SU1574610A1 - Method of obtaining hydrated dien-nitrile polymer - Google Patents

Abstract

This invention relates to a process for the preparation of hydrogenated diene-nitrile polymers that can be used to manufacture RTI. The increase in the stability of the hydrogenated polymers to the thermo-oxidative effect is achieved by the fact that in the process for the preparation of the hydrogenated polymer selective hydrogenation of the double bonds of the diene nitrile polymer with hydrogen in an organic solvent is carried out. In this case, the catalyst used is a catalyst of the general formula (RCOO) ₂ PD, where R is methyl, or propyl deposited on a carboxyl-containing butadiene-nitrile copolymer cross-linked with divinylbenzene with a carboxyl group content of 5.2-2.30.4 wt.% while the amount of palladium in the polymer catalyst is 5.2 - 12.1 wt.%. 6 tab.

Description

The invention relates to the technology of producing synthetic high-molecular compounds, in particular, to the method of selectively hydrogenating the double bonds of carbon-chain polymers, and can be used in the petrochemical industry, and the copolymers obtained as the basis for products of the oil and gas industry, tire industry and electrical industry.

The aim of the invention is to increase the resistance of the hydrogenated polymer to thermo-oxidative effects,

The catalyst used is a catalyst of the formula (RCOO) 7Pd, where R is methyl, propyl, deposited on a polymer substrate. As the polymer substrate is used transversely.

Cross-linked carboxyl-containing butadiene-nitrile polymer obtained by emulsion copolymerization of butadiene, acrylonitrile (NAC) and methacrylic acid (MAA) in the presence of divinylbenzene (5 wt.% for the sum of monomers). A crosslinked carboxylate butadiene-nitrile copolymer is obtained containing 5.2% by weight of carboxyl groups, 30.5% by weight of acrylonitrile units, having a degree of swelling in methyl ethyl ketone (MEK), 22%. In tab. 1 shows the recipe of the polymerization mixture.

The polymerization of the monomers is carried out in a 20-liter apparatus at a temperature of 20 ± 2 ° C until the dry residue content in the latex is 25.0 wt. After the termination of the polymerization, the unpolymerized monomers are distilled off. Gas station

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ABOUT

A stabilizing latex with a dry residue of 17.1% in an amount of 4 liters is alkalinized to pH 8-9, coagulated with a 24% solution of sodium chloride and the pH adjusted to 8% acetic acid to a value of 4-, 5.

The coagulation temperature of C. The resulting rubber crumb is separated from the serum, washed with softened water at. 50-55 ° C, wring out and dried in an air dryer at 70-80 ° C.

The structure of the cross-linked polymer should provide a degree of swelling in the solvent 5-SC of masD.

To obtain a catalyst, 1 g of a crosslinked copolymer is subjected to swelling at 25 ° C in 25 ml of methyl ethyl ketone (MEK). The gel is broken with a mechanical stirrer to form a slurry that does not delaminate for 2-5 minutes. Then to the reaction mass is poured a solution of 0.26 g of acetic acid palladium in 25 ml of IEC. The reaction mass is stirred until the solution becomes colorless over the gel, after which the catalyst is separated by filtration, washed with methyl ethyl ketone, dried in vacuum at 0–50 ° C to a constant weight. After drying, the catalyst has a particle size of 0.07-0.2 mm. The product does not cake, can be easily fractionated. The content of palladium in the catalyst is 9.5 mas.

Example 1: For Hydrogenation

10 g of the copolymer is dissolved in 150 ml of MEK, purged with an inert gas. A portion of 0.2 g of a dry catalyst with a fraction of 0.071-0.125 mm is poured with 10 ml of MEK, incubated for 0.5 h, then mixed with a solution of a hydrogenated polymer and fed into the hydrogenation reactor. The content of palladium in the catalyst is 9.5 May D. The hydrogenation is carried out at 0 ° C and hydrogen pressure (MPa kgf / cm2) for C h. After hydrogenation, the catalyst is separated by filtration, the polymer is separated with alcohol or by evaporation of NEC in vacuum and analyzed for the content of double bonds (iodometrically or on the DAB-analyzer of double bonds).

In tab. 2 shows the results of rubber hydrogenation.

Characteristics of the original rubber content of NAC bound 0.2%; conditional stiffness according to Defoe

670 gs, unsubstantiation 1.03 mol double bonds / 100 g

PRI mme R 2. Similar to the above description of a method for producing a catalyst based on crosslinked butadiene-NAK-MAC copolymers with different contents of carboxyl groups, catalysts containing different amounts of fixed palladium are obtained.

In tab. 3 shows the results of rubber hydrogenation on the resulting catalysts. The hydrogenation is carried out analogously to example 1. The catalyst weights are varied at the rate of the palladium dosage of 0.18 wt.% Per the hydrogenated copolymer.

i

PRI me R 3. In a manner similar to that shown in Example 1, the method on sample of catalyst 8 (described in Example 2 in Table 3) was used to hydrogenate in the IEC a linear ternary copolymer of butadiene-NAK-MAK (monomer ratio 60:30:10 May D).

