DE2548425A1 - PROCESS FOR BLOCK POLYMERIZATION OF VINYL CHLORIDE - Google Patents

Description

Summary (abstract) of the invention: The invention relates to an improved process for the block polymerisation of vinyl chloride monomer or a mixture of monomers mainly containing this compound in a polymerisation vessel. According to the invention, the inner walls of the vessel and other surfaces that come into contact with the monomer or monomers have previously been coated with a compound which has a JT electron bond and / or at least one atom from the group consisting of nitrogen, sulfur, phosphorus and oxygen has electrons belonging to a lone pair of electrons. This coating can greatly reduce the deposition of polymer crusts on the walls and other surfaces and produce high quality polymer.

State of the art;

The invention relates to bulk polymerization of vinyl chloride monomer or a mixture of monomers consisting mainly of vinyl chloride consists.

When polymerizing vinyl chloride in bulk or in bulk, it separates usually on the inner walls of the polymerization vessel and on surfaces of the stirrer blades and in contact with the monomer other auxiliary equipment from polymer crusts. It is therefore necessary to use the polymerization vessel and the auxiliary equipment provided therein Clean after each run of a polymerization. Such cleaning requires a great deal of labor and time. aside from that the deposition of polymer crusts on the inner walls of the polymerization vessel reduces the heat transfer through the vessel walls,

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which lowers the production output, and also lead to crumbling Parts of the crust that get into the product lead to a deterioration in product quality.

Numerous attempts have therefore been made to prevent the formation of polymer crusts in the block polymerization of vinyl chloride through improved design of the stirrer blades and other auxiliary equipment to prevent, but has not yet achieved satisfactory results.

It is therefore an object of the present invention to provide a method for bulk polymerizing vinyl chloride monomer or mainly to create existing monomer mixture of vinyl chloride, with the deposition of polymer crusts on the walls of a Polymerization vessel can be prevented.

Such a polymerization process should also increase production output of the polymerization vessel increased and the production of vinyl chloride polymer or copolymer in one relatively short cycle times of the polymerization runs are made possible.

Furthermore, a vinyl chloride polymer is said to be produced by such a process or copolymers of significantly improved quality can be produced in a simple and economical manner.

Description of the invention;

This object is achieved and the desired consequences are achieved by coating the inner walls of a polymerization vessel and other surfaces that come into contact with the monomer or monomers with a compound prior to the polymerization in such a block polymerization, as stated at the beginning % -Electron bond and / or at least one atom from the group nitrogen, sulfur, phosphorus and oxygen, which has electrons belonging to a lone pair of electrons.

Examples of those to be used in the method of the present invention Compounds are (1) compounds containing 7 ^ -electron bonds, e.g., olefin compounds such as 1-pentene and 2-hexene; Diene compounds, such as 4-chloro-1,3-butadiene and divinylacetylene; aromatic

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see compounds such as styrene, oC-methy1styrene, cumene, pentaphenylethane and ethylbenzene; aromatic compounds with condensed rings, such as β-vinylnaphthalene, and those contained in tars are separated from heavy fuel oils; (2) nitrogen-containing compounds, e.g., amine, amide, linin, amidoimide compounds with an azo, a nitro, a nitroso or an azomethine group on the side chain or main chain; heterocyclic Compounds with an azine ring (e.g. a pyrazine, a pyrimidine, a pyridazine, an oxazine and a thiazine ring), a pyrrole, an imidazole, a pyrazole or a pyridine ring; other nitrogenous higher heterocyclic compounds and nitrogen-containing resins such as ethylenediamine, tetramethylenediamine, ethanolamine, Diethanolamine, oC-naphthylamine, ethylene diisocyanate, m-phenylenediamine, Polyethyleneimine, dicyandiamide, diaminodiphenylmethane, ethylenediaminetetraacetic acid, Azomethane, azobenzene, nitrobenzene, nitrosobenzene, Monoaminomononitrosoazobenzene, ethylideneaniline, pyrazine, pyrimidine, pyradazine, oxazine, thiazine, pyrazole, pyridine, pyrrole, Imidazole, Hydron Blue G, Helindon Yellow R, Dimethylxanthine, Thiazolyl benzimidazole, Palatin Real Pink BN, 'Acridine Orange N, Vitamin Bp » Folic acid, nigrosine black, spirit black, oil black, aniline black, Morpholine, Indulin, Safranin T, Threne Blau RS, 6,9-Dimethylflavin, Benzocinnoline, 2-vinylpyridine, phthalocyanine blue, oil blue, Indigo carmine, diethy1vinylamine, vinylcarbazole, vinylsuccinimide, Diphenylguanidine, polyurethane, melamine resin, urea resin, Guanamine resin, polyamide resin and nitrogen-containing epoxy resin;

