CN111363094A

CN111363094A - Selective hydrogenation method for conjugated diene rubber latex

Info

Publication number: CN111363094A
Application number: CN202010026548.9A
Authority: CN
Inventors: 王辉; 马韵升; 黎艳艳; 任学斌; 郭宗磊; 刘振学; 郝福兰; 周德芳; 曹峰; 佟伟超; 杜庆之; 栾波; 王孝海; 王耀伟
Original assignee: Shandong Jingbo Zhongju New Materials Co ltd; Qingdao University of Science and Technology; Shandong Chambroad Petrochemicals Co Ltd
Current assignee: Shandong Jingbo Zhongju New Materials Co ltd; Qingdao University of Science and Technology; Shandong Chambroad Petrochemicals Co Ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2020-07-03

Abstract

The invention provides a selective hydrogenation method of conjugated diene rubber latex, which comprises the following steps: carrying out hydrogenation reaction on conjugated diene latex and a VIII family metal compound catalyst shown in a formula (I) to obtain a hydrogenated polymer; the solid content of the conjugated diene rubber latex is 10-30%. The invention adopts the metal compound catalyst of the VIII family shown in the formula (I) to catalyze the conjugated diene latex and hydrogenate the emulsion, and the catalyst does not use any cocatalyst and any organic solvent in the using process, nor uses any substance except the catalyst; compared with the prior art, the catalyst has high hydrogenation efficiency on NBR latex and low catalyst usage amount; the catalyst has the advantages of low hydrogenation condition and low temperature and pressure. Meanwhile, by controlling the solid content of the specific conjugated diene latex, the catalyst has high catalytic activity and high catalytic efficiency on the latex under mild temperature and pressure, and is favorable for realizing rapid industrialization.

Description

Selective hydrogenation method for conjugated diene rubber latex

Technical Field

The invention relates to the technical field of catalysts, in particular to a selective hydrogenation method for conjugated diene rubber latex.

Background

The research and development of hydrogenated diene-based rubber products mainly refer to obtaining rubber products with required performance through formula design and subsequent processing methods according to the application environment of rubber parts. At present, hydrogenated diene-based rubbers, hydrogenated parent diene-based unsaturated polymers such as nitrile rubber (also referred to as NBR) prepared by polymerization of acrylonitrile and butadiene, are well known, whether in laboratory or industrial production, mainly by 3 means, as exemplified by NBR, in particular as follows.

(1) Acrylonitrile-ethylene copolymerization. In the copolymerization of ethylene and acrylonitrile, since reactivity ratios of acrylonitrile and ethylene are greatly different (0.04 for acrylonitrile and 0.8 for ethylene), the charging ratio of the reaction raw materials must be strictly controlled. In addition, group rearrangement easily occurs in the copolymerization reaction process, side reactions are more, the randomness of chain segments is poor, the performance of the obtained product is poor, and the processing performance of the product is finally influenced, so the method is still in the research stage at present.

(2) Emulsion hydrogenation: adding a heavy metal catalyst into the butyronitrile latex for hydrogenation to prepare HNBR. The United states Goodyear company firstly proposed a process for preparing emulsion HNBR by using diimide as a reducing agent in 1984, NBR latex can directly generate HNBR (related US patent application: US4452950A) under the action of hydrazine hydrate, oxygen or hydrogen peroxide as an oxidizing agent and iron and copper metal ion initiators, but the reduction mode is easy to generate gel, the utilization rate of hydrazine or hydrogen peroxide is low, and the recovery is difficult. The emulsion hydrogenation has the advantages of mild reaction conditions compared with solution hydrogenation, simple process, no need of solvent, reduced cost and pollution, and the product can be recycled (the product is emulsion and can be used as special coating). Therefore, NBR emulsion hydrogenation processes are receiving increasing attention. The disadvantage is that the unhydrogenated double bonds can undergo crosslinking reactions, which leads to an increase in the viscosity of the system and can impair the subsequent processing. The NBR solution hydrogenation method has complex process, needs a solvent in the reaction process, and causes environmental pollution due to the discharge of the solvent. The emulsion polymerization of NBR leads to difficulties in product separation due to the severe crosslinking reactions which make the product gel-forming easily. Meanwhile, the emulsion hydrogenation method has the problem of slow hydrogenation rate, and is not suitable for large-scale production. In recent years, Yue Dongmei et al, the university of Beijing chemical industry, has improved the hydrogenation method of NBR latex, reduced the gel content of HNBR latex, and increased the hydrogenation degree (related Chinese patent applications: CN101486775A, CN 101704909A).

At present, the ethylene-acrylonitrile copolymerization method and the NBR emulsion polymerization method are stoppedAnd the method is left in a laboratory research stage, and no precedent of industrial application exists. The only industrialization is NBR solution hydrogenation, which is used by german langerhans, japanese rapes and zanan technologies. Due to the difference of catalytic systems used in hydrogenation reactions, the Japan Rui Wen corporation mainly adopts palladium/white carbon black heterogeneous catalyst with white carbon black as a carrier to prepare HNBR; the Langshan company mainly adopts a rhodium-based homogeneous catalyst RhCl (P (C)₆H₅)₃)₃Preparing HNBR; the Zanan company mainly adopts ruthenium catalyst to prepare HNBR.

(3) Solution hydrogenation process

The NBR solution hydrogenation method comprises a heterogeneous solution hydrogenation method and a homogeneous solution hydrogenation method, wherein during operation, NBR is crushed and dissolved in a proper organic solvent, and the used solvent mainly comprises cyclohexanone, xylene, chloroform and the like. And placing the HNBR in a high-temperature high-pressure reactor, reacting the HNBR with hydrogen under the action of a noble metal catalyst, and carrying out selective hydrogenation to prepare HNBR. The solution hydrogenation method is the main method for industrially producing HNBR at present. In the hydrogenation, only the double bonds of the butadiene units are selectively hydrogenated to reduce them to saturated single bonds, without hydrogenating the nitrile groups. The key to the solution hydrogenation process is the choice of catalyst. The NBR solution hydrogenation method can be classified into heterogeneous hydrogenation using a group viii metal coated on an inorganic carrier as a catalyst and homogeneous hydrogenation mainly using a catalyst such as a rhodium-based, ruthenium-based, or palladium-based catalyst. The heterogeneous catalyst adopted by the heterogeneous solution hydrogenation method is a supported catalyst which takes palladium, rhodium, ruthenium and the like as active components and takes alumina, silica, active carbon, carbon black, alkaline earth metal carbonate and the like as carriers, and a hydrogenation product is directly separated from the catalyst by adopting a filtration or centrifugal separation method after the hydrogenation reaction is finished. In the 80 th century of the Japan Ruizui company, the supported catalyst is used for NBR hydrogenation reaction at the earliest, the heterogeneous carrier catalyst is a palladium/carbon catalyst taking carbon as a carrier, the catalyst has high selectivity, the hydrogenation rate can reach as high as 95.6%, but in the hydrogenation reaction, the carbon is easy to adsorb rubber molecules, so that the agglomeration is caused, and the product performance is influenced. The main advantage of the heterogeneous supported catalyst is that the catalyst is easy to separate, but the activity and selectivity of the hydrogenation catalyst are greatly influenced by the environment. In addition, most of active components of the supported catalyst prepared by the traditional method are distributed in the pore channel, NBR molecules must diffuse into the pore channel to carry out hydrogenation reaction, in order to improve the reaction rate, the reaction must be carried out under the conditions of high pressure and strong stirring, the reaction time is long, the energy consumption of the process is high, and the performance of the polymer is easy to deteriorate.

