DE2539132A1 - HYDROGENATION OF POLYMERS - Google Patents

Description

Hydrogenation of polymers

The invention relates to a process for the production of partially hydrogenated copolymers from a & > ß-unsaturated carboxylic acid or its derivatives and a hydrocarbon with conjugated double bonds.

From DRP 570 980 and DRP 658 172 are from such Monomers, randomly structured copolymers are known. They are obtained by emulsion copolymerization of e.g. acrylonitrile with conjugated dienes such as butadiene.

US Pat. No. 3,700,637 discloses regularly alternating Produce copolymers from butadiene and acrylonitrile and with the help of rhodium complexes as catalysts with preservation to hydrogenate the nitrile groups.

In the context of the present invention, copolymers are intended to be both regularly alternating and also randomly constructed Copolymers of an Ot, ß-unsaturated carboxylic acid or their Derivatives and an unsaturated hydrocarbon with conjugated double bonds are understood.

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Suitable carboxylic acids and their derivatives are e.g. (methacrylic acid, Fumaric acid, its esters and amides and the corresponding carboxylic acid nitriles, such as (meth) acrylonitrile. Suitable conjugated dienes are e.g. butadiene, isoprene, dimethyl butadiene and piperylene. Preference is given to that according to the invention Process for partial hydrogenation carried out with copolymers of (meth) acrylic acid or its derivatives and butadiene. Copolymers of 90-45% by weight butadiene are particularly preferred and 10-55% by weight of acrylonitrile (each based on the total amount of the copolymer).

The copolymers mentioned contain unsaturated structural units apart from the functional groups originating from the carboxylic acid or its derivatives, e.g. the nitrile group, which are a 1.2 linkage of the dienes used Vinyl groups and the cis- or transconfigured olefinic double bonds.

According to the present invention, the copolymers are dissolved in suitable organic solvents and hydrogenated in the presence of a rhodium complex and optionally triphenylphosphine at elevated pressure and elevated temperature while retaining the nitrile group. It has surprisingly been found that when chlorobenzene is used as the solvent, the vinyl groups and the trans-configured double bonds in the copolymers mentioned are selectively completely hydrogenated. If other solvents are used, however, the vinyl groups are completely hydrogenated, but the trans-configured double bonds are only partially hydrogenated; Depending on the choice of solvent, the degree of hydrogenation of the trans-configured double bonds is 10-90 %. It was not foreseeable by the person skilled in the art that, in the case of a hydrogenation carried out with the same reaction bonds, the specific use of certain hydrogenation

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Solvent selectively the vinyl groups completely and the trans-configured double bonds completely or partially can be hydrogenated.

The invention relates to a process for selective hydrogenation the vinyl groups and the trans-configured double bonds in copolymers from an oC, ß-unsaturated carboxylic acid or their derivatives and an unsaturated hydrocarbon with conjugated double bonds, characterized in that a 1-2o% solution of the copolymers in suitable organic solvents in the presence of 0.01-10 wt .- ^ of a catalyst a complex compound of 1- or 3-valent rhodium halides and optionally 5-25% by weight of the ligands bound in the complex (in each case based on dissolved copolymer) is hydrogenated at 5o-15o C and 5-300 atm. The selective hydrogenation of the vinyl groups and the trans configured double bonds in the copolymers is carried out in chlorobenzene as the solvent. In no detectable hydrogenation of the cis-configured double bonds and the polar groups (e.g. Nitrile groups) instead. If, according to the invention, solutions of the copolymers in solvents such as B. toluene, benzene, xylene, dimethylformamide, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, Cyclohexanone or methylene chloride are used, there is only one hydrogenation of the vinyl groups in addition to the complete hydrogenation partial hydrogenation of the trans-configured double bonds.

The degree of hydrogenation of these double bonds depends on the solvent and decreases in the series benzene → dimethylformamide, xylene> ethyl acetate> methyl ethyl ketone, cyclohexanone> tetrahydrofuran, toluene> methylene chloride from around 90 to around 10%. Mixtures of solvents are not required for the process of the invention. Of course, they can also be used.

The solutions contain 1-20% by weight, preferably 2.5-10% by weight of the copolymers, based on the above-described solvent to be used in each case for the process according to the invention.

