DE2125413A1 - Partially hydrogenated block copolymer and its hydrohalogenated derivatives - Google Patents

Description

The invention relates to partially hydrogenated block copolymers with at least one polymer block from an aromatic Vinyl hydrocarbon and at least one polybutadiene block »its hydrohalogenated derivatives 30 as processes for their Manufacturing.

A special class of block copolymers can be represented by the general formula AB- (B -A) _n in which A is a polymer block of an aromatic vinyl hydrocarbon, B is a polybutadiene block and η is a gana number from 0 to 6 «If η is O, the block copolymer has the formula A -B, which means a copolymer of two blocks. When η is 1 the block copolymer has the formula

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A - B - A, which signifies a linear copolymer of three blocks. When η 2 Ms 6, the block copolymer can have a nonlinear structure, also known as radial or star-shaped Structure is called.

Block copolymers of the general formula given above may have thermoplastic elastomeric properties, i.e. they can be without vulcanization at normal temperature elastomeric properties including strength properties

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th that with those / vulcanizates made of synthetic Polyisoprene, polybutadiene or copolymers of styrene and butadiene are comparable with a statistical distribution and that they become soft and easy to process when heated and their strength and elastomeric properties when cooled get back again · These properties depend on the relative proportions of the polymer blocks. If the block copolymer contains less than 55% by weight of the polymer blocks A} it has thermoplastic elastomeric properties.

The polybutadiene block usually contains a cream! different structures, the ale cie-1,4- »trans-1,4- * md 1,2 structure.

Clay block copolymers with at least one polymer block of an aromatic vinyl hydrocarbon and at least a Polybuta diene block can be made by hydrohalogenation, Halogenation, carbonylation, epoxidation, hydroxylation and chlorosulfonation derivatives can be obtained. The so educated polar derivatives would be suitable for many commercial purposes, but their instability to heat or light, which occurs when an effective proportion of polar groups are present is often leads to loss of your desired physical Properties. The instability of these derivatives is a major obstacle to their commercial use

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Obviously this instability comes from cycling, which occurs during the treatment of the block copolymer, and the presence of polar groups on tertiary carbon atoms in the main carbon chain.

It has been shown that certain partially hydrogenated Block copolymers are particularly promising gate steps, which are suitable for the formation of polar derivatives that do not tend to cyclize.

(The invention relates to partially hydrogenated block copolymers

with at least one polymer block of an aromatic vinyl hydrocarbon and at least one polybutadiene block, which are characterized in that the polybutadiene block has 8 to 80 ie 1,2 structure and the remainder 1,4 structure and that at least 50 i »of the unsaturated bonds in of the 1,2-structure and not more than 50 36 of the unsaturated bonds that are saturated in the 1,4-structure of the polybutylene bloom

Preferably, the partially hydrogenated Blpckcopolymere have a polybutadiene block of 20 to 60 Jt 1,2-structure and the rest of 1,4-structure has, at least 50 i> of the unsaturated bonds in the 1,2-structure and not more than 50 i f> the unsaturated bonds in the 1,4 structure of the polybutadiene block are saturated.

It has been shown that these block copolymers are particularly suitable as precursors for the production of refractory and self-extinguishing polymers which can be obtained by substantially complete hydrohalogenation.

The hydro-halogenated, partially hydrogenated block copolymers lter to-the invention are characterized in that the Polybuta0: 1 entlock 20 to 60 # 1,2-structure und4en residue has and 1,4-structure that at least 50 $ of the unsaturated

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Bonds in the 1,2 structure and not more than 50 % of the unsaturated bonds in the 1,4 structure of the polybutadiene block are saturated and the block copolymers are completely hydrohalogenated.

The polymer block made from the aromatic vinyl hydrocarbon can of styrene, α-methylstyrene and ring alkylated Styrenes, with styrene and α-methylstyrenes being preferred Are monomers.

The average molecular weight of the vinyl aromatic hydrocarbon polymer block can be 2,000 to 50,000 while the polybutadiene block has an average molecular weight of 10,000 to 250,000, preferably 50,000 to 125,000 may own. The proportion of polymer blocks from the aromatic vinyl hydrocarbon is 5 to 70 # of the entire block copolymer.