(3) sulfur-containing compounds, e.g. thiol, sulfide, thioaldehyde, Thioketone, thioacetal, and sulfonium compounds, heterocyclic compounds with a thiophene, a thianethrene, Phenothiazine or benzothiazole ring and other higher sulfur-containing compounds, such as thioglycolic acid, thiourea, thiocarbanilic acid, Thiocarbamic acid, thiobenzoic acid, butyl mercaptan, ethyl thioglycolate, Ethyl vinyl sulfide, divinyl sulfone, trimethylene dithioisocyanate, Thiophene, thiazole, thianethrene, phenothiazine, benzothiazole, 2-vinylthiophene, 2-vinylthiazole, dipentene sulfide, methylene blue, Threne Yellow GF, Basic Flavin 8G, Sulfur Blue 9, Threne Orange R, Thioindigo, Thioindigo Bordeaux and Mercaptobenzothiazole;

(4) Phosphorus-containing compounds, e.g. esters of phosphorous, der Phosphoric and pyrophosphoric acid, such as tributyl phosphite, tri-n-decyl phosphite, Phenylpentamethylphosphine and alkyldithiophosphates; and

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(5) oxygen-containing compounds, such as cetyl alcohol, octyl alcohol, Formaldehyde, acetaldehyde, benzaldehyde, p-benzoquinone and stearic acid. Of the above-mentioned phosphorus compounds, those preferred which are soluble in an organic solvent.

According to the invention, at least one of the number given above is used Compounds selected compound on the various surfaces coming into contact with the monomer or monomers applied, i.e. on the inner walls of the polymerization vessel, a stirrer and especially its blades, and other devices, such as a cooler, a heat exchanger, valves, piping, sensors and baffles, followed by drying if necessary and then the monomer or monomers in the so coated Given a vessel and the bulk polymerization is initiated in the presence of a polymerization initiator.

The coating compounds according to the invention can, depending on their Kind to be used with a solvent if necessary. Examples of solvents that can be used for this purpose are lower alcohols, such as methanol and ethanol; lower ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; lower esters, such as methyl, Ethyl and butyl acetate; aromatic hydrocarbons such as benzene, toluene and xylene; straight-chain or cyclic hydrocarbons, such as n-pentane, η-hexane, n-heptane and cyclohexene; Petroleum solvents such as petroleum ether; lower ethers, such as ethyl ether; and halogenated Hydrocarbons such as methylene chloride, trichlorethylene and carbon tetrachloride.

The coating measures can be carried out by any conventional method carried out, e.g. brushing or spraying. In other words, it can be any known conventional coating method can be used as long as you use stirrer blades on the various surfaces, e.g. the inner walls of the polymerization vessel etc. receives uniform coatings.

The amounts of the coating compounds should be in the range from 0.001 to 100 g / m, preferably from 0.01 to 50 g / m of the coated Area.

If the compounds are insoluble in any solvent, can usually be found in the paint, varnish or printing ink indus-

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The methods applied can be used with success. Particularly, a solvent-insoluble compound becomes in a solvent together with a film-forming agent, such as a paint, varnish, gelatin, a cellulose derivative, polyvinyl alcohol, Bitumen, a modified resin (rosin), a gumarone resin, a drying oil such as linseed oil, or a synthetic resin such as polyvinyl chloride or polyvinyl acetate, and the dispersion obtained is applied to the various surfaces in the polymerization vessel applied and then dried to fix the compound on the substrates. It can also be the usual lining technology may be applicable when using certain polymeric compounds as coating compounds to get voted.

