DE1046312B - Process for the preparation of polymers and copolymers of basic monomers - Google Patents

Description

GERMAN

The present invention relates to a process for the preparation of polymers and copolymers of basic monomers. The term "basic monomer" as used here includes monomeric compounds which contain both a ^ C = C CC group and a basic nitrogen atom, such as e.g. . B. primary, secondary and tertiary amines of the aliphatic, cycloaliphatic, aromatic or heterocyclic type, and corresponding quaternary ammonium compounds.

Aqueous, acidic catalyst systems that contain reducible chlorate ions and oxidizable sulfoxy ions, have been successful in polymerizing various vinyl compounds including vinyl chloride, Acrylonitrile, vinyl acetate, etc. are used. You have chosen the homo- and copolymerization of Acrylonitrile to polymers with excellent properties for the production of synthetic fibers in particular proved suitable. The components of an oxidation, reduction or redox catalyst system of this type can also be used as chloric acid or sulphurous acid, but are these acids are relatively unstable. It is therefore generally more convenient to use the polymerization system the desired ions in the form of a water-soluble chlorate and a water-soluble sulfite together with a suitable acid such as sulfuric acid, phosphoric acid or acetic acid. For economic Considerations out is generally chosen sulfuric acid.

During the polymerization in one a chlorate sulfoxy catalyst combination containing aqueous system, the chlorine is reduced and the sulfur is oxidized at the same time.

To achieve optimal results, it is recommended that the oxidation and reduction components are present in oxidation and reduction equivalents; ie 3 moles of sulphurous acid or sulphite per mole of chloric acid or chlorate. The ratio is the same for bisulfite, but only 1.5 mol of a metabisulfite are required, since these salts dissociate to _{form HSO 3 ions.} To achieve the same results per mole of chlorate, only 1.5 moles of a thiosulfate or a salt of hydrosulphurous acid (H ₂ S ₂ O ₄ ) are required, since these have twice the reduction potential of sulfites. Of course, you are not bound to these proportions: it is possible to deviate largely from the ideal ratio, e.g. B. by using equimolar amounts of sodium bisulfite and sodium chlorate or by using 6 moles of bisulfite per mole of chlorate, but with a waste of catalyst material. In general, the amount of chlorate ions used should be between about

Process for the preparation of polymers and copolymers of basic monomers

Applicant:

American Cyanamid Company,
New York, NY (V. St. A.)

Representative: Dr. F. Zumstein
and Dipl.-Chem. Dr. rer. nat. E. Assmann,
Patent Attorneys, Munich 2, Bräuhausstr. 4th

Claimed priority:
V. St. v. America May 20, 1955

John Arthur Price, Stamford, Conn.,
and Walter Moreland Thomas, Noroton Heights, Conn.

(V. St. Α.),
have been named as inventors

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0.01 and 1.0% by weight of the polymerizable monomeric material and that of the sulfoxy ions between about 0.01 and about 3.0 weight percent on the same basis. There can be catalyst components 3 or more percent chlorate ions, 9 or more percent sulfoxy ions are used, without achieving further advantages.

When the polymerization medium according to the invention contains nitrate ions, there is a noticeable increase of conversion achieved if monomers with a ^ C = C ^ C group and a basic nitrogen atom are polymerized and one or more such monomers with one or more unsaturated Compounds are copolymerized. Strangely enough, nitrate ions do not produce any marked improvement in the polymerization of vinyl compounds of a non-basic nature in the absence achieved by the aforementioned basic monomers. The reasons for these effects are not fully known.

The present process can be applied to the polymerization of basic monomers either alone or in the presence of other monomers that are amenable to copolymerization. the Unsaturated basic compound can be an extremely small amount of the total polymerizable present Material make up, e.g. only 0.5%, and yet a noticeable improvement in the yield

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Polymerization in the presence of .Nitra'rionen result. In addition to a basic nitrogen atom, these basic monomers must have one or more contain unsaturated double bonds. These unsaturated bonds can either be conjugated or unconjugated. The present method is particularly suitable for monomers that contain a single terminal ethylene group, so the most important starting materials in technology are now subjected to vinyl or mixed polymerisation. The new process can be used in a suitable pressure device with gaseous monomers, also carried out with liquid or solid substances will. Among the many suitable monomers are: vinyl pyridines, such as 2-methyl-5-vinyl-pyridine, 2-vinyl-5-ethyl-pyridine, 4-vinylpyridine and 2-vinyl-pyridine; Allylamines, such as allylamine, Diallylamine and diallyl methyl amine; 3-N-dimethylaminopropyl - acrylamide, 2 - N - dimethylaminoethyl methacrylate, 2-vinylbenzimidazole, N-vinylimidazole, Ν, Ν-dimethyl-oallyl-isourea, N-vinyl-N-ethyl-guanidine, Methacryl-guanamine, acrylamidopropyl-benzyl-dimethyl-ammonium chloride, N-2-oxyethyl - 2 - vinyl - pyridine - sulfate, dimethylaminoethyl fumarate and S-N-cyclohexylaminopropyl acrylamide.