Diene-based unsaturated polymers, such as nitrile rubber (also known as NBR) prepared by polymerization of acrylonitrile and butadiene, are well known in the art. Processes for the copolymerization of acrylonitrile and butadiene are described, for example, in U.S. Pat. No. 3, 3690349, U.S. Pat. No. 3, 5770660 and CN 102532414. Depending on the preparation conditions, such polymers can be obtained as latices in aqueous media. Diene-based unsaturated polymers such as NBR are used for various industrial purposes, and hydrogenation processes for such unsaturated polymers are also well known in the art.

The art of catalytic hydrogenation of polymers based on organic solutions is well established and relevant patents include US-A-6,410,657, US-A-6,020,439, US-A-5,705,571, US-A-5,057,581 and US-A-3,454,644. It is known that carbon-carbon double bonds in diene-based polymers can be selectively hydrogenated by treating the polymer in organic solution with hydrogen in the presence of a catalyst to produce their saturated polymers having significantly improved end-use properties. Such a process may be selective for the double bond to be hydrogenated, so that, for example, the double bond in an aryl or cycloalkyl group is not hydrogenated and the double or triple bond between carbon and other atoms, such as nitrogen or oxygen, is not affected. The art includes many examples of catalysts suitable for such hydrogenation, including cobalt, nickel, rhodium, ruthenium, osmium, and iridium-based catalysts. The suitability of the catalyst depends on the desired degree of hydrogenation, the rate of hydrogenation reaction and the presence or absence of other groups such as carboxyl and nitrile groups in the polymer.

US 6410657 teaches a process for the selective hydrogenation of unsaturated double bonds in the conjugated diene units of a homopolymer or copolymer in the presence of a homogeneous organotitanium-based catalyst. The use of a catalyst mixture consisting of a substituted or unsubstituted monocyclopentadienyl titanium compound and lithium hydride derived from the reaction of an alkyl lithium with hydrogen in solution exhibits a high degree of hydrogenation and hydrogenation reproducibility.

US 6020439 describes a process for the hydrogenation of living polymers comprising mainly conjugated double bond monomers and aromatic vinyl monomers. A polymer produced from at least one conjugated diene compound is contacted with hydrogen in the presence of a catalyst. The catalyst is formed from a cyclopentadienyl titanium compound. The promoter is provided in the form of a lithium alkoxide compound. The catalyst system selectively hydrogenates unsaturated double bonds within the conjugated diene units of the living polymer in solution.

US 5705571 provides a process for the selective hydrogenation of conjugated diene polymers. The process comprises contacting a conjugated diene polymer with hydrogen in an inert organic solvent in the presence of a hydrogenation catalyst composition comprising a substituted or unsubstituted bis (cyclopentadienyl) group VIII transition metal compound and an organolithium compound. It is claimed that the hydrogenation can be carried out under mild conditions in the presence of a small amount of the hydrogenation catalyst composition and that the hydrogenation conversion and the selectivity to conjugated diene units are high.

US 5057581 teaches a process for the selective hydrogenation of carbon-carbon double bonds of conjugated diene copolymers in homogeneous solution in an organic solvent in the presence of certain divalent ruthenium carbonyl complex catalysts comprising phosphine ligands with bulky alkyl substituents.

US 3454644 teaches the use of a ruthenium or osmium metal complex as catalyst which is bonded to two electronegative species selected from hydrogen and halogen and which is coordinated to at least two organic stabilizing ligands such as carbonyl or tertiary phosphines,

Nitriles, unsaturated organic compounds having from 2 to 20 carbon atoms which are not part of aromatic carbon double bonds and carbon-carbon triple bonds are hydrogenated in solution.

In summary, the research in this field, i.e. the hydrogenation of diene-based polymers, is very successful if the polymers are dissolved in organic solvents, but there are drawbacks and problems associated with the dissolution of the polymers in organic solvents.

However, many diene-based polymers/copolymers are prepared by emulsion polymerization and are in the form of a latex when discharged from the polymerization reactor. It would therefore be highly desirable to develop a process which allows the direct hydrogenation of diene-based polymer latices. Direct hydrogenation of polymer latices has received increasing attention in the last decade. Much effort has been expended to implement this method as described below.

US 6552132 claims a process for the hydrogenation of polymers composed of diene monomer units and nitrile group-containing monomer units, in which the hydrogenation is carried out in the presence of hydrazine and an oxidizing compound in the form of an aqueous dispersion.

US 6521694 describes a process for hydrogenating the carbon-carbon double bonds of unsaturated polymers in the form of an aqueous dispersion, to which (1) a reducing agent selected from hydrazine and hydrazine-releasing compounds, (2) an oxidizing compound and (3) a catalyst are added, wherein the catalyst contains an element of group 13 of the periodic table of the elements.

US 5272202 describes a process for the selective hydrogenation of carbon-carbon double bonds of nitrile group-containing unsaturated polymers with hydrogen in the presence of a hydrogenation catalyst. Relates to an aqueous emulsion of an unsaturated polymer containing nitrile groups. Optionally, an organic solvent capable of dissolving or swelling the polymer is present in a volume ratio of aqueous emulsion to organic solvent in the range of 1: 3 to 1: 0. A palladium compound is used as the hydrogenation catalyst. The aqueous emulsion is contacted with gaseous or dissolved hydrogen while maintaining the emulsified state.

JP02178305 describes a process for the hydrogenation of nitrile rubbers by contacting the emulsion with hydrogen in the presence of a Pd compound and optionally swelling the emulsion in an organic solvent. Thus, 100ml of a 10% nitrile rubber emulsion (containing 39.4% units derived from acrylonitrile) was mixed with 63.3mg of palladium benzoate in 50ml of benzene and heated at 50 ℃ for 6 hours under a hydrogen pressure of 30atm to give a 90.2% hydrogenated emulsion.

