DE1264065B - Process for the production of homo- or copolymers of acrylonitrile - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C08f

German class: 39 c -25/01 ,.

Number: 1 264 065

File number: E 26720 IV d / 39 c

Filing date: March 28, 1964

Open date: March 21, 1968

It is already known to polymerize acrylonitrile in solution. However, the known methods of this type have serious disadvantages. As a rule, they either require relatively long polymerization times or else the polymer yields are poor, and there is also the fact that some of the polymers available have molecular weights that are too low and are often undesirably discolored. From J. of Polymer Science, 17, p. 275 (1955), it is known, for example, that ίο in the polymerization of acrylonitrile in ethylene carbonate and in dimethylformamide with azobis (butyronitrile) as a catalyst yields of 44 ° / ₀ and 30 °, respectively / ₀ can be obtained, in the latter case a product with an inherent viscosity of only 0.5 is obtained. This poor result is attributed to the chain-transferring and retarding effect especially of dimethylformamide. From British patent 849 864 it is known to polymerize acrylonitrile in dimethylformamide solution in the presence of ammonium persulfate as a polymerization catalyst. This process is unsatisfactory because it requires high temperatures of 50 ° C. or above and polymerization times of more than 35 hours.

From the laid out documents of the Belgian patent 606 616 it is known to polymerize acrylonitrile in an organic solvent at temperatures of 5 to 12O ⁰ C in the presence of Peroxydkatalysatoren and reducing compounds such as alkali metal bisulphites. It has been found, however, that such a catalyst combination offers no advantages.

From the German Auslegeschrift 1066355 it is further known to polymerize acrylonitrile optionally together with other polymerizable monomers in the presence of Diacylperoxyden at temperatures from 30 to 8O ⁰ C and polymerization times of 10 to 60 hours.

Finally, it is known from Belgian patent 572 665 to polymerize acrylonitrile in a solvent in the presence of various peroxides and SO ₂ as an activator for this and to add certain sulfur compounds to interrupt the reaction of the reaction mass.

There has now been a process for the production of homo- or copolymers of acrylonitrile by polymerizing acrylonitrile or mixtures of at least 50 percent by weight of acrylonitrile and up to 50 percent by weight of other monoethylenically unsaturated compounds with a CH ₂ = C < group in solvents for polyacrylonitrile in the process for the production of homo- or
Acrylonitrile copolymers

Applicant:

Eastman Kodak Company,

Rochester, N. Y. (V. St. A.)

Representative:

Dr.-Ing. W. Wolff, H. Bartels, Dr. J. Brandes
and Dr.-Ing. M. Held, patent attorneys,
8000 Munich 22, Thierschstr. 8th

Named as inventor:

John Richard Caldwell,

Clarence C. Dannelly, Kingsport, Tenn. (V. St. A.)

Claimed priority:

V. St. v. America April 3, 1963 (270197) - -

Temperatures from -70 to -IOO ⁰ C in the presence of redox catalyst systems

(a) Hydroperoxides of the general formula:

R-OOH

wherein R is a monovalent aliphatic, alicyclic or aromatic group represented by a carbon atom is linked to the hydroperoxy group and

(b) reducing sulfur compounds found, by then at relatively low temperatures and within a very short time Time polymers of high and controllable molecular weight are obtained when as reducing sulfur compounds, lower oxides of sulfur, sulfur-oxygen acids a low oxidation state or alkyl esters of these acids, sulfur halides, organic sulfur compounds of the general formulas

R \

, S =

X '

809 519/658

3 4

or else the two catalyst components

R '.0 added continuously. For a practically full

\ g constant response time required is between

/ \ about 0.5 to 48 hours if polymerisation tem-

XO 5 temperatures in the range from -5 to + 50 ° C

be turned. The final mix is then

wherein R 'is a hydrocarbon radical with 1 to stirred, optionally under nitrogen or under 7 carbon atoms and X a halogen atom in another inert gas. Under mild temperature means or alkaebisuffitaddition connections conditions it can happen that the new of aldehydes or ketones can be used. The polymer formed does not initially dissolve; it solves

however, when the mixture reaches normal temperature

According to the method of the invention, doors can be heated. For example, if the polymerization in N, N-dimethylformamide is carried out, preferably at temperatures from -50 to + 50 ° C., in polymer yields below 30 ° C. in only about 2 ¹ I ₂ to 4 hours, the polymer dissolves easily at 85 Obtained ° / ₀ and higher. The polymers are obtained when the mixture is heated to 40 ° C., practically colorless.
The molecular weights can be compounds of the general formula as desired

to be different. In particular, polymers -n OOH

obtained with intrinsic viscosities of 0.5 to 2.5. the

Advantages of the new process are based quite openly - in which R is a monovalent aliphatic, alicyclic visible on the simultaneous presence of an aromatic or radical means by one Hydroperoxy compound and one of the special carbon atoms with the hydroperoxy group containing sulfur Reducing agent. are: Ethyl hydroperoxide, 1-Oxyäthylhydro-

