DE1645276C - Process for the production of thermally stable, spinnable acrylonite homo or copolymers with a high acrylic content - Google Patents

Description

I 645

• Ο

From those produced by the usual methods Spinning solutions of Acrylonilrilhonio- and Niischpolyniensalen with high acrylic metal content in dimethyl film As is well known, one generally receives be-Irächllicli yellow filaments, and the solutions selhsl 5 are very dark.

The production is from the Belgian patent 572 6f> 5 of spunbonded acrylic polymers or copolymers!) with sodium allyl sulfonate and Mcihylacivlai in dimethylformamide using m known from catalysts. Either organic peroxides alone can be used here as catalysts but preferably (ichraucli made of a redox systcin. that of an organic Pero \ yd (or an Azovei bond), SO., And a Ion of an oxidizable metal, such as Ie, or an anilite crival.

As can be seen, in this known process the presence of a reducible compound such as SO _{2 is} necessary, the SO ₂ obviously representing part of a redox catalyst which always consists of a radical generator and a reducing compound.

The main disadvantages of this known process are the inevitable corrosion effects the .sulfur dioxide exerts on the metal parts of the device, as well as the health risks Uedieniingspersoiials.

With the use of reducing agents, preferably \ on Ί hioliainstolTilioxyd in amounts \ on I to jo } (icwiclilspro / cnl. Based on the (iewichl of the monomers, lsi in the polymerization of acrylonitrile in a concentrated solution of an inorganic I hiocyaual ·. At pl l- Wc-rlen from. '.;> to. \ 5 in i \ cn lall hel.anul. In which al-, catalysts azo compounds, 3S such as azodhsolnitv ronitrile are used. This makes it possible to keep the pII values would be 1111 the pole, η ier isation the I u rl ν of the spin η solution zii \ ei better and> \ d, to get out, which shows a constant behavior in the heat (dent- μ> siIk · \ ii-.lei.eM Iw ill I ίΙΧ ¹ ) 172).

\ uth the possibility. / Nerve init ilpolv iiui isallösim-J ¹ CIi in dimethylformamide vr later (ielbfäi bum ¹ / n preserve by adding I luoharnMolfdioxvd 054 454. Hek.iiiiit. The Ihioharnsioffdioxul winl in amounts of more than 1 "/", based on the Polymcrisalgcwichl. 'Egg helix.

Is v.iiide mm a Vei drive for the production of son ;, <> thermally stable, spinnable acylnilnl homo- or -ιπί · ι.Ιιρ (> Ιν ineiisaten with a high proportion of acrylonitrile diiivh Pr.lvineiisienien of acrylonitrile, possibly together with) Sulphate and Melhylmelliacry IaI or with Alhvlacrylal. found in dimethylforinamide in the presence of an organic peroxide analyte which is characterized thereby. dal.) in (iegcnwarl of I hiourea dioxide in an amount of less than 0.1 "/", based on the (iusaintgcwichl der Moiioinefeii. pol> mciisiert is 6 »

It has been ascertained that! mau dadimli Can produce polymers, which in turn result in spun thread, because lic is the most desirable (irail der Wcil.'e, ti. II. the most suitable optical characteristics In η for industrial Virwirlunj; own.

I s ImI see shown that the / usal / animal »is rather small Miiijrn I hn'h.iinslolTdioxyd not only the ittldung silii hellt 1> pinnbari 1 I ösiiiigen by atil'eisl sthwacher Yellowing enables, but also the other important advantage that. " the spinning solutions and the spun threads obtained from them later in the warmth do not have the known harmful (yellow color exhibit.

The applicable procedure is in particular for the production of learning copolymers from more than S "/" acrylonitrile together with Nalriuniallylsulfonat and Methylmeihacrylal angi "andt.

In this case, the polymerization process is preferably carried out in one mass, but a high one Monoineienanleil contains, and the polymerization is interrupted at a point in which only one Part, in principle not more than a third, of the monomers is converted.

The invention thus brings with it a significant and unexpected technical problem, the has a double effect: on the one hand on the thermal stability of the spun threads obtained from spinning solutions obtained by polymerizing acrylonitrile in dimethylformamide using of organic peroxides, for example l.auryl peroxide. are produced as catalysts, and for others especially with regard to the surprising fact that already very low, under 0.1 "/" (based on the weight of the monomers) amounts of thiourea dioxide are all capable are to bring about an important improvement in the degree of brightness of the spinning solutions obtained.

In particular, it was surprisingly found, dall the purposes specified already be achieved when instead of over l. _"; Shares in I hioharnstolTdiowd lying _lp which so far as necessary w eiaehtet nid.-η. the Ί hioharnstofldioxsd in quantities of only 0:02 to 0:04 "" (Based on the weight of the monomers used) added. Reducing the amount of iourea dioxide to more than 0.1% does not result in any improvement in the results.

IJ e i s ρ i e I I

In a Rcaklion.sgef.il! au ·. Glass with a capacity of 2 liters. four llKcu. an agitator, I lierinometer. Return oil cooler. Stick toffemlali tubes and an I! ιιτηιο>! ilen set to (.0 C) Introduced in sequence:

1. (it / 5 g of distilled dimethylformamide,

2. 3.2r> g nairium allyl sulfonate.

Ϊ MWg distilled acrylonitrile.