EP 1705194A 1 discloses a process for the direct hydrogenation of diene-based polymer latices using organometallic catalysts and high-pressure gaseous hydrogen. The organometallic catalyst was RhCl (PPh3) 3. A 300ml glass lined stainless steel autoclave with temperature control, stirrer and hydrogen addition point was used. A butadiene-acrylonitrile polymer latex is used which is limited to an acrylonitrile content of about 38% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of about 29. The latex had a solids content of 14.3% by weight. The average diameter of the polymer particles in the latex was about 75 nm. A reactor was charged with 50ml of this latex, 100ml of water, 0.0378g of the catalyst RhCl (PPh3)3 and 0.594g of PPh 3. The latex was then degassed with hydrogen. The temperature was raised to 145 ℃ and the hydrogen pressure increased to 900psi (6.1 MPa). After 87 hours, the degree of hydrogenation reached 92%. No gel was produced and the resulting polymer was soluble in methyl ethyl ketone. The main problems of this technique are the slow reaction rate, the very long time that results, and the low catalytic efficiency of the catalyst.

In summary, there are two main approaches to the above field of research: one approach is similar to conventional solution catalytic hydrogenation, which hydrogenates the polymer in latex form; another approach involves the use of hydrazines and the like, in which a source of hydrogen is generated in situ as a result of a redox reaction. Currently, both approaches suffer from bottlenecks to achieve rapid hydrogenation reaction rates, high conversion rates and elimination of gel formation.

Therefore, it is highly necessary to develop a catalyst system capable of rapidly and efficiently performing selective hydrogenation of diene-based polymer latex without using any organic solvent, with a high degree of hydrogenation reaction, and without any gel problem.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a method for selectively hydrogenating conjugated diene rubber latex, wherein the catalyst system provided by the present invention is suitable for selectively hydrogenating conjugated diene rubber latex, does not use any organic solvent and any catalytic assistant, and has high hydrogenation efficiency and low catalyst usage amount.

The invention provides a selective hydrogenation method of conjugated diene rubber latex, which comprises the following steps:

carrying out hydrogenation reaction on conjugated diene latex and a VIII family metal compound catalyst shown in a formula (I) to obtain a hydrogenated polymer; the solid content of the conjugated diene rubber latex is 10-30 percent;

wherein M is a group VIII metal element,

X¹and X²Independently selected from the group consisting of anionic ligands,

l is an uncharged electron donor,

y is selected from O, S, N-R¹Or P-R¹Group, wherein R¹One or more selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulfonate or alkylsulfinyl;

R²、R³、R⁴and R⁵Independently selected from hydrogen, halogen, nitro, CF3, C1-C30 alkyl, C3-C20 alkynyloxy, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, C6-C24 aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkylamino, C1-C20 alkylthio, C6-C24 arylthio, C1-C20 alkylsulfonyl or C1-C20 alkylsulfinyl;

R⁶selected from hydrogen radicals, alkyl radicals, alkenyl radicals, alkynyl radicals or aryl radicals.

Preferably, the hydrogenation temperature is 35-200 ℃; the hydrogenation reaction time is 10 min-24 h; the hydrogenation pressure is 0.5-35 Mpa.

Preferably, the conjugated diene rubber latex is obtained by polymerizing diene monomers and comonomers.

Preferably, the diene monomer is selected from one or more of 1, 3-butadiene, isoprene, 1-methylbutadiene, 2, 3-dimethylbutadiene, piperylene and chloroprene, and the comonomer is selected from one or more of acrylonitrile, methacrylonitrile, styrene, α -methylstyrene, propyl acrylate, butyl acrylate, propyl methacrylate, butyl methacrylate, fumaric acid, maleic acid, acrylic acid and methacrylic acid.

Preferably, the group VIII metal compound represented by the formula (I) is selected from one or more of a Heveda-Grubbs II catalyst and a Graela (grela) catalyst.

Preferably, the catalyst accounts for 0.0001-5 wt% of the conjugated diene rubber latex;

the solid content of the conjugated diene rubber latex is 10-25%;

the conjugated diene rubber latex can be added at one time or added in 2 or more batches, for example, in the embodiment 5-8, the rubber latex is added twice, and the mass ratio of the two rubber latexes is 1:1, add latex-add catalyst-add latex.

Preferably, M is osmium or ruthenium;

X¹and X²Independently selected from hydrogen, halogen, pseudohalogen, linear or branched C1-C30 alkyl, C6-C24 aryl, C1-C20 alkoxy, C6-C24 aryloxy, C3-C20 alkyldione, C6-C24 aryldione, C1-C20 carboxylate, C6-C24 alkylsulfonate, C6-C24 arylsulfonate, C1-C20 alkylthiol, C6-C24 arylthiol, C1-C20 alkylsulfonyl or C1-C20 alkylsulfinyl;

l is selected from one or more of phosphine, sulfonated phosphine, phosphate, phosphonate, arsine, stibine, ether, amine, amide, sulfoxide, carboxyl, nitrite, pyridine, thioether and N-heterocyclic carbene ligand;

r1 is selected from one or more of C1-C30 alkyl, C3-C20 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, C6-C24 aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkylamino, C1-C20 alkylthio, C6-C24 arylthio, C1-C20 alkylsulfonyl and C1-C20 alkylsulfinyl;

R⁶selected from hydrogen, C1-C30 alkyl groups, C2-C20 alkenyl groups, C2-C20 alkynyl groups or C6-C24 aryl groups.

Preferably, X is¹Selected from chlorine, CF₃COO、CH₃COO、CFH₂COO、(CH₃)₃CO、(CF₃)₂(CH₃)CO、(CF₃)(CH₃)₂CO, phenoxy, methoxy, ethoxy, tosylate (p-CH)₃-C₆H₄-SO₃) Methanesulfonic acid (CH)₃SO₃) Or trifluoromethanesulfonate (CF)₃SO₃)；

L is a structure represented by formula (II-a) to formula (II-f):

wherein R is⁸、R⁹、R¹⁰、R¹¹Independently selected from hydrogen, straight or branched C1-C30-alkyl, C3-C20-cycloalkyl, C2-C20-alkenyl, C2-C20-alkynyl, C6-C24-aryl, C7-C25-alkylaryl, C2-C20-heteroaryl, C2-C20-heterocycle, C1-C20-alkoxy, C2-C20-alkenyl, C2-C20-alkynyloxy, C6-C20-aryloxy, C2-C20-alkoxycarbonyl, C1-C20-alkylthio, C6-C20-arylthio, -Si (R)₃、-O-Si(R)₃、-O-C(＝O)R、C(＝O)R、-C(＝O)N(R)₂、-NR-C(＝O)-N(R)₂、-SO₂N(R)₂、-S(＝O)R、-S(＝O)₂R、-O-S(＝O)₂R, halogen, nitro or cyano;

R¹²、R¹³and R¹⁴Independently selected from C1-C20 alkyl.

