DE1520207A1 - Process for the post-chlorination of polyvinyl chloride in aqueous suspension - Google Patents

Description

FRANKFURT (MAIN),

Lonza AG ·, Gampel (Canton Valais), Switzerland. Management: Basel (Sohweiz).

Process for the JUaohchlorierung of polyvinyl chloride in aqueous suspension.

The invention relates to the production of polymers with polyvinyl chloride that is higher than that of non-post-chlorinated polyvinyl chloride Softening point and greater thermal stability chlorination of polyvinyl chloride.

It is known to post-chlorinate Poiv; Manufacture synthetic resins which differ in their _ from the initial properties.

be liable

is also known to carry out the chlorination of polyvinyl chloride in aqueous suspension at 'temperatures below 65 ⁰ G in the presence of chlorinated hydrocarbons with a G-atom and liestranlung to actinic light. The strong light absorption leads to inhomogeneous irradiation and thus to an irregular course of the reaction. In addition, it is industrially very laborious and expensive to irradiate large amounts of reaction medium.

It is also known. Polyvinyl chloride in chlorinated

009826/1943

BATH ORIGINAL.

-S

Suspending hydrocarbons and cachchlorination in the presence of azo compounds "at temperatures below 80 ° 0 to be carried out in order to promote the chlorination process » becomes the hydrogen chloride formed during the chlorination continuously discharged. With this method, the viscosity increases the suspension im buying the reaction esu what an uneven Distribution of the chlorine in the reaction mixture and thus a uniform chlorination results. This method also requires long reaction times and is due to the consumption of large amounts of chlorinated hydrocarbons and methanol to precipitate the post-chlorinated polyvinyl chloride very uneconomical,

It has now been found that a for üachchiarieren of polyvinyl chloride wad over the aforementioned prior i'eciinik technologically improved process to products with increased softening point greater 'Jhermostabilität leads, the special advantage is the rapid absorption of the chlorine. The rapid execution of the jaachlarierung is important because in the iiaehchlorierung. if it is effected over a longer period of time, the length of the molecular chains is reduced.

The process of the invention for the post-chlorination of polyvinyl chloride in the presence of low-boiling aliphatic chlorine-substituted hydrocarbons and hydrochloric acid at temperatures below 70 ° by the action of chlorine is characterized in that the awake chlorination reaction in the presence of radical-forming azo compounds at temperatures of 30 ° -70 ° C, preferably 45-55 ° C, is carried out.

In this way, not only homomers of vinyl chloride with different K values can be post-chlorinated, but also copolymers of vinyl chloride with small proportions of other unsaturated compounds «,

According to the invention it is possible to use polyvinyl chloride chlorine different K values.

009826/19 A3

BATH ORIGINAL

Zweokmäseigerweise an aqueous suspension with a Solids content of 100-1500 g polymer / 1 water used.

The low-boiling aliphatic monosubstituted hydrocarbons, z. B. Tetraohioraethan, ethylene dichloride and Carbon tetrachloride, as well as preferably Öhioroform two-mass wise in the ratio of 20 to 13o wt. $, preferably 4o - 7o wt., Based on the amount of polymer, the aqueous dispersion added.

The halogenation catalysts used are radical-forming azo compounds, z. "JB .. azomethane, diazomethane, Mazoami do benzene, Cyanuric acid triazide, azoisopropane, azobenzene, azotoluene, Azodiisobutyramide, azo-bis- {a, Y) -dimethylvaleronitrile, azohexanedihydrobenzonitrile and preferably azoisobutyric acid nitrile is used.

The halogenation catalysts are expediently dispersed in the reaction medium in a ratio of 0.1-5% by weight, preferably 0.75-2% by weight, based on the amount of polymer. However, it is advantageous vorgangig to dissolve the catalyst aliphatic in low boiling ohlorsubstituierten hydrocarbon and admix until the suspension · The Itatalysatorhaltige suspension is heated to temperatures of 3o - 7o ⁰ C, preferably 45 - 55 ° G, heated, and there are too - 1500 g, preferably 200-1000 g, of chlorine gas per hour fed to 100 g of polymer to be olilated.

About the formation of the oxidizing hypochlorous acid to avoid the suspension with such an iaenge Acidified hydrogen chloride, which - based on the iOlymyr 5o - 300 wt. J ", preferably 100 - 17o wt.>", One 36 ', iLgen aqueous hydrogen chloride solution.