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For the hydrogenation, the solutions of the copolymers are used as Catalyst 0.01-10% by weight, -96, preferably 0.1-5% by weight (based on on dissolved copolymer) of a complex compound of 1- or 3-valent rhodium halides added. Suitable Complex compounds are those of the general formula I.

wherein RC ₁ -C ₈ -AIlCyI, Cg-C ₁ ^ -aryl or C ^ -C ₁ ^ -aralkyl,

B P, As, S or S = O and

X mean Cl or Br and

m the value 2 or 3 and

η has the value 1 or 3.

Preferred complex compounds of this type are tristriphenylphosphine) rhodium (I) chloride, Tristriphenylphosphine) rhodium (III) chloride and tris (dimethylsulfoxide) rhodium (III) chloride.

The pressure at which the hydrogenation according to the invention is carried out can be varied over a wide range. Pressures between 5 and 300 atm, preferably between and 100 atm, are suitable. The hydrogenation is carried out at temperatures between 50 and 150 ^° C., preferably at 75 to 115 ^° C. Under these conditions, the selective hydrogenation ends after about 3 to 7 hours.

The process described in DT-AS 1 558 can be used to separate off the catalyst.

The hydrogenation product is separated from the reaction solution by treatment with steam or by pouring into methanol and then dried under reduced pressure at about 70 ⁰ C.

The qualitative and quantitative determination of the hydrogenated or still present double bonds in the according to the invention hydrogenated copolymers are carried out by IR spectroscopy

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Analysis. The iodine number and the glass transition temperature using TMA and shear modulus measurements are used for further characterization the hydrogenation products determined.

The copolymers hydrogenated by the process of the present invention exhibit increased tensile strength with increased tensile strength Elongation at break and, in addition, improved elasticity. There are vulcanizable rubbers that are considered to be temperature resistant Materials, e.g. can be used in the sealing sector.

The following examples use three different acrylonitrile-butadiene copolymers used. The percentages are always percentages by weight.

The quantitative data refer to catalysts and triphenylphosphine each on the dissolved copolymer.

Copolymer I: from 82 % butadiene and 18 % acrylonitrile Copolymer II: from 72% butadiene and 28 % acrylonitrile Copolymer III: from 62 % butadiene and 38 % acrylonitrile

(in each case based on the total amount of the copolymer).

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example 1

A 2.5% solution of the copolymer I in chlorobenzene is mixed with 1% _{ZIc 6} H ₅ ), p7 ₃ Rh ¹ Cl and 10 % (C ₆ H ₅ J ₃ P and 5.5 'hours at 100 ⁰ C and 60 atm hydrated.

After the hydrogenation has ended, the catalyst is separated off in accordance with DT-AS 1,558,395. The reaction products are precipitated by pouring the reaction solution into methanol and then dried ^{at about 70 ° C. under reduced pressure.}

The hydrogenation product obtained has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 100 % of the trans double

ties

Glass transition temperature: T_ = -31 ⁰ C

e iodine number: Jz = 14

The hydrogenation products of the following examples are worked up and characterized as in Example 1.

Example 2

A 2.5 S & Lge solution of the copolymer II in chlorobenzene is mixed with 1 % Z £ C ₆ H ₅ ) ₅ P_7 ₃ Rh ¹ Cl and 10 % (C ₆ H ₅ J ₃ P and 4.5 hours at 100 ° C and 60 atm hydrated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 100 % of the trans double

ties

Glass transition temperature: T = - 30 ⁰ C Iodine number: Jz = 26

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Example 3

A 2.5% solution of the copolymer II in chlorobenzene with 1% Z (C ₆ H _{5) 3} Cl ₃ p7 ₃ ¹¹¹ Rh, and 10% (C ₆ H ₅ J ₃ P were added and 5.5 hours at 100 ⁰ C and 60 atm hydrogenated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 100 % of the trans double

ties

Glass transition temperature: T = -30 ⁰ C Iodine number: Jz = -22

Example 4

A 2.5 % solution of the copolymer III in chlorobenzene is mixed with 1% ZlC ₆ H ₅ ) ₃ p7 ₃ Rh ¹ Cl and 10 % (C ₆ H ₅ J ₃ P and hydrogenated at 100 ° C. and 60 atm for 6 hours.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 100 % of the trans double

ties

Glass transition temperature: T = -27 ⁰ C Iodine number: Jz = 22

Example 5

A 2.5% solution of Copolymeren'I in toluene is mixed with 1% _{ZXCgH 5} ) ₃ P7 ₃ Rh ¹ Cl and 10 % (CgH ^ P and hydrogenated at 100 ° C. and 60 atm for 4.5 hours.

