DE2352846A1 - POLYMERIZATION PROCESS - Google Patents

Description

DR. ING. A. VAN DERWERTH DR. FRANZ LEDE RE R

21 HAMBURG 9O β MÖNCHEN 8O

W1LSTORFER STR 32 TEL. (O4O> 77 08 61 'LUC! LE-GRAHN-STR. 22 TEL.tO8 III 47 29 * 7

Munich, October 19, 1973 Case CPE 54-23

BP CHEMICALS DRDERHAiDIOHAL LIMITED Britannic House, Moor Lane, London EC2X

• England

Polymerization process

The invention relates to a method for the polymerization of Yiny! Halides "

The polymerization of Yinylhalogenid containing monomers in aqueous emulsion using a water-soluble initiator, d _o - h "an initiator which largely distributed in the ifößrigen phase is" known In such polymerization, the necessary components under polymerization) CONDITIONS be stirred.! or otherwise mixed with one another. To maintain the dispersion of the monomer and / or the polymer in the aqueous phase, emulsifiers are used, and the particle size of the dispersion can be controlled by regulating the amount of emulsifier present

409818 / 11.04

DEUTSCHE BANK AO .. HARBURG 93/20813 POSTSCHECKi HAMBURG II732O-206 TEL EC RAM M Es LEATHER PATENT MÖNCHEN

it cannot be easily separated e.g. B. by conventional centrifugation procedures.

The use of an initiator soluble in the monomer in such a system results in a breakdown of the dispersion and the polymer is not in the form of discrete, dispersed Particles made. So far it has been used for manufacturing of a latex with an initiator soluble in the monomer is deemed necessary, drops of the monomer are desired To pre-form size prior to polymerization, usually by vigorous stirring or more often by homogenizing of the monomer with the water and the emulsifier »This technique has characteristics that are of a conventional emulsion polymerization are different, and therefore it is often referred to as the "microsuspension method". The main differences lie in the fact that only certain emulsifiers can be used to produce a stable microsuspension, and that the particle size depends almost entirely on the conditions used to prepare the initial microsuspension became. This means that the average particle size is usually larger and not due to changes in the Emulsifier content responds in the way that this is the case with a conventional emulsion polymerization is the case «, with a Microsuspension processes also generally involve very gentle agitation during the polymerization applied to avoid breakdown of the micro suspension.

It is an object of the invention to provide an improved emulsion polymerization process using an oil soluble Initiator.

The inventive method for the polymerization of a vinyl ■ halide-containing Monomers, in which the monomer is in a containing an emulsifier and a free radical initiator,

4098 18/1104

aqueous phase is polymerized, is characterized in that the initiator is an azo initiator and the polymerization ' at or below the saturation vapor pressure of the monomeric material under the prevailing conditions and "in practical absence of monomer droplets is carried out during the entire polymerization.

The vinyl halide-containing monomer should advantageously contain at least 70% by weight of vinyl halide. Monomeric compounds, which are known to copolymerize with vinyl halides, can constitute up to 30% by weight of the material. Examples of copolymerizable materials are: ethylene, propylene, Vinyl laurate, vinyl stearate, vinylidene chloride and acrylonitrile. The method according to the invention is particularly applicable to homopolymerization of vinyl chloride and for its copolymerization with less than 20% by weight of other copolymerizable materials applicable.

The aqueous phase and emulsifier are used as in the known emulsion polymerization procedures. These are z. B. in Volume IX of the monographs on the chemistry, physics and technology of high polymer substances, published by * Interscience Publishers, Inc., New York. Conventional Emulsifiers such as long chain alkyl or alkaryl sulfates or sulfonates can be used, but emulsifiers are in the form of soaps of saturated fatty acids, such as the alkali metal or ammonium salts of lauric, stearic, palmitic or myristic acid.

A free radical azo initiator must be used, examples of azo initiators include 2,2 · ^I-azo-bis- (2, ^2} dimethylvaleronitrile), 2,2 ^l-azo-bis- (2,4,4 -trimethylvaleronitrile), 2.2 ^l -azo-bis- (2,4-dimethyl-4-metho: xyvaleronitrile) or 1,1-azobis- (cyclooctanecarbonitrile). The preferred initiator is azobis (isobutyronitrile). ■ - ·

409818/1104

Practical absence of monomer droplets can be ensured by keeping the pressure in the reaction vessel at or below the saturation vapor pressure of the monomeric material is kept at the temperature prevailing in the reaction vessel. Liquid monomer is in equilibrium with steam at saturation vapor pressure, however, the presence can an insignificant amount of liquid monomer can be allowed. This result can be in an equilibrium system or continuous system, which does not contain any liquid monomer, by feeding the monomer into the polymerization vessel at no greater rate than that at which the monomer polymerizes.

The usual temperatures and phase ratios for the emulsion polymerization of. Vinyl halide can be applied.

