NO167748B - PROCEDURE FOR FREE-RADICAL-MASS, SOLUTION, SUSPENSION OR EMULSION POLYMERIZATION OF MONOMERS. - Google Patents

Description

The invention relates to a method for free-radical mass, solution or emulsion polymerization of monomer, which comprises bringing monomer into contact with initiator, solvent and suspending or emulsifying agent, in the presence of an agent for regulating molecular weight.

In any polymerization process, it is necessary to be able to regulate the molecular weight of the produced polymer so that it can suit a specific use or a specific need. By e.g. undisturbed polymerization systems which in principle tend to give polymers with a high molecular weight, it may be desirable or necessary to limit the molecular weight of the polymers produced, and this must be done in a predictable and controllable manner. Such molecular weight limitation may be desirable or necessary in the production of polymer solutions for use in paints and varnishes which require high solids content to ensure reduced release of solvent during application, and which nevertheless require low viscosity to facilitate rapid application.

In free-radical polymerizations, there are conventional ways to effect such molecular weight limitation,

but all have noticeable drawbacks. These include:

(1) Use of a high initiator/monomer ratio, but this is costly in terms of initiator consumption. (2) Polymerization at high temperatures, e.g. about.

150°C, which is undesirably energy-intensive.

(3) Addition of stoichiometric amounts of thiol chain transfer agents to the polymerization system, but the concomitant incorporation of sulfur-containing agents into the polymer makes it less durable than desirable. (4) Odor problems associated with the use of sulfur-containing chain transfer agents.

Catalytic chain transfer to the monomer as a means of controlling molecular weight in the radical polymerization of methyl methacrylate and styrene in the presence of cobalt(II) porphyrin complexes is known in the art. N. S. Enikolopyan et al., J. Polym. Sei., Polym. Chem. Ed., vol. 19, 879 (1981) describes the kinetics and molecular weight control achieved by the free radical polymerization of methyl methacrylate in the presence of a cobalt complex of hematoporphyrin tetramethyl ether. The use of this cobalt complex is also discussed by B.R. Smirnov et al. in Vysokomol. soyed., A2_3, No. 5, 1042

(1981) and by B.R. Smirnov et al. in Doc. Acad. Nauk SSSR, 253, 891 (1980). In a similar investigation, B.R. describes Smirnov et al., Doc. Acad. Nauk SSSR, 254, 127 (1980) studies carried out with hematoporphyrin tetramethyl ester. The authors conclude that only the combination of cobalt and a tetrapyrroleporphyrin ligand apparently allows the realization of catalysis of chain transfer to the monomer, and that it has been ruled out that analogous phenomena will be discovered by the investigation of complexes that resemble the porphyrins in terms of spatial and electronic structure , such as phthalocyanines, corrines, cobaloximes etc. B.R. Smirnov et al., Vysokomol. soyed., A23, No. 11, 2588 (1981) describes the catalytic chain transfer observed in the radical polymerization of styrene in the presence of a cobalt complex of the tetramethyl ester of hematoporphyrin IX. THE. Pashchenko et al., Doc. Acad. Nauk SSSR, 265, 889 (1982) describes chain transfer studies with cobalt porphyrins in the polymerization of methyl methacrylate. As far as this reference is concerned, it is not understood what is meant by "cobalt complexes of porphyrins and cobalt oximes", as there is no further indication of "cobalt oximes" in the English language version of the article; moreover, the term "cobalt oximes" does not appear in the original Russian text, but instead the term "cobalt amines", which are vitamin B]_2-related structures that resemble the porphyrin structures described in this article and in the other publications listed above. Although the use of porphyrin complexes circumvents many of the problems associated with the previously mentioned common commercial methods, the complexes add too much color to the final product and render it unusable or less desirable in many applications, such as in certain paints and varnishes. Moreover, the cost of the porphyrin complex is quite high. A. F. Burczyk et al., J. Polym. Sei., Polym. Chem. Ed., vol. 22, 3255 (1984) reveals that cobalt oximes, i.e. bis-dimethylgloximatocobalt complexes, are often used as analogues of cobalt porphyrins in research studies, and that they further include the use of cobalt oxime, synthesized from Co(II) acetate and dimethylglyoxime as a relatively inexpensive chain transfer agent by the free-radical polymerization of methyl methacrylate. The cobalt oxime of Burczyk et al. is shown on page 3256 with the following formula

where B is a coordinating base ligand, such as triphenylphosphine. Similar descriptions have been made by A.F. Burczyk in a thesis for the University of Waterloo, Waterloo, Ontario, 1984.

In the U.S. patent document no. 4 526 945 also describes the use of cobalt(II)-dimethylgloxime and similar cobalt(II)-dioxime pyridine complexes, such as those derived from 2,3-butanedione, 2,3-hexanedione, 2,4 -heptanedione, 2,5-dimethyl-3,4-hexanedione, 3-methyl-2,4-hexanedione, 1,2-cyclohexanedione, 3-phenyl-2,4-pentanedione, 2-naphthylglyoxal, camphorquinone, 4-chloro -1,2-benzoquinone, 1,2-naphthoquinone, 3,7-dimethyl-1,2-naphthoquinone, 3-chloro-1,2-naphthoquinone or substituted 1,2-anthraquinones as molecular weight regulating agents in homogeneous polymerizations.

H.C. Rai et al., Indian Journal of Chemistry, vol. 18A, 242 (1979) describes the preparation of the cobalt chelates of cobalt(II) and 4,7-diaza-2,9-dihydroxyimino-3,8-dimethyl-deca-3,7-diene and cobalt(II) and 4,8 -diaza-2,10-dihydroxy-imino-3,9-dimethylundeca-3,8-diene. There is no description of the use of these compounds as catalytic chain transfer agents. E. Uhlig et al., Z. anorg. general Chem., 343, 299 (1966) describes the preparation of the ligands 4,7-diaza-2,9-dihydroxyimino-3,8-dimethyldeca-3,7-diene and 4,8-diaza-2,10-dihydroxyimino-3,9-dimethylundeca -3,8-diene.

J. Bremer et al., J. prakt. Chem., 323, 857 (1981) describes the preparation of the chelate of cobalt(II) and 1,4,8,11-tetra-aza-2,3,9,10-tetramethyl-1,3,8,10-cyclotetradecatetraene (TTCT). G. N. Schrauzer, Inorg. Syn., 11, 62, 64 (1968) describes the preparation of diaqua-bis(2,3-dihydroxyimino-butanato)Co(II) and chloropyridino-bis(2,3-dihydroxyimino-butanato)CO(IIl). A. Bakac et al., J. Am. Chem. Soc, 106, 5197 (1984) describes the preparation of Co(II)(2,3-dioxyiminobutane-BF2)2(H2O)2•

The purpose of the invention is to provide a method for free-radical mass, solution or emulsion polymerization of monomer using cobalt chelates of vicinal iminohydroxyimino compounds, dihydroxyimino compounds, diazadihydroxyimino- • dialkyldecadienes, diazadihydroxyiminoalkylundedecadienes,_ tetraazatetraalkylcyclotetradecatetraenes, tetraazatetra-alkylcyclododecatetraenes, N , N'-bis(salicylidene)ethylenediamines, dialkyldiazadioxodialkyldodecadienes and dialkyldiazadioxodialkyltridecadienes which act as highly effective catalytic chain transfer agents for controlling homopolymer and copolymer molecular weights while imparting very little, if any, color to the final products, making them more useful in many applications, such as in paints and varnishes.

The procedure takes place at moderate temperatures, e.g. 65-110°C, with limited amounts of initiator and in the absence of stoichiometrically reacting chain transfer agents.

The present invention thus provides a method by free-radical mass, solution, suspension or emulsion polymerization of monomer, preferably monomer selected from: methacrylate, acrylate. acrylic acid, styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl halides of formula CH2=CHX, where X is Cl or F, vinylidene halides of formula CH2=C(X)2, where each X, independently of each other is Cl or F, substituted butane- dienes of the formula CH2=C(R)C(R)=CH2, where each R, independently of one another, is H, C1_10~alkyl, Cl or F, ethylene sulfonic acid derivatives of the formula CH2=CHS03X where X is Na, K, Li, N(R)4, H, R or (CH2)nZ, where each R is independently C1_10_alkyl, n is an integer from 1-10, Z is COOY, OH, N(R)2 or SO3Y and Y is H, Li, Na, K or N(R)4, acrylamide derivatives of formula CH2=CHCON(R)2 where each R, independently of each other is H, C^^ø-alkyl, or (CH2)nZ, n is an integer from 1-10, Z is COOY, OH, N(R)2 or SO3Y and Y is H, Li, Na, K or N(R)4, methacrylamide derivatives of the formula CH2=C(CH3)CON(R )2, where each R, independently of one another is H, C₁-LQ alkyl or (CH2)nZ, n is an integer from 1-10, Z is COOY, OH, N(R)2, SO3Y and Y is H, Li, Na, K or N(R) 4, vinyl acetates of formula CH 2 =CHOOCR where R is C 1-6 -alkyl, and mixtures thereof, which comprise bringing monomer into contact with initiator, solvent and suspending or emulsifying agent, in the presence of an agent for regulating molecular weight.