For the preparation of the polymers, the peroxide, isopropyl hydroperoxide, isobutyl hydropermonomer acrylonitrile or monomeric acrylonitrile 25 oxide, tert-butyl hydroperoxide, 1,1-dimethylpropyl together with a second monomer in organic hydroperoxide, ^ -Bromo-ljl-dirnethylpropylhydropernischen liquids, are used oxide, tert-butoxymethyl hydroperoxide, methylethyl polyacrylonitrile, z. B. Ν, Ν-dimethylformamide, ketone hydroperoxide, l-oxycyclopentyl hydroperoxide, Ν, Ν-dimethylacetarnide, y-butyrolactone, ethylenecar- l-ethylcyclohexyl hydroperoxide, 1-oxyhexyl hydroperbonate or dimethylsulphoxide, α-dimethyl, p-α-dimethyl, dissolved or with it 30 Isopropyl mixed. Instead of one of the mentioned solutions benzyl hydroperoxide, p-isopropyl-ÖCA-dimethylbenzylmittel, mixtures of these solvents hydroperoxide, tetralin hydroperoxide, 1,1-diphenyl to each other in any ratio and mixtures of ethyl hydroperoxide, l-methyl-l-torylundecyl hydroperd of these solvents with up to 25 ° can be used / ₀ other, low-oxide, decahydronaphthyl hydroperoxide, cumene hydroactive solvents, such as lower alkanols, peroxide, p-menthane hydroperoxide, phenyl- and naph-ketones, hydrocarbons and in particular acetyl hydroperoxide, p-methoxy-aja-dimethylbenzyltonitrile, can be used. The relative ratio of hydroperoxide, the hydroperoxide of 5- (4-isopropyl monomer, to solvents is more advantageous - phenyl) -2-pentene. Preferred hydroperoxides are wise in the range from 5 to 60% acrylonitrile, cumene hydroperoxide, p-menthane hydroperoxide, based on the total weight of the mixture, 40 butyl hydroperoxide, diisopropylbenzene hydroperoxide, preferably solutions are used which are between and methyl ethyl ketone hydroperoxide. The amount of 10 to 40 ° / ₀ containing monomer. The solvent preferred for the inventive hydroperoxide can be from 0.01 to 5.0% according to the process and preferably 0.05 to 3.0%, based on the N, N-dimethylformamide, with what weight of the in Both polyacrylonitrile solutions and solutions 45 monomers present in the reaction mixture vary.

of copolymers of acrylonitrile with alkyl acrylates Suitable reducing agents for the invention are

and methacrylates can be obtained. After each of the numerous oxygen and sulfur contains the monomeric acrylonitrile in the selected compounds, ie the sulfur atom should be dissolved or mixed with it under mild conditions due to the selected solvent, the reaction mixture is first cooled or 50 hydroperoxide compounds can be oxidized. The heated to the desired working temperature. The oxygen and sulfur-containing compounds, the invention is feasible satisfy this request in a temperature, can be in the following range of -70 to + 100 ° C, which temperatures are classified groups: are preferably between -50 to +50 ⁰ C. Thereafter

acids or compounds are added which serve to 55 1. Lower oxides of sulfur, such as sulfur _{sesquid, the oxygen} which is favorable for polymerization (j. _and sulfur dioxide.

Adjust pH to regulate viscosity.