The process is applicable not only to the homopolymerization of the basic organic compounds but also to the copolymerization of two or more of them and also to the copolymerization of one or more basic monomers with one or more of the non-basic compounds of the type described below. Although the process is particularly suitable for the production of copolymers of acrylonitrile as the main component, e.g. B. 50 to 95 percent by weight, with a minor part of a basic monomer, such as 5 to 15 percent by weight, with or without other copolymerizable substances, but is not limited to these substances or amounts. These are polymers which have proven particularly suitable for spinning into synthetic fibers which have excellent properties including dyeability. For this particular purpose, feeds of monomers containing 80 to 90 percent acrylonitrile, 5 to 10 percent 2-methyl-5-vinyl pyridine, and 5 to 10 percent vinyl acetate are highly recommended. A large number of conjugated and unconjugated compounds which contain a Z ^ -C = Cd group and do not have a basic nitrogen atom are suitable partners for the copolymerization. Compounds having a single CH ₂ = Cd group are particularly important because most of the art monomeric vinyl compounds fall into this class. Additional monomers that may be mentioned include: allyl alcohol, ethylene, styrene, essentially mono- and disubstituted methyl, ethyl, chloro, nitrostyrenes, acrylic compounds in general, e.g. B. acrylic acid, methacrylic acid, alkyl, aryl and aralkyl esters of acrylic and methacrylic acid, the corresponding amides and mono-N-alkyl derivatives of these, methacrylonitrile, etc., unsaturated ketones such as methyl vinyl ketone, mixed vinyl compounds such as vinyl chloride, vinyl acetate , Vinyl chloroacetate, vinyl butyrate. Vinyl stearate etc .. butadiene, vinylidene chloride, acrolein, diallyl phthalate, vinyl ethyl ether, various olefinic fluorine compounds, ζ. B. trifluorochloroethylene, fumaric acid diethyl ester, maleic acid dimethyl ester.

To achieve the advantages according to the invention, the nitrate ions must be present in the polymerization medium together with the chlorate and sulfoxyiones. Nitric acid or any of its inorganic salts can be used for this purpose since all of these nitrates are water soluble. Since, in the polymerization reaction, a p _H value of between 1 and 5 necessary and nitric acid has sufficient stability on storage, it is best to use free nitric acid, which also serves to adjust the p _H to the desired value. this

ίο makes the introduction of any foreign substances, such as sulfate ions in the form of sulfuric acid, which have no activating or catalyzing effect on the reaction, superfluous. In general, the amount of nitrate ion can be from about 0.5 to 80 percent of the total weight of the polymerizable material in the system; a preferred range is 1 to about 20 percent. The necessary amount of nitrate ion can also be specified in another manner, that is, as equivalent to the amount of nitric acid that is at least necessary to a _pH value of about 1 to 5 in a polymerization system containing the basic monomers, sodium or potassium chlorate and sodium - Or contains potassium bisulfite or other of the aforementioned sulfoxy salts. This amount will of course vary somewhat depending on the basicity of the particular unsaturated basic monomers selected at each p _H. If desired, additional nitrate ions may be added without noticeable influence on the p _H -value, z. B.

Sodium, potassium, calcium, magnesium, aluminum nitrate, etc.

The polymerization can be carried out in aqueous solutions, dispersions or emulsions of the monomers will. If copolymers of acrylonitrile suitable for spinning into fibers are produced, aims to polymerize in aqueous solution or dispersion in the absence of any surface-active substances Funds are executed; the elimination of such an agent from the polymer before Spinning is then avoided. If, on the other hand, water-insoluble monomers are polymerized, then should acid stable emulsifiers or other surface active agents can be used, e.g. B. from the anionic Type, such as sulfonated paraffin oil, alkylated naphthalene sulfonates, sodium lignosulfonates, salts of long chain Alkyl sulfates and sulfonates, such as sodium cetyl sulfate and sodium lauryl sulfate and sodium, potassium and amine soaps of long chain fatty acids (12 to 22 carbon atoms); or cationic emulsifiers, such as cetyl trimethyl ammonium bromide, benzyl dimethyl dodecyl ammonium chloride and dimethyl-oxyethyl-stearamido-propyl-ammonium chloride.