The partially hydrogenated block copolymers according to the invention can be prepared by selective hydrogenation under the selected conditions, .so that at least 50 #, preferably 60 to 100 tf> the YInylgruppen be hydrogenated and that the monovinyl hydrocarbon blocks are not hydrogenated. Some of the double bonds in the 1,4-structure in the main carbon chain of the polybutadiene block are hydrogenated inevitably simultaneously, but the saturation of these double bonds must be kept to a minimum of less than 50 J and preferably less than 25% of the double bonds prior to hydrogenation, block copolymers, where only 30 5% of the total diene polymer units are hydrogenated are suitable.

The hydrogenation is preferably carried out in solution in an inert hydrocarbon, preferably the same hydrocarbon solvent, like it during the polymerization

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is used, using as a catalyst a cobalt, nickel or iron carboxylate or alkoxide, such as an acetylacetonate of nickel or cobalt, which is reduced with an aluminum alkyl compound, and hydrogen at 1 to 105 kg / cm, preferably from 3.5 to 85 kg / cm and at temperatures of 20 to 100 ⁰ C, preferably 25 to 50 ° 0 applied mi 7 to 35 kg / cm. The time for hydrogenation under such conditions is usually 0.1 to 2 hours, preferably 0.1 to 1 hour.

The product resulting from the hydrogenation can be examined by infrared analysis to determine whether it is present or not Determine the absence of vinyl groups. In the usual infrared analysis shows each trans structure a strong one Absorbance at 10.35 / µm while each cis structure shows an absorption at 13.60 / µm. The 1,2 structure shows a Absorbance at two different wavelengths, namely 10.98 and 10.05 / µm. It is desirable that in the final product the infrared absorption observed at either 10.05 or 10.98 µm is relatively small, preferably near does not exist.

The iodine number of the block copolymer precursor is hydrogenated from 200 to 400 to the order of 140 to 280, preferably 50 to 150 reduced. The iodine number refers to the usual Pett analysis method and the units are given in grams of iodine per 100 g of block copolymer. the Iodine number of the block copolymer precursors depends on the ratio the polybutadiene block to the monovinyl hydrocarbon polymer block falls, however, in the most suitable products, the iodine number falls in the range given above before and after Hydrogenation.

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The hydrogen halide is added to the remaining aliphatic double bonds in this polymer intermediate after hydrogenation by treating the polymer with anhydrous hydrogen halide gas while it is dissolved in an inert solvent. After precautionary measures have been taken to exclude air from the system, the hydrogen halide is forced into the reaction vessel at once and the reaction is carried out until hydrogen halide has been added to essentially all of the aliphatic double bonds in the hydrogenated polymer. Hydrogen chloride, hydrogen bromide and hydrogen iodide are examples of hydrogen halides which are suitable for the purposes of the invention. Suitable solvents are alkanes, cycloalkanes and halogenated hydrocarbons. The temperature during the hydrogen halide addition can be 0 to 100 ^° C., but is preferably in the range from 20 to 40 ^° C. The hydrogen halide pressure can be 1 to 30 atm. The reaction time is generally 1 hour to 1 week, although 3 to 48 hours is usually required.

From the solution of the hydrohalogenated product in the reaction vessel, the pressure is released to remove excess Halogen water st off gas to remove. It will then be with Washed water to remove dissolved hydrogen halide and recovered from the solution by coagulation with hot water. The wet eeagulated product can be rolled by briefly rolling on a hot two-roll laboratory roll or im Vacuum dried.

Alternatively, one can diffuse the hydrogen halide into a solid sample of selectively hydrogenated block copolymer and can be added to the double bonds. E.g. can a solid piece of a copolymer such as a block or sheet or tape immersed in a non-dissolving solvent and the solvent can be mixed with gaseous

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Hydrogen halides become saturated until all aliphatic Double bonds have essentially reacted.