The method is characterized by the fact that a cobalt chelate chain transfer agent with the formula is used as the agent for regulating molecular weight

or where each R, independently of each other, is phenyl or C\-\ 2~ alkyl where each α-carbon atom contains two hydrogen atoms, i.e. is unsubstituted, or R and R on adjacent carbon atoms together are C5_s-cycloalkylene, unsubstituted in a the -positions, -CH=CH-CH=CH-, orR<2> is H or <C>xH2x+1 where x is 1-12; each R<4>, independently of one another, is H or CxH2x+i where x is 1-12, or both R<4> groups together are -0-Z 0-; n is 2 or 3; Z is BF2, BC12, BBr2 or BR2, and X" is NO3", Cl", Br", I", BF4", PF6", SbF6" or R8COO" where R<8> is C]__]_2~alkyl .

where R, R 2 , n and X have the meanings given above for the chain transfer agent, and where R < 3 >, independently of each other, is H or branched or straight-chain C 3 -alkyl, R 6 is 0 or

NH; however, under the condition that either each or both of the aromatic rings in XII is optionally substituted with a benzo group and optionally contains up to four substituents.

The invention lies in polymerization processes where cobalt (II) chelates are used as catalytic chain transfer agents for regulating the molecular weights of the homopolymers and copolymers produced. The cobalt chelates consist of cobalt(II) semipolarly bound to the following ligands: vicinal iminohydroxyimino- and dihydroxyiminophorbin compounds (I) and (III), diazadihydroxyiminodialkyldecadienes and

-undecadienes (II), tetraazatetraalkylcyclotetradecatetraenes and -dodecatetraenes (V), N,N'-bis(salicylidene)ethylenediamines (IV) and dialkyldiazadioxodialkyldodecadienes and -tridecadienes (VI). By "ligand", as the term is used herein, is meant any atom, radical or molecule that can be bound to a characteristic or central element in a complex. The structural formulas for the above-mentioned ligands are reproduced below. In the formulas given above, each R is, independently of one another, phenyl or C^- to C12-alkyl where each α-carbon atom contains two hydrogen atoms, i.e. is unsubstituted, and R and R on adjacent carbon atoms together are C5~ to C3 -cycloalkylene, unsubstituted in the a-positions, -CH=CH-CH=CH-,

each R<1>, independently of one another, is H, CxH2X+i where x is 1_ 12, or OH, at least one being OH; R<2> is H or Cx<H>2X+i

where x is 1-12; each R 1 is, independently, H or branched or straight chain C 1- to C 12 alkyl; R<5> is OH or NH2 and n is 2 or 3. Further to structural formula V, any or both of the aromatic rings may be unsubstituted or substituted with up to four substituents compatible with the use of the complex as a chain transfer agent. Examples of such substituents include OR<2>, -NR<2>, -Cl, -Br, -I, -NO2

7 7 2

and -R' where R' is CxH2x+i where x is 1-12. In addition, any or both of the aromatic rings may be substituted with a benzo group to form a naphthalene derivative. The corresponding structural formulas for the cobalt chelates of these ligands are given below. More specifically, VII is the cobalt chelate corresponding to structural formula I, VIII and X correspond to structural formula II, IX corresponds to structural formula III, XI corresponds to structural formula IV, XII corresponds to structural formula V and XIII corresponds to structural formula VI.

In the formulas VII-XIII, R, R<2>, R<3>, R4, R6, Z, n, X", x and R<8> are as defined previously. The cobalt chelates with the above formulas can also, but need not not, be semipolarly bound to additional ligands derived from materials present in the reaction medium, such as water, alcohols, or ketones.As for structural formula XII, any or both of the aromatic rings may be unsubstituted or substituted, as described above for structural formula V.

Preparation of the various ligands and corresponding cobalt chelate compounds of formulas VII-XIII can be carried out using methods known in the art, such as those set forth in H.C. Rai et al., Indian Journal of Chemistry, vol. 18A, 242, (1979); E. Uhlig et al., Z. anorg. general Chem., 343, 299 (1966); G. N. Schrauer, Inorg. Syn., 11., 62, 62 (1968); J. Bremer et al., J. prakt. Chem., 323, 857 (1981); P. J. McCarthy et al., J. Am. Shem. Soc, 22, 5820 (1955) and A. Bakac et al., J. Am. Chem. Soc, 106, 5197 (1984).

As will be apparent to those skilled in the art, these chelates can also be prepared in situ from appropriate reactants. The in situ fabrication is demonstrated in a number of the examples below.

Cobalt chelate compounds of formulas VII and VIII can be used in polymerizations carried out either in the absence of a polymerization medium, such as a bulk polymerization, or alternatively in the presence of a polymerization medium, such as a solution, suspension or emulsion polymerization. Monomers which can be used in such polymerizations include methacrylate, acrylate, acrylic acid, styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl halides of the formula CH2=CHX where X is Cl or F; vinylidene halides of the formula CH2=C(X)2 where each X, independently of one another, is Cl or F; substituted butadienes of the formula CH 2 =C(R)C(R)=CH 2 where each R, independently of one another, is H, C 1 - to C 1 -q alkyl, Cl or F; ethylene sulfonic acid derivatives of formula CH2=CHS03X where X is Na, K, Li, N(R)4, H, R or (CH2)nZ, each R is, independently of one another, C]_- to C]_o~alkyl, n is an integer from 1-10, Z is COOY, OH, N(R)2 or SO3Y and Y is H, Li, Na, K or N(R)4; acrylamide derivatives of the formula CH2=CHCON(R)2 where each R, independently of one another, is H, C]- to <C>10-alkyl or (C<H>2)nZ, n is an integer from 1- 10, Z is COOY, OH, N(R)2 or SO3Y and Y is H, Li, Na, K or (N)R4; methacrylamide derivatives with the formula CH2=C(CH3)CON(R)2 where each R, independently of each other, is H, C2- to C10-alkyl or (CH2)nZ, n is an integer number from 1-10, Z is COOY, OH, N(R)2 or SO3Y and Y is H, Li, Na, K or (N)R4; vinyl acetates of the formula CH2=CHOOCR where R is C1- to C10-alkyl; and with any and all monomer mixtures thereof.

The bulk and solution polymerizations using compounds VII and VIII are most efficiently carried out with styrene, methacrylate ester and methacrylonitrile monomers. The suspension and emulsion polymerizations are carried out most efficiently with methacrylate ester monomers. Methacrylates which can be used in this invention include branched alkyl or n-alkyl esters of C 3 -alcohols and methacrylic acid, e.g. methyl and ethyl methacrylate. Other monomers include, but are not limited to, allyl, glycidyl, hydroxyalkyl (eg, hydroxyethyl and hydroxypropyl), allyloxyethyl, 2,4-hexadienyl (sorbyl), and dialkylaminoalkyl methacrylates. Among the chelates comprised by formulas VII and VIII, the preferred chain transfer agents are cobalt(II) salts which are semipolarly bound to the ligands of formula I where both R<4> groups together are -0-Z 0-. Most preferred are Co(II)(2,3-dioxyiminobutane-BF2)2» Co(II)(1,2-dioxyiminocyclohexane-BF2)2 and Co(II)(1,2-diphenyl-1,2-dioxy- iminoethane-BF2)2•

Polymerizations using cobalt chelate compounds of formulas IX-XIII can be carried out either in the absence of a polymerization medium, as in a bulk polymerization, or in the presence of a polymerization medium, as in a solution polymerization. Methods using compounds IX-XIII are carried out most effectively with styrene and methacrylate ester monomers, but acrylate esters can be included as comonomers together with the methacrylate esters and/or the styrene, without the advantages of the method according to the invention being reduced. Methacrylates which can be used in the invention include branched alkyl or n-alkyl esters of C1_j_2~ alcohols and methacrylic acid, e.g. methyl and ethyl methacrylate. Other monomers include, but are not limited to, allyl, glycidyl, hydroxyalkyl (eg, hydroxyethyl and hydroxypropyl), allyloxyethyl, 2,4-hexadienyl-(sorbyl), and dialkylaminoalkyl methacrylates. The preferred chain transfer agents among the chelates encompassed by formulas IX-XIII are the cobalt(II) salts semipolarly bound to the ligand 4,7-diaza-2,9-dihydroxyimino-3,8-di-methyldeca-3,7 - the day.