Preferably, the reaction is carried out in a reaction kettle; the reaction kettle adopts a polytetrafluoroethylene lining.

Preferably, the reaction further comprises degassing the latex with argon; the degassing pressure is 0.1-6 MPa; the degassing time is 10min-300 min; the degassing temperature is 0-50 ℃.

Compared with the prior art, the invention provides a selective hydrogenation method of conjugated diene rubber latex, which comprises the following steps: carrying out hydrogenation reaction on conjugated diene latex and a VIII family metal compound catalyst shown in a formula (I) to obtain a hydrogenated polymer; the solid content of the conjugated diene rubber latex is 10-30%. The invention adopts the metal compound catalyst of the VIII family shown in the formula (I) to catalyze the conjugated diene latex and hydrogenate the emulsion, and the catalyst does not use any cocatalyst and any organic solvent in the using process, nor uses any substance except the catalyst; compared with the prior art, the catalyst has high hydrogenation efficiency on NBR latex and low catalyst usage amount; the catalyst has the advantages of low hydrogenation condition and low temperature and pressure. Meanwhile, by controlling the solid content of the specific conjugated diene latex, the catalyst has high catalytic activity and high catalytic efficiency on the latex under mild temperature and pressure, and is favorable for realizing rapid industrialization.

Drawings

FIG. 1 is an infrared chart of 0/5/10 hours of catalytic hydrogenation of the latex of example 1

Detailed Description

The invention provides a selective hydrogenation method of conjugated diene latex and application of a metal compound catalyst of a VIII family, and a person skilled in the art can realize the method by appropriately improving process parameters by referring to the content. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope of the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.

wherein M is a group VIII metal element,

X¹and X²Independently selected from the group consisting of anionic ligands,

l is an uncharged electron donor,

y is selected from O, S, N-R¹Or P-R¹Group, wherein R¹Selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulfonate or alkylOne or more of alkylsulfinyl;

Such catalysts of the formula (I) according to the invention are generally insoluble in water. In this application, "water insoluble" means that at 24+/-2 ℃, a material in an amount of 0.001 or less by weight can be completely dissolved in 100 equivalents of water, while at 24+/-2 ℃, if a catalyst in an amount exceeding 0.5 by weight can be completely dissolved in 100 equivalents of water, the catalyst is considered "water soluble".

Wherein M is a group VIII metal element, preferably osmium or ruthenium.

In the group VIII metal compound represented by the formula (I) of the present invention, wherein: x¹And X²Independently selected from anionic ligands, preferably, X¹And X²Independently selected from hydrogen, halogen, pseudohalogen, linear or branched C1-C30 alkyl, C6-C24 aryl, C1-C20 alkoxy, C6-C24 aryloxy, C3-C20 alkyldione, C6-C24 aryldione, C1-C20 carboxylate, C6-C24 alkylsulfonate, C6-C24 arylsulfonate, C1-C20 alkylthiol, C6-C24 arylthiol, C1-C20 alkylsulfonyl or C1-C20 alkylsulfinyl; the X1 radicals listed above may also be substituted further by one or more radicals, such as halogen, preferably fluorine, C1-C10-alkyl, C1-C10-alkoxy or C6-C24-aryl. Conversely, these radicals may also be substituted by one or more halogen-containing radicals, preferably fluorine, C1-C5-alkyl, C1-C5-alkoxy and phenyl.

In a preferred embodiment of the invention, X¹And X²Selected from halogen, especially fluorine, chlorine, bromine, iodine, benzoic acid, C1-C5-carboxylate, C1-C5-alkyl, phenoxyC1-C5 alkoxy, C1-C5 alkylthiol, C6-C14 aromatic thiophenol, C6-C14 aryl or C1-C5 alkylsulfonate.

In a particularly preferred embodiment, X¹And X²Selected from chlorine, CF3COO, CH3COO, CFH2COO, (CH3)3CO, (CF3)2(CH3) CO, (CF3) (CH3)2CO, phenoxy, methoxy, ethoxy, tosylate (p-CH3-C6H4-SO3), mesylate (CH3SO3) or triflate (CF3SO 3).

L represents a ligand, preferably an uncharged electron donor, and the ligand L is preferably one or more selected from phosphine, sulfonated phosphine, phosphate, phosphonate, arsine, stibine, ether, amine, amide, sulfoxide, carboxyl, nitrite, pyridine, thioether and N-heterocyclic carbene ligand;

in the present invention, the term "hypophosphorous acid" includes: phenyl diphenyl hypophosphorous acid, cyclohexyl dicyclohexyl hypophosphorous acid, isopropyl diisopropyl hypophosphorous acid and methyl diphenyl hypophosphorous acid.

The term "phosphite" includes: triphenyl phosphite, tricyclohexyl phosphite, tri-tert-butyl phosphite, triisopropyl phosphite and methyl diphenyl phosphite.

The term "stibine" includes: triphenyl radical

Tricyclohexyl radical

And trimethyl

The term "sulfonate" includes: triflate, tosylate and mesylate salts.

The term "sulfoxide" includes: (CH3)2S (═ O) and (C6H5)2S ═ O.

The term "thioether" includes: CH3SCH3, C6H5SCH3, CH3OCH2CH2SCH3, and tetrahydrothiophene.

The term "pyridyl ligand" is used as a generic term for all pyridine-based ligands or derivatives thereof.

The term "pyridyl ligand" includes pyridine itself, picolines (e.g., α -, β -, and γ -picolines), lutidines (e.g., 2,3-,2,4-,2,5-,2,6-,3,4-, and 3, 5-lutidines), collidines (2,4, 6-collidines), trifluoromethylpyridines, phenylpyridines, 4- (dimethylamino) -pyridines, chloropyridines, bromopyridines, nitropyridines, quinolines, pyrimidines, pyrroles, imidazoles, and phenylimidazoles.

In the present invention, L represents phosphine as an electron donor in the general formula (I), and then its general formula is preferably (IIf).

Wherein R is¹²、R¹³And R¹⁴Are identical or different, preferably identical, and are preferably C1-C20-alkyl, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, n-hexyl, neopentyl, C3-C8-cycloalkyl; most preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, C1-C20 alkoxy, substituted or unsubstituted C6-C20 aryl; most preferred are phenyl, biphenyl, naphthalene, phenanthrene, anthracene, tolyl, 2, 6-dimethylphenyl, trifluoromethyl, C6-C20 aryloxy, C2-C20 heteroaryl having at least one heteroatom in the ring, C2-C20 heterocyclyl having at least one heteroatom in the ring, or halogen, preferably fluorine.

