copolymer with excellent mechanical properties and. excellent optical clarity. The vinyl substituted ones used for the present invention aromatic hydrocarbons include e.g., styrene, X-IIe ethyl styrene, p-methyl styrene, 3,5-diethyl styrene, 4-n-propyl-styrene, 2,4,6-trir.iethy 1-styrene, 4-n-propyl-styrene, 2,4,6 ~ Triraethyl-styrene and 3-l-ethyl-5-n-he: ^ l-styrene and in The invention will now be based on styrene as an example of the vinyl-substituted aromatic hydrocarbon to be discribed.

The conjugates used for the purposes of the present invention Dienes include s.B, 1,3-butadiene and isoprene. The method according to the invention is preferably used Styrene in an Ilen ^ e from GO to 95 percent by weight, in particular 75 to 05 percent by weight, based on the total monomers, the remainder consisting of conjugated dienes can.

The inactive hydrocarbon solvents used for this process include aromatic hydrocarbons, such as. 3. Benzene, toluene, cylene and. Ethylbenzene; aliphati-Dehe hydrocarbons such as η-hexane and cyclohe: can and mixtures thereof.

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It is preferred to previously remove any impurities which the initiator or those used for the invention May decompose monomers, such as. B, moisture, oxygen, carbon dioxide, "certain sulfur! Compounds or acetylene.

The block polymerisation of styrene and the conjugated The service is usually performed at about -20 ° C to 100 ° C, preferably carried out at about 20 ° C to 65 ° 0. The block copolymerization time depends on the polymerization conditions and is usually up to 43 hours, preferably up to 24 hours.

Geoäß the single-stage Bloekcopolyaerisation of the present invention, first, the conjugated diene susaaraen ax a small amount of styrene polyaerisiert, wherein a elastocierer copolyaerer block is formed, wherein the diene abnimnt towards allaählich to the block ends. Styrene is then polymerized onto the ends of the block, where L ·. Liosopolyiaere styrene blocks are created. In the copolymeric Hittelbloek the conjugated diene is in raittlereo. Enriched area «

To inactivate the starter and the active end groups of the block copolymer obtained, methanol or isopropyl alcohol is added after the block copolymerization has ended. furthermore, a small amount of an antioxidant is added, such as. B, 4-hydrosmethyl-2,6-di-t-butyl-plieiiol 'and the like. then the block copolymer obtained is precipitated by adding an excess of methanol or isopropyl alcohol, filtered off and dried.

As already mentioned above, it succeeds with the help of the inventive concept Procedure to produce blocks ο poly kidney, which have excellent impact resistance by

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nan a conjugated diene and styrene in a one-step reaction polymerized in the presence of an initiator, which by using lithium and. a non-condensed η polycyclic aromatic hydrocarbon in one polar medium was produced, the polar medium a cyclic ether or an aliphatic polyether and where the complex obtained has a low kenge Diene is given, un this to the dianion of the diene oligomer to convert.

The preserved Bl ο elco ο poly kidney has remarkable mechanical ' Properties such as high yield strength, high tensile strength and tensile elongation. It is therefore suitable for a wide variety of Plastic products. In addition, it has notice Distinguished optical properties, such as a noteworthy one Clarity.

The advantageous properties of the obtained block polyner result from the new structure, which consists of a three-block copolymer, its inner block has a content of conjugate diene which decreases from the inside out. In the following, the invention is intended to apply explained in more detail by exemplary embodiments Λ «? αβη.

A 1 l flask is equipped with a sealed stirrer, a hot flow condenser, a gas inlet pipe, an inlet for the Kealttanten, a funnel and a thermometer, in this flask 250 ml of ethylene glycol diraethyl ether are placed in which 7 »7 S diphenyl is dissolved became. Furthermore, 1.7 g of lithium, which is dispersed in a quantity of 30 percent by weight in solid paraphin, are placed in the basket, the solution dividing a deep green complex.

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The flask is then placed in a dry is-alcohol bath. given to cool the contents to a temperature of less than - ^) ⁰ 6 and then 50 g of butadiene were slowly introduced. The butadiene is introduced so slowly that the deep green color of the contents does not change to a reddish brown color. After the butadiene has been introduced, which takes about 1 hour, the reaction product is left to stand at room temperature. The color of the reaction product changes to reddish brown.

The reaction product is up to the boiling point of the solvent heated and refluxed several Kinuteη and then the solvent is distilled off and the product is dried in vacuo. ! Laugh sufficient drying 300 ml of benzene are added and again distilled off, so that a dry product is obtained. 400 ml dry Benzene is added again and the solution is filtered, 500 ml of a reddish brown solution are obtained.

The product is countered with 0.1 Ii IiOl in Hethand water Phenolphthalein titrated as an indicator, showing a concentration of 0.36 IT / l results.

30 ml of the catalyst solution are placed in an autoclave or in a pressure vessel equipped with a stirrer and is kept at 50 ° C. In the autoclave were previously given 1.5 l of dehydrated and air-free benzene, and 400 g of styrene and 100 g of butadiene. When entering the The catalyst solution changes the color of the mixture a reddish brown, ilite decreasing butadiene content turns it to yellow. The initial pressure of the butadiene is about 0.5 kg / ora. Br takes about 20 minutes Atmospheric pressure. The reaction solution takes about 30 minutes each , a red color and the polymerization of the styrene leads to an increase in temperature by a excöaerme reaction. Haoh about 1 hour from the start of the

Reaction becomes, the viscous reddish solution nit several Milliliters, a mixture of benzene and Hetlianol added, a clear colorless solution being obtained. The viscosity of the solution is reduced by about 5000 cp. Down to i; u about 1500 cp, at 50 ° 0.

The product is precipitated with methanol and in vacuo dried, 495 g of block copolymers being obtained. The molecular weight of the obtained block copolymer becomes determined by the method of osmotic pressure in toluene and is 125,000. The styrene content is according to the method of the refractive index and is 79 percent by weight.

example

The block copolymerization according to Example 1 is repeated, however, in each reaction period 50 ml of the solution of the reaction product were removed. Every sample is included a small amount of the benzo 1-methanol-Iliscliung added. The viscosity, the yield after precipitation in methanol and the styrene content of the polymer are measured. the The values obtained are summarized in Table 1 ..

Table 1

Reaction Viscosity Yield Styrene Content of Period (* 1) (GP) (* 2) (^) Polymers (* 3)

190 11 PO 340 19th 34 500 25th 37 1500 99 79 1450 98 81

1 0 9 β 4 9/1 θ 3 1

* 1 50 B1 of the reaction product are with 5 al one Fulfillment of benzol and methanol in a volume ratio treated by 4: 1. The sample is measured with an Esiller viscometer at 50 ° C.

* 2 10 times of the reaction product will be ita vacuum dried an aluminum foil.

* 3 The χα vacuum-dried reaction product is dissolved in CSg and the solution is dried by an air blower on an Abbe refractometer. Βετ · styrene content is measured via the refractive index of the product.

The block copolymerization according to Example 1 as ^ d repeated, but the total amount of styrene and butadiene is 500 g and the ratio of styrene to butadiene iia Bereiela τον. 70/30 Ms 90/10 lies.

The various properties of the obtained block copoly-yerem are summarized in Table II.

Table II

Ge v / iolits ratio of 65/35 70/30 75/25 30/20 85/15 90/10 ei ti (re 3 e tcte π styrene zn butadiene

Weight sver—

liältiiio styrene / 63.5 / 36.5 71.5 / 28.5 74/26 78/22 86.5 / 13.5 93/7

Butadiene in the block copolymer

Molecular weight
(x10 *) (* 2) 10.1 10.6 10.8 7th 11.0 12.1 11.0 Tensile strength _1Qt r
(kg / cm) t * 3) ¹ ^ 187 198 15.0 217 305 385 Elongation -, r- «
<5i) X * 3) ³⁵ ° 275 172 126 104 67 Dynstat-
Anti-Slip ₂ ""
ability (kg cia / cin)
(* 4) - 130 110 26th Ro clevre 11 ^ hardness
(H-scale 1/4)
(* 5) - 11.0 24.5 32.5 Srübfr
(JS) (* 6) 21.0 17.0 11.0 , 6.3 4.6

(* 1) The KLockcopolyneire was dissolved in GSp utid a «rcli a Air-dried on an Abbe refractometer. That The ratio of styrene to butadiene was measured using the refractive index *

(* 2) It was after eier ifeiäipde of the Osraotic pressure in 12e .-> measured ethanol.

(* 3) Bs ip * ^ en fianl ^ l-shaped double crochets of 2 am DiGke, 10 cn Width and 80 tup is used long.

("^;:" 4) The Dynstat-äclilagfeßigkeit was after HUT ^ οινιεααοη.

Samples 2 απ thick and 10 ππ wide were used nde t,

(* 5) It was after. Λ3ΤΙΙ D-785 -; eressen. (* 6) According to Α3ΪΙ-Ι D-IOO ^ £ e ne s s e π.

Example 4

11.5 £ o-Therphenyl and 1.7 ^: lithium are set in 2 50 ml of tetrahydrofuran in accordance with Example 1 above. rJoüami becomes butadiene to the ilealrtionsprodulct. ^ e (: e be η und dan ou; j tetrahydrofuran "ordering solvent is replaced by. Benzene, with 500 al of a ncliwl'r ^ light-reddish-brown reaction mixture: earhalten ve ν C, cn Titruvion. Do j Produlctes ait UCj er,; i "bt aich a concentration of 0.50 IT / 1.

According to the yeriOl-.ren geaäw example 1, the ijloc;.: - copolyaerisation of utyrol and butadiene under Je rv; e n υ η ;; this Zatalysato lwoun ^ ^ v / iederliolt, v.'obei jev; eiln the Geiiontaange tone ütyrol butadiene and 500 g octi ¹ U ^ t and wherein the Ve ^rl: Sj ^J, nis of styrene to butadiene between 70/50 to 90 / 10 entered,

The pX ^r alkaline. EisenscLafteΰ Ges erlnlteneu Lloclicopoly y.icren are in Table III. ". Us-3: - ^r :, e" -res divides.

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BATH ORIGINAL

Table III

Go v / i eil t s ve r -

ratio of 65/35 70/30 75/25 80/20 85/15 90/10

used
styrene z \ 3 butadiene

Ge v / i ent ο ratio styrene / 64.5 / 55.5 G9 / 51 74.5 / 25.5 80/20 35/15 89/11 ..butadiene ia
^ loclrcopoly-

DGTG η

v / icht (x 10 ) 10.5 9.9 11.1 9.5 S, 9 10.1 .Su £ festi £ ±: e it 175 200 225 197 282 370 Elongation 385 272 170 102 94 40

Dynstat-

0CIiIa ₀ XG- - - - 104 64.5 20

Iioc! R, / ell hardness
(Ιί-olzale 1/4) - , 0 - 0 - , 0. 8th 5 21st 39 Cloudiness 23 18 17th 12.6 , 0 4.5

Dilapidated clisbe la piel_1

In the following example of a comparison, the difference is shown sv / ischen the inventive method and the herirörinlicheii Manufacture of Ulockcopolyueren explained v / erden, Avoid using the same catalyst solution as in example 1 been. Butadiene and ötyrol polyerinated in uv / ei stages, v / o be L aunäcljst butadiene alone is polymerized and v / obei the air from the vessel after the butadiene pressure has been relieved

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is removed and 0.1 nl sec-Butyl-Lithium in 11 Be sol are entered and. then the vessel is charged with styrene. It v / urde α it don οηο nerve rhaltni ssen q3uü3 Examples 3 and 4 worked. The results of this comparative example are shown in Table IV.

Table IV

Weight ratio of

Monomers. 65/35 70/30 75/25 80/20 85/15 90/10

Styrene /

Butadiene

Weight loss / ⁶² > 5 / 37.5 71.5 / 28.5 74.5 / 25.5 87/13 86.5 / 13.5 91/0

Butadiene in the block polymer

Molecularly Ge
weight,
(:: 10 ⁴ ) 11.7 12.1 10.1 13.1 12.6 . 11.0 Tensile strength
speed
(kg / ca) 198 201 250 272 321 405 Elongation 170 52.1 25.5 12.5 10 7th

Dynstat-

3clilag- 70 35 2.5 21.0 11.5

strength

(kg m / cm)

ilockwell-

Hardness 7 22 25 27 31

(H-Sksla

Cloudiness

It is found that the Blοokcopolymeren prepared according to this comparative example, in two stages are inferior to block copolymers prepared by the fiction, modern single-stage process in Beaug on the impact strength and the elongation. 109849 / 1S31

j3ciaj) iel_5

Egg "5 1 piston becomes.;:; It one;) served ie η Hülirer, one ¹ ..; liückfluaalcükler, one G-aseinluoc, one. Inlet for the '.1ea-: aunt, one: Tricliiier and one ;. : Thermometer unplugged '!;. 300 oil' Tetrahydrofuran, which boiled over a lTatriur.1-Ilaliur.-Alloy,.; Or. Reflux, -; e and was then distilled, v / ground lulled If it was not crystallized and dried, it is likewise hastily dissolved and dissolved in the tetrahydrofuran. 1 nl of styrene are also added.

30 liters of argon gas are then poured into the reaction vessel over a period of 30 minutes initiated. The argon gas was sur dehydration by a layer of titanium gcin.'anrj heated to 800 ° and passed through molecular sieve. Then waöen etv / a 0.5 i.iaol SeI: unaar-3utyl-Lit; iiur., Added to the content, in front of this a pale yellow coloration anniiarnt. Continue to be 10 1 argon gas introduced for 10 minutes. 70 ag Lithium, which in a concentration of 30 percent by weight in solid.] Paraphin is dispersed are added and the content niraat after 2 bic 3 Kminutes a green Coloring.

Then, given the Heaktionskolben in a dry ice-IIethanol BCD, abzuküiileu UVJ oen content and 3 nl isoprene are added and the contents Λ / ird 30 Hinuten stirred. The flask is then removed from a dry ice / ethanol bath and placed in a water bath at a temperature of 30.degree. C., the tetrahydrofuran is removed in the water. Then 300 rjl of benzene are added, which has previously been freed from air by gas and: .. ittelc se c-3u ty I-lithium is dehydrated. This benzene will then be used again in Valruur .; abducted. Then 1.5 1 benzene trno 400 g styrene were added, which had previously been dehydrated and freed from air by the same process. Further

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v / ground 10Og isoprene added ge be η, which is about sodium aMistilled. The content takes on a pale yellow-reddish-brown Coloring.

It is stirred and during the reaction I increase the InIx old viscosity gradually. After about 50 minutes the contents take on a red color and the polymerization of the styrene begins. ITach. increased about 10 minutes the temperature to 70 ° ö to 80 ° C and a Vüsahl of vesicles is observed. After about 1.5 hours from the start of the polymerization, it becomes low Henge added to a mixture of ethanol and benzene and the reaction product is obtained by adding ethanol precipitated and dried in vacuo.

^{1 c} / j 4 ~ Eydrozymethyl-2,6-di-t-butyl-phenol are added to the dried polymer and the product is processed into granules with the aid of an extruder. The granules obtained are shaped into test specimens in the shape of a dumbbell or rod, which are 2 mm thick, 10 µm wide and 3 mm long on iron. These test specimens are produced by injection molding. The physical properties of the product obtained are shown in Table Y.

Table V

Weight ratio of used

Styrene / isoprene 80/20

Molecular weight (x 10) 8.9

Tensile strength (kg / cm) 1370

Elongation ■ (#) 37

Dynstat impact strength (kg cm / cm) 25

Rockwell hardness (Il scale 1/4) 31

'Turbidity (> i) 7.5

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j3example_6

1 g para-terphenyl and. 100 rag lithium will be according to example 5 in. Tetrahydrofuran unset. 5 g of butadiene are added and the tetrahydrofuran is distilled off and replaced with benzene. 1.5 l benzene, 425 g styrene and 75 g butadiene are added and the goose is polymerized at 50 G. The polymerization of butadiene ait a slight After about 35 minutes, the amount of styrene will continue to polymerize des Gtyrols, with the temperature of the contents of the reaction vessel increased to about 100 ° G.

After the polymerization, the block copolymers are separated. It falls in an amount of 495 g sn. The molecular weight ^

is determined according to the method of osmotic pressure in toluene. It is 12.5,000. 1 yi of 4-hydroxy methyl 1-2,6-di-t-butyl-phenol are added to the block copolyraeren and this is processed into granules with the aid of an extruder. Specimens are obtained from the granules by a Spritsgußverfahren formed by Hantelforn or Stabehenfor m, which has a thickness of 2 mm, a width of ram 10 and have a length of 80 απ. The physical properties of the product obtained are shown in Table YI.

Table VI

; A.

Weight ratio of styrene / butadiene used 85/15

Molecular weight (x 10 * J 12.5

Tensile strength (kg / cra ^Z ) 320

Elongation ($ ί) 70

Dynatat impact strength (kg cm / cm) 107

Eockwell's I-Marks (M-scale 1/4) 23

Gloomy ( ^c / o) 7.0

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10 g of diphenyl and 2.5 g of lithium will a In 250 ml of tetrahydrofuran implemented according to Example 1. 30 g of butadiene are added and then the tetralydroftirane is replaced by benzene replaced, with 600 nl of a sctowärzlicii — rötlion — brown Eeaktionslösung receives. By titration with hydrochloric acid a concentration toe 0.45 IT / l was found. According to the example 1 is 400 g of styrene and 100 g of isoprene. In benzene at 35 ° C implemented using 20 oil of the catalyst solution.

For 40 minutes the contents of the reaction vessel turn red and the polymerization of the styrene begins at an oeniperature above 100.degree. After the reaction has ended, the copolymer obtained is precipitated by methanol and dried in a yakuum. 1 $ £ 4-Hydro2j ~ raethj "l-2,6-di-t-biitylphenol is added and the copolymer obtained is granulated with the aid of an extruder Sample bodies have a thickness of 2 απ, a width of 10 am and a length of 80 sti. The physical properties of the product obtained are summarized in Table YII «

l'abeiie vxx 30/20 Weight ratio of used
S.}. Yrol / lsoprene 8 _f 5 Molecular weight (s 10) 520 Tensile strength (kg / cia} 60 Elongation (^) 55 Dynstat impact strength (kg cm / ora) 29 Rockifell hardness (M scale 1/4} 5 _f 0 Turbidity 0 &)

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Example_8

Ec are the polymerization tests according to the preceding Examples repeated, but the GeGaotwenge of styrene and isoprene is each 500 g and the ratio of styrene to isoprene in the range of 70/30 to 90/10 is selected. The properties of the block copolyraeren obtained are shown in Table VIII susaraoe «.

Table VIII

Weight ratio of 70/30 75/25 80/20 35/15 90/10 circumscribed
Styrene / isoprene

KoIe kul arge, - 10.1 9.5 7.9 9.0 · 8.5

weight (χ 10 ⁴ )

280 290 330 370 420 Elongation 105 70 50 35 21

Dy ns tat-Schlagfestig-Irish it (kg approx

Ilocla / ell hardness
(Il-Sicala 1/4)

Cloudy- (£) 6.8 7.0 5.5 5.0 3.3

Comparative example 2

Ζυΐ "Clarification of the differences between the inventive equipment Process and traditional blookcopolyerization the following experiments are carried out. Under Terv / ending of the same catalyst as in Example 7 are isoprene and styrene polymerized in two stages, with isoprene initially polymerizing alone at 50 ° C. for 50 minutes v / ird and then cooled to 25 ° C. Then, styrene becomes

109849/1631

Give Mn SU and polymerize at 30 minutes. The ratio of styrene to isoprene ία range from 70/30 to 90/10 is selected. Each of the treated and dried copolymers obtained is mixed with 1 * Ό 4-iIydro :: ymethyl-2,6-di-t-butyIphenol and processed into test specimens. The physical properties of the resulting copolyraeren are shown in Table IX.

Table IX

Weight ratio of 70/30 75/25 80/20 85/15 90/10 used
Styrene / isoprene

Get kul ar ge j
weight (χ ΙΟ ⁴ ) 8.5 7.5 9.0 10.1 10.5 tensile strenght
(Kg / cm) 310 300 350 390 440 Elongation (^) 50 20th 15th 17th 5 Dynstat blow
strength
(Kg cm / cia) 22nd 25th 18th 19th 15th Rockwell hardness
(Il scale 1/4) 32 33 35 39 45 Turbidity (^) J ₁ O 7.5 7.7 6.0 3.0

10 9 8 4 9/1631

Claims (8)

Claims : 'M block copolymers of a vinyl-substituted aronate hydrocarbon and a conjugated diene, characterized by a 3-block structure with an elastomeric copolymeric middle block of the conjugated diene and a small amount of the vinyl-substituted aromatic hydrocarbon, the frequency of the structural units formed by the conjugated diene being dependent on the The bottom of the smock block gradually decreases towards its ends and. with two terminal ho rao polymer η blocks from the vinyl-substituted aromatic hydrocarbon. 2. Block copolymer according to claim 1, characterized aacLnrcli, that the vinyl substituted aromatic hydrocarbon Styrene and the conjugated diene is butadiene or isoprene, 3. Block copolymer according to one of claims 1 or 2, characterized in that the weight ratio of vinyl-substituted aromatic hydrocarbon to conjugated diene is 60:40 to 95: 5. 4. Process for the preparation of the block copolymer according to one of claims 1 to 3> gekenn.seichnet by a single-stage "living" polymerization of a mixture of a vinyl-substituted aromatic hydrocarbon and a conjugated diene in a non-polar solvent in the presence of an initiator, which by reacting lithium with a non-condensed polycyclic aromatic hydrocarbon . was presented. MIi / 1631 5. The method according to claim. 4, characterized in that that a starter is used, which is obtained by reacting lithium with a non-condensed polycyclic aromatic hydrocarbon in a polar medium, preferably in tetrahydrofuran, tetrahydropyran, ethylene glycol dialkyl ether or bioethylene glycol dialkyl ether
was produced. 6. The method according to claim 5, characterized in that
a catalyst is used in its manufacture
after the reaction has ended, the polar medium is replaced by a non-polar solvent to form a homogeneous catalyst solution. 7. The method according to any one of the sprays 4 to 6, characterized j that the starter comprises a dianion. 8. The method according to one of claims 4 to 7 »characterized ο that a starter is used in the manufacture of which a diene was used.