Finally, the constituents of the catalyst oxygen acids 2. of the sulfur are low-valued combinations added, either all at once, like sulphurous acid, subliminal

or in portions or continuously during the 60 acid and thiosulfuric acid. ^ entire reaction process The _purpose> in detail _{3 alkyl esters of genann} th acids such Dialkylbenutzte method depends depend on which Maten- ^ _Mk yi _{m] ioxy} i _{ate and} Thiosulfite whose

alien to be used. If ζ B. sulfur dioxide the alkyl group in each case 1 to 4 carbon

Reduküonsmittel it is cheaper to get the desired _atQme ^ _{m like z ß diethylsulfit Äth h}

Amount during the completion of the polymer 65 sulfoxylate, diethyl thiosulfite. add cation reaction. In contrast, esters are the

Sulphurous acid with regard to the rate of addition. 4. Organic derivatives of low oxygen deficiency much less sensitive. In most cases, acids such as B. alkyl esters of sulfenic and sulphate

of example 10, by far the best. A comparison also shows that a tert-butyl hydroperoxide as the sole catalyst is not nearly as effective as the catalyst _{combination consisting of tert-butyl hydroperoxide and SO 2.}

In the following Table II, tests are compiled which were carried out in order to compare the polymerization of acrylonitrile to polyacrylonitrile in aqueous systems and in organic solvent systems with one another. Experiments No. 1, 2, 5 and 7 were made in ethylene carbonate, N ₅ N-dimethylformamide, ethylene carbonate and N, N-dimethyl

thylformamide as a solvent with a hydroperoxide and a tetravalent sulfur compound carried out, while for experiments 3 and 4 as the only catalyst an organic hydroperoxide used and the polymerization is otherwise carried out in a solvent for the polymer. Experiment no. 6 was carried out in water and using a hydroperoxide and sulphurous Acid (sulfur dioxide) carried out. All

o searches were carried out under the same temperatures and other conditions, with the exception of the Solvent and the particular catalyst used.

Table II

attempt
No. Grams of hydro
peroxide each
100 g of polymer Grams of sulfur
connection ever
100 g of polymer solvent found
sulfur
Parts per million Affinity for
basic
Dyes For a 90 ° / ₀ ige
conversion
required time
in hours 1 0.5 tert-butyl 0.1 SO ₂ Ethylene carbonate 39 excellent 4.5 2 0.5 tert-butyl 0.15 SO ₂ N, N-dimethyl
formamide 42 excellent 6th 3 1.0 tert-butyl without Ethylene carbonate <6 very bad 72 4th 1,5-cumene- without Dimethyl
sulfoxide <6 very bad 56 5 0.5 cumene 0.4 adduct
of NaHSO ₃
and acetone Ethylene carbonate 26th Well 6.8 6th 0.5 tert-butyl sulphurous acid water <15 bad 10 to 12 7th 0.5 tert-butyl 0.05 SO ₂
1.5 NaHSO ₃
Adduct of
acetone N, N-dimethyl
formamide 36 excellent 6.5

The test results compiled in Table II show that tests Nos. 3, 4 and 6 were inferior in two respects, namely a) reaction times of 72.56 and 10 to 12 hours, respectively, compared with only 4 ¹ Z ₂ to 6 hours were required for the process of the invention to achieve 90% conversion of the monomer to polymer and by b) the polymers obtained in Runs Nos. 3, 4 and 6 contained much less bound sulfur and, consequently, compared with the polymers of experiments 1, 2, 5 and 7 had practically no affinity for basic dyes, while the polymers obtained by the process of the invention (experiments 1, 2, 5 and 7) had good to excellent affinity for basic dyes. Accordingly, the polymerization reaction of acrylonitrile carried out in an organic solvent and using the catalyst system used in the process according to the invention differs fundamentally from one carried out using the same catalyst system in water or with a hydroperoxide catalyst alone in an organic solvent with regard to the reaction rate and the properties of the Polymers.

As well as polyacrylonitrile, useful copolymers can also be used according to the process of the invention of acrylonitrile. Suitable comonomers are vinyl, isopropenyl and allyl esters of carboxylic acids having 2 to 7 carbon atoms, such as Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and the corresponding isopropenyl and Allyl ester; Allyl alcohol; Alkyl acrylates and alkyl methacrylates, whose alkyl group contains 1 to 10 carbon atoms, such as methyl acrylate, ethyl acrylate, Butyl acrylate, tert-butyl acrylate, hexyl acrylate, decyl acrylate and the corresponding methacrylates; alicyclic acrylates and methacrylates, their alicyclic Group contains 5 to 8 carbon atoms or more, such as cyclopentyl acrylate, cyclohexyl acrylate,