If L represents a phosphine of the general formula (IIf) and acts as an electron-donating ligand in the structure shown in formula (I), such phosphine is preferably PPh3, P (P-Tol)3, P (o-Tol)3, PPh (CH3)2, P (CF3)3, P (P-FC6H4)3, P (P-CF3C6H4)3, P (C6H4-SO3Na)3, P (CH2C6H4-SO3Na)3, P (isopropyl) 3, P (CHCH3(CH2CH3))3, P (cyclopentyl) 3, P (cyclohexyl) 3, P (neopentyl) 3 or P (neopentyl) 3, where Ph represents phenyl and Tol represents tolyl.

The n-heterocyclic carbene ligand is a cyclic carbene ligand having at least one nitrogen as a heteroatom in the ring. The rings may have different substitution patterns. Preferably, this substitution pattern provides a degree of spatial crowding.

In this invention, the n-heterocyclic carbene ligands (hereinafter referred to as "NHC-ligands") are preferably based on imidazoline or imidazolidine groups.

In the present invention, L is NHC-ligand, and is generally represented by the formulae (II-a) to (II-e):

in the groups presented above in relation to R8, R9, R10 and R11, R, which are identical or different, represent hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, aryl or heterocycloaryl.

In the representative formulae (IIa) to (IIe), the carbon atom bonded to the ruthenium metal center is present in the form of carbene.

Optionally, one or more of R8, R9, R10 and R11 may be substituted independently of each other by one or more substituents, preferably straight-chain or branched C1-C10-alkyl, C3-C8-cycloalkyl, C1-C10-alkoxy, C6-C24-aryl, C2-C20-heteroaryl, C2-C20-heterocycle, and a functional group selected from the group consisting of hydroxyl, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, carbamate, and halogen, where the abovementioned substituents may, in turn, be chemically substituted to some extent by one or more substituents, preference is given to halogen-containing, in particular chlorine or bromine, C1-C5-alkyl, C1-C5-alkoxy and benzene. For the sake of clarity, it is added that the NHC-ligand structures of the general expressions (IIa) and (IIb) depicted in the present patent application and the structures (IIa- (i)) and (IIb- (i)) frequently encountered in the literature for such NHC-ligands, respectively, are the same and the carbene character of the NHC-ligand is to be emphasized. The same applies to the further structures (IIc) to (IIe) and also to the preferred structures described below in connection with (IIc) - (IIe).

Among the preferred NHC-ligands in the catalyst represented by the general expression (A)

R8 and R9 are identical or different and represent hydrogen, C6-C24-aryl, preferably benzene, straight-chain or branched C1-C10-alkyl, more preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl or tert-butyl, or form a cycloalkyl or aryl structure bound to a carbon atom.

Preferably and more preferably, R8 and R9 may be substituted by one or more functional groups comprising linear or branched C1-C10-alkyl or C1-C10-alkoxy, C3-C8-cycloalkyl, C6-C24-aryl, and a group selected from the group comprising hydroxyl, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, carbamate and halogen, wherein these substituents may in turn be substituted by one or more substituents, preferably comprising halogen, especially chlorine or bromine, C1-C5-alkyl, C1-C5-alkoxy and benzene.

In a further preferred NHC-ligand in the catalyst represented by the general formula (A)

R10 and R11 are identical or different, preferably linear or branched C1-C10-alkyl, more preferably i-propyl or neopentyl, C3-C10-cycloalkyl, more preferably adamantyl, substituted or unsubstituted C6-C24-aryl, more preferably phenyl, 2, 6-isopropylbenzene, 2, 6-xylyl, or 2,4,6-trimethylphenyl, C1-C10-alkylsulfonate, or C6-C10-sulfonic acid.

Preferably, R10 and R11 may be substituted by one or more substituents selected from the group consisting of linear or branched C1-C10-alkyl or C1-C10-alkoxy, C3-C8-cycloalkyl, C6-C24-aryl, and a functional group selected from the group consisting of hydroxyl, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, alkoxycarbonyl, carbamate and halogen, wherein these substituents may in turn be substituted by one or more substituents, preferably comprising halogen, especially chlorine or bromine, C1-C5-alkyl, C1-C5-alkoxy and benzene.

R8 and R9 are identical or different and represent hydrogen, C6-C24-aryl, more preferably benzene, straight-chain or branched C1-C10-alkyl, more preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, or form a cycloalkyl or aryl structure bound to a carbon atom.

Particularly preferably, the NHC-ligand has the structure shown below in (IIIa) to (IIIu), wherein "Ph" represents phenyl in each case and "Bu" represents butyl in each case, i.e. any of n-butyl, tert-butyl, isobutyl, or tert-butyl. "Mes" stands for 2,4,6-trimethylphenyl in each case, "Dipp" for 2, 6-diisopropylbenzene in each case and "Dimp" for 2, 6-dimethylphenyl in each case.

NHC-ligands contain not only one "N" (nitrogen) but also one "O" (oxygen) in the ring, which makes the substitution pattern of R8, R9, R10 and/or R11 more prone to provide some degree of steric crowding.

Y is selected from O, S, N-R¹Or P-R¹Group, wherein R¹One or more selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulfonate and alkylsulfinyl; these substituents may be optionally substituted with one or more alkyl, halogen, alkoxy, aryl or heteroaryl groups.

Preferably, the substituent R¹Typically C1-C30-alkyl, C3-C20-cycloalkyl, C2-C20-alkenyl, C2-C20-alkynyl, C6-C24-aryl, C1-C20-alkoxy, C2-C20-alkenyloxy, C2-C20-alkynyloxy, C6-C24-aryloxy, C2-C20-alkoxycarbonyl, C1-C20-alkylamino, C1-C20-alkylthio, C6-C24-arylthio, C1-C20-alkylsulfonyl or C1-C20-alkylsulfinyl, which substituents may be optionally substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl groups.

R1 is more preferably C3-C20-cylcopakyl, C6-C24-aryl or a linear or branched C1-C30-alkyl radical, the latter being able, where appropriate, to be interrupted by one or more double or triple bonds or one or more heteroatoms, preferably oxygen or nitrogen. R1 is particularly preferably a straight-chain or branched C1-C12-alkyl radical.

Among these, C3-C20-cycloalkyl includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl.

A C1-C12-alkyl radical may be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, n-hexane, n-heptyl, n-octyl, n-decyl or n-dodecyl. In particular, R1 is methyl or isopropyl.

C6-C24-aryl is an aromatic radical having from 6 to 24 skeletal carbon atoms. As preferred monocyclic, bicyclic or tricyclic carbocyclic aryl groups containing from 6 to 10 skeletal carbon atoms, can be synthesized from benzene, biphenyl, naphthalene, phenanthrene, anthracene or anthracene.