According to the inventive method described above, the coating mixture or solution is applied to the various with the Monomer or surfaces that come into contact with the monomers are applied in the polymerization vessel, then dried if necessary, whereupon the monomer or monomers are introduced and the block polymerization is initiated. In some cases it is beneficial to the monomer or the monomer mixture, which in the

To be placed in the polymerization vessel, to add a small amount of the used or another coating compound, where the amount is in the range of about 1 to 100 ppm (parts per million) based on the weight of the monomer or monomer mixture. Such an addition of the coating compound can be carried out not only before the start of the polymerization but also during the course of the polymerization, although in the latter case the result is a little worse.

Examples of monomers, which with vinyl chloride an inventive Other vinyl halides are capable of forming a useful mixture of monomers as vinyl chloride such as vinyl fluoride and vinyl bromide; Olefins, such as ethylene, propylene and η-butene; Vinyl esters, such as vinyl acetate, Vinyl propionate, vinyl laurate and vinyl stearate; unsaturated acids such as acrylic acid, methacrylic acid and itaconic acid; Ester of

unsaturated acids; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; Maleic acid, fumaric acid, maleic anhydride and its derivatives ; Acrylonitrile and its derivatives; Vinylidene chloride and vinylidene fluoride.

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Furthermore, suitable polymerization initiators for the invention Block polymerization free radical initiators that are soluble in monomer. Examples are acyl peroxides, such as lauroyl peroxide imd benzoyl peroxide; Peroxyesters of organic acids such as tert-butyl perisobutyrate and tert-butyl peroxypivalate; Peroxydicarbonates, such as Diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate; Azo compounds, such as azobisisobutyronitrile, azobismethoxydimethylvaleronitrile and azobisdimethylvaleronitrile; and acetylcyclohexylsulfonyl peroxide. In general, the polymerization initiator is used in an amount of from 0.005 to 3 percent by weight based on the weight of the Monomer or the monomers used.

For the vessel in which the inventive block polymerization of Vinyl chloride monomer or a mixture thereof with a copolymerizable monomer or monomers do not exist special restrictions. It can be a reactor designed for the

Carrying out the polymerization with a polymerization mixture composed mainly of the monomer or monomers without using a large amount of a liquid medium for the purpose of heat transfer and formation of monomer droplets is suitable. The actual vessel is usually lined with glass or made of stainless steel and equipped with a cooler, heat exchanger, pump, valves, piping, measuring instruments, baffles, etc.

In the process of the present invention for bulk polymerization of vinyl chloride monomer or one of these together with a copolymerizable one Monomer or monomer-containing monomer mixture the polymerization itself is carried out by a conventional method. That is, after coating the various, with the surfaces coming into contact with the monomer or monomers with the particular coating compound the atmosphere in the polymerization vessel is flushed with nitrogen gas and the monomer or monomers together with a polymerization initiator in the Polymerization vessel are given, whereupon one stirs up

30 to 100 ° C heated to initiate the polymerization reactions. At this point, an additive or various additives, e.g. a chain transfer agent, a heat stabilizer, a modifier such as rubber and an organic filler can be used if necessary. The block according to the invention

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Polymerization can be either a one-step or a two-step process be performed.

The invention is further illustrated by the following examples. In the examples, all amounts (parts) given are amounts by weight.

Example 1 :

A horizontal stainless steel autoclave of 4 liters capacity, equipped with a frame stirrer, was used as the polymerization vessel used. The surfaces of the inner walls of this autoclave and the stirrer that come into contact with the vinyl chloride monomer were coated with a solution of one of the compounds listed in Table I in a solvent. In any case, it was fraudulent the amount of the coating compound about 0.02 g / m 2. After the coated surfaces had dried, the autoclave was evacuated and filled with nitrogen gas. Then 1400 g of vinyl chloride and 0.7 g of a 20% solution of azobisdimethylvaleronitrile in toluene filled into the autoclave. The polymerization was carried out with stirring at a speed of 100 revolutions per minute at a temperature of 57 ° C for 8 hours. The polymer product was withdrawn from the autoclave, and the amount of polymer crusts deposited on the wall and the stirrer surfaces was decided. The results are given in Table I.

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Table I.