2-norcamphanyim methacrylate; Vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; Vinylidene halides such as vinylidene chloride, vinylidene bromide, vinylidene chloride bromide, vinylidene fluoride; Acrylamide; Methacrylamide; N-alkyl acrylamides and N-alkyl methacrylamides, the alkyl groups of which contain 1 to 4 carbon atoms, such as N-methylacrylamide, N-isopropylacrylamide, N-butylacrylamide, N ₅ N-dimethylacrylamide, N, N-diisopropylacrylamide and the corresponding methacrylamides; Methacrylonitrile; Styrene compounds such as styrene itself, α-methylstyrene, α-acetoxystyrene, p-methylstyrene, p-acetaminostyrene; Vinyl pyridines such as 2-vinyl pyridine, 4-vinyl pyridine; N-vinyl lactams such as N-vinyl pyrrolidone; Acrylic acid; Methacrylic acid; α-chloroacrylic acid and salts of these acids; cyclic imides such as vinyl succinimide; Vinyl alkyl ketones, vinyl alkyl ethers and N-vinyl alkyl urethanes, the alkyl group of which in each case contains 1 to 4 carbon atoms, such as vinyl methyl ketone,

fic acids, the alkyl group of which has 1 to 4 carbon atoms contains, such as methyl, ethyl, butyl esters of methanesulfenic acid and the corresponding Ethanesulfenic acid esters, p-methylbenzenesulfinic acid as well as the corresponding free acids.

5. Simple halides such as thionyl chloride and sulfuryl chloride.

6. Organic halogen derivatives of the general formulas

X '

and

R '

: s = o

.0

X '

wherein R 'is in each case a hydrocarbon radical having 1 to 7 carbon atoms, such as a methyl, Ethyl, butyl, hexyl, cyclopentyl, cyclohexyl, phenyl or benzyl radical and X is a halogen atom, such as chlorine or bromine.

7. Alkali bisulfite addition compounds of aldehydes and ketones. These include addition products of acetone, methyl ethyl ketone or acetaldehyde with sodium bisulfite or addition products of acetophenone with potassium bisulfite.

The amount of the reducing sulfur compound can be from 0.0001 to 5.0 percent by weight, preferably 0.001 to 3.0 percent by weight, based on the monomer present, vary. Because sulfur dioxide is particularly effective is in

ίο In some cases only one track required. Dialkyl sulfites too are very well suited.

In addition, other known additives, such as phenols or alkyl mercaptans, for example tert-dodecyl mercaptan, in amounts of 0.001 to 2.0 percent by weight, based on the monomer to be polymerizing mixture can be added to regulate the molecular weight as usual. To the To set the desired pH, acids such as oxalic acid or phosphoric acid are added.

Those for the polymerization can be found in Table I below of acrylonitrile in comparison to the known processes carried out in solution Advantages of the method of the invention clearly emerge. Apart from the "initiator system", these examples always use the same substances. The chosen polymerization conditions correspond the optimal reaction conditions determined for each case.

Table I. example

procedure

Temperature, ⁰ C

Time, hours

Amount of catalyst, based on
monomeric material,%

"Initiator"
Solvent.

Yield,% ■
Color (a)

Inherent viscosity

Tear strength of threads spun from the solution

Bonding temperature of the threads, ⁰ C

(a) The color was measured by comparison with standard solutions of sodium dichromate.

(b) benzoyl peroxide as the sole catalyst can not be used at 3O ⁰ C, because the reaction rate is too small

Thermal
Decomposition of
Peroxides Peroxide with
Amine promoter Hydroperoxide Hydroperoxide
-SO ₂ 50 (b) 35 35 30th 8th 24 24 24 2 2 peroxide
0.1 amine 2 1 hydroperoxide
0.5 SO ₂ Benzoyl peroxide Acetyl peroxide
triethylamine tert-butyl
hydroperoxide tert-butyl
hydroperoxide Dimethyl
formamide Dimethyl
formamide Dimethyl
formamide Dimethyl
formamide 40 52.3 <10 93.2 B> 150 parts
per million 70 teüe
per million not
detectable <5 parts
per million 0.36 0.98 - 1.57 1.2 g / den 1.73 g / den not spun 2.89 g / den 193 226 240

In detail it can be seen from the table that according to the method of the invention (Example D) in lower temperatures compared to a yield of only 52.3% for Example B, 40% for the example A and less than 10% for the example C, very high yields of 93.2% can be obtained. It also has polyacrylonitrile of example D has the highest inherent viscosity. Threads spun from it have the highest tear strength and sticking temperature. The color of the polyacrylonitrile obtained by the process according to the invention is also except for those of the product