There are significant differences when comparing a block copolymer that selectively partially hydrogenates and then hydrohalogenated with the same copolymer that has been hydrohalogenated without prior -Hydrogenation. The product, which is first partially hydrogenated and then hydrochlorinated, is a resilient rubber with good thermal stability, while the product, which is hydrochlorinated, has plastic properties without prior hydrogenation has shafts, is friable and has poor heat stability. Obviously the hydrogenation is leading of the vinyl groups hanging on the main chain in order to eliminate them as points of attack for the cyclization clear difference in the character of the resulting product.

The heat and light stability of the hydrohalogenated products according to the invention can be further improved by adding stabilizers of the type normally used commercially for polyvinyl chloride resins. Such suitable stabilizers include three λ basic lead sulfate silicate, dibasic lead phthalate and barium-cadmium compounds · The effective amounts vary with the type of stabilizer, but it has been shown that 5 $ tribasic lead sulfate silicate by grinding or rolling is incorporated, the products according to the invention are sufficiently protected that they are just as heat-stable as stabilized polyvinyl chloride. In a typical test, a stabilized, hydrochlorinated, partially hydrogenated polystyrene-polybutadiene-polystyrene block copolymer withstood rolling very well and also heated to 210 for 10 minutes without discoloration or signs of degradation or destruction.

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the fire resistance is better. A comparison with two commercially available substances are given in the following table. The hydrohalogenated products are from one partially hydrogenated polystyrene-polybutadiene-polystyrene block copolymer, injdem the polybutadiene block 57% 1,2 microstructure before hydrogenation and has an iodine number of 92.

Chlorine, 10 - - Chlorine, 10 5 * Sb ₂ O ₅ Chlorine, 20 5 i ° Sb ₉ O, Bromine, 20 mm Polyvinyl chloride, 57 - - Polycarbonate, 0 - -

Halogen content (wt .- ^) Addition (#) related to oxygen index (a)

on the polymer

0.17 0.22 0.22 0.28 0.41 0.24

(a) mole fraction oxygen; in the gas surrounding the polymer, the is required to burn a vertical specimen entertain that is ignited at its upper end in a flowing gas system ASTM solid D-2863-70 *

For comparison, has a commercially available polyvinyl chloride containing 57 $> gebundes chlorine, contains an oxygen index of 0.41 and a polycarbonate, the $ 19> oxygen, an oxygen index of 0.24. Both products are called refractories. Neither of these materials is elastomeric.

The invention is illustrated in more detail by the following examples.

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A

■ cmrn © be Blßelasa with 46 ^ 1 sS-Mik ^ osfeiikfer (yinyl groups) in üma BoljMiia-iisffifels-sl:;. '' I £ "le produced and selectively

All © KsasüSifS anä l ^ BH ^ siaittisl W2üi;: i treated to ¥ as3SE _s Sfmssr ^ df ;;; : -? - £ ü yolzi: n iiilsstasseii su removsa and the a © aätiGHiuK ^: - i -> ^ - tjg ^ C .; ^ Saallsä. gsEeinigt and with Sticketsff gsspaltc Dk: ^ aeai £ ti3iüsge: i-Ii3 aasäs with 4 ZOQ g QjqIq- h ^ & aiL · naß. 4β8 ^ S ^ j'rol fciSii-iiökt; S ^ j Liveried Murder -war, ua 2? Eaktl0Es £ afeig6 TsrmnjeiF * ^ it _γ-λϊ5. ays ^ xrc ^ en · Daim were 0j031 Molseke-EutyllithltJüs Ia 275 SC ^ iT ^ Äexan added to the Polymerlsatisn in Saiig sa fesiv:,; ^; ... T in which almost all of the styrene laüö ^ lialli -JOki 1 k l - ^ "-. ¹ ^ Q ⁰ Z in Polj3tjrol © it ^ asi © o Ils Γ; /? Ϊ́> ΰ ¥ oi 1" 2 g was used for analyssn-

DI © res & Iicihe Iröauag 3ea leöeaclss P3 ^ rmers wui? D @ in ei? i s*j$3.t@s iGiiktloasgefä-ß geleliea «-sss 2 160 g butadiene, 11 535- g öjoloiiexsa and 50 g iOetre & fcx ^ ofiiiiaa Mtalüa 20s 1) satkielt ^ ^ la ^ v'-mer with

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in the reaction vessel

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given, forming a third block of the copolymer became. After 1 hour at 45 ° C., the polymerization was complete. A third sample was taken for analysis and the The rest of the polymer solution is hydrogenated.