The presence of hydrogen chloride in the reaction mixture. Has not just the binn, the formation of under-chlorinated acid to avoid, but also the one, the receptivity of the

0 0 9 8 2 6/1943 ^BAD original

liquid phase for chlorine to enlarge. This leads to a homogeneous reaction process.

example 1

For three comparison tests, 15o g (A) and 25o g (B) or 4-00 g (σ) polyvinyl chloride suspension polymer from K value Yo suspended in boo ml of water. This will be under Stir 125 ml of chloroform in which 3 β azodiisobutyrnitrile are dissolved, introduced into the suspension. Sehlieeelioh nooh 4oo ml of 36% hydrochloric acid are added.

Each of these mixtures is placed in a chlorination apparatus and treated in the same way.

The chlorination apparatus consists of a 3 Jüiter round bottom flask, which is equipped with an intensive agitator, a gas inlet pipe with frit and a reflux system is. The Rückfiussystera must be of very intense effect (energy cooler) so that the chloroform is not removed from the reaction mixture by the outflowing chlorine can be. The chlorination apparatus is located in a thermostatted water bath at 55 ° C.

To remove the oxygen, nitrogen is passed through the reaction mixture for about 5 minutes. Chlorine is then passed in at a flow rate of 800 ml / min. After 3-5 minutes, the increase in the reaction temperature shows (at 5-7 ⁰ C) and the decrease in Chiorabflussgeschwindigkeit to the onset of the reaction. The reaction is carried out with exclusion of power.

After 2 hours, the supply of chlorine is interrupted, nitrogen is passed through to remove the chlorine from the reaction mixture, the end product is filtered, washed, in i? ^c / öiger soda solution neutralized (about 1 hour), washed again and dried at about 50 - 60 ° C.

The softening temperatures of the end products are:

009826/1943

Prod. A: ί Prod, Bi Prod. C: Starting PVO

146 ⁰ O with a chlorine content of: 71.25 f> 137 ^a G with a chlorine content of: 68.28 $ 129 ° 0 with a chlorine content of: 67 »74. St.

77 ° E with a chlorine content of *, 56.23 S *.

The softening temperature is determined on pressed test pieces 2 mm thick, 20 mm wide and 80 mm long, which are clamped in a holder frame in such a way that 20 mm of length are clamped and 60 mm freely overhanging horizontally. The samples are g loaded at its front end with a weight of 4 and suspended horizontally in a heating furnace with gleiohmassiger temperature distribution "The temperature increase is 5 ⁰ C per hour * When reaching the softening temperature of the front-loaded end of the specimen begins turn"

The products A, B, C and the starting material are used for the thermal stability test to a mass of the following composition processed;

94 parts PTO

4 parts bibasisohes lead phosphite 1 part lead stearate
1 part toibasisohes lead carat «,

The thermostability is determined by the larbveränderung at 1o-minutigem heating 2 - 4 g of substance determined in a test tube at 2OO ⁰ C,

The following results are achieved:

Color after 10 minutes after eating at 200 ° C

Prod. Av light brown to white

Prod * B: light brown

Prod. C: light brown to brown

Starting product: black (+ blistering as a result of strong

HCl elimination)

BATH ORIGINAL 009826/1943

Example 2

15o g PGlyvinyleiiloriä-SuapenaioiispoljnBisPisat. a K-Wert®s 7ο - Ti. are eixspskcliert in 3oq ml barrel "The suspension becomes ice. © solution \ ^? os. 1.5 g asodiisobutyronitrile. Ie 60 ml of chloroform added and then nooh-300 ml of concentrated Saissäiirs added.

The B ^ alrfeioEstemperature »are at the beginning 55 ° ö and reach a maximum of 61 - 62 ⁰ G ₉ The oklordurchfiussgswindig speed is 400 mx / min. The Aufaroeltisig- mid test of the end product is carried out as in Example 1 «, -.

Reaction time - öJi.Lorgeha.lt Sliermostabiiitat Soften-

(fcolor) temperatures

111 ⁰ O

145 ⁰ O

D. 0 »5 Ii 65 _? 6? * Brown until 2) 1 , ο H 66y 7o light brown
Brown until 3) 1 , 5 H To, 12th hel ± brown
Brown

300 g Polyvinjlöhiorid-Siispensionpölymerisat vom K-tfert 55 are suapeadied in 65o ml of water »to be in the suspension a solution of 2.5 g of aaodiisobutyronitrii under strong covering 4oo ml concentrated in 1 o mi oil form and attached to it Hydrochloric acid added · The% 3 action temperatures are on Atifaag 55 ° ö and reach a maximum of 61 ° 0. the Oral flow rate is set to 500 ml / min. The end product is worked up and tested as in the previous examples.