At a palladium dosage of 0.1 wt.% Per copolymer, the degree of hydrogenation after 2 and k hours is 9b, 3 and 98.5%, and the residual metal content in the polymer is 5-1Q-3 masD. According to a known method, the degree of hydrogenation is 78.5 and 91%, respectively, and the content of metal in the polymer is 175 U-3 May D.

PRI me R. A low molecular weight isoprene copolymer with acrylonitrile (75:25 mAb) is hydrogenated as a 15% solution in chlorobenzene at 50 ° C and a hydrogen pressure of 6 MPa in the presence of a sample of catalyst 8 from a table. 3 of Example 2 (dosage of palladium 0.2 masad per polymer). After 6 hours, a product with a degree of hydrogenation of 9.5% is obtained (according to a known method, the degree of hydrogenation is 67%)

PRI me R 5. A crosslinked carboxylate nitrile-butadiene copolymer containing 5.2 wt% of carboxyl groups, 0.5 wt% of NAC units, is treated with a solution of acetic acid palladium in acetone, similarly to the description given, and products with different contents are obtained. palladium in the complex. The results of SKN-40 hydrogenation (the method of hydrogenation is similar to Example 1) are given in Table. .

The catalyst weights were taken at the rate of 0.2 masD of palladium on the copolymer to be hydrogenated.

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Example 6: Similar to the above description of the preparation of a catalyst by treating a crosslinked carboxylate butadiene-nitrile copolymer (containing 5.2% by weight of carboxyl groups and 30.5% by weight of NAC units) with organic compounds of palladium, catalysts with various substitute palladi.

The results of the hydrogenation of polymers are shown in Table. 5. Hydrogenation is carried out analogously to example 1.

In tab. 6 shows data on the resistance of samples of hydrogenated polymers to thermo-oxidative effects.

Films of thickness 0,, 01 mm are pressed from polymers. Films weighing 0.5 g are subjected to oxidation with a manometric unit and the time until the onset of oxygen absorption (induction period) is determined.

In the installation used, the absorption by the polymer was fixed.

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0.05% by weight of oxygen, which corresponded to a pressure change in the system of 1.0 mm Hg

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Claims (1)

Invention Formula A method of producing a hydrogenated diene nitrile polymer by selectively hydrogenating double bonds of a diene nitrile polymer with hydrogen in an organic solvent in the presence of a catalyst of the general formula (RCOOLPd, where R is methyl or., Propyl, in order to increase the stability of the hydrogenated polymers to thermo-oxidative effects, the catalyst used is applied to a transversely 20 crosslinked carboxyl-containing divinylbenzene containing -: - nitrile-butadiene copolymer with a carboxylic acid content of 5.2-30.4 masD, while The amount of palladium in the polymer catalyst is 5.2–12.1 wt.%. T a b l and c a 1 Recipe polymerization charge Component Butadiene Acrylonitrile Methacrylic acid Divinylbenzene Sodium alkyl sulfonate Leykanol Hyperies Rongalite Trilon B Tertiary dodecyl mercap Water Stopper (sodium nitrite) ) Similarly, get copolymers with a different content of NAC and MAC. Ma.h. per 100 mah., monomers 55 five 3.5 0.3 0.05 0.03 0.04 0.6 200 0.2 Table Hydrogenation rubber SKN- + O Initial rate of hydrogenation ml H1 / g Pd min-1600 Degree of hydrogenation of double bonds,% through: 1 h6,5 2h82  h93,2 The residual content of palladium in the polymer after separation, wt.% J 0.17 ) The initial dosage is 0.18% w / w per hydrolimeter. Table Hydrogenation of CKH- tO at CO ° C, MPa 1 Hydrogenation conditions by a known method: hydrogen pressure of 5 MPa; reaction time 3 hours; T 50 C. Table 4 Hydrogenation of SKN-40 with catalysts containing different amounts of metal Hydri - Degree of hydrogenation,% driven co-when the content of palladium in the catalyst, wt.% 0.48 j i, lj 2.4 5.2 J 8.0 9.7 | l2.1 SKN-40 25.3 96 96.5 98.1 98.3 98.5 98.5 Table 5 The activity of catalysts in the hydrogenation of polymers Replace-Hydri-Use-Degree the body (R) of the zuyuyu hydrim is a compound-copoly dissolution, palladium impregnator (RCOO) 7 Pd Methyl KSN-40 IEC 98.5 Propyl SKN-40 Acetone 98 Stearyl SKN-40 IEC 83.2 Table 6 Oxidation of hydrogenated BNK in oxygen atmosphere at 150 ° С Indicator Method sustainable- these samples from the proposed vested The degree of hydrogenation of BNK,% 97.2 97.3 98.1 98.5 99.0 Induction period of oxidation, min 37. 92 121 126 135 Compiled G.Ovchinnikova Editor A.Makovska Tehred L.Serdyukova Proofreader S.Cherni Order 1757 Circulation 435 Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101