4. 15 g of distilled methylene methacrylate.

5. 0.12 g of I hiohainsloffdioxyd.

The Ί hioliarnstoffdioxyd represents, as from above Quantities can be seen, practically about 0.02.1 ". ',, de «weight of the introduced monomers.

The mass introduced is slowly stirred and heated to a temperature of about 58 ° C. Then 2.K g of 1 aurylpcroxyd is dissolved in 50 g of dimethylformamide, which forms one of the f.05 g listed at the beginning. The temperature rises by a few (IRAD. Meaning that the polymerization has begun. After 20 minutes, the mass erseheint turbid, and the polymerization is continued with stirring at a temperature -r / wipe 60, and ( "5 C. After 4stiindigcf polymerization, when the mass has assumed a doughy, thick consoles /, 55.0 g of cold dimethylformamide are added in order to interrupt the conversion at the desired value.

The local, homogeneous mass is de- * i illicit with a vacuum until one obtains 120 μl of a clear solution which contains a mixed polymer. This solution is very easy to produce a WeiUegrad hesil / s, compared to that of Mm filaments that are erhallen from a solution, which was prepared in the same manner but without addition of the indicated very small amount ThNihurnsioffdioxyd. much improved isl. i _Q

These solutions are therefore extremely cheap for the Proof of spun thread with high qualitative properties, be it because of the stated reasons.! - tigeiischaflen. be it because of their molecular weight \ (iii 65 I) OU (especially suitable for spinning), be it because of the high polyacrylonitrile content.

H e i s ρ i e I 2

In a reaction vessel 1 with a 3 liter capacity, four necks, a stirrer, Ihermomeler, RüeklluBkühler, Slicklaffeinlal.iröhrehen iiiul thermostats are introduced in sequence:

1. 605 g of distilled dimethylformamide,

2. K, 5 g Nalriuinallylsulfonat,

3.5'JOg acrylonitrile,

4. 15 g methyl methacrylate,

5. 0.16 g Ί I iourea dioxide.

The polymerisation process is initially carried out as in As described in Example I, i. H. the one on 5S C heated mass becomes a l. o in 50 g of dimethylformamide, which form a listed 605 g, added.

The polymerization is thereby turned on. and the temperature rises in a period of 20 minutes.! 5 a few (irad. After this period, the polymerization takes about 4 hours at M) to 65 C foihie-U ¹ IzI. after which the mass becomes doughy and no stirring / t. Is then becomes one from 550 g of dimethylformamide. 5 g of methyl methacrylate and lau- [ orylproxyd existing solution added, and the 'mass, which is again IHK, ig. will be continued. The permissible temperature rises to about 70 ° C. and we work under such controlled conditions that the polymerization can proceed regularly until a cicsanite conversion of 70 "" is reached.

The liquid mass becomes the unreacted Monomers immediately sealed under vacuum. • The distillation is continued until pure Dimethylformamide passes over. Only enough dimethylformamide is added to the viscous solution that one a \ iscose solution with 20 "" mixed polymer is obtained, which is slightly yellow in color and from which spun threads are made with a high degree of whiteness. The copolymer obtained had a molecular weight from 50,000.

U e i s ρ i e I 3

Ir. a 2-liter reaction gradient according to the Ik-ispiel I.

1. a mix of

426 g dimethylformamide,

5 ¹ K) g of acrylonitrile.

32 g of ethyl acrylate,

0.17 g of thiourea dioxide and

2. 13Sg introduced a filtered 6 "_'ll strength Natriuinallylsulfonallösung in Dimethylformamiil.

After heating to 58 ° C. with stirring, 2 g of lauryl peroxide dissolved in 40 g of dimethylformamide are added to the seed (part of the 426 g DMF- under I) added.

The polymerization is carried out until the end of the day 4 hours for the first polymerization period at M) to C carried out analogously to Example 2, after which a further 550 g of dimethylformamide, in which I g of lauryl peroxide dissolved 11I, are added and the mass, which reaches a temperature of 70 C, is stirred until a conversion level of about 70 "" is reached. The unreacted monomers are then distilled off from the mass in vacuo. Man receives a viscous solution, the approx. 20 "" mixed polymer \ om molecular weight 52 0 (M) contains. The viscous solution has a high brightness> i: rad and delivers filaments with very good VV -.- iligra-.l.

Claims (2)

Patent claims: 1. Procedure for learning from Iheinii Ji stable, \ spinnable Aerylnilrilhoino- or -mixed polymers !! with a high \ nkil of acrylonitrile by polymerizing \ ciyliutril. possibly together with N.anumallylsulfuii.il and Mclhylmelhacry IaI or with Alhy latry 1.11. in Dimethylformamide in the presence of an οιυμμι Pei'iK \ ydkatalysators, marked thereby e i c h net that in (legend of [hioh.iinstoffdioxyd in an amount of less than 0.1 "". based on the (total weight of the Moiiomeun, is polymerized. 2. The method according to claim I, characterized gekennz.-jchncl, since »0.0? up to 0.04 ",,, based on d: u (i cs.m.tgjwitht of the mononures, thiourine dioxide be-.ctzl and the polymerization is interrupted. if the in the initial enjoyment no more than a third of the monomers contained therein are polymerized, after which the Separating monomers from the solution.