DK150524B - PROCEDURE FOR POLYMERIZATION OF VINYL CHLORIDE USING A CRUSHING PREVENTION - Google Patents

Description

- 1 - 15052Λ

The invention relates to a process for the polymerization of vinyl chloride as set forth in the preamble of claim 1.

In order to prevent polymer crust deposition on the various surfaces, some methods have been proposed which include coating the surfaces with polar organic compounds such as amine compounds, quinone compounds and aldehyde compounds, dyes and pigments, (see Japanese Patent Publication 30343/1970 and 30835/1970). However, the prior art has not been shown to be effective in a polymerization process in which vinyl chloride is polymerized in the presence of emulsifiers or in combination with one or more comonomers, or where the polymerization mixture contains acyl peroxides such as benzoyl peroxide, lauryl peroxide or higher carboxylic acids such as lauric acid. Furthermore, the effect of crust prevention according to the prior art can hardly be sustained through several polymerization processes.

The object of the invention is therefore to provide a method for polymerizing vinyl chloride or a monomer mixture consisting essentially of vinyl chloride, in which the process of depositing polymer crust on the inner walls of a polymerization container and other surfaces in contact with monomer can be practically possible. is avoided by all types of polymerization.

The process according to the invention is characterized by the characterizing part of claim 1.

The aforementioned polar organic compounds of the compounds (a) are e.g. the following: 30 (1) Nitrogen-containing organic compounds selected from the compounds having an amino, imino, azo, nitro, nitroso or azomething group or an azin ring and amine, imine and quaternary ammonium compounds, e.g. azomethane, azobenzene, nitrobenzene, nitrosobenzene, monoaminomononitroazobenzene, pyrazine, pyridine, thiazine, aniline, oxazines (morpholine, etc.), benzalaniline, EDTA, o (and / 3-naphthylamines, ethanol- - 2 - 150524 amine, diethylamine methylene blue, nigrosine black, oil black, alcohol black, diaminonaphthalenes, diphenylamine, hydrazine, Ν, Ν-dimethylaniline, urea, laurylamine, cetyltrimethylaminone imrichloride, polyamides and polyethyleneimines.

(2) Sulfur-containing organic compounds selected from the compounds having a thiocarbonyl, thio-ether or thioalcohol group, e.g. thioglycolic acid, thiourea, thiocarbanilic acid, thiocarbamic acid, thiobenzoic acid, thioether with the general for flour RSR '(wherein R and R *, which may be the same or different, each represent an alkyl group), such as dimethyl sulfide and ethyl methyl sulfide and mercaptans such as propyl mercaptan and butyl mercaptan, polysulfides, polysulfones and sulfonic acids such as p-toluenesulfonic acid, cyclohexyl sulfonic acid, o (-naphthalenesulfonic acid, anthraquinone sulfonic acid, metalic acid, dodecylbenzenesulfonic acid and salts thereof with sodium and alkali metals.

(3) Oxygen-containing organic compounds selected from quinones, ketones, aldehydes, ethers, alcohols and alkali metal salts thereof, esters, carboxylic acids and salts thereof, sulfoxides and oxides, e.g. p-benzoquinone, anthraquinone, benzophenone, acetophenone, diisopropyl ketone, formaldehyde, acetaldehyde, benzaldehyde, octyl alcohol, cetyl alcohol, benzyl alcohol, phenol, cresol, hematein, propargyl alcohol, hydroquinoline, fluorescein, fluorescein, fluorescein, fluorescein , polyvinyl alcohol, diisopropyl ether, diphenyl ether, cellulose ethers, amyl acetate, ethyl benzoate, stearic acid, benzoic acid, salicylic acid, maleic acid, oxalic acid, tartaric acid, potassium sodium tartrate, succinic acid, malic acid, isonicotinic acid, phenylglycine, phenylglycine Polyacrylic acid.

- 3 - 15052 /; (4) Phosphorus-containing organic compounds selected from phosphorus and polyphosphoric acid esters and alkali metal or ammonium salts thereof, e.g. mono-lauryl phosphate, sorbitan hexametaphosphate, polyoxyethylene sorbitan triphosphate and phytic acid.

(5) Tar, pitch, resin and wax with difficult to define chemical structure.

In addition, examples of the organic dyes, as compounds (a), are as follows: , anthron-type dyes, alizarin dyes and dispersed anthraquinone dyes, indigo dyes such as brilliant indigo B, red violet RH and printing type B, sulfide dyes such as sulfur blue FBB and sulfur blue B and sudan B , nitrosol dyes, thiazole dyes, xan then dyes, acridine dyes, azin dyes, oxazine dyes, thiazine dyes,

benzoquinone, naphthoquinone dye and cyanine dye, as well as water-soluble organic dyes such as direct brilliant yellow G (direct dye), acid light yellow 2G (acid dye), levafix yellow 4G 30 (reaction dye), procion brilliant orange G

(reaction dye), direct solid scarlet GS (