Many common organic solvents are suitable as solution polymerization media. These include aromatic hydrocarbons, such as benzene, toluene and the xylenes; ethers such as tetrahydrofuran, diethyl ether and the commonly available ethylene glycol and polyethylene glycol monoalkyl and dialkyl ethers, including the various Cellosolve® and Carbitol®; alkyl esters of acetic, propionic and butyric acids; mixed ester ethers, such as monoalkyl ether monoalkanoate esters of ethylene glycol; and amides, such as formamides and pentanone and hexanone, are suitable, as are alcohols, such as methanol, ethanol, propanol and butanol. Water can be used as a solvent for water-soluble monomers. In some cases it may be advantageous to use mixtures of two or more solvents.

In the case of emulsion and suspension polymerizations, the suitable medium is water mixed with any conventional suspending or emulsifying agent. Emulsifiers can be anionic, such as sodium dodecyl sulfate, or cationic, such as hexadecyltrimethylammonium bromide. The suspending agent used in the reaction may be Acrysol A-3, a polyacrylic acid produced by the Rohm & Haas Company.

Bulk and solution polymerizations can be carried out at 50-150°C, the preferred range being 80-110°C. The emulsion and suspension polymerizations can be carried out at 25-90°C, the preferred range being 65-80°C.

Any of the known class of azo polymerization initiators is suitable, provided it has solubility in the solvent, monomer mixture, or water, as the case may be, and has a suitable half-life at the polymerization temperature. "Appropriate half-life", as used here, is a half-life of approx. 1-4 hours. Typical of such initiators, but not limited to these, are azocumene, 2,2<1->azobis(isobutyronitrile), 2,2'-azobis-(2-methyl)-butanenitrile, 4,4'-azobis(4- cyanovaleric acid) and 2-(t-butyl-azo)-2-cyanopropane. Other suitable non-azo initiators with a suitable half-life may also be used, including, but not limited to, benzoyl peroxide, lauroyl peroxide, persulfates and molecular hydrogen.

The method according to the invention can be carried out either as a batch method or a method with addition. In both method types, the polymer is isolated by stripping off solvent and unreacted monomer, or by precipitation with a non-solvent. Alternatively, the polymer solution can be used as such if this is appropriate for the application.

To ensure maximum catalyst activity, the polymerizations should be carried out substantially in the absence of oxygen under an inert atmosphere, such as nitrogen, argon or other non-oxidizing gas. "Deaeration", as the term is used herein, essentially means the removal of oxygen.

The invention is further described in the examples below. The polymerizations described there were carried out mainly in accordance with the following general procedures, except where otherwise indicated. In the general procedures and examples, all parts are parts by weight and all temperatures are in °C, unless otherwise indicated. It should be noted that where values are less than 1000, molecular weight is difficult to determine with accuracy. Nevertheless, the decrease in molecular weight shown at these values is an accurate reflection of molecular weight regulation.

General procedures

A. Solution polymerization

In a nitrogen-containing drying vessel, 21.4 ml (0.2 mol) of methyl methacrylate, which had previously been bubbled through with nitrogen and passed through a column of Woelm alumina (fineness grade 1), was added to a 100 ml volumetric flask. To this was added the desired amount of cobalt catalyst, and the volume was brought to 100 ml with distilled methanol.

To a 300 mL round-bottomed flask was added 0.062 g (2.5 x 10"<4> mol) of 2,2-azobis(2-methyl)butanenitrile and the contents of the volumetric flask. The reaction mixture was then stirred to dissolve 2, 2'-azobis(2-methyl)butanenitrile, and a gas chromatography sample was withdrawn. The round-bottomed flask was closed with a water-cooled condenser, removed from the drying vessel, and heated to reflux under nitrogen for 6 hours. The reaction mixture was then allowed to cool to room temperature, and another gas chromatograph was sampled. The produced poly(methyl methacrylate) was isolated by removing solvent and monomer from the reaction mixture via a rotary evaporator. Gel permeation chromatography (GPC) was used to determine the weight average molecular weight (M^) and the quantity forged

clay molecular weight (Mn) of the produced polymer.

B. Suspension polymerization

In a nitrogen-containing drying vessel, 21.4 ml (0.2 mol) of methyl methacrylate, which had previously been bubbled through with nitrogen and passed through a column of Woelm alumina (fineness grade 1), 0.248 g (1.0 x 10"<3 > mol) of 2,2'-azobist2-methyl]-butanenitrile and the desired amount of cobalt catalyst placed in a 300 ml three-necked, round-bottomed flask equipped with a reflux condenser, a rubber membrane and a mechanical stirrer. The flask was removed from the drying vessel, and 60 ml aqueous Acrysol A-3 (prepared by adding 75.5 g of Acrysol A-3 to 1500 mL of water and degassing overnight) was added under a nitrogen atmosphere.The flask was placed in a bath at 65°, the stirrer set at 400 rpm, and the reaction was allowed to proceed for 2 hours. A nitrogen atmosphere was maintained in the flask throughout the course of the reaction. After the measured time, the reaction mixture was cooled to room temperature and the polymer collected by filtration. The polymer was washed with water and dried. GPC was used to determine 1^ and M n to the produced polymer.

C. Emulsion polymerization

In a nitrogen-containing drying vessel, 21.4 ml (0.2 mol) of methyl methacrylate, which had previously been bubbled through with nitrogen and passed through a column of Woelm alumina (fineness grade 1), 0.374 g of 4,4'-azobis(4- cyanovaleric acid) and the desired amount of cobalt catalyst placed in a 300 ml three-necked, round-bottomed flask equipped with a reflux condenser, a rubber diaphragm and a mechanical stirrer. The flask was removed from the drying vessel, and 60 mL of 0.1 M aqueous sodium dodecyl sulfate (degassed) was added under a nitrogen atmosphere. The flask was placed in a bath at 80°, the stirrer set at 400 rpm, and the reaction allowed to proceed for 4 hours. A nitrogen atmosphere was maintained in the flask during the course of the reaction. After the measured time, the reaction mixture was cooled to room temperature, and the polymer precipitated by adding 150 ml of methanol. The polymer was collected by filtration, washed with methanol, washed with water and air dried. GPC was used to determine and Mn of the produced polymer.

Examples 1-3

A. Preparation of [Co(II)(DHIB-BF?)2(H?0)?]

[DHIB = 2,3-dioxyiminobutane]

The title compound was prepared by the method of A. Bakac et al., J. Am. Chem. Soc, 106, 5197-5202 (1984).

The suspension obtained after the addition of 10 ml of BF 3 .Et 2 to 2 g of Co(OAc) 2 -4H 2 O and 1.9 g of 2,3-dihydroxyimino-butane in 150 ml of diethyl ether was stirred at room temperature overnight. The resulting solid [Co(II)(DHIB-BF2)2(H2O)2] was collected by filtration, placed in 250 mL of methanol and heated to reflux. The solid that did not dissolve was removed by filtration (0.336 g). The remaining clear solution was placed in a freezer overnight. The crystallized product was recovered by filtration and dried (0.468 g). The remaining solution was reduced to a volume of 30 ml under vacuum and placed in a freezer (+25°C) overnight. An additional 0.101 g of product was recovered. The infrared spectra of the product showed bands at 3581 cm-<l> (H2O) and 1623 cm-<l>, 950 cm-<1> (BF).

B. The Use of [Co(II) (DHIB-BF2)<2>(^0)23 as a Catalytic Chain Transfer Agent in the Free-Radical Solution Polymerization of Methyl Methacrylate

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-B<F>2)2(<H>20)2 as catalyst. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 45,800, Mw 122,000 and Mw/Mn 2.66.

Reconciliation examples 1-2

Experiments on the use of Co(II)(DHIB-H)2(Ph3P) and Co(II)(DHIB-H)2(C5H5N) as catalytic chain transfer agents in the free radical solution polymerization of methyl methacrylate

[PH3P = triphenylphosphine]

The general procedure for solution polymerization was followed using the indicated type and amount of Co(II) catalyst. The results are reproduced below.