In the present invention, R²、R³、R⁴And R⁵Independently selected from hydrogen radicals, organic radicals or inorganic radicals;

in a suitable embodiment, R2, R3, R4, R5 are the same or different and each can be hydrogen, halogen, nitro, CF3, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, hydroxyethylaryl sulfide, alkylsulfonyl, or alkylsulfinyl, which substituents can be optionally substituted with one or more alkyl, alkoxy, halogen, aryl, or heteroaryl groups.

R2, R3, R4, R5 are generally identical or different and may each be hydrogen, halogen, preferably chlorine or bromine, nitro, CF3, C1-C30-alkyl, C3-C20-alkynyloxy, C2-C20-alkenyl, C2-C20-alkynyl, C6-C24-aryl, C1-C20-alkoxy, C2-C20-alkenyloxy, C2-C20-alkynyloxy, C6-C6-aryloxy, C6-C6-alkoxycarbonyl, C6-C6-alkylamino, C6-C6-alkylthio, C6-C6-arylthio, C6-C6-alkylsulfonyl or C6-C6-alkylsulfinyl, these substituents may be substituted by one or more C6-C6-alkyl, C6-C6-alkoxy, halogen, C6-C24-aryl or heteroaryl.

In a particularly preferred embodiment, R2, R3, R4, R5 are identical or different and may each be nitro, straight-chain or branched C1-C30-alkyl, C5-C20-cylcoakyl, straight-chain or branched C1-C20-alkoxy or C6-C24-aryl, preferably phenyl or naphthyl. The C1-C30-alkyl groups and C1-C20-alkoxy groups may be interrupted by one or more double or triple bonds or one or more heteroatoms, preferably oxygen or nitrogen.

Furthermore, two or more of the groups R2, R3, R4 or R5 may also be linked by an aliphatic or aromatic structure. For example, R3, R4, and the carbon atoms to which they are attached on the phenyl ring in the formula (B), can form a fused phenyl ring, and in general, a naphthyl structure results.

According to the invention, R⁶One or more selected from hydrogen radical, alkyl, alkenyl, alkynyl and aryl(ii) a R6 is preferably selected from hydrogen, C1-C30-alkyl groups, C2-C20-alkenyl groups, C2-C20-alkynyl groups or C6-C24-aryl groups; r6 is particularly preferably hydrogen.

The source of the group VIII metal compound of the structure of the formula (I) is not limited in the present invention, and it can be commercially available or prepared by a method disclosed in the prior art.

Such as the methods disclosed in US-A-2008/0064882, US-A2009/0076226, J.Am.chem.Soc,2000,1228168-.

The group VIII metal compound represented by the formula (I) is most preferably selected from one or more of a Hoveda-Grubbs II catalyst and a Graela (grela) catalyst.

The structural formula of the Holveda-Grubbs II catalyst is shown as a formula a;

HoledA-Grubbs II (HoveydA-Grubbs II) (CAS:301224-40-8, see, e.g., US-A-2008/0064882, US-A2009/0076226, J.am. chem. Soc,2000, 1228168-. Chinese name: (1,3-bis (2,4,6-trimethylphenyl) -2-imidazolidinylidene) dichloro (o-isopropoxybenzylidene) ruthenium, english name: (1,3-bis- (2,4,6-trimethylphenyl) -2-imidozolidin-2-ylidine) dichoro (o-isopropylphenyl methyl) ruthenaum.

The invention provides application of a metal compound based on the VIII group in the structure of the formula (I) in catalysis of hydrogenation reaction of conjugated diene latex. The method is an organic solvent-free hydrogenation method; the catalyst system can effectively hydrogenate the latex; and any organic solvent and any catalytic assistant are not used, so that the industrial cost is reduced, and the method is beneficial to green chemical industry. The reaction rate is accelerated, the use amount of the catalyst is greatly reduced, the cost can be reduced, the reaction condition is mild, the reaction efficiency is high, and the rapid industrialization can be realized.

The conjugated diene rubber latex of the invention is hydrogenated with a metal compound catalyst of the VIII family shown in the formula (I) to obtain the hydrogenated polymer.

The invention firstly adds polymer latex and catalyst into a reaction kettle with a temperature control device, a stirrer and a hydrogen gas adding point, and then carries out degassing for hydrogenation reaction.

According to the invention, the mass percentage of the catalyst in the conjugated diene rubber latex is preferably 0.0001-5 wt%; more preferably 0.001 to 0.009 wt%.

The preferable hydrogenation temperature is 35-200 ℃; more preferably 60 to 200 ℃; most preferably 80-180 ℃; most preferably 90-160 ℃; the hydrogenation reaction time is preferably 10 min-24 h; more preferably 15min to 20 h; most preferably 30 min-8 h; most preferably 1-4 h; the time can be 1-3 h. The hydrogenation pressure is 0.5-35 Mpa; more preferably 3-10 Mpa; the hydrogen is substantially pure hydrogen.

The latex system is preferably degassed with an inert gas, preferably argon, prior to the hydrogenation reaction described herein; the latex system is degassed with argon before hydrogenation, preferably at a pressure of 0.1 to 6MPa, more preferably at a pressure of 0.5 to 4MPa, more preferably at a pressure of 1 to 3MPa, most preferably at a pressure of 1.2 to 2.5 MPa. The degassing time is preferably 10min to 300min, more preferably 20min to 240min, most preferably 30min to 120min, and most preferably 50min to 70 min. The degassing temperature is preferably from 0 to 50 ℃, more preferably from 10 to 30 ℃, most preferably 25 ℃.

In general, the hydrogenation process of the invention can be carried out in a suitable reactor equipped with a temperature regulator and stirring means. According to the invention, the polymer latex can be fed to the reactor, optionally degassed, and the catalyst can then be added in pure raw material form or in some cases in solution with a small amount of organic solvent, and the reactor is then pressurized with hydrogen, or in an alternative embodiment the reactor can be pressurized with hydrogen and the catalyst can be added in pure raw material or solution or, according to the invention, the catalyst can be fed in pure raw material form to the reactor, and the polymer latex can then be fed to the reactor and optionally degassed.

Generally, according to the present invention, no catalyst promoter is used. When the hydrogenation reaction is complete to the desired extent, the reaction vessel may be cooled and vented. The resulting hydrogenated latex may be used in the form of a latex or coagulated and washed as necessary to obtain a hydrogenated polymer in a solid form.

According to the invention, the conjugated diene rubber latex is obtained by polymerization of diene monomer and comonomer; the conjugated diene rubber latex is added in several times; preferably, the two additives are added in two times, wherein the weight ratio of the two additives is preferably 10: 1-1: 10, and most preferably 1: 1. namely adding latex, adding catalyst and then adding latex.