9 10

Vinyl ethyl ketone, vinyl butyl ketone, vinyl methyl ether, cleaning spun into threads. The receiving

Vinyl butyl ether, N-vinyl ethyl urethane, N-vinyl butyl threads were drawn by 400%.

urethane; Vinyl sulfonamide compounds such as vinyl tear strength 35 g / denier

sulfonamide, N-vinylmethylsulfonamide, N-vinylbutyl elongation 3l '° /

sulfonamide; Vinyl sulfonic acid and allyl sulfonic acid 5 color almost white

and alkali metal salts of these acids, such as vinylsulfonic tack 245 ⁰ C.

acid sodium; unsaturated acid sulphates and pour point 256 ° C

Phosphates, such as sodium allyl sulfate, disodium allyl

phosphate and other compounds of this type, of. . who are known to have an affinity for basic dyestuffs io B e ι s ρ ι e 1 2 substances, such as maleic, fumaric, itaconic and 400 g of acrylonitrile were with 32 g of N-isopropylacryl-citraconic acid; further dialkyl maleate, dialkyl amide and 1150 g Ν, Ν-dimethylformamide mixed, fumarate, dialkyl itaconate and dialkyl citraconate. 1 g of phosphoric acid was added and the alkyl groups in each case heated to 1 to 35 ° C. The reaction mixture containing 4 carbon atoms, such as dimethyl maleate, 15 was stirred under nitrogen and, based on the dibutyl fumarate; Amides and ester amides, such as fumaric monomers, 1.0 ° / ₀ cumene hydroperoxide and 1.0 ° / ₀ amide, maleamide, itaconamide, N-Methylfumaramid, Diäthylsulfit over a period of 16 hours NN-Diäthylfumaramid; Fumaramate, maleamate, added. After 24 hours a viscous solution was itaconamate and citraconamate; Ethylene, isobutylene, emerged that 93.6 ° / ₀ of the theoretically possible propylene. The proportion of the comonomer can contain any amount of polymers. This solution was almost worth up to 50 percent by weight of the monomeric colorless, ie it was less colored than a solution mixture would assume, with the remainder consisting of acrylonitrile of 5 parts of sodium dichromate in a million. However, preferred monomeric mi- parts become water. The inherent viscosity of the mixture used, which was about 70 to 95 weight copolymers, was 1.42. Filaments spun after a dry spinning percentage of acrylonitrile and 30 to 50 percent by weight were almost white and contained the comonomer in question. possessed the following characteristics:

The method of the invention can also be advantageous. ,. ".. _{/ rN} .

possibly in the presence of various known tensile strengths 2.44g / denier

Additives such as fillers, pigments, carried out advertising ^ T ¹ ™ ² <Izo '£

the. The method of the invention may be 228 C because of the glue temperature

Reaction times and the extremely rapid reaction flow point 242 ° C

speed between the hydroperoxide and _. . ., - ,,,,. ,, ■ ■ _1N

of the reducing sulfur compound also B e 1 s ρ 1 e 1 3 (comparative example)

be carried out continuously. This example shows the disadvantages for the sake of comparison

The use of benzoyl peroxide alone or in combination with procedures which have been carried out in practice can be lysator components continuously in various combinations with sulfur dioxide as a catalyst Zones of the reaction vessel are introduced. The one carried out in Ν, Ν-dimethylformamide solution The reaction vessel itself consists in its simplest polymerization of acrylonitrile. Form from a cylinder, on its surface 50 g of acrylonitrile were with 100 g of N, N-dimethyl

and numerous openings 40 mixed with formamide along the longitudinal axis. To the mixture was added 0.5 g has through which the catalyst components are added a phosphoric acid and then the mixture can be injected. The mono is heated to 35 ° C. About one was added to the mixture mers or the monomers, the solvents and a period of 16 hours 0.5 g in 10 ml of N, N-Didie "Regulators" at one end of the reaction methylformamide, dissolved benzoyl peroxide is pumped in, After this time, only a trace of poly-polymerizing material had remained Mixture is formed to the extent that it is added. The attempt was made using is how the mixture through the reaction vessel of 0.5 g of benzoyl peroxide and 0.1 g of sulfur dioxide, flows. In the reaction vessel, the polymer is also deposited over a period of 16 hours obtained solutions that were added directly to films or threads in a distributed manner, repeated. Again was can be processed. 50 polymer formed only in traces, although the

Preferably normal atmospheric pressures will be the reaction mixture had discolored considerably for the polymerization process of the invention

used, regardless of whether the procedure Example 4

is carried out batchwise or continuously.