The process is suitable for both discontinuous and continuous operations; in general one limits the amount of water introduced into a continuous polymerization system is such that the total weight of polymerizable monomers is between about 15 and 50% of the all of the material which is introduced during the polymerization reaction is located. This is especially true when the polymerizable material contains a substantial amount of acrylonitrile, then so The resulting polymer suspension is easy to pump around and has excellent filtering properties owns. When processing and handling smaller volumes of reaction mixture, of course additional economic benefits achieved. Namely, there were no difficulties in the deposition of the monomer observed, since the polymerizable material with one of the polymerization

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speed corresponding speed is added in such a way that the system never starts monomeric acrylonitrile is saturated.

The p _H optimum for continuous polymerization of monomers, which for the most part consist of acrylonitrile, is between about 1.8 and 2.5, and for batch work it is about 2.8 to 3.5.

Relatively low polymerization temperatures, e.g. B. those of about 20 to 70 ° C are appropriate and temperatures of about 30 to 50 ° C are particularly recommended.

It is convenient to carry out the process in the absence of oxygen, which has a noticeable inhibitory effect the polymerization has to carry out. Suitable inert gases such as nitrogen and carbon dioxide can can be used in place of air in the reaction zone.

In some cases the polymer or copolymer formed will become virtually completely out of solution retire. In other cases it may be useful to use a precipitation or coagulation electrolyte, such as sodium chloride, sodium sulfate, aluminum sulfate, hydrochloric acid, calcium chloride, etc., of the reaction mixture to add. After coagulation in one way or another, the polymer easily separates nitrate from the liquid medium, wash and dry.

Fillers, dyes, pigments, plasticizing, other natural or synthetic resins and the like to incorporate the polymers and copolymers before, during or after the polymerization, in order to particularly to achieve suitable products for the respective purpose, e.g. B. for molding compounds and coating compounds, Glues, threads, etc.

For the production of spinnable acrylonitrile polymers or copolymers, an average one has proven itself Molecular weights of about 60,000 to 90,000 have been found to be particularly useful. It's an advantage of the Process that a uniform, average molecular weight through the continuous addition of the catalyst system of the polymer can be achieved.

The following examples are intended to explain the invention in more detail. All parts are given in parts by weight on an anhydrous basis unless otherwise noted. For example, the acidity of various solutions and feeds is expressed as anhydrous or 100% HNO ₃ and H ₂ SO _{4 for} convenience, although aqueous nitric acid and sulfuric acid are actually used. In order to obtain clear comparisons of the effects brought about by the addition of nitrate ions, it was necessary to use relatively few monomers and mixtures of those with limited variations in the catalyst concentrations and other reaction conditions. The examples are therefore not to be regarded as attempts to highlight all the possibilities for the reaction conditions or suitable monomers.

example 1

A reaction vessel equipped with a stirrer, reflux condenser, thermometer and gas inlet tube is placed in a constant temperature bath kept at 40.degree. A solution of 95.4 parts of acrylonitrile, 5.3 parts of 2-methyl-5-vinyl-pyridine, 5.3 parts of vinyl acetate, 950 parts of demineralized water and 2.76 parts of HNO _{3 are} introduced into the vessel. The p _H of the initial solution is 3.2. A rapid stream of prepurified nitrogen is passed over the surface of the solution for 30 minutes and then reduced to two to four bubbles per second. A solution of 0.440 parts of sodium chlorate and 1.575 parts of sodium sulfite in 100 parts of water is prepared and a second solution is prepared by adding 1.17 parts of HNO ₃ to 100 parts of water. Portions of these solutions are introduced into the reaction vessel at 25-minute intervals over a period of 2½ hours. The polymerization is continued for a total of 4 hours. After this time the product is collected on a Buchner funnel and washed with 2000 parts of demineralized water. The polymer is dried in an oven at 70 ° C for about 16 hours. The yield of dry, white polymer of acrylonitrile, 2-methyl-5-vinylpyridine and vinyl acetate is 77 parts, corresponding to a 73% conversion.

Attempt a

The same conditions and quantities as in Example 1 are used except that 2.76 parts used in the original batch HNO ₃ are replaced by 2.175 parts of H ₂ SO _4, and the _pH value of the mixture is 3.2. The 1.17 parts of HNO ₃ in the acid additive are also replaced by 0.91 parts of H ₂ SO ₄ . In this case the yield of dry, white terpolymer of acrylonitrile, 2-methyl-5-vinyl-pyridine and vinyl acetate is 70 parts, which corresponds to a 66% conversion or a relative yield of about 10% less than with nitric acid .