The polymerization process according to the invention can be carried out batchwise or continuously. In particular, that is Process well suited for continuous operation, since the preferred mode of operation is to keep the polymerization system free of conomer droplets is continuous To introduce monomer into the system at no greater rate than that at which it is consumed by the polymerization. ■

The latex formed can be any of those known in the art Methods for obtaining vinyl halide polymer latices are obtained, e.g. B. by spray drying, coagulation or partial agglomeration with subsequent centrifugation.

In addition, suspending agents can also be present without seriously impairing the stability of the latex.

409818/1104

The invention is explained in more detail below with the aid of examples:

example 1

Vinyl chloride, 8350 ml

soft water '74-50 ml

Azo bis (isobutyronitrile)

(AZD10 19.1 g

Lauric acid _ - "

(Distec A 103) 152.8 g

Ammonia (880) 200 ml

6150 ml of water, which contain 15-3 g of lauric acid and 20 ml of ammonia in solution, and the AZDN were filled into the reaction vessel. The reaction vessel was flushed twice with pure nitrogen (white spot nitrogen) and evacuated. The contents were heated with stirring at 400 rpm at 60 ⁰ C, and there were pumped 835 nil vinyl chloride in the reaction vessel at a rate such that the pressure of 8.79 kg below /

ο
cm was held. This took 1 hour. The contents were held at 60 C until the pressure dropped below 7 * 035 kg / cm in 50 minutes, then the reaction vessel was cooled, vented and the product, a 4.4 % solids latex, was removed. . ·

The latex formed was erneut.eingefüllt seed material in the cleaned reaction vessel as seed do h _e, and the contents were purged and evakuiert.-The reaction vessel was heated to 60 ⁰ C, with 400 rpm. was stirred. The remaining 7515 vinyl chloride was pumped in at such a rate as to keep the pressure below 8.79 kg / cm, the ammonium laurate solution (137-5 S lauric acid, 180 ml ammonia) and 1300 ml water being pumped in proportionally. The pumping in was completed after 5 hours. The reaction vessel was cooled back and vented and the product removed.

4 0 9 8 18/1104

- O -

The product was a latex with a solid content of 4-5 »3 % and a particle size of about 0.2 m.

Example 2

Vinyl chloride 7230 ml

soft water 5 ^ -90 ml

AZDN 19.5 S.

Lauric acid 138 g

Ammonia (0.88) 176 ml

PVC seed latex produced according to the invention Method (28.4% solids) 2750 g

The PVC latex, the AZDR and 4-350 ml of water were added to the Filled into the reaction vessel, which was rinsed and evacuated three times.

The contents were heated to 60 ⁰ C with stirring at 400 rpm.

The monomer and the soap solution (lauric acid / ammonia / 1140 ml Water) were pumped in, the pressure being kept below saturation pressure. The rates were:

Hour conomer (ml) soap solution (ml)

180 220 260 290 285 90

The product after cooling and blowing off consisted of a latex with a solids content of 47.7% of the particles up to 0.2 µm.

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1 1050 2 1200 3 15 ^ 4th 1640 5 1630 5-5 1/3 170

-V-

Example 3
filling

distilled water 14,600 g

2,2'-azo-bis (2,4-dimethyl)

valeronitrile) "■.

(Trade name Genitron DHVlT) 8 g ■

Lauric acid

(Trade name Distec A 103) 43 g

Potassium hydroxide 17 g

Vinyl chloride 3,000 g

Way of working

The lauric acid and potassium hydroxide were dissolved in a ratio of 4: 1 in distilled water. This aluminum laurate solution together with the 2.2 ^l azo-bis (2,4-dimethylvaleronitrile) and the remainder of the distilled water were poured into a stainless steel reaction vessel, which was then sealed, rinsed and evacuated. The filling was left to react at 60 ° C. for 22 hours.

During the first 16 hours, the vinyl chloride was added to the reaction vessel in order to keep the pressure at 8.44 atmospheres. The saturation vapor pressure of vinyl chloride is approximately 10.2 atmospheres at this temperature. The final solids content was 14.8% and the latex particle size was 0.05 -. 0.1 nm The reaction vessel wall and the stirrer were coated with a thin film of the polymer \ g of weighed about 200. -

Examples 4-6

filling

distilled water 14,600 ml

AZDU (Genitron) 8g

Vinyl chloride 3,000 g

See Table I for emulsifier and weight

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Example Emulsifier Weight Solid Particle

(g) content (%) size (um)

4th Sodium lauryl sulfate
(Empicol LXV) 61 16, 6th 0 , 03-0 , 06 LfN Sodium decylbenzene
sulfonate
(Santomerse S) 192 9, 3 0 , 05-0 , 3 6th Sodium dioctyl sulfo-
succinate
(Manoxol OT) 61 14, 0 0 , 02-0 , 05 Way of working

The procedure was similar to Example 3 with the exception that various emulsifiers were used, which are listed in the table above. The response times varied considerable, being 4.5 hours, 14 hours and 10.5 hours respectively for the example 4, 5 and »6 respectively.