However, higher or lower pressures than 55 480 g acrylonitrile, 32 g Ν, Ν-dimethylacrylamide, Atmospheric pressures may be used. 4 g oxalic acid and 1150 g Ν, Ν-dimethylformamide

were mixed and ^{kept at 30 0} C in a

Example 1 brought reaction vessel. 4.5 g p-menthane hydroper

oxide and 1.5 g of sulfur dioxide were in each case

50 g of acrylonitrile were dissolved with 100 g of N, N-dimethyl 60 20 ml of Ν, Ν-dimethylformamide. These solutions were mixed with formamide and the mixture cooled to -40 ⁰ C were then cooled in the course of 16 hours with the same. For this purpose, 0.5 g of cumene hydroperoxide and speeds were pumped into the reaction vessel. 0.01 g of sulfur dioxide in the course of 16 hours. After 24 hours, the reaction was stopped and added (continuously). It has a 93 ° / "strength was obtained from the in yield of polymer, the solution obtained in the 65 Ν, Ν-Dimethylf ormamid dissolved polymer a 92.3 ° / _o yield, medium at 35 ° C was soluble . This solution was less colored than a solution

To demonstrate beneficial properties, 2 parts of sodium dichromate in a million this solution without filtration or any other additional parts of water.

11 12

To demonstrate advantageous properties, threads were spun in water by pulling openings from it threads spun by the solution in an oriented and drawn through state. Heat heated chamber (190 ° C) and stabilized by small openings, pressed and then the threads in the ratio _, ",".,. . "_.", _.

4: 1 were drawn. 5 Tensile strength 3.21 g / denier

Elongation 26%

Denier 7 adhesive temperature 240 ⁰ C

Tear strength 2.51 g / denier, pour point 256 ° C

Elongation 28%

Gluing temperature 242 ° C

Pour point.,. 255 ° C ¹⁰ Example 8

Ironing temperature 220 ° C _ _,,. _. . _{τ Λ} , -. , _ _r . ,

Color ... excellent ¹ ^ Jf ^{1 J} f ⁸ ^ f ⁴ ^ sdraebenen method

94 g of acrylonitrile and 6 g of methyl acrylate were in

The color stability of a 300 g γ-butyrolactone woven from these threads is polymerized. To the polymeri fabric to initiate or effect in 2% sodium carbonate solution at 15 sation, 1 g 100 ° C for one hour was excellent, cumene hydroperoxide and 1.5 g diethyl sulfite were added although no stabilizer or pigment was added to the At 25 ° C it was a 96% yield in 16 hours Material was added. of the polymer. The polymer solution was

spun into fibers that exhibited excellent physical properties Example 5 ^ao.

28 g of acrylonitrile were mixed with 72 g of dimethyl sulfoxide. Example 9

mixed and added 0.1 g of phosphoric acid. These

Mixture was heated to 45 ° C and 0.028 g of tert-80 g of acrylonitrile and 20 g of methyl acrylate were in

Butyl hydroperoxide and 0.028 g of di-n-propyl sulfite as 300 g of Ν, Ν-dimethylacetamide according to the set in Example 4. After 24 hours, a 94.2% yield of the process described had polymerized. Based on the colorless polymer formed which had its own, the monomers were 1% methyl ethyl ketone hydro viscosity of 1.67. The polymer was added in peroxide and 0.5% diethyl sulfite. Soluble in the solvent. Temperature of Q ⁰ C was the polymerization in

From the solution were directly, i. H. without every 30 32 hours (practically) ended. It became a solution further cleaning, films poured. As a casting base for a polymer with an inherent viscosity of 2.1 glass plates were used for this, which were then obtained in This polymer solution provided excellent water were soaked to the solvent nete films.

to remove. The films obtained were colorless, example 10

transparent and of excellent strength and 35

Dimensional stability after orientation. Following the procedure described in Example 4

. . a copolymer with the composition 85%

Example 6 Acrylonitrile and 15% methyl methacrylate at -50 ° C

Prepared according to the procedure described in Example 5. The solvent used was N, N-dimethyl Acrylonitrile polymerized in γ-butyrolactone. There 40 acetamid and for the initiation and implementation was a 91.0% yield of polymers with the polymerization of 1% tert-butyl hydroperoxide and Obtained an inherent viscosity of 1.37, from the films used 0.5% sulfuryl chloride. It got a 91% rate of excellent transparency and filaments obtained with yield of the copolymer. Out of the solution drawn color and strength. of the copolymer films could be produced The following table shows the properties of the 45 which had excellent properties spun by a wet spinning process and

then threads drawn in a ratio of 4: 1 Example "11 ■

compiled.