Examples 4-6

The use of Co(II)(DHIB-BF2)2(<H>20)2 as a catalytic chain transfer agent in the free-radical solution polymerization of methyl acrylate

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(H2O)2 as catalyst, methyl methacrylate as monomer, 2,2'-azobis(isobutyronitrile) as initiator and methyl ethyl ketone as solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 17,300, Mw 56,500 and Mw/Mn 3.27.

Examples 7-9

The use of Co(II)(DHIB-B<F>2)2(<H>20)2 as a catalytic chain transfer agent in the free-radical solution polymerization of styrene

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(H2O)2 as catalyst, styrene as monomer, 2,2'-azobis(isobutyronitrile) as initiator and methyl ethyl ketone as solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 21,700, Mw 48,700 and Mw/Mn 2.24.

Examples 10-12

The use of Co(II)(DHIB-B<F>2)2(<H>2°)2 as a catalytic chain transfer agent in the free-radical solution polymerization of methyl methacrylate

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(H2O)2 as catalyst, methyl methacrylate as monomer, 2,2'-azobis(isobutyronitrile) as initiator and methyl ethyl ketone as solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 37,100, Mw 77,400 and Mw/Mn 2.09.

Examples 13-15

The use of Co(II)(DHIB-BF2)2(<H>20)2 as a catalytic chain transfer agent in the free-radical solution polymerization of methylacrylonitrile

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(<H>2°^2 as catalyst, methacrylonitrile as monomer, 2,2'-azobis(isobutyronitrile) as initiator and methyl ethyl ketone as solvent. The cobalt catalyst was prepared according to the procedure described in Examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 1,140, Mw 1,950 and Mw/Mn 1.71.

Examples 16-18

The use of Co(II)(DHIB-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical solution polymerization of isoprene

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(<H>2<0>)2 as catalyst, isoprene as monomer, 2,2'-azobis(isobutyronitrile ) as initiator and methyl ethyl ketone as solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The molecular weight values were determined using nuclear magnetic resonance spectroscopy (NMR). The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalysis-v

ter gave Mw 320.

Examples 19-21

The use of Co(II)(DHIB-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical solution polymerization of vinyl acetate

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(H20)2 as catalyst, vinyl acetate as monomer, 2,2'-azobis(isobutyronitrile) as initiator and methyl ethyl ketone as solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 1,660, Mw 3,579 and Mw/Mn 2.16.

Examples 22-24

The use of Co(II)(DHIB-B<F>2)2(H2O)2 as a catalytic chain transfer agent in the free-radical solution polymerization of acrylonitrile

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(^0)2 as catalyst, acrylonitrile as monomer, 2,2'-azobis(isobutyronitrile) as initiator and methyl ethyl ketone as a solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. In the results reproduced below, [n] is the intrinsic viscosity number which is proportional to the molecular weight. The higher the value of [n], the higher the molecular weight. These values were determined by capillary viscometry (CV).

A colorless product was observed.

A repetition of the above experiment without any catalyst gave [n] dl/g 0.5533.

Example 25

The use of Co(II)(DHIB-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical solution polymerization of 2-acrylamido-2-methylpropanesulfonic acid

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(H2O)2 as catalyst, 0.1 mol of 2-acrylamido-2-methylpropanesulfonic acid as monomer, 1.0 x 10"<3> mol of 2,2'-azobis(isobutyronitrile) as initiator and 100 ml of dimethylformamide as solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The contents were heated to 100°C under a nitrogen atmosphere in 90 min The result reproduced below was determined using CV [n] is defined in Examples 22-24.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave [n] dl/g 0.1525.

Example 26

The use of Co(II)(DHIB-BF2)2(<H>20)2 as a catalytic chain transfer agent in the free-radical solution polymerization of 2-acrylamido-2-methylpropanesulfonic acid

The general procedure for solution polymerization was followed using the indicated amount of Co(II)(DHIB-B<F>2)2(H2O)2 as catalyst, 0.1 mol of 2-acrylamido-2-methylpropanesulfonic acid as monomer, 0.374 g of 4,4'-azobis(4-cyanovaleric acid) as the initiator and 100 ml of water as the solvent. The cobalt catalyst was prepared according to the method described in examples 1-3. The contents were heated at 100°C under a nitrogen atmosphere for 30 min. The result, which is reproduced below, was determined using CV. [n] is defined in examples 22-24.

A colorless product was observed.

A repetition of the above experiment without any catalysis-

Thursday gave [n] dl/g 0.8078.

Example 27

The use of Co(II)(DHIB-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical solution polymerization of methacrylic acid

Example 26 was repeated using methacrylic acid as monomer. The result is reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave [n] dl/g 0.6862.

Examples 28-31

The use of Co(II)(DHIB-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical suspension polymerization of methyl methacrylate

The general procedure for suspension polymerization was followed using the indicated amount of Co(II)(DHIB-BF2)2(<H>2O)2 as catalyst. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 110,000, Mw 865,000 and Mw/Mn 7.86.

Examples 32-34

The use of Co(II)(DHIB-BF2)2(H2°)2 as a catalytic chain transfer agent in the free-radical emulsion polymerization of methyl methacrylate

The general procedure for emulsion polymerization was followed using the indicated amount of Co(II)-(DHIB-BF2)2(H2O)2 as catalyst. The cobalt catalyst was prepared according to the method described in examples 1-3.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 675,000, Mw 3,694,000 and Mw/Mn 5.48.

Examples 35-37

The use of Co(II)(DHIB-BF2)2(<H>2°)2 as a catalytic chain transfer agent in the free radical suspension polymerization of methyl methacrylate

The general procedure for suspension polymerization was followed using the indicated amount of Co(II) (DHIB-BF2)2(^<0>)2 as catalyst and 0.025 g of initiator. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 481,000, Mw 3,283,000 and Mw/Mn 6.83.

Examples 38-40

The use of Co(II)(DHIB-BF2)2(<H>2°'2 as a catalytic chain transfer agent in the free-radical emulsion polymerization of methyl methacrylate

The general procedure for emulsion polymerization was followed using the indicated amount of Co(II)-(DHIB-BF 2 ) 2 (H 2 O) 2 as catalyst and 0.037 g of initiator. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 2,926,000, Mw 7,002,000 and Mw/Mn 2.39.

Example 41

The use of Co(II)(DHIB-BF2)2(H2°^2 as a catalytic chain transfer agent in the free-radical emulsion polymerization of methyl methacrylate

The general procedure for emulsion polymerization was followed using the indicated amount of Co(II)-(DHIB-B<F>2)2(H2O)2 as catalyst and 0.0037 g of initiator. The cobalt catalyst was prepared according to the method described in examples 1-3. The result is reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 2,254,000, Mw 4,736,000 and Mw/Mn 2.10.

Examples 42-43

The use of Co(II)(DHIB-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical emulsion polymerization of methyl methacrylate

The general procedure for emulsion polymerization was followed using the indicated amount of Co(II)-(DHIB-BF2)2(H2O)2 as catalyst and hexadecyltrimethylammonium bromide [0.025 M] as the cationic emulsifier. The cobalt catalyst was prepared according to the method described in examples 1-3. The results are reproduced below.

A colorless product was observed.

A repetition of the above experiment without any catalyst gave Mn 368,000, Mw 3,655,000 and Mw/Mn 9.93.

Example 44

A. Preparation of Co(II) (DDE-H) ? (H?Q)

[DDE = 1,2-diphenyl-1,2-dioxyiminoethane]

Co(II)(DDE-H)2(H2O)2 was prepared using the method of G.N. Schrauzer, Inorg. Syn., 11, 64 (1968).

B. Preparation of Co( II)( DDE-BF?)?(H?0)?

In a drying container was. 5.0 g Co(II)(DDE-H)2(H2O)2, 10.0 ml BF3.0(C2H5)2 and 100 ml (021*5)20 placed in a round-bottomed flask. The contents were stirred for 24 hours, after which the suspended solids were recovered by filtration and washed with diethyl ether. The recovered solids were dried under vacuum. Product yield = 5.56 g.

C. Use of Co(II)(DDE-BF2)2(H2O)2 as a Catalytic Chain Transfer Agent in the Free-Radical Emulsion Polymerization of Methyl Methacrylate

The general procedure for emulsion polymerization was followed. The concentration of Co(II)(DDE-BF2)2(H2°)2 was 2.5 ppm. The resulting polymer had Mn 171,000, Mw 1,349,000 and Mw/Mn 7.88. A colorless product was observed.