According to the invention, the latex is added in batches, so that the catalyst has better performance and dispersion and better catalytic effect.

According to the invention, the conjugated diene latex is obtained by polymerization of a diene monomer and a comonomer.

Wherein the diene monomer comprises at least one conjugated monomer D; the diene monomer is preferably selected from (C4-C6) conjugated dienes; more preferably one or more selected from 1, 3-butadiene, isoprene, 1-methylbutadiene, 2, 3-dimethylbutadiene, piperylene and chloroprene; 1, 3-butadiene and isoprene or mixtures thereof are particularly preferred. 1, 3-butadiene is very particularly preferred.

The comonomer is selected from one or more of acrylonitrile, methacrylonitrile, styrene, α -methyl styrene, propyl acrylate, butyl acrylate, propyl methacrylate, butyl methacrylate, fumaric acid, maleic acid, acrylic acid and methacrylic acid.

Conjugated diene D constitutes from 15% to 100% by weight of the polymer containing carbon-carbon double bonds in latex form if a copolymerizable monomer a is used and is selected from styrene and α -methylstyrene, the styrene and/or methylstyrene monomers preferably constitute from 15% to 60% by weight of the polymer, if other copolymerizable monomers a are used and are selected from acrylonitrile and methacrylonitrile, the acrylonitrile and/or methacrylonitrile monomers preferably constitute from 15% to 50% by weight of the polymer and the conjugated diene constitutes from 50% to 85% by weight of the polymer.

If other copolymerizable monomers A are used and are selected from acrylonitrile and methacrylonitrile and additionally from unsaturated carboxylic acids, the acrylonitrile or methacrylonitrile constitutes from 15% to 50% by weight of the polymer, the unsaturated carboxylic acids constitute from about 1% to 10% by weight of the polymer and the conjugated dienes constitute from 40% to 85% by weight of the polymer.

Preferred products of the invention include styrene-butadiene polymers, butadiene-acrylonitrile polymers and butadiene-acrylonitrile-methacrylic acid polymers, either random or block type. Preferred butadiene-acrylonitrile polymers have an acrylonitrile content of about 15 wt% to about 50 wt%.

The NBR latex of the invention is preferably Ningbo cis latex.

Particularly suitable copolymers are nitrile rubbers (nitrile rubber), which are copolymers of α -unsaturated nitriles, preferably acrylonitrile, and conjugated dienes, particularly preferably 1, 3-butadiene, and optionally one or more other copolymerizable monomers, for example α -unsaturated monocarboxylic or dicarboxylic acids, their esters or amides.

As the α -unsaturated monocarboxylic or dicarboxylic acid in such a nitrile rubber, fumaric acid, maleic acid, acrylic acid and methacrylic acid are preferred.

As the ester of α -unsaturated carboxylic acid in such nitrile rubbers, it is preferred to use their alkyl esters or alkoxyalkyl esters, the particularly preferred alkyl esters of α -unsaturated carboxylic acids are methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, t-butyl acrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and octyl acrylate, the particularly preferred alkoxyalkyl esters of α -unsaturated carboxylic acids are methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and methoxyethyl (meth) acrylate.

Preferred terpolymers are those of acrylonitrile, 1, 3-butadiene and a third monomer selected from fumaric acid, maleic acid, acrylic acid, methacrylic acid, n-butyl acrylate and t-butyl acrylate.

The synthesis of the polymers of the invention can be carried out using the latex form. The solid content of the conjugated diene rubber latex is preferably 10-30%; more preferably 10 to 25%.

The reaction is preferably carried out in a reaction kettle; the reaction kettle adopts a polytetrafluoroethylene lining.

The degree of hydrogenation of the carbon-carbon double bonds in the hydrogenated polymer of the invention is at least 50%, preferably from about 70 to 100%, more preferably from 80 to 100%, still more preferably from 90 to 100%, most preferably from 95 to 100%

The invention provides a selective hydrogenation method of conjugated diene rubber latex, which comprises the following steps: carrying out hydrogenation reaction on conjugated diene latex and a VIII family metal compound catalyst shown in a formula (I) to obtain a hydrogenated polymer; the solid content of the conjugated diene rubber latex is 10-30%. The invention adopts the metal compound catalyst of the VIII family shown in the formula (I) to catalyze the conjugated diene latex and hydrogenate the emulsion, and the catalyst does not use any cocatalyst and any organic solvent in the using process, nor uses any substance except the catalyst; compared with the prior art, the catalyst has high hydrogenation efficiency on NBR latex and low catalyst usage amount; the hydrogenation condition of the catalyst is not harsh, the temperature and the pressure are not high, the catalytic activity of the catalyst on latex is high under mild temperature and pressure, the catalytic efficiency is high, and the rapid industrialization can be realized.

In order to further illustrate the present invention, the following examples are provided to describe the selective hydrogenation method of conjugated diene latex and the application of the group VIII metal compound catalyst.

Examples table of basic materials

Example 1

Holvela-grubbs II catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 23.6% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.000236g of Holveda-Grubbs II catalyst. The latex was then degassed with argon at 30 deg.C under 2MPa for 50min, the temperature was raised to 100 deg.C, and the hydrogen pressure was raised to 1000psi (6.89MPa) for 10 h. After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 96.4%. The reaction produced a gel of about 0.1%.

Example 2

Gray catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 23.6% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.00118g of Gray Rad catalyst. The latex was then degassed with argon at 30 deg.C under 2MPa for 50min, the temperature was raised to 100 deg.C, and the hydrogen pressure was raised to 1000psi (6.89MPa) for 10 h. After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods

The results show that after 10 hours, the degree of hydrogenation reached 94.8%. The reaction produced a gel with a gel content of 0.1%.

Example 3

Holvela-grubbs II catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 11.8% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.000118g of Holveda-Grubbs II catalyst. The latex was then degassed with argon at 30 deg.C under 2MPa for 50min, the temperature was raised to 100 deg.C, and the hydrogen pressure was raised to 1000psi (6.89MPa) for 10 h. After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 94.6%. The reaction produced a gel of about 0.2%.

Example 4

Gray catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 11.8% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.00059g of Gray Rad catalyst. The latex was then degassed with argon at 30 deg.C under 2MPa for 50min, the temperature was raised to 100 deg.C, and the hydrogen pressure was raised to 1000psi (6.89MPa) for 10 h. After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods

The results show that after 10 hours, the degree of hydrogenation reached 92.3%. The reaction produced a gel with a gel content of 0.1%.