The hydrogenation product has the following properties:

Hydrogenation degree: 100% vinyl and 48% trans double bonds glass transition temperature: T = -43 ⁰ C.
Iodine number: Jz = 50

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Example 6

A 2.5% solution of the copolymer II in toluene is mixed with 1% / Ic ₆ E ₃ ) JPj ^ Rh ¹ Cl and 10 % (C ₆ H ₅ ) ^ P and 5.2 hours at 100 ° C. and 60 atm hydrogenated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 42 % of the trans double

bonds Glass transition temperature: T = -26 ⁰ C

Iodine number: Jz = 95

Example 7

A 2.5% solution of the copolymer III in toluene is made with 1 % / Xc ^ H ₅ ) ₃ p7, Rh ¹ Cl and 10 %
Hydrogenated at 100 C and 60 atm.

Rh ¹ Cl and 10 % (C ₆ H ₅ ) ^ P added and 5 hours at

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 30 % of the trans double bond

fertilize

Glass transition temperature: T = -26 ⁰ C Iodine number: Jz = 60

Example 8

A 2.5% solution of the copolymer II in chlorobenzene is mixed with 1% / TCH ₃ ) ₂ S = 07 ₃ Rh ^III Cl ₃ and 10 % (CH ^) ₂ S = O and at 100 ° C. for 7.5 hours 60 atm hydrated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100% of the vinyl and 100% of the trans double

bonds Glass transition temperature: T = - 29 ° c

Iodine number: Jz = 29

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Example 9

A 2.5% solution of the copolymer II in benzene is mixed with 1% / Xc ₆ H ₅ ), p7 ₃ Rh ¹¹¹ Cl ₃ and 10 % (C ₆ H ₅ ), P and at 100 ^° C. for 6.2 hours and 60 atm hydrogenated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 90 % of the trans double

ties

Glass transition temperature: T = -30 C Iodine number: Jz = 19

Example 10

A 2.5% solution of the copolymer II in ethyl acetate is mixed with 1% _{ZlC 6} H ₅ ) ₃ p7 ₃ Rh ¹ Cl and 10 % (C ₆ H ₅ ) ₃ P and at 100 ^° C. and 60 for 5.5 hours atm hydrogenated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 50 % of the trans double

ties

Glass transition temperature: T = -38 ⁰ C iodine number Jz = 77

Example 11

A 2.5% solution of the copolymer II in methyl ethyl ketone is mixed with 1% _{ZXc 5} H _{5 I 3} Pj ₃ Rh ¹ Cl and 10 % (C ₅ H ₅ I ₃ P and ^{hydrogenated at 100 °} C. and 60 atm for 6 hours .

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 40 % of the trans double

ties

Glass transition temperature: T = -39 ° c Iodine number: Jz = 119

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Example 12 ^

A 2.5% solution of the copolymer II in xylene is mixed with 1% Z ^ C ₆ Hc) ₃ EZ ₅ Rh Cl and 10 96 (C ₆ H ₅ ) ^ P and 6.5
Hydrogenated for hours at 100 ^° C. and 60 atm.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 59 % of the trans double

ties

Glass transition temperature: T = -39 ° C iodine number Jz =

Example 13

A 2.5% solution of the copolymer II in dimethylformamide
1 96 ZlC ₆ H ₅ UPZ ₃ Rh ¹ Cl and 10 % (C ₅ H ₅ ) ^ P are added and the ^{mixture is hydrogenated at 100 °} C. and 60 atm for 4 hours.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 59 96 of the trans double

ties

Glass transition temperature: T ₀ . = -42 C

Iodine number: Jz =

Example 14

A 2.5% solution of the copolymer II in cyclohexanone is mixed with 1% ZlC ₆ H ₅ J ₃ Pj ₃ Rh ¹ Cl and 10 % (C ₆ H ₅ UP and
Hydrogenated for 4 hours at 100 ^° C. and 60 atm.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 38 % of the trans double

ties

Glass transition temperature: Tg = -4i ° C Iodine number: JZ =

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Example 15 M.