Example 45

Use of Co(II)(DDE-B<F>2)2(H2°)2 as a catalytic chain transfer agent in the free-radical suspension polymerization of methyl methacrylate

The general procedure for suspension polymerization was followed. The cobalt catalyst was produced according to the method described in example 44. The concentration of Co(II)(DDE-BF2)2(<H>2<0>)2 was 2.5 ppm. The resulting polymer had Mn 7,420, Mw 20,900 and Mw/Mn 2.81. A colorless product was observed.

Example 46

A. Preparation of Co( II)( DC- H)?(H?0)?

[DC = 1,2-dioxyiminocyclohexane]

Co(II)(DC-H)2(H2O)2 was prepared by the method of G.N. Schrauzer, Inorg. Syn., 1JL, 64 (1968).

B. Preparation of Co( II) ( DC- BF-?) ? (H?0) 7

In a drying vessel, 5.0 g Co(II)(DC-H)2(H20)2, 10.0 ml BF3.0(<C>2<H>5)2 and 100 ml {02^) 2° placed in a round-bottomed flask. The contents were stirred for 24 hours, after which the suspended solids were recovered by filtration and washed with diethyl ether. The recovered solids were dried under vacuum. Product yield = 4.09 g.

C. Use of Co(II)(DC-BF2)2(H2°'2 as a Catalytic Chain Transfer Agent in the Free-Radical Emulsion Polymerization of Methyl Methacrylate

The general procedure for emulsion polymerization was followed. The concentration of Co(II) (DC-BF2)2(^0)2 was 2.5 ppm. The resulting polymer had Mn 14,500, Mw 31,500 and Mw/Mn 2.17. A colorless product was observed.

Example 47

Application of Co(II)(DC-BF2)2(H2O)2 as a catalytic chain transfer agent in the free-radical suspension polymerization of methyl methacrylate

The general procedure for suspension polymerization was followed. The cobalt catalyst was produced according to the method described in example 43. The concentration of Co(II)(DC-BF2)2(H20)2 was 2.5 ppm. The resulting polymer had Mn 8,080, Mw 18,300 and Mw/Mn 2.26. A colorless product was observed.

Comparison examples 3-6

Experiments on the use of Co(II)(DHIB-H)2(H20)2, KCo(CN)5 and Co(II)Salen as catalytic chain transfer agents in the free radical emulsion polymerization of methyl methacrylate

The general procedure for emulsion polymerization was followed using the indicated type and amount of Co(II) catalyst and hexadecyltrimethylammonium bromide (0.025 M) as the cationic emulsifier. The results are reproduced below.

Example 48

A. Preparation of 4,7-diaza-2,9-dihydroxyimino-3,8-di-methyldeca-3, 7-diene (DDDD-H?)

A mixture of 40.4 g (0.4 mol) of 3-hydroxyiminobutan-2-one and 12 g (0.2 mol) of ethylenediamine in 400 ml of ethanol was refluxed for half an hour. The mixture was cooled to 5°C and 24.2 g (54% yield) of white crystals were deposited, m.p. 176-177°C [m.p. stated in the literature 166°C: U.S. patent specification 2,400,876 and E. Uhlig and M. Friedrich, Z. anorg. general Chem., 343, 299 (1966)]. Analysis: Calculated for C10<H>18<N>4°2<:> C: 53 f1' H: 8'0' N: 24.8. Found: C: 52.9, H: 7.9, N: 24.6.

B. Preparation of [Co(II)DDDD-H]+ CH? COO~

To a deaerated solution of 50 mg of cobalt(II) acetate tetrahydrate in 200 ml of methyl ethyl ketone was added 45 mg of DDDD-H2 (prepared as in part A) and the mixture was stirred for 18 hours under a nitrogen purge , film-sealed bottle. The solution was brown-beige and was cloudy with a trace of finely divided material. The concentration of the thus formed [Co(II)(DDDD-H)]<+> CH3COO" was 1.0 x 10~<3> M.

C. Use of [Co(II)DDDD-H]<+> C^COO" as a catalytic chain transfer agent in the free-radical polymerization of methyl methacrylate. Batch process

A reaction vessel was filled with 79 ml of reagent grade methyl ethyl ketone and 21 ml (0.2 mol) of commercial grade inhibited methyl methacrylate. The mixture was stirred under nitrogen for half an hour, and 0.33 g (0.002 mol) of 2,2'-azobis(isobutyronitrile) was added; stirring was continued for another 15 min. The molar ratio of monomer to initiator (M/ I) was 100. To this was added 20 ml (2 x 10"<5> mol) of the catalyst from part B via a syringe (catalyst/initiator, C/I was thus 0.01). The mixture was boiled under to -reflux for 5 hours. The reaction mixture was beige at first, developed a reddish color during the first hour of reflux, and then lost color and became cloudy and yellowish-brown. The solution was cooled,

5 mg of hydroquinone was added and the solvent was stripped on a rotary evaporator. The product was a viscous, colorless oil which was obtained in 48% conversion. The NMR of the oil was almost perfect for a trimer of methyl methacrylate, with a methyl group at one end and a vinyl group at the opposite end, and with the formula

6 0.93-1.2, multiplet, main peak 6 1.17, 9H, C- CH?; 6 1.88-2.18, multiplet, 2H, C^- chain; 6 2.51-2.70, multiplet, main peak 2.63, 2H, - CH2 next to vinyl group; 6 3.63, 3.66, 3.78, 9H, -OCH3; 6 5.57, 6.25, 2H, terminal = CH?.

A double experiment carried out without the catalyst gave poly-(methyl methacrylate) with the following characteristics: Mn 4,830, Mu 10,900, 1^/^ 2.25, peak MW 7,940.

Example 49

Application of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the free-radical polymerization of methyl methacrylate. In situ formation of catalyst

A 0.198 g portion of a solution of cobalt(II)-2-ethylhexanoate, henceforth called cobalt octanoate, in naphtha (6% Co, commercial source) was diluted with 200 ml of methyl ethyl ketone, thereby obtaining a 1 x 10~<3> M resolution.

Likewise, a 1 x 10"<3> M solution of the ligand from Example 48A was made by dissolving 45 mg in 200 ml of methyl ethyl ketone.

A reaction vessel was filled with 21 ml (0.2 mol)

methyl methacrylate and 60 ml of methyl ethyl ketone and then cooled to 0-5°C. To it was added 0.33 g (0.002 mol) of 2,2'-azobis(isobutyronitrile) (M/I = 100), and the mixture was stirred under a nitrogen atmosphere for one hour. Into the mixture was introduced 20 ml of each of the above-mentioned cobalt salt and ligand solutions. The homogeneous solution turned a dirty straw color instantly. The cooling bath was removed and the mixture was refluxed for 5 hours. Application of heat resulted in a lightening of color. The mixture was worked up as in example 48C. The product was a viscous, straw colored oil (12.3 g, 61% conversion) very similar in composition to the product of Example 48C.

Example 50

Application of [Co(II)DDDD-H]4" n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the free-radical co-polymerization of styrene and methyl methacrylate

A polymerization vessel was charged with 5 ml (0.044 mol) of commercial grade inhibited styrene, 16.5 ml (0.156 mol) of methyl methacrylate and 91 ml of methyl ethyl ketone. The mixture was cooled to 0-5°C, 0.33 g (0.002 mol) of 2,2'-azobis(iso-butyronitrile) was added, and the solution was stirred under a nitrogen atmosphere for 0.5 hour. To the cold solution was added 4 ml of both the cobalt octanoate and ligand solution prepared as in Example 49. The addition of the ligand solution immediately produced a light beige color. The procedure was the same as described in Example 49, with the exception of the reflux cooling time which was . 6 hours. The product was a foamy solid shown by GPC to have: Mn 717, 2170, M^/ K^ 3.02, peak MW 1650. The NMR spectrum characteristically showed two pairs of well-resolved vinyl proton resonances at 6 5 ,4 and 6.1, and 6 5.2 and 6.0.

A double experiment carried out without the catalyst gave a copolymer of styrene and methyl methacrylate with the following characteristics: Mn 4 540, <M>rø 9 590, Mw/Mn 2.11, peak MW 8000, it lacked the characteristic NMR vinyl resonances.

Example 51

Molecular weight of poly(methyl methacrylate) as a function of concentration of [ Co ( II) DDDD- H3+ n- C4Ho CH( C2Hc;) COO~

Potassium carbonate (83 mg, 0.006 mol), 0.136 g (0.0006 mol) of ligand from Example 48A, a magnetic stir bar, and 200 mL of methyl ethyl ketone were added to a bottle which was then sealed with a rubber membrane. Under magnetic stirring, nitrogen was bubbled into the mixture for one hour through a syringe needle, the flask being vented to a bubble chamber. Then 0.6 ml (0.0006 mol) of cobalt octanoate was added to naphtha

(6% Co, as in Example 49) was injected, the nitrogen bubbling was stopped, and the mixture was stirred for 16 h. The catalyst concentration was nominally 0.003 M. The solution was deep

reddish-brown and contained a suspension of finely divided matter.