Trial No. Coating compound Amount of ___________ crusts (g)

1 2-Hexen 58

2 © C-methylstyrene 41

3 ethylenediamine 62

4 ethylenediaminetetraacetic acid 6Ü

5 nitrobenzene 51

6 thiazolylbenzimidazole 38

7 Spirit black 22

8 6,9-dimethylflavin. 35

9 thiobenzoic acid 45

10 2-vinylthiazole 40

11 Thioindigo Bordeaux -30

12 tri-n-decyl phosphite 52

13 phenylpentamethylphosphine 50

14 octyl alcohol 55

15 stearic acid 48

16 (comparison) - not used - 230

Example 2;

A combination of two autoclaves was used, namely one first vertical stainless steel autoclave with a capacity of 2 liters, which was equipped with a turbine blade stirrer, and a second Horizontal autoclave made of stainless steel with a volume of 4 liters, which was equipped with a frame stirrer. The surfaces of the interior walls this autoclave and the stirrer were with a solution of one of the compounds listed in Table II in a solvent coated, the amount of the compound used being 0.02 g / m 2, followed by drying. Then each autoclave was evacuated and then filled with nitrogen gas. In the first autoclave 700 g vinyl chloride and 0.105 g azobismethoxydimethylvaleronitrile given, and the polymerization was carried out with stirring at a speed of 700 revolutions per minute 62 ° C for one hour. The reaction mixture obtained was transferred to the second autoclave into which 700 g of vinyl chloride and 0.6 g of azobxdimethylvaleronitrile had been introduced, and it was continued with stirring at a speed of 100 um-

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polymerized rotations per minute at 57 ° C for 8 hours. As a result of these experiments, data were obtained on the amount of polymer scale deposited on the inner wall and the stirrer surfaces in the first and second autoclaves, the particle size distribution of the polymer product obtained, and the occurrence of "fish eyes ^11" in the articles molded from the same polymer product.

For the purpose of investigating the occurrence of fish eyes, 100 parts of the polymer produced, 1 part lead stearate, 1 part barium stearate, 0.5 part titanium dioxide, 0.1 part carbon black and 50 parts dioctyl phthalate were mixed and ^{kneaded on a roller mill at 150 °} C. for 7 minutes to finally form a film 0.2 mm thick. the

2 Number of un-

Any remaining particles were determined

to show the extent of the occurrence of fish eyes.

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(1) Experiment no.

(2) coating compound

(3) Amount of crust (g)

18th Tabel II 20th 21 22nd 23 17th Ethylbene
zol 19th ex. -Naph-
thylamine Hydron
Bl au G Nigrosine
black Oil-
black ß-vinyl
naphthalene tar

36

43

45

41

30th

29

O CO OO

O CO CO

(4) Particle size distribution ( % of particles passing through the Tyler test sieves)

a) 0.37 ram (40 mesh) 96.6 94.0

b) 0.246 mm (60 mesh) 90.1 89.0

c) 0.147 mm (100 mesh) 40.3 43.3

d) 0.074 mm (200 mesh) 10.1 10.5

(5) Occurrence of fish eyes, number of pieces

95.0 93.0 97.0 98 ,8th 93.9 I. 90.1 91.2 91, 7 92 , 0 91, 0 O
I. 41, 3 37.6 41, 8 41 , 0 3.9.0 6.8 6.1 7.3 5 , 0 4.0

20th

30th

29

22nd

15th

Continuation (1)

25th

26th

27

29

30th

(2) Aniline-Thiogly-Methylene-Indigo-Thio-Threne Tributyl-Black colic acid blue carmine indigo orange R phosphite

(3)

(4) a) b) c). d)

(5)

32

96.6 90.1 40.3 10.1

20th

42

95.1

92.1

39.4

5.5

25th

37

98.0

95.0

40.1

3.5

10

24

97.3

94.0

38.0

7.0

29

94.0

90.3

37.0

4.0

14th

48

94.1
91.9
39.0
10.1

17th

31

Benzaldehyde

75

94.1

88.0

40.5

9.0

58

32 (comparison)

not used

200

91.5 83.5 36.0 16.0

380

er · £ ■ * ■

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Example 3:

The same combination of first and second autoclaves as indicated in Example 2 was used. A coating solution from 10 parts spirit black in 70 parts toluene with or without the addition of a film-forming agent (i.e. a modified resin or coumarin resin) was used to clean the areas in contact with the monomer in both autoclaves in the same way as in Example 2 to coat. The subsequent polymerization in the first and second autoclave was carried out in the same way as in Example 2, except that isobutyroyl peroxide instead of azobismethoxydimethylvaleronitrile is used as a polymerization starter in the first autoclave and that the polymerization starter contained in the second autoclave was 0.420 g of isopropyl peroxydicarbonate instead of 0.6 g of azobisdimethylvaleronitrile was.

The indicated two-stage polymerization was three to fifteen times repeated as shown in Table III, but without further coating treatment, and thereafter the / were formed Amount of crust determined .. For comparison, a test was carried out without coating and addition of the film-forming agent, its Result is also given in the table. * <after 3-5-10-15 runs in total>

Table III

Try film-forming no. Compound

number of
Polymerization
runs

Amount of crust (g)

33

not used

10

22 31 40

modified 34 rosin

5 10

15th

21 23 28

35

Coumarin resin

5
10

22 30

36 Veraleich

without coating

225

The above data clearly shows that the polymerization without the coating and the film-forming agent for forming a very substantial amount of crust in the form of thick deposit layers on the

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Surfaces leads, even with only one polymerization run, during the polymerization after coating with or without the addition of the film-forming agent leads to the binding of much fewer crusts, even with repeated polymerization runs. It is also clear that the use of the film-forming agent prevents crust formation effectively reduced.

Example 4:

The same autoclave as in Example 1 was used. The inner wall of the autoclave and the stirrer blades in the autoclave were coated with about 0.05 g / m 2 of a coating material, as shown in Table IV stated. The polymerization was carried out under the same conditions as in Example 1 and the amounts of scale formed were determined and are given in the table.

Table IV

Experiment no. Coating amount of crust connection

37 polyethyleneimine 15

38 melamine resin 24

39 guanamine resin 10

Example 5:

The polymerization was carried out in the same manner as in Example 2 except that oil black or thioindigo as a coating compound were used in various amounts, as indicated in Tables V-1 and V-2. The tables also contain the the amount of crust formed.

Table V-1

Coating compound: oil-black

Experiment No. Coating amount g / m Amount of crust (g)

40 0.001 35

41 0.005 29

42 0.010 26

43 0.020 27

44 0.0005 130

45 0.0001 165

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Table V-2
Coating compound: thioindigo

Experiment No. Coating amount g / m Amount of crust (g)

46 0.001 30

47 0.005 24

48 0.010 20

49 0.020 19

50 0.0005 98

51 0.0001 170

Example 6;

A horizontal autoclave made of stainless steel with a capacity of four liters, the one with a frame stirrer and a water-cooled condenser with an inner diameter of 40 mm, a length of 600 mm and

2 was provided with a heat transfer area of about 765 cm used as a polymerization vessel. A solution from Nigrosin-Schwärζ in toluene was applied to the surfaces of the inner wall of the autoclave, stirrer and condenser. The polymerization was carried out under the same conditions as in Example 1, and

the amount of crust deposited on the condenser surface was certainly. For comparison, a test was carried out without a coating. The results are given in Table VI below.

Table V

Experiment no * Amount of crusts deposited on the condenser surface (g)

52 0.5

53 (comparison) 4.5

Example 7:

It was the same combination of the first and second autoclave as used in Example 2 for two-stage polymerization, with the inner walls, stirrer and other auxiliary equipment, including Line pipes, valves, etc. were coated with aniline black in an amount of 0.02 g / m 2 of the area, while in a comparative experiment the corresponding parts were not coated in each case.

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In each first autoclave with or without a coating, 1400 g Vinyl chloride monomer, 0.21 g of acetylcyclohexylsulfonyl peroxide and a Additive, namely oC-naphthylamine, spirit black or aniline black at 10 ppm (parts per million) based on the weight of the vinyl chloride monomer, and the polymerization was then carried out at 62 ° C for two hours. The reaction mixture was transferred to the second autoclave,

which contained 5000 g lauroyl peroxide, and there with stirring with 100 Revolutions per minute at 57 ° C for 8 to 10 hours further polymerized. The crust deposits obtained in these experiments on the various surfaces were determined and are given in Table VII. An experiment with the same combination of autoclaves and the same procedural measures but without the coating with aniline black and without any Additions carried out, the result of which in the same table is specified.