Examples 7-10

The latex particle sizes were varied by the amount of _$ emulsifier as shown below, has changed. The amounts for distilled water, AZDN (Genitron) and vinyl chloride were similar to those in Examples 4 to 6. The procedure was comparable to that of Example 3.

Table II Emulsifier weight Solid 0.044 example (G) salary (%) 0.031 Sodium lauryl sulfate 30.5 15.8 0.137 7th Sodium lauryl sulfate 122 16 ₉ 9 0.034 8th Potassium laurate 30.5 15.4 9 Potassium laurate 122 14.5 10

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5 .000 S. 14th .600 S. 62 G 78 S. 8th G

Example 11 and Comparative Examples 1a and 2a

The polymerization was carried out using the following approach:

Vinyl chloride
distilled water lauric acid

(Trade name Distec A 1Oj) ammonia (0.88)
initiator

The procedure was as follows: A solution of the ammonia and the lauric acid in distilled water was placed in a stainless steel reaction vessel with a capacity of 18.2 liters. The initiator was then added and the reaction vessel closed, flushed and evacuated. The charge was stirred at 400 ÜPM and heated to 60 ⁰ C. The vinyl chloride was pumped into the reaction vessel at a rate such that conditions of supersaturation for the monomer with a maximum pressure of 9-14 atmospheres were maintained in the reaction vessel.

After all of the monomer had been pumped into the reaction vessel, the temperature was kept at 60 ^° C. until the pressure had dropped to 4.22 atmospheres, then the filling was cooled to room temperature. The unconverted monomer was vented to the atmosphere and the resulting latex was analyzed for solids content.

The results of the comparative polymerizations with im monomers Soluble non-azo type initiators are shown in Table III demonstrated, 'percarbonate and peroxide made large amounts of resin and not very much latex.

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Table III

Example initiator

Response time (hj

Total solid state of the substance content of the reaction Latex (%) vessel

Azo-to-

(isobutyronitrile - AZDK - (trade name Genitron)

Comparison of di-t-butylcyclo-1a hexyl peroxydicarbonate (trade name Perkadox Y16) "

Comparison of Lauroy peroxide 2a

16

clean

10

very heavy deposition of resin

heavy deposition of resin

Comparative example 5a

A polymerization was carried out with the following approach: using the procedure described in Example 11:

Vinyl chloride distilled water

Sodium Lauryl Sulphate (trade name Empicol LXV)

Caprylyl peroxide

3. 000 G 14th 600 G 62 G 8th

It was found that most of the product was in the form of a deposit of the resin. The existing latex possessed a total solids content of only 2%. ■ -

Comparative example 4a

A polymerization was carried out with the following approach:

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ITinyl chloride. 3,000 g

distilled water 14,600 g

Sodium lauryl sulfate

(Description of goods

impicol LXV) 62 g

AZDN

(Description of goods

Genitron) 8 g

The procedure was as follows: A solution of the sodium lauryl sulfate in distilled water and the AZDN was placed in a stainless steel reaction vessel with a capacity of i8.2 1 filled; this was closed, flushed and evacuated ». .

The yinyl chloride was sucked in to form a phase of liquid monomer and the filling was extracted at 400 rpm. The filling was ^{heated to 60 °} C. for 4 hours and then cooled to room temperature before the unconverted vinyl chloride was vented into the atmosphere.

Most of the product was in the form of a deposit from. Resin Before = The latex that was left had one Pesticide content of only 6%. Same approach with the Monomers that were pumped in under conditions of undersaturation resulted in a stable latex and germs of resin depletion.

Example e 12-14

Polymerizations are carried out using the following approaches;

Yinylchlorid ■ 3 _o g Ö0Q

distilled water 14 _o 600 g

U Sodium Lauryl Sulphate

(Trade name Empicol LXV) 61 g

AZDN

(Trade name Genitron) 8 g

Suspending agent 3g

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The procedure was comparable to that described in Example 11. The suspending agent was dissolved in the emulsifier solution, before this was poured into the reaction vessel.

The suspending agents were hydrolyzed polyvinyl acetate (Trade name Alcotex 88-10), hydroxyethyl cellulose (trade name Cellosize QP44-00L) and hydroxylpropylmethyl cellulose (Trade name Methocel 65 HG50). In all cases they were Products stable latices with pesticide contents of around 15% resins (Deposits) were not formed.

The comparative tests showed that an azo initiator and monomer deficiency conditions, d. H. Undersaturation of monomers required for the formation of a latex. Examples 12 to 14 show that latices can still be produced even if additional suspending agent is used is available.

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Claims (2)

Claims 1 »Process for the" polymerization of a vinyl halide-containing ■ Monomers, in which the monomer is an emulsifier and an aqueous containing free radical initiator ! Phase is polymerized, thereby g e k e η η ζ e i ö h net, that the initiator is an Azo * initiator, and the ! Polymerization at or below the saturation vapor pressure of the monomeric material under the prevailing conditions and in the practical absence of monomer droplets the entire polymerization is carried out. 2. The method according to claim Ί, thereby marked ζ calibrate e t that azo'-bis (isobutyronitrile) is used as initiator will*