Three reactors were set up, each with 21 ml (0.2 mol) of methyl methacrylate and 97 ml of methyl ethyl ketone, each was cooled and vented as previously described, then 0.002 mol of 2,2'-azobis(isobutyronitrile) was added to each

(M/I = 100). This was followed by the addition of 1.7, 3.4 and 6.8 ml of the catalyst from the above section so that the respective C/I ratios were 0.0025, 0.005 and 0.01. Polymerization and work-up was carried out as described in Example 48C. Additional molecular weights are shown in Table I.

From these data, it can be seen that the molecular weight of the produced polymer is inversely proportional to the catalyst concentration.

Example 52

A. Preparation of [ Co( II) TTCT]+2 2 NO?

The chelate in question was prepared as a 0.3 M solution in methanol following the procedure of J. Bremer et al., J. prakt. Chem., 323, 857 (1981). Into a 125 mL Erlenmeyer flask containing a magnetic stir bar was placed 5.8 g (0.02 mol) cobalt(II) nitrate hexahydrate; the flask was flushed with nitrogen and sealed with a rubber membrane. Using a syringe, 67 ml deaerated reagent-grade methanol was added, and the mixture was stirred for 15 min. to dissolve the salt. While still stirring, 6.6 mL (5.9 g, 0.08 mol) of 1,3-diaminopropane was injected, and the solution changed to dark reddish brown. This was followed by the addition of 7.0 mL (6.9 g, 0.08 mol) of 2,3-butanedione, after which the solution turned deep pink. A 2.0 mL portion of the mixture was removed and diluted to 200 mL with deaerated methanol in a nitrogen-purged, foil-sealed bottle, yielding a 0.003 M solution.

B. Preparation of [ Co( II) TTCT]+ 2 2[ n- C4HQ CH( C2H5) COO"

Into a nitrogen-flushed, 60 mL membrane-sealed bottle containing a magnetic stir bar, 10 mL of cobalt(II) octanoate in naphtha (1 M, 6% Co) and 20 mL of absolute ethanol were injected, while stirring, nitrogen was bubbled into 0 .5 hours. To the stirred mixture was added 3.3 ml (0.04 mol)

1,3-diaminopropane, followed by 3.5 mL (0.04 mol) of 2,3-butanedione, the mixture was stirred for 5 min. A 2.0 ml portion of the mixture was removed and diluted with 198 ml deaerated methyl ethyl ketone to give a 0.003 M solution.

Alternatively, a 0.1 M solution of catalyst in ethanol can be prepared in the same way from 10 ml of the 1 M cobalt octanoate, 3.3 ml of 1,3-diaminopropane, 3.5 ml of 2,3-butanedione and 90 ml of ethanol.

C. Application of [Co(II)TTCT]<+2> 2 N03~ and [Co(II)TTCT]<+2 >2[n-C4H9CH(C2H5)COO]" as catalytic chain transfer agents in the free-radical polymerization of methyl methacrylate

Two polymerizations were carried out in a manner similar to that described in Example 51, except that in one the catalyst comprised 6.7 ml of 0.003 M [Co(II)TTCT]<+2 >2 NC>3~ solution from part A, and at the other 6.7 ml of

[Co(II)TTCT]<+2>2[n-C4H9CH(C2H5)COO]~ from part B, so that C/I = 0.01 in each. Molecular weight data for the polymer products are shown in Table II.

These data can be compared to those reported in Example 48C for the non-catalyzed control.

Example 53

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the free-radical polymerization of methyl methacrylate. Process with addition

Five reaction vessels, equipped with stirrers, reflux condensers and pumps for supplying monomer, were filled respectively. 85, 94, 95, 92 and 100 ml of methyl ethyl ketone and then vented by stirring under nitrogen for approx. 0.5 hour. To each was added 0.33 g (0.002 mol) 2,2'-azo-bis(isobutyronitrile), followed by equal volumes of 0.003 M cobalt octanoate and DDDD-H2 (Example 48A) ligand solutions in methyl ethyl ketone, to obtain the decreasing C/I ratios shown in Table III, the latter without catalyst serving as a control. The pumps were filled with 21 ml (20 g, 0.2 mol) of methyl methacrylate, the contents of the polymerization vessels were rapidly heated to reflux, and the monomer was fed into the mixtures under reflux during a period of approx. 2.5 hours. Refluxing was continued for an additional hour, and the mixture was then cooled and stripped free of solvent (60°C, 15 torr). Table III shows the effect on the molecular weight of the produced poly(methyl methacrylate) of changing the C/I ratio.

These experiments show that catalysis of chain transfer occurs in both continuous and batch processes.

Example 54

A. Preparation of 4,8-diaza-2,10-dihydroxyimino-3,9-dimethylundeca-3,8-diene (DDUD-H2)

A solution of 20.2 g (0.2 mol) of 3-hydroxyiminobutan-2-one in 200 ml of ethanol was heated to reflux, and a solution of 7.1 g (0.1 mol) of 1,3-diaminopropane in 50 ml of ethanol was added over a period of 0.5 hour. After the addition, reflux was continued for a further 2 hours, then 100 ml of the solvent was distilled off, and the mixture was cooled to room temperature. A small portion (about 1 ml) was removed and diluted with water until solids formed, the bulk was then crystallized with the solids and placed in a refrigerator for 2 hours. The crystalline solid (8.3 g) that formed was collected and recrystallized from 50 mL of ethanol to give 5.5 g (23% yield) of pure product of DDUD-H2, m.p. 140-141°C. Analysis: Calculated for C11<H>20<N>4°2: C: 55'0' H: 8'4> N: 23.3. Found: C: 55.1, H: 8.5, N: 23.0.

A 0.003 M solution of DDUD-H2 in methyl ethyl ketone was prepared for later use.

B. Use of [Co(II)DDUD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the free-radical polymerization of methyl methacrylate. Method of addition

Reaction vessels were set up as described in Example 53, except that they were charged with 0.003 M solutions of DDUD-H 2 (part A) and cobalt octanoate in methyl ethyl ketone to obtain C/I values as indicated in Table IV. Polymerizations were then carried out as described. The effects of catalyst on the molecular weight of poly(methyl methacrylate) are summarized in Table IV.

Example 55

Use of [Co(II)DDDD-H]4-n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, n-butyl methacrylate and hydroxyethyl methacrylate

A monomer mixture of styrene, n-butyl methacrylate and hydroxyethyl methacrylate with a low degree of acidity, respectively. 15/50/35% by weight, was prepared. Each of the four reaction vessels was charged with 157 g (1.2 mol) of the monomer mixture and 293 ml of methyl ethyl ketone, and the contents were stirred under nitrogen for 0.5 hour. To each was added 2.0 g (0.012 mol) of 2,2'-azobis(isobutyronitrile), and then to three of the containers were added respectively 27, 13.5 and 7 mg DDDD-H2 (Example 48A), followed respectively. of 120, 60 and 30 ml of 1 M cobalt octanoate in naphtha to obtain the C/I ratios shown in Table V. The polymerization carried out in the fourth vessel, without the catalyst, served as a control experiment. The mixtures were refluxed for 3 hours, then cooled and stripped. The effects of catalyst on the molecular weights of the produced copolymers are summarized in table V.

Example 56

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COC<T> as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate. Methyl ethyl ketone solvent

A monomer mixture that contained styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate with low acidity, respectively. 15/10/45/30% by weight, was prepared. Each of three reaction vessels was charged with 185 g (1.2 mol) of the monomer mixture, 345 ml of methyl ethyl ketone and 2.0 g (0.12 mol) of 2,2'-azobis(isobutyronitrile). Two of the containers were charged with ligand and cobalt octanoate as described in Example 55 to achieve C/I ratios of 0.01 and 0.005, the third container was kept free of catalyst and served as a control. The polymerizations were carried out as described in example 55. The effects of catalyst on the molecular weights of the copolymers produced are summarized in Table VI.

Example 57

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate. Toluene solvent

Similar polymerizations to those described in Example 56 were carried out, except that the methyl ethyl ketone solvent was replaced with 320 ml of reagent grade toluene. The molecular weight data are summarized in Table VII.