Reaction time Chlorine content Thermostability
(I _a rbe) Softening
temperatures 1) 1 h 65.37 mill Brown 12o ° C 2) 1.5 h 66.29 mill light brown to
Brown 13o ° C 3) 2.5 h 7o _f 43 Jt light brown 135 ° C Example 4

009826/1943

& AD ORIGINAL

- ^η ~

300 g of polyvinyl chloride suspension polymer from K-tfert are suspended in 65o ml of water} 2.5 g of azo-bis (a, Y) -dimethylvaleronitrile in 10 * o ml of chloroform and then 400 ml of 36% sales acid are added with vigorous stirring. The reaction temperature is set ^{to 55 ° C .;} it reaches during the reaction a maximum value of 60 ⁰ C. The ChlordurohflueBgeBchwindigkeit is set to 5oo ml / min. After processing and testing the end product according to Example 1, the following values are determined:

Reaction time chlorine content thermostability expansion. (Color) temperatures

1) 1 h 65, 67 * Brown 12o ⁰ G 2) 2.5 h Yo. 12 J6 light brown 135 ° σ Example 5 •

12o g Polyvinylchiorid-BmulsionspolymeriBat K value 7o are suspended in a mixture of 21o ml ffasser and 24o ml of 36? AIGER hydrochloric acid \ 45 ml of chloroform, which contains 1.5 g Azodiieobutyramid are added with stirring. The reaction temperature is adjusted to 50 ° C. The chlorine flow rate is 800 ml / min. The processing and testing of the end product is carried out according to Example 1.

Reaction time Chlorine content Thermostability
(Colour) Softening
temperatures 1) 2 h 6ö, 16? I light brown 137 ° G 24 hours 7o, 45 Ψ light brown to
White 145 ° G Example 6

120 g of polyvinyl chloride suspension polymer from K-Wet 70 are suspended in a mixture of 210 ml of water and 24o ml. 36% hydrochloric acid; 45 ml of Ohloroform, which contains 1.5 g of azohexanedihydrobenzonitrile, are added with stirring. The reaction temperature is set at 55 ⁰ C.

00 9 826/19 43

The increased chlorine flow rate is 100 ml / min. The processing and testing of the end product takes place according to example 1 «

Reaction time chlorine content thermostable! Did softening

(Color) temperatures

D. 2 H 66 .16 * light brown
fool around until 137 • 0 2) 4th H 7o .45 * light brown 145 • c 3) β H 72 , 13 # light brown
White until 148 • c

The softening temperatures given in the above examples are significantly higher than the K values given for the non-hollowed polyvinyl chloride, which are in the Bereloh tone 77 - 6o ^e G «

009826/1943

Claims (6)

Claims J. 1. Process for Jüaehchloriertn of polyvinyl chloride in aqueous suspension in the presence of low-boiling aliphatic chlorine-substituted hydrocarbons and hydrochloric acid at temperatures below 70 °. The action of chlorine, characterized in that the Haohohlorierungsreaktion in the presence of azo compounds radikalbildendtη at temperatures of 3o - 7o ° C _f is preferably 45 - 55 ° C, is performed. 2 · The method according to claim 1, characterized in that an aqueous suspension with a solids content of Too - 1500 g of polymer is used per liter of water. 3. The method according to claim 1 or 2, characterized gekennzeicnnet, that the low-boiling aliphatic chlorine-substituted hydrocarbons in a ratio of 20-13o wt.> 6, preferably 4o - 7o G6W.S &, based on the amount of polymer, the aqueous suspension can be added. 4 · / experienced according to claims 1-3 »daduroh characterized, that the radical-forming azo compounds in proportion of 0.1-3 parts by weight, preferably 0.75-2 parts by weight, based on the amount of polymer used 5. Process according to claims 1-4, characterized in that the radical-forming azo compound is azodiisobuttereaurenitrile is used. 6. The method according to claims 1-5, daduroh characterized in that with an amount of chlorine gas of 1oo-15oo g, preferably 2oo - 1ooo g, chlorine gas per hour, based on 1ooo g polymer to be chlorinated, is worked. / 7 · method according to claims 1-6 »daduroh characterized, that it is carried out in a reaction medium, the hydrogen chloride in an amount of 5o - 3oo Gew.?i, berecJinet based on a 36% "aqueous chlorinated wa * 8" solution on the polymer. 002826/1943