_. "" ..,. "._ _lr . . Following the procedure described in Example 4

_Tear strength 2.42 g / denier χο ^^ _{eiQ 90} “ _{/ o acrylonitrile and 10} % methyl acrylate

in w ^ng '''+"'" ilrJ »containing copolymer. in ethylene carbonate

Temperature 238 C _3S * _{C nergesteUt} A ₁₅ polymerization catalysts

hüeUpunlct, 256 C were 1% p-menthane hydroperoxide and 1% one

. -17 adducts of sodium bisulfite and cyclohexanone,

Example _g5 j _ewe u _s based on the monomers used. It

480 g of acrylonitrile were with 1150 g of Äthylencarbo- was an 89% yield of the copolymer in

of course mixed. For this purpose, 4.5 g of diisopropylbenzene were obtained for 24 hours. From this after a wet spinning

Hydroperoxide and 3.5 g of di-n-butyl sulfite added in the process produced threads were practically colorless

and the reaction mixture is heated to 35 ° C. Gradually and possessed excellent physical properties

For 24 hours a colorless solution of poly-shafts became. . . ;

meren received. This solution was based on its color BeisDiell2 Stability examined by taking a week on

80 ° C was heated. After a week had to follow the procedure described in Example 4

the solution developed a color that became the color of an 80% acrylonitrile and 2Q% of the aerylic acid

Solution of 10 parts in one million parts of water containing 65 esters of 2-norcamphanylmethanol

dissolved sodium dichromate. Copolymers made in N, N-dimethylformamide.

The end product was obtained in the form of a solution to demonstrate advantageous properties.

from this solution by squeezing through small th, the; exhibited very little haze.

13 14

Example 13 Experiment C: Use of a catalyst system

according to the method of the invention for polymer

According to the method described in Example 4 _sat i _on of acrylonitrile in dimethyl sulfoxide as

became a copolymer containing 80% acrylonitrile and solvent
Contained 20% S-methyl ^ -norcamphanyl methacrylate, 5

polymerized in Ν, Ν-dimethylformamide. The poly In a reaction vessel, 1100 g of dimethyl

mere was obtained in the form of a solution that directly sulfoxide, 400 g of acrylonitrile, 2 g of tert-butyl hydroper-

to films and threads with excellent physical oxide and 1.0 g of an acetone-sodium bisulfite additive

Kalischen properties could be processed. tion connection introduced.

If instead of in the previous examples io The reaction mixture was stirred at 25 ⁰ C play comonomers listed other comonomer After a reaction time of 3 hours, was mere either in the same amount or in reacting a polymer in a yield of 80 to any amount within the stated range up to 85%. After a polymerization time of 4 hours, 50% of the comonomer content had been replaced, the polymer yield was 90%. The poly-like solutions obtained, which likewise had an intrinsic viscosity of 1.52 directly merisate, and could be spun into threads or spun directly into shaped articles for this reason. The solution, which had excellent properties in every case, had only a slightly yellow color, which could be processed. - compared to the APHA (American Public Health

. . , Association) scale - equivalent to 200 ppm.

Example 14 _ao If the reaction was ^{carried out at 40 °} C., it was obtained

To further illustrate the comparison with the one by 2 ¹ / _a hour reaction time, the polymer

drive the invention achievable progress were in a yield of 88.3% The product was also

the following experiments A to, E carried out: if hardly discolored.

Experiment D: The acetone-sodium bisulfite addition

Experiment A: Use of a catalyst system ^Z5 Compound of the catalyst redox system of Ver. According to the process of the invention for polymer _suc hc was replaced by sodium bisulfite
sation of acrylonitrile in dimethylformamide as (comparative experiment)

Solvent ^. ,,. ,,,. ",." _. .., ^. ,.