Example 58

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, n-butyl methacrylate, butyl acrylate and hydroxyethyl methacrylate. Methyl ethyl ketone solvent

A monomer mixture was prepared from styrene, n-butyl methacrylate, butyl acrylate and hydroxyethyl methacrylate, respectively. 15/25/25/35% by weight. Two polymerization vessels were each charged with 100 g (0.78 mol) portions of the monomer mixture and 186 ml of methyl ethyl ketone, and vented as in Example 55, then to each was added 1.3 g (0.008 mol) of 2,2'-azobis(isobutyronitrile ), and to one of them 18 mg of DDDD-H2 (Example 48A) ligand (0.00008 mol) and 80 ml of 1 M cobalt octanoate (0.00008 mol). The polymerizations were carried out as described in Example 55, and the molecular weight data are summarized in Table VIII.

Example 59

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, n-butyl methacrylate, butyl acrylate and hydroxyethyl methacrylate. Toluene solvent

Example 58 was repeated, except that 172 mL of toluene was used as the solvent. The molecular weight data are summarized in Table IX.

Example 60

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate. Method of supply

To a 62 g (0.4 mol) portion of the monomer mixture described in Example 56, contained in the reservoir of a pumping device, was added 0.66 g (0.004 mol) of 2,2'-azobis(isobutyronitrile), 4.5 mg DDDD-H2 (Example 48A) ligand (0.00002 mol) and 30 ml of 1 M cobalt octanoate in naphtha (0.00002 mol), so that C/I = 0.005. Some ligand remained undissolved. The mixture was stirred constantly at room temperature to keep undissolved ligand in uniform suspension while it was pumped into 47 ml of toluene under reflux under a nitrogen atmosphere. Pumping time was 1.5 hours, and heating at reflux cooling temperature was continued for another 0.5 hours. The mixture was thereby cooled and stripped free of solvent. A similar procedure was carried out on a portion containing twice the amount of catalyst ingredients and also on a control portion containing only 2,2'-azobis(isobutyronitrile). Molecular weight data are summarized in Table X.

Similar results were obtained with 2,2'-azobis(2-methylDbutanenitrile) as initiator, this has greater solubility in the monomer and therefore gives greater freedom of action when formulating product mixtures. In an experiment with C/I = 0.005, the copolymer product had the following characteristics: Mn 3,650, 6,320, M^/Mj^ 1.73, peak MW 4,600.

Example 61

Alternative catalyst preparation: [Co(II)DDDD-H]<+> n-CjjHg-CH( C2H5) COO~♦ Toluene solution

For some purposes it is preferable to prepare and isolate cobalt(II) octanoate rather than to use commercially available material. With this goal in mind, a mixture of 12 g (0.1 mol) anhydrous cobalt(II) carbonate and 28.8 g (0.2 mol) 2-ethylhexanoic acid in 200 ml xylene was refluxed under nitrogen in an apparatus with a head for water removal. 75 ml of solvent was distilled off during the first 6 hours, then simple reflux was maintained for 60 hours. The deep violet solution was cooled to room temperature, suction filtered through a medium free glass funnel, and the filtrate was freed from solvent on a rotary evaporator at 90°C, 15 torr. The yield of viscous violet syrup was 34.7 g (100%). Analysis showed it to be 88% pure.

To prepare the catalyst, a flask was charged with 1.72 g (5 mmol) of the cobalt octanoate from the above section, 100 mL of toluene, and a magnetic stir bar. The container was sealed with a rubber membrane. The mixture was deaerated by bubbling nitrogen and stirring for one hour, then 1.13 g (5 mmol) of DDDD-H 2 (Example 48A) ligand was added and the vessel was resealed under air-free conditions. Stirring was continued for 18 hours, and the solution was placed in a refrigerator at 5°C until further use. The concentration was 0.05 M. For some purposes, a concentration of 0.1 M was preferred, as in Example 62, where the previously mentioned preparative amounts are suitably regulated.

B. Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of

. styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate. Process with feed and catalyst formed in advance

A similar system to that in Example 60 was set up, except that 0.77 g (0.004 mol) of 2,2'-azobis(2-methyl)butanenitrile and 0.4 ml of 0.05 M catalyst solution were added to the monomer mixture from part A (C/I = 0.005). Supply time and processing were as described in Example 60. The copolymer product obtained in 98% conversion had the following characteristics: Mn 6,000, Mn 9,150, W^/Kn 1.53 and peak MW 8,300.

Three additional experiments were performed with varying amounts of catalyst, as in Example 60. Molecular weight data are summarized in Table XI.

These data can be compared with the data for the control in example 60.

Example 62

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)C00~ as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, n-butyl methacrylate and 2,4-hexadienyl-(sorbyl) methacrylate

A monomer mixture of styrene, methyl methacrylate, n-butyl methacrylate and sorbyl methacrylate, respectively. 10/22/58/10 mol%

(7.9/16.8/62.7/12.6 wt%) were prepared. To a 50 g (0.38 mol) portion, 0.68 g (0.0038 mol) of 2,2'-azo-bis(2-methyl)butanenitrile and 0.19 ml of 0.1 M catalyst solution were added from Example 61A (C/I = 0.005). The mixture was introduced into 38 ml of toluene under reflux for 30 min., and the reflux was continued for another 30 min. The mixture was cooled and stripped free of solvent. Conversion to the expected copolymer was 68%, Mn 4,590, Mn 15,400, Mw/Mn 3.35 and peak MW 7,400. A control polymerization without catalyst gave a product with Mn 11,400, Mu 324,000, K^/Kn 28.45 (trimodal with peaks at 10,000, 35,000 and 1,400,000.

Example 63

Application of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, n-butyl methacrylate and allyloxy-ethy Irne thacry lat

A similar monomer mixture to that used in Example 62 was prepared, except that the sorbyl methacrylate was replaced with allyloxyethyl methacrylate, and the respective amounts of monomers in the mixture were (7.9/16.7/62.5/ 12.9 weight%). A similar polymerization (C/I =0.01) was carried out.

Conversion to the expected copolymer was 80%, Mn

5,780, Mn 15,300, %,/ Mn 2.65, peak MW 8,800. A control polymer without catalyst formed gel during the 30 min. the long period of reflux cooling after supply.

Example 64

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, n-butyl methacrylate, sorbyl methacrylate and allyloxy methacrylate

A monomer mixture of styrene, methyl methacrylate, n-butyl methacrylate, sorbyl methacrylate and allyloxyethyl methacrylate, respectively. 10/30/45/5/10 mol% (8.0/23.2/49.3/6.4/13.1 wt%) were prepared. To a 50 g (0.39 mol) portion was added 0.7 ml (0.004 mol) of 2-(t-butylazo)-2-cyanopropane and 0.2 ml of 0.1 M catalyst solution from Example 61A, so that C /I = 0.005. The mixture was introduced into 38 ml of toluene under reflux for 30 min., and reflux was continued for another 30 min. Workup in the usual manner gave an 84% conversion to the expected copolymer, Mn 6,960, 32,500, M^/Mn 4.6, peak MW 10,000. An uncatalyzed control gelled 10 min. after completion of the supply.

Example 65

Catalyzed chain transfer in the copolymerization of methyl methacrylate, n-butyl methacrylate, allyloxyethyl methacrylate and sorbyl methacrylate with different catalysts

A monomer mixture of methyl methacrylate, n-butyl methacrylate, allyloxyethyl methacrylate and sorbyl methacrylate, respectively. 40/45/10/5 mol% (31.0/49.4/13.2/6.4 wt%) was prepared. To 50 g (0.39 mol) portions were added 0.74 g (0.0039 mol) of 2,2'-azobis(2-methyl)-butanenitrile and suitable catalyst. The catalyst used was [Co(II)DDDD-H]"1"nC4H9CH-^C2H5^COO~ (Example 61A). Similar polymerizations with feed as those according to example 2 were carried out. The results are summarized in Table XII.

Example 66

Catalyzed chain transfer in the copolymerization of styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate with different catalysts

Portions of a monomer mixture of styrene, methyl methacrylate, lauryl methacrylate and hydroxyethyl methacrylate (as in Example 56) were mixed with 2,2'-azobis(2-methyl)butanenitrile so that the molar ratio between monomer and initiator was 60, and with [ Co(II)TTCT]<+2> 2[n-C4H9CH(C2H5)COO]" in ethanol (Example 52B), so that C/I = 0.005. Similar experiments with addition in toluene solvent as those in Examples 60 and 61B were carried out with a feed time of 0.5 hour for a 0.25 mol monomer portion.The results are summarized in table

XIII.