Additive Table VII Crusts
lot
■ g ** Crusts
lot attempt
No. <x -naphthylamine Coating
with aniline
black 75 2.5 54 * Il no 28 1.0 55 Spirit black Yes 65 2.2 56 * Il Il no 2 0.5 57 Aniline black Yes 70 2.4 58 * Il Il no 24 1.0 59 not used Yes 210 8th 60 * no

* Comparison

** Deposited on the inner walls and stirrer blades

*** Separated to the other, with the monomer in the autoclave Parts in contact, including pipes and valves.

Example 8:

A two-stage bulk polymerization was carried out with the same first and second autoclaves and in the same manner as in Example 2 performed except that methylene blue was the only coating compound "was used", and that aniline black dissolved in toluene was added to the starting monomer in the various amounts, as in

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Table VIII. Alongside each of these attempts were similar Tests carried out without the coating with methylene blue. as The result of these tests was the deposition of crusts on the various surfaces and also the occurrence of discoloration of the molded articles produced from the polymer obtained are determined as shown in Table VIII.

The discoloration test was carried out in the following manner. 3.0 parts of dibutyltin maleate and 1.0 part of stearic acid were mixed with 100 parts of each of the polymer products, and each mixture was ^{kneaded at 170 °} C. for 10 minutes by means of a roller mill to produce a sheet. The coloration of these sample films was compared with the standard sample film which was produced from the polymer product obtained in Comparative Experiment No. 32 of Example 2.

Table VIII

attempt
No. Amount of zu
substitute ** Coating with
Methylene black Crusts
amount (g) Discoloration 61 * 3 no 81 no 62 3 Yes 29 no 63 * 10 no 70 no 64 10 Yes 25th no 65 * 80 no 68 no 66 80 Yes 23 no 67 * 200 no 72 Yes u8 200 Yes 24 Yes 32 * 0 no 200 no

* Comparison

** In ppm based on the weight of the monomer.

Example 9:

Using the same combination of the first and second autoclave as in Example 2, the inner walls and stirrer with a of the coating compounds given in Table IX below were coated in an amount of 0.02 g / m 2, the two-stage polymerization was carried out as follows. In the first Autoclaves were 1,300 g of vinyl chloride, 100 g of vinyl acetate and 0.210 g

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Acetylcyclohexylsulfonyl peroxide was added, and the polymerization was carried out at 62 ° C for two hours. The reaction mixture 'was transferred into the second autoclave had been introduced into the 7 _f 56 g of azobisisobutyronitrile, and polymerization was continued with stirring at 100 revolutions per minute at 57 ° C 8 to 9 hours. The occurring in these experiments crust formation was again determined as shown in Table IX.

Table IX Experiment No. Coating compound Amount of crust (g)

69 indigo carmine 28

70 spirit black. - 30

71 (comparison) without coating 210

Example 10;

Using the same combination of first and second autoclaves as in Example 2, the inner walls and stirrers of the autoclaves being coated with one of the coating compounds given in Table X in an amount of 0.02 g / m ² and then dried at 60 ° C. for one hour the two-stage polymerization was carried out as follows. Into the first autoclave, 700 g of vinyl chloride, 16.5 g of lead stearate, 6.5 g of tribasic lead sulfate, 3.3 g of paraffin wax and 0.105 g of isobutyroyl peroxide were charged, and polymerization was carried out at 62 ° C. for one hour. The reaction mixture was transferred to the second autoclave into which 700 g of vinyl chloride and 7.56 g of benzoyl peroxide had been charged, and the polymerization was carried out at 57 ° C. for a further 8 hours with stirring at 100 revolutions per minute. The resulting polymer was then withdrawn from every other autoclave, and it was found that the walls of the second autoclave had retained a metallic luster, while small amounts of crust were deposited on the agitator blades, as Table X shows.