Comparative example 1

Holvela-grubbs II catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 60% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.00006g of Holveda-Grubbs II catalyst. The latex was then degassed with argon. The temperature was raised to 100 ℃ and the hydrogen pressure increased to 1000psi (6.89 MPa). After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 69.3%. The reaction produced a gel with a gel content of 0.1%.

Comparative example 2

Holvela-grubbs II catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 40% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.0004g of Holveda-Grubbs II catalyst. The latex was then degassed with argon. The temperature was raised to 100 ℃ and the hydrogen pressure increased to 1000psi (6.89 MPa). After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours the degree of hydrogenation reached 76.7%. The reaction produced a gel with a gel content of 0.2%.

Comparative example 3

Holvela-grubbs II catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 6% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.00006g of Holveda-Grubbs II catalyst. The latex was then degassed with argon. The temperature was raised to 100 ℃ and the hydrogen pressure increased to 1000psi (6.89 MPa). After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 65.2%. The reaction produced a gel with a gel content of 0.1%.

Comparative example 4

Gray catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 60% by weight. The average diameter of the polymer particles in the latex was about 88 nm. The reactor was charged with 100ml of this latex, 0.003g of Gray Rad catalyst. The latex was then degassed with argon. The temperature was raised to 100 ℃ and the hydrogen pressure increased to 1000psi (6.89 MPa). After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 67.2%. The reaction produced a gel with a gel content of 0.1%.

Comparative example 5

Gray catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 40% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.002g of Gray Rad catalyst. The latex was then degassed with argon. The temperature was raised to 90 ℃ and the hydrogen pressure increased to 1000psi (6.89 MPa). After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 72.3%. The reaction produced a gel with a gel content of 0.3%.

Comparative example 6

Gray catalyst

A300 mL Teflon high pressure reactor (Parrinstruments) with temperature control, stirrer and hydrogen addition point was used. A cis-butadiene-acrylonitrile polymer latex having an acrylonitrile content of about 33% by weight and a Mooney viscosity (ML1+4@100 ℃ C.) of 55 was used. The latex had a solids content of 6% by weight. The average diameter of the polymer particles in the latex was about 88 nm. A reactor was charged with 100ml of this latex, 0.0003g of Gray Rad catalyst. The latex was then degassed with argon. The temperature was raised to 90 ℃ and the hydrogen pressure increased to 1000psi (6.89 MPa). After the reaction was completed, the hydrogenated NBR latex was coagulated with ethanol to obtain an HNBR copolymer. The coagulum was then dissolved in MEK for analysis of the degree of hydrogenation. The degree of hydrogenation was measured using a FT-IR instrument and calculated using standard methods.

The results show that after 10 hours, the degree of hydrogenation reached 63.2%. The reaction produced a gel with a gel content of 0.1%.

TABLE 1 comparison of hydrogenation results for catalysts of the examples of the invention

Examples 5 to 8

The preparation processes of the embodiments 1 to 4 are respectively carried out, except that the latex is added in two batches, and the adding modes of the catalyst and the latex are as follows: 50mL of latex was added, catalyst was added, and 50mL of latex was added.

The hydrogenation degree of the products obtained in examples 5 to 8 was measured according to the test method of example 1, and the results are shown in Table 2.

TABLE 2 hydrogenation effect of catalysts of examples 5 to 8 of the present invention

As can be seen from Table 2, after the latex is added in batches, the hydrogenation time of 8 hours can reach the hydrogenation degree of 10 hours when the latex is added at one time, and compared with the addition of the latex and the latex at one time, the addition of the latex in batches can improve the dispersibility of the catalyst, so that the catalyst can better contact rubber latex particles, and the hydrogenation degree is improved.

Comparative examples 7 to 12

The preparation processes of comparative examples 1 to 6 were carried out, respectively, except that the latex was added in two batches, and the catalyst and latex were added in the following manner: 50mL of latex was added, catalyst was added, and 50mL of latex was added.

The hydrogenation degree of the products obtained in examples 5 to 8 was measured according to the test method of example 1, and the results are shown in Table 3.

TABLE 3 hydrogenation effect of catalysts of comparative examples 7 to 12 of the present invention

As can be seen from the comparison between tables 3 and 2, after the latex is added in batches, the hydrogenation time of 8 hours can reach the hydrogenation degree of 10 hours when the latex is added at one time, so that the dispersity of the catalyst can be improved by adding the latex in batches, the hydrogenation activity of the catalyst can be increased, and the hydrogenation degree can be improved.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A method for selectively hydrogenating a conjugated diene latex, comprising:

wherein M is a group VIII metal element,

X¹and X²Independently selected from the group consisting of anionic ligands,

l is an uncharged electron donor,

2. The method according to claim 1, wherein the hydrogenation temperature is 35 to 200 ℃; the hydrogenation reaction time is 10 min-24 h; the hydrogenation pressure is 0.5-35 Mpa.

3. The method of claim 1, wherein the conjugated diene latex is polymerized using diene monomers and comonomers.

4. The method of claim 3, wherein the diene monomer is selected from one or more of 1, 3-butadiene, isoprene, 1-methylbutadiene, 2, 3-dimethylbutadiene, piperylene and chloroprene, and the comonomer is selected from one or more of acrylonitrile, methacrylonitrile, styrene, α -methylstyrene, propyl acrylate, butyl acrylate, propyl methacrylate, butyl methacrylate, fumaric acid, maleic acid, acrylic acid and methacrylic acid.

5. The method according to claim 1, wherein the group VIII metal compound of formula (I) is selected from one or more of the group consisting of Hoveda-Grubbs II catalyst and Graela (grela) catalyst.

6. The method according to claim 1, wherein the catalyst is 0.0001 to 5 wt% of the conjugated diene rubber latex;

the solid content of the conjugated diene rubber latex is 10-25%.

7. The method according to claim 1, wherein M is osmium or ruthenium;

8. The method according to claim 7, wherein X is¹Selected from chlorine, CF₃COO、CH₃COO、CFH₂COO、(CH₃)₃CO、(CF₃)₂(CH₃)CO、(CF₃)(CH₃)₂CO, phenoxy, methoxy, ethoxy, tosylate (p-CH)₃-C₆H₄-SO₃) Methanesulfonic acid (CH)₃SO₃) Or trifluoromethanesulfonate (CF)₃SO₃)；

L is a structure represented by formula (II-a) to formula (II-f):

R¹²、R¹³and R¹⁴Independently selected from C1-C20 alkyl.

9. The process of claim 1, wherein the reaction is carried out in a reaction kettle; the reaction kettle adopts a polytetrafluoroethylene lining.

10. The method of claim 1, wherein the reacting further comprises degassing the latex with argon; the degassing pressure is 0.1-6 MPa; the degassing time is 10min-300 min; the degassing temperature is 0-50 ℃.