Example 67

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, lauryl methacrylate and glycidyl methacrylate

A 100 g (0.67 mol) portion of a monomer mixture of styrene, methyl methacrylate, lauryl methacrylate and glycidyl methacrylate, respectively. 15/15/40/30% by weight was mixed with 1.3 g (0.0067 mol) of 2,2'-azobis(2-methyl)butanenitrile and 0.67 ml of freshly prepared 0.1 M [Co(II)DDDD -H]+ n-C4H9CH(C2H5)COO" in toluene from Example 61A (C/I = 0.01). Addition to 77 ml of toluene under reflux was carried out as previously described. The copolymer product, which was obtained in 88% conversion, had the following characteristics: Mn 8,270, Mn 21,900, Mv^/Mn 2.65, peak MW 32,000. The control experiment, which was carried out with azobis(2-methylisobutyronitrile) as initiator, gave copolymer with the following characteristics: Mn 13,700, Mn 42,900, ^/ nn 3.14, peak MW 32,000.

Example 68

Use of [Co(II)DDDD-H]<+> n-C4H9CH(C2H5)COO" as a catalytic chain transfer agent in the copolymerization of styrene, methyl methacrylate, lauryl methacrylate, glycidyl methacrylate and hydroxyethyl methacrylate

A monomer mixture of styrene, methyl methacrylate, lauryl methacrylate, glycidyl methacrylate and hydroxyethyl methacrylate, respectively. 15/15/40/15/15 wt% was polymerized as in Example 67. The copolymer was prepared in 88% conversion, Mn 5,760, Mn 11,800, M^/Mn 2.04, peak MW 8,300. A non -catalyzed control experiment gave copolymer with the following characteristics: Mn 12,400, Mn 33,700, 1^/% 2.72, peak MW 27,000.

Example 69

Use of [Co(II) Salen as a catalytic chain transfer agent in the free-radical polymerization of methyl methacrylate

In a nitrogen-containing drying vessel, 21.4 ml (0.2 mol) of methyl methacrylate, which had previously been bubbled through with nitrogen and passed through a column of Woelm alumina (fineness grade 1), was added to a 100 ml volumetric flask. To this was added the desired amount of [Co(II) Salen], a commercially available material, and the volume was brought to 100 ml with distilled methanol.

62 mg was added to a 300 ml round bottom flask

(2.5 x 10'<4> moles) of 2,2'-azobis(2-methyl)butanenitrile, and a G.C. sample was withdrawn. The round-bottomed flask was fitted with a water-cooled condenser, removed from the drying vessel and heated to reflux under nitrogen for 6 hours. The reaction mixture was then allowed to cool to room temperature and a second G.C. sample was taken. The poly(methyl methacrylate) produced was isolated by removing solvent and monomer from the reaction mixture via a rotary evaporator. The results are reproduced in Table XIV.

Example 70

A. Preparation of 5,8-diaza-2,11-dioxo-4,9-dimethyldodeca-4,8-diene (ACEN-H2)

ACEN-H2 was prepared using the method of P.J. McCarthy et al., J. Am. Chem. Soc, 77, 5820-4 (1955).

9.00 g (0.15 mol) of ethylenediamine was added slowly to 30.00 g (0.30 mol) of acetylacetone. After the addition, the mixture became solid. The solid was filtered off and filled with water. The solid was recrystallized from water and dried for 24 hours at 65°C under vacuum to give 23.82 g (70.9% yield) of ACEN-H2.

B. Preparation of [Co(II)ACEN]

A 0.002 M solution of [Co(II)ACEN] was prepared in situ by adding 45 mg of ACEN-H2 from part A and 50 mg of Co(II)(OAc)2.4H2O to 100 mL of methanol. C. Use of [CodDACEN] as a catalytic chain transfer agent in the free-radical polymerization of methyl methacrylate ■?

Example 69 was repeated using [CodDACEN], prepared in Part B as the catalytic chain transfer agent. The results are shown in Table XV.

Claims (12)

1. Process for free-radical mass, solution, suspension or emulsion polymerization of monomer, preferably monomer selected from: methacrylate, acrylate. acrylic acid, styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl halides of the formula CH2=CHX, where X is Cl or F, vinylidene halides of the formula CH2=C(X)2, where each X, independently of each other, is/are Cl or F, substituted butane -dienes of the formula CH2=C(R)C(R)=CH2, where each R, independently of one another, is H, C10-alkyl, Cl or F, ethylene sulfonic acid derivatives of the formula CH2=CHS03X where X is Na, K . , N(R)2 or SO3Y and Y is H, Li, Na, K or N(R)4, acrylamide derivatives of the formula CH2=CHCON(R)2 where each R, independently of each other, is/are H, C^.^ ø-alkyl, or (CH2)nZ, n is an integer from 1-10, Z is COOY, OH, N(R)2 or SO3Y and Y is H, Li, Na, K or N(R)4, methacrylamide derivatives with the formula CH2=C(CH3)CON(R)2, where each R, independently of each others, is H, C₁₋alkyl or (CH₂)nZ, n is an integer from 1-10, Z is COOY, OH, N(R)₂, SO₃Y and Y is H, Li, Na, K or N(R)4, vinyl acetates of the formula CH2=CHOOCR where R is C1 iq-alkyl, and mixtures thereof, comprising bringing monomer into contact with initiator, solvent and suspending or emulsifying agent, in the presence of an agent for regulating molecular weight, characterized in that a cobalt chelate chain transfer agent is used as the agent for regulating molecular weight with the formula where each R, independently of each other, is phenyl or C2_12-alkyl where each α-carbon atom contains two hydrogen atoms, i.e. is unsubstituted, or R and R on adjacent carbon atoms together is C5-8-cycloalkylene, unsubstituted in the rearrangements, -CH=CH-CH=CH-, foT or /^s_^v. 1<>ach-ch- CoJoTr R<2 > H or 1-12; \-^\^ch-ch-; R2 is H or CxH2x+i where x is 1-12; each R<4>, independently of one another, is H or CxH2x+i where x is 1-12, or both R<4> groups together are -0-Z 0-; n is 2 or 3; Z is BF2, BC12, BBr2 or BR<2>, and X" is NO3", Cl", Br", I", BF4", PF6~, SbF6" or R<8>COO" where R<8> is <C>1_12"alkyl, with the proviso that when R4 is H or C H_ ., the formula is x 2x+l or that in the case of free-radical bulk or solution polymers in acrylic and/or styrene monomer, a cobalt chelate chain transfer agent with the formula is used or where R, R<2>, n and X~ have the meanings given above for the chain transfer agent, and where R<3", independently of each other, is H or branched or straight-chain C^^-alkyl, R<6> is 0 or NH; however, on the condition that either each or both of the aromatic rings in XII is optionally substituted with a benzo group and optionally contains up to four substituents. 2. Method according to claim 1, characterized in that it is a mass or solution polymerization carried out at 80-110<6>C. 3. Method according to claim 1, characterized in that it is a suspension or emulsion polymerization carried out at 65-80°C. 4. Method according to claim 1, characterized in that the cobalt chelate chain transfer agent has formula VII. 5. Method according to claim 1, characterized in that both R<4-> groups together are -0-Z 0- and Z is BF2" 6. Method according to claim 1, characterized in that the cobalt chelate chain transfer agent is selected from co(II)-(2,3-dioxyiminobutane- BF2)2, Co(II)(1,2-dioxyiminocyclohexane-BF2)2 and Co(II)(1,2-diphenyl-1,2-dioxyiminoethane-BF2)2. 7. Method according to claim 1, characterized in that the cobalt chelate chain transfer agent has formula X. 8. Procedure according to claim L, characterized in that the cobalt chelate chain transfer agent has formula XII and wherein the aromatic ring is substituted with up to four substituents selected from -OR2, -NR<2>, -cl, -Br, -I, -NO2 and -R<7> where R<7> is Cx<H>2x+1 where x is 1-12. 9. Method according to claim 1. characterized in that the initiator is selected from azocumene, 2,2'-azobis(isobutyronitrile), 2,2'-azobis-(2-methyl)-butanenitrile, 4,4'-azobis(4-cyanovaleric acid and 2-( t-butylazo)-2-cyanopropane. 10. Method according to claim 1, characterized in that the initiator is selected from benzoyl peroxide, lauroyl peroxide, persulphates and molecular hydrogen. 11. Method according to claim 1, characterized in that the suspending agent is a polyacrylic acid. 12. Method according to claim 1, characterized in that the emulsifier is selected from sodium dodecyl sulfate and hexadecyltrimethylammonium bromide.