Attempt B

Example 1 is repeated under the same conditions, except that a different monomer charge is used which consists of 100.7 parts of acrylonitrile and 5.3 parts of methyl acrylate and contains no basic monomer. The _pH value of the reaction mixture is from 2.9 to 3.2. The yield of dry, white copolymers of acrylonitrile and methyl acrylate is 92 parts, which corresponds to a conversion of 87%.

Attempt C

4-5 Experiment B is repeated exactly except that 2.175 parts of H ₂ SO _{4 are used} in place of the nitric acid in the initial charge and 0.91 parts of H ₂ SO ₄ in place of the nitric acid in the catalyst solution. A yield of 92 parts of acrylonitrile-methyl acrylate copolymers is again obtained, indicating that the improvement achieved with nitric acid is specific to compositions containing basic monomers.

Example 2

The procedure is as in Example 1, with the exception that 10.6 parts of sodium nitrate are still added to the reaction vessel with the initial charge. Here the initial ρ _Ξ 3.2. The yield of white, dry copolymers of acrylonitrile, 2-methyl-5-vinyl-pyridine and vinyl acetate is 83 parts, corresponding to a 78% conversion.

Attempt D

Manufacture of a ternary polymer from a mixture of 90 percent by weight acrylonitrile, 5 percent by weight 2-methyl-5-vinyl-pyridine and 5 percent by weight vinyl acetate.

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The copolymerization is' continuously taking Use of an apparatus carried out which consists of a reaction vessel having an overflow tube at the top. First is by continuous Circulate the contents of the reaction vessel mixed by means of a high-speed centrifugal pump. Means a motor-driven stirrer is additionally stirred in the reaction vessel. The temperature will regulated by a heat exchanger placed in the external circulating system. Under use Pumps with speed control become solutions of the monomer material, the acid and the catalyst described below are introduced into the reaction vessel.

The reaction vessel is equipped with a previously prepared 28% strength aqueous slurry of a 2-component copolymer of about 95% acrylonitrile and 5% methyl acrylate charged. Then do the following solutions at the given speeds added at the same time.

Add 1 part per hour

Sodium chlorate 3.78

Sodium sulfite 13.4

Demineralized water 1060.0

Addition 2

Acrylonitrile 774.0

2-methyl-5-vinyl-pyridine 43.0

Vinyl acetate 43.0

Addendum 3

H ₂ SO ₄ 23.7

Iron sulfate 0.0224

Demineralized water 1050.0

The temperature of the slurry becomes 40 ° C held, the mean pg value is about 2.2. the mean residence time is 2 hours and the copolymerization reaction is terminated after 5 hours. The ternary polymer is isolated from the final reaction slurry by centrifugation, then it is washed in the centrifuge with 40,000 parts of demineralized water and about 16 hours dried in an oven at 70 ° C. The weight of the dry, white, ternary polymer of acrylonitrile, 2-methyl-5-vinyl-pyridines and vinyl acetate is 1100 parts, corresponding to a 64% conversion.

Example 3

Experiment D is repeated using the following additives, which are mainly characterized by the Differentiate between replacing sulfuric acid with nitric acid. The same apparatus is used, and the product of the slurry that remained in the reaction vessel from Experiment D is used for Start the current reaction.

Add 1 part per hour

Sodium chlorate 3.73

Nairium sulfite 13.3

Demineralized water 1180.0

Ingredient 2

Acrylonitrile 774.0

Vinyl acetate 43.0

Addendum 3

2-methyl-5-vinyl-pyridine 43.0

Again, the temperature of the slurry is kept on at 40 ° C, and the median p _H is 2.2. After 5 hours the reacted slurry is isolated, washed and dried in the same manner as described in the previous example. The small amount of iron, which is present as iron sulfate, helps to create a "flowable" slurry that, despite its high concentration of solids, can be pumped out. ίο The yield of dry, white, ternary polymer from acrylonitrile, 2-methyl-5-vinyl-pyridine and vinyl acetate is 1340 parts, which corresponds to a 78% conversion and a relative improvement over the yield in Experiment D of 22%.

Example 4

The ternary polymer of Experiment D is prepared in exactly the same way using the following additives:
aö addition! Parts per hour

Sodium chlorate 4.47

Sodium sulfite 15.9

Demineralized water 1060.0

Addition 2

^Z 5 acrylonitrile 774.0

2-methyl-5-vinyl-pyridine 43.0

Vinyl acetate 43.0

Addendum 3

. ENT ₃ 22.1

Demineralized water 1050.0

The _pH value during the entire reaction is virtually 2.1. The yield of dry, white, ternary polymer from acrylonitrile, 2-methyl-5-vinylpyridine and vinyl acetate is 1460 parts, corresponding to a conversion of 85%.