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Table X Experiment No. Coating compound Amount of crust (g)

72 indigo carmine 45

73 nigrosine black 25

74 Spirit black 30

75 (comparison) (without coating) 290

Example 11:

The bulk polymerization of vinyl chloride was carried out using the the same autoclave and application of the same measures as in Example 1, except that a solution was used as the coating compound of nigrosine black in a mixed solvent of toluene and methanol (1: 1) and the compounds given in Table XI were used as the polymerization initiator. As a result of the trials the data given in the table on the amount of crust deposited on the inner wall and the stirrer, the grain size distribution, were obtained of the polymer product obtained and the occurrence of fish eyes in the articles molded from this product.

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Attempt no.

Coating with
Nigrosine black

Polymerization initiator

76 77 *

yes no lauroyl peroxide

Table XI 80 81 * 82 83 * 78 79 * Yes No Yes No Yes No Diisopropyl per-
oxydicarbonate tert-butyl per-
oxypivalate Azobisdimethyl
valeronitrile

Amount of crust (g) 23

Grain size distribution
{% of the total,
which goes through the following Tyler test sieves:

0.37 mm (40 mesh) 96.9

0.246 mm (60 mesh) 94.0

0.147 mm (100 mesh) 40.1

0.074 mm (200 mesh) 4.9

Fish eyes 7

(Number of pieces)

210

200

29

225

25th

230

92.3 81, 3 37.0 10.4

280

98.0 91 , 5 96.0 83 , 5 43.0 36 , 0 1.8 16 , υ

300

95.0 89.0 88.4 80.4 39.3 38.6 4.0 ■ 14.0

350

97.0 90 , 4 co 93.0 81 , 2 I. 40.5 34 , 5 5.3 10 ,8th

300

* Comparison

From the data in Table XI it is evident that the inventive Method is very effective for preventing scale formation using bulk polymerization of vinyl chloride any peroxide or azo compound as a polymerization initiator. This is in contrast to the previous view of the professional world that Peroxides and azo compounds are not as effective for this purpose.

Example 12;

A glass-lined 5 liter horizontal autoclave equipped with a turbine blade stirrer was used as the polymerization vessel. The total area of the inner walls of the autoclave was coated with a solution of 12 parts of one of the compounds listed in Table XII in 88 parts of a solvent mixture of methanol and toluene (1: 1) in an amount of 0.02 g / m and then for one hour 60 ⁰ C dried. Then, 2500g vinyl chloride monomer and 1.25 g of acetyl were added to the autoclave, and the polymerization was carried out for two hours at 62 ⁰ ° C. The reaction mixture was withdrawn from the autoclave. The scale deposits on the autoclave walls were determined as indicated in Table XII.

Table XII

Attempt no. Coating compound Crust amount (g) 84 OC -Methylstyrene 5.5 ■ 5 Ethylenediaminetetraacetic acid 8.0 86 Indigo carmine 7.0 87 Phthalocyanine blue 5.0 88 Oil blue 6.0 89 (comparison) (without coating) 50

From the above data it is evident that the coating of the present invention works even with glass-lined polymerization vessels is effective.

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Claims (19)