The mixture was stirred at 25 ° C. After a

1100 g of dimethyl were placed in a reaction vessel. The reaction time was 4 hours formamide, 470 g of acrylonitrile, 4.7 g of tert-butyl hydroper polymer, 26.3%. The solution had a dark oxide and 3.4 g of an acetone-sodium bisulfite addition yellow color, which - compared with the APHA compound brought in. Scale - 500 ppm corresponded.

The mixture was stirred ^{at 25 ° C.} After a 24 hour reaction, the

The reaction time of 3 hours was a polymer. Yield of polymer was only 26.8%. As with B obtained in a yield of 80 to 85%. This was undissolved sodium bisulfite in the reaction solution was slightly light yellow in color. Watch the poly- mix.

merisat had an inherent viscosity of 1.2 and was also suitable from this comparison test

excellent for spinning. that sodium bisulfite is not due to its insolubility

After a reaction time of 4 hours, it was 40 as the reducing component of the catalyst redox system Polymer yield 87.6%. can work.

The reaction was ^{carried out at 25 0} C, since at

higher temperatures, the implementation rate is so large that the documents of patent 606 616, which were removed during the polymerization

standing heat is difficult to dissipate 45 (comparative experiment)

Two attempts were made, namely:

Experiment B: Use of sodium bisulfite at 1. with methyl isobutyl ketone peroxide as a catalyst site of the addition used in experiment A ^and d

Product (comparison test) 5 <> ₂ . with a mixture of methyl isobutyl ketone

^ _xr,. ,,. , _TT ",, peroxide and sodium bisulfite as a catalyst.

The procedure described under Experiment A was used

repeated, with the exception that, instead of the

Acetone-sodium bisulfite addition compound this time, 67% polymer was obtained.

Sodium bisulfite was used. Mixture 55 In Experiment 2, the yield improved

was again stirred at 25 ⁰ C. Not after 24 hours of a 3 hour reaction time.

no polymer had yet formed. The result of these experiments clearly shows that

the reaction temperature increased to 60 to 70 ° C, a catalyst combination consisting of one

A small amount of polymer formed. This organic peroxide and an alkali bisulfite, none

however, possessed a low molecular weight and was 60 advantages.

colored dark yellow. Experiments A and C clearly show that

It was clearly observed that the Na- that used in the method of the invention

trium bisulfite did not dissolve in the reaction mixture. Catalyst systems at low temperatures high

This comparative experiment shows that the polymer yields good color properties Alkali bisulphite due to its insolubility in the reac- 65 and good spinning properties. The solutions tion mixture cannot be spun directly as part of the catalyst redox without further treatment System can have an effect what also becomes out of the non-merging. From experiments B, D and E enter a polymerization of the acrylonitrile emerges. clearly shows that when using sodium

Msulfite as a reducing part of the "catalyst system" Do not allow the desired results to be achieved, in particular one gets doing so, even with strong extended reaction times, lower yields of polymer, which are also heavily discolored. That • The molecular weight of the polymers produced according to experiments B, D and E was low. A direct one Spinning the polymer solutions from experiments B, D and E was not possible because they contained undissolved sodium bisulfite contained.

IO

Claims (1)

Claim: Process for the production of homo- or copolymers of acrylonitrile by polymerizing acrylonitrile or mixtures of at least 50 percent by weight of acrylonitrile and up to 50 percent by weight of other monoethylenically unsaturated compounds with a CH ₂ = C = c group in solvents for polyacrylonitrile at temperatures from -70 to +100 ⁰ C in the presence of redox catalyst systems a) Hydroperoxides of the general formula R-OOH wherein R is a monovalent aliphatic, alicyclic or aromatic group, the is linked to the hydroperoxy group by a carbon atom and b) reducing sulfur compounds, characterized in that as reducing sulfur compounds, lower oxides of sulfur, sulfur-oxygen acids a low oxidation state or alkyl esters of these acids, sulfur halides, organic sulfur compounds of the general formulas R \ : s = o or X '
R \ X ' ¹ N wherein R 'is a hydrocarbon radical having 1 to 7 carbon atoms and X is a halogen' atom means, or alkali bisulfite addition compounds of aldehydes or ketones can be used. Considered publications: German Auslegeschrift No. 1066 355;
Belgian Patent No. 572 665;
laid out documents of Belgian patent No. 616. 809 519/658 3.68 © Bundesdruckerei Berlin