Example 5

The procedure of Example 4 is followed except for Charge 3 as well 18.4 parts of sodium nitrate are added. The yield of dry, white polymer from acrylonitrile, 2 ^ methyl-5-vinyl-pyridine and vinyl acetate is 1560 parts, corresponding to one conversion of 91%.

Example 6

This example shows the preparation of a ternary polymer containing about 88.5 percent by weight acrylonitrile, 6.5 percent by weight of 2-methyl-5-vinyl-pyridine and Contains 5.0 percent by weight of vinyl acetate units, the procedure of Experiment D in general is applied.

ENT,

Iron sulfate;

Demineralised water 940.0

27.1
0.0232

Add 1 part per hour

Sodium chlorate 7.3

Sodium sulfite 26.0

Demineralized water 1030.0

Addition 2

Acrylonitrile 850.0

Vinyl acetate 75.0

Addendum 3

2-methyl-5-vinyl-pyridine 75.0

ENT ₃ 48.5

Iron sulfate 0.0256

The temperature of the slurry is maintained at 50 ° C. After 6 hours of run time, equilibrium conditions are adjusted with a _pH value of about 2.0, and the slurry is in 2stün-

at numerous intervals over the next 18 hours. The polymer of each part of the slurry is isolated, washed and dried as described above. The mean conversion for that 18 hour period is 84%.

Example 7

Example 6 is repeated with the following additions.

Add 1 part per hour

Sodium chlorate 6.2

Sodium sulfite 22.3

Demineralized water 1030.0

Addition 2

Acrylonitrile 850.0

Vinyl acetate 75.0

Addendum 3

2-methyl-5-vinyl-pyridine 75.0

ENT ₃ 43.8

Sodium nitrate 19.4

Iron sulfate 0.0256

The temperature of the slurry is maintained at 50 ° C and the pg is again about 2.0. To After 6 hours of running, equilibrium conditions have been reached and the slurry will collected, washed and dried at 2 hour intervals over the next 18 hours. the mean conversion for the 18 hour period is 94%.

Example 8

64.8 parts of 3-N-dimethylamino-propyl-acrylamide, 950 parts of demineralized water and 19 parts of HNO _{8 are introduced} into a reaction vessel equipped as described in Example 1. The p _H of the starting solution is about 3.0. A rapid stream of prepurified nitrogen is passed over the surface of the solution for 30 minutes and then reduced to two to four bubbles per second. A solution of 0.880 parts of sodium chlorate and 3.15 parts of sodium sulfite in 100 parts of water is prepared. A second solution is prepared by adding 2.40 parts of HNO ₃ to 100 parts of water. Portions of these solutions are introduced into the reaction vessel at 25-minute intervals over a period of 2/2 hours. The polymerization is then continued for a total of 4 hours at 40 ° C. After this time the viscosity of the solution is much greater than at the beginning, which shows that most of the 3-N-dimethylaminopropyl-acrylamide-nitrate has polymerized to a water-soluble polymer.

Claims (5)

Patent claims: 1. Process for the preparation of polymers and copolymers of basic monomers, which are both a ^ C = CC group as well as a basic one Containing nitrogen atom using a chlorate-sulfoxyion polymerization catalyst system, characterized in that the polymerization is carried out in the presence of nitrate ions will. 2. The method according to claim 1, characterized in that the polymerization is carried out in an aqueous solution of a _pH value of about 1 to 5, which, based on the weight of the polymerizable material is at least about 0.01% chlorate ions and at least about Contains 0.01% oxidizable sulfoxy ions in the form of sulfite, bisulfite, hydrosulfite or thiosulfate ions and at least about 0.5% nitrate ions. 3. The method according to claim 1, characterized in that a solution is used that of 0.01 to 3% chlorate ions, 0.01 to 9% oxidizable sulfoxy ions in the form of sulfite, sulfite, Hydrosulfite or thiosulfate ions and 0.5 to 80% nitrate ions, based on the weight of the polymerizable Materials, contains. 4. The method according to any one of claims 1 to 3, characterized in that one or more Compounds with a> C = C C group and. a basic nitrogen atom with an or several other monomers that have a! ^ = C = CC group and are free of basic nitrogen atoms, can be copolymerized. 5. The method according to any one of claims 1 to 3, characterized in that as polymerizable Material such as 80 to 90 percent by weight acrylonitrile, 5 to 10 percent by weight 2-methyl-5-vinyl-pyridine and contains 5 to 10 weight percent vinyl acetate is used. Documents considered: French Patent No. 1,061,952. t 809 698/579 12:58