Claims ₄ 1. A process for the bulk polymerization of vinyl chloride monomer or a monomer mixture containing this and a copolymerizable monomer or copolymerizable monomers, characterized in that the inner walls of a polymerization vessel and other surfaces which come into contact with the monomer or monomers are coated with a compound before the polymerization , which has a JC -electron bond and / or at least one atom from the group nitrogen, sulfur, phosphorus and oxygen, which has electrons belonging to a lone pair of electrons. . ' 2. The method according to claim 1, characterized in that the one TZT electron bond having compound at least one compound selected from the following group: olefin compounds, diene compounds and aromatic compounds. 3. The method according to claim 2, characterized in that the olefin compound having an IC electron bond is 1-pentene or 2 witches is. 4. The method according to claim 2, characterized in that the aromatic compound having a TC electron bond is at least one from the following group of compounds: styrene, ed-methylstyrene, cumene, pentaphenylethane, ethylbenzene, β-vinylnaphthalene and tars. 5. The method according to claim 1, characterized in that the connection, which contains at least one atom with electrons belonging to a lone pair of electrons, at least one containing nitrogen Compound from the group of the following compounds: amine, amide and imine compounds, compounds with an azo, Nitro, nitroso or azomethine groups, nitrogen-containing heterocyclic compounds and nitrogen-containing resins. 6. The method according to claim 5, characterized in that the amine compound is at least one compound from the following group: ethylenediamine, tetramethylenediamine, ethanolamine, diethanolamine, oC-naphthylamine, ethylenediaminetetraacetic acid, ethylideneaniline. 609820/0998 7. The method according to claim 5, characterized in that the one Azo, nitro, nitroso or azomethine group is at least one from the following group: azomethane, azobenzene, Nitrobenzene, nitrosobenzene and monoaminomononitrosoazobenzene. 8. The method according to claim 5, characterized in that the nitrogen-containing heterocyclic compound is at least one compound with a ring selected from the group pyrazine-r, Pyrimidine, pyridazine, oxazinthiazine, pyrrole, imidazal, pyrazole and pyridine rings. 9. The method according to claim 5, characterized in that the heterocyclic compound containing a nitrogen atom is at least one compound from the group of the following compounds: pyrazine, pyrimidine, pyradazine, oxazine, thiazine, pyrazole, pyridine, pyrrole, imidazole, hydron blue G. , Helindon Yellow R, Dimethylxanthine, Thiazolylbenzimidazole, Palatin Real Pink BN, Acridine Orange N, Vitamin B ₂ , Folic Acid, Nigrosine Black, Spirit Black, Oil Black, Aniline Black, Morpholine, Indulin, Safranine T, Threne Blue RS, 6,9-dimethylflavin, phthalocyanine blue, oil blue and indigo carmine. 10. The method according to claim 5, characterized in that the nitrogen-containing resin at least one resin from the group polyethyleneimine, Is melamine resin and guanamine resin. 11. The method according to claim 1, characterized in that at least an atom with an electron-containing compound belonging to a lone pair of electrons at least one of the following Group selected compound is: thioglycolic acid, thiourea, thiocarbanilic acid, thiocarbamic acid, thiobenzoic acid, butyl mercaptan, Ethyl thioglycolate, ethyl vinyl sulfide, divinyl sulfone, trimethylene dithioisocyanate, Thiophene, thiazole, thianethrene, phenothiazine, benzothiazole, 2-vinylthiophene, 2-vinylthiazole, dipentene sulfide, methylene blue, Threne Yellow GF, Basic Flavin 8G, Sulfur Blue 9, Threne Orange R, Thioindigo, Thioindigo Bordeaux and Mercaptobenzothiazole. 12. The method according to claim 1, characterized in that the at least an atom with electrons belonging to a lone pair of electrons containing at least one phosphorus-containing compound 609820/0998 A compound from the following group is: esters of phosphorous acid, phosphoric acid ester and pyrophosphoric acid ester. 13. The method according to claim 1, characterized in that the at least an atom with an electron-containing compound belonging to a lone pair of electrons at least one oxygen-containing compound Compound from the following group: cetyl alcohol, octyl alcohol, Formaldehyde, acetaldehyde, benzaldehyde, p-benzoquinone and stearic acid. 1-4. Method according to one of Claims 1 to 13, characterized in that that the amount of the compound used in the coating is in the range of 0.001 to 100 g / m 2. 15. The method according to claim 14, characterized in that the The amount of the compound used in the coating is in the range from 0.01 to 50 g / m of the coating. 16. The method according to any one of claims 1 to 15, characterized in that that the compound is applied in the form of a solution in an organic solvent and the coated surfaces are then dried. 17. The method according to any one of claims 1 to 16, characterized in that that at least one of the compounds is in addition to the vinyl chloride monomer or the monomer mixture in an amount from 1 to 100 ppm (parts per million) based on the weight of the monomer or the monomer mixture, is added. 18. The method according to any one of claims 1 to 17, characterized in, that the coating compound has at least one film-forming Means is added. 19._Verfahren according to claim 18, characterized in that the film-forming agents are selected from the group of the following agents: gelatin, cellulose derivatives, polyvinyl alcohol, bitumen, rosins, Coumarone resins and drying oils. 609820/0998