A 2.5% ± ge solution of the copolymer II in tetrahydrofuran is treated with 1% ZIc ₆ H _{5) 3} Cl p7 ₃ Rh ¹ and 10% (CGH ₅₎ ^ P and 3.2 hours at 100 ⁰ C and 60 atm . hydrogenated.

The hydrogenation product has the following properties:

Degree of hydrogenation: 100 % of the vinyl and 31 % of the trans double

ties.

Glass transition temperature: Tg = -39 ° C Iodine number Jz = 113

Example 16

A 2.5% solution of the copolymer II in methylene chloride is _{mixed with 1% (C 6} Hg) ₃ PJ ₃ Rh ¹ Cl and 10% (CgH ₅ ) ₃ P and hydrogenated for 6.5 hours at 100 ° C. and 60 atm .

The hydrogenation product has the following properties:

Degree of hydrogenation: 100% of the vinyl and 12% of the trans double bonds

Glass transition temperature: T = -40 ° C Iodine number: Jz = 160

The results of Examples 1-16 are summarized in Table 1 below.

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Table 1

Ib

U)

νο

-j σ co

ο oo OO

I ro

example Copolymer solvent catalyst Hydrogenation
Vinyl- degree (%)
trans double T Jz 1 I. Chlorobenzene / "(C ₆ H ₅ ) 3Pj ₃ Fh ¹ Cl 100 100 -31 14th 2 II Il Il 100 100 -30 26th 3 H η / ^ (C ₁ JH ₁ -). ^ Py _Rn Cl_ 100 1CO -30 22nd 4th III η ZtC ₆ H ₅ ) ₃ PZ Ph ¹ Cl 100 100 -27 22nd 5 I. toluene η 100 48 -43 50 6th II N N 100 42 -26 95 7th III N η 100 38 -26 60 8th II Chlorobenzene / "(CH ₃ ) ₂ S = O / ₃ Fh Cl 100 100 -29 29 9 II benzene / - (C ₆ H ₅ ) HZ ₃ Rh ¹¹¹ Cl ₃ 100 90 -30 19th 10 II Ethyl acetate / "(C ₆ H ₅ ) 3PZ ₃ Fh ¹ Cl 100 50 -38 77 11 n Methyl ethyl ketone H 100 40 -39 119 12th II Xylene η 100 59 -39 73 13th n Dimethylfbrmandd H 100 59 -42 144 14th π Cyclohexanone Il 100 38 -41 114 15th II Tetrahydrofuran Il 100 31 -39 113 16 II Methylene chloride H 100 12th -40 160

O'CD

P i

c_

^r 4

ro cn co

CD

co ro

Claims (6)

Claims Λ J Process for the selective hydrogenation of the vinyl groups and the trans-configured double bonds in copolymers of a ^ C, ß-unsaturated carboxylic acid or its derivatives and an unsaturated hydrocarbon with conjugated double bonds, characterized in that a 1-20 # solution of the copolymers in suitable organic solvents in the presence of O, O1 - 10% by weight of a catalyst made from a complex compound of 1- or 3-valent rhodium halides and optionally 5-25% by weight of the ligands bound in the complex (each based on the dissolved copolymer) at 50-150 ⁰ C and 5 to 300 atm, is hydrogenated. 2. The method according to claim 1, characterized in that one rhodium complex compounds with sulfur-containing ligands used. 3. The method according to claim 1 and 2, characterized in that that chlorine-substituted aromatic solvents with 6-12 carbon atoms are used and a selective, complete hydrogenation of the vinyl groups and the transconfigured Double bonds takes place. 4. The method according to claim 1, characterized in that the solvent used is toluene, benzene, ethyl acetate, methyl ethyl ketone, xylene, dimethylformamide, cyclohexanone, tetrahydrofuran, methylene chloride and others and depending on the choice of solvent in addition to the vinyl groups between 10 - 90 % of the trans configured double bonds are hydrogenated. Le A 16 349 - 13 - 709811/0881 INSPECTED JIr 5. The method according to claim 1, characterized in that the copolymer to be hydrogenated is a copolymer of (meth) acrylic acid, their esters and amides or (meth) acrylonitrile and butadiene, isoprene, dimethylbutadiene or piperylene is. 6. The method according to claim 1, characterized in that a butadiene-acrylonitrile copolymer for the hydrogenation 90-45 wt% butadiene and 10-55 wt% acrylonitrile (in each case based on the total amount of the copolymer) is used. Le A 16 349 - 14 - 7W811 / 0881