The analysis of each of the three samples taken during the polymerization using the tritium method showed an average molecular weight of the three blocks of 13,000 64,000-15,000. The average polybutadiene block of the polymer contained 46% 1,2-microstructure as with the aid of infrared analysis due to the absorption occurring at the wavelengths given above can be detected konr.t-,

Partial hydrogenation

The polymer solution from the policy separation stage was placed in a hydrogenation autoclave. 6 mmol of nickel acetylacetonate with 12 sjM, 'j3. (Eriäthylaluminium in 15oo ml cyclohexane 15 rain at? ^V c ntagesetst and then added to the system. Ia system. Autoclave, a hydrogen pressure of 35 kg / cm produced * The Heaktionstemperatür rose to 50 ^e C and after 25 min cite hydrogenation was stopped " The selectively hydrogenated polymer had an iodine number of 81 and essentially no more 1,2-microstructure.

After recovery by coagulation and Trsocrxen. and When molded to make typical rubber workpieces, the partially hydrogenated polymer had the following physical properties Properties.

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Yield strength, 23 ° C 492.1 kg / cm

300 # module, 23 ⁰ C 45.7 kg / cm ²

Elongation at break, 23 ° G '590%

Fracture bend, 23 ⁰ C 2D #

Example 2

A partially hydrogenated polystyrene-polybutadiene-polystyrene block © polymer ,, which had been prepared in the same way as the polymer in Example 1 was made by adding Treated hydrogen chloride. Before hydrogenation, the polymer had an average molecular weight of the individual blocks of 14,000 to 68,000 to 15,000 and $ 38 of the olefinic double bonds were in the middle polybutadiene block ; L * ß vinyl groups. The polymer was up to an iodine number of 92 hydrogenated, with the Yinjl double bonds essentially got lost. The remaining olefinic double bonds were mainly in the trans-1,4 structure.

A 1 liter reaction vessel was charged with 43 g of the above-described partially hydrogenated block copolymer in 270 g of cyclohexane and 300 g of dry benzene. After purging the reaction system with nitrogen, an anhydrous hydrogen chloride pressure of 21.1 kg / cm was generated in the reaction vessel, and after shaking by hand to facilitate the dissolution of the hydrogen chloride, the vessel was kept at 25 ° C for 19 hours ditched. The excess hydrogen chloride was vented and the polymer solution was washed with water to remove dissolved hydrogen chloride. The polymer was recovered by coagulation with isopropanol and dried in vacuo. The 47 _# g of the product contained 10.4% by weight of chlorine. This value is so close. on the theoretical amount of chlorine (11 wt .- $) as calculated for a complete reaction of all remaining double bonds that only a small one

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Isomerization and cyclization may have occurred. 5 parts of tribasic lead silicate sulfate per 100 parts of polymer were added to the polymer, which was then briefly rolled at 180.degree. C. on a laboratory rubber roller with two rollers. The product was a thermoplastic rubber and did not require vulcanization. It was molded at 200 ⁰ C, to produce rubber test pieces. When pulled by hand, the products exhibited the typical behavior of rebounding rubber. The test pieces showed the following properties when they were examined by the test methods customary for rubber.

Tensile strength, 23 ° C 302.3 kg / cm ²

300 # module, 23 ⁰ C 49.2 kg / cm ²

Elongation at break, 23 ⁰ C 540 #

Fracture bending, 23 ⁰ G 25 f>

Although this product was not self-extinguishing when lit, it became self-extinguishing when one was added small amount (5 crew .- #) of antimony trioxide.

Example 3

In this experiment, hydrogen chloride became a non-hydrogenated polystyrene-polybutadiene-polystyrene block copolymer admitted. The polymer used was the same as that described in Example 2 but not hydrogenated.

A 11 reaction vessel was charged with 30 g of the blook copolymer in 570 g of benzene. After purging with nitrogen, the pressure of anhydrous hydrogen chloride of 21.1 kg / cm was generated in the reaction vessel. The reaction vessel was briefly shaken by hand and then at 25 ^° C. for 23 h. allowed to stand, excess hydrogen chloride was vented, and the polymer was washed with water and then coagulated with isopropanol and dried. A product was obtained

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Tensile strength, 23 ° C, 421.8 kg / cm ²

300 io module, 23 ⁰ C 105.5 kg / cm ²

Elongation at break, 23 ° C 36Ö #

Bending at break, 23 ⁰ C 19 %

This product was self-extinguishing when lit. and the source of ignition has been removed. No additives were required to achieve the self-extinguishing properties to improve, so that the polymer fulfilled the objects of the invention very well.

Claims

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Claims (12)

Patent claims 1.! Partially hydrogenated block copolymer with at least a polymer block of an aromatic vinyl hydrocarbon and at least one polybutadiene block, thereby characterized in that the polybutadiene block Has 8 to 80% 1,2-structure and the remainder 1,4-structure, at least 50 # of the double bonds in the 1,2-structure and not more than 50 % of the double bonds in the 1,4-structure are saturated in the polybutadiene block. '■ - ■ - 2. Block copolymer according to claim 1, characterized in that the polybutadiene block 20 to 60 # 1,2 structure and the rest .... 1,4 structure. 3. Block copolymer according to claim 1 or 2, characterized in that 60 to 100 96 of the double bonds are hydrogenated in the 1,2 structure in the polybutadiene block. 4. A block copolymer according to claim 1 to 3 _t characterized in that less than 25% of the double bonds are hydrogenated in 1,4-structure of the polybutadiene block. - 17 - 109849/1775 - 17 - 1A-39 564 5. Block copolyraer according to claim 1 Ms 4 »thereby characterized in that it is completely hydrohalogenated. 6. Block copolymer according to claim 1 to 5 »characterized characterized in that the polymer block from the aromatic Yinyl hydrocarbon of styrene or a-Methylstyröl is formed. 7. Block copolymer according to claim 1 to 6, characterized in that the polymer block consists of the aromatic vinyl hydrocarbon a medium one Molecular weight of 2000 to 50,000 and the polybutadiene block an average molecular weight of 10,000 to 250,000, preferably 50,000 to 125,000 and the proportion of the polymer blocks from the aromatic vinyl hydrocarbon 5 to 70 # based on the total block copolymer. 8. Process for the preparation of a block copolymer according to claim 1 to 4t, characterized in that the block copolymer in an inert hydrocarbon solvent in the presence of a cobalt, nickel or iron carboxylate or alkoxide which has been reduced with an aluminum J alkyl compound at a hydrogen pressure of 1 to 1o5 kg / cm ² and at a temperature of 2o to 100 ° C is hydrogenated. 9. The method according to claim 8, characterized in that g β ke η η, that a nickel or cobalt acetylacetonate is used as a hydrogenation catalyst, which with a Aluminum alkyl compound is reduced. 10. The method according to claim 8 or 9 _t characterized ge k en η that the hydrogenation is carried out at a pressure from 3 _f 5 to 85 kg / cm ² and at a temperature of 25 to 50 ° C. 109849/1775 - 18 - 1A-39 564 11. Process for the preparation of the block copolymer according to claim 5 »characterized in that a partially hydrogenated block copolymer is dissolved in an inert solvent and ^{treated with anhydrous hydrogen halide at a temperature of 0 to 10O 0} C and a pressure of 1 to 30 atm. 12. The method according to claim 11, characterized in ge k e η η that one uses as hydrogen halide, hydrogen chloride, hydrogen bromide or hydrogen iodide. 13 · Procedure according to. Claim 11 or 12, characterized in that the solvent an alkane, a cycloalkane or a halogenated hydrocarbon used. 14. Process according to Claims 11 to 13, characterized in that the hydrohalogenation is carried out at 20 to 40 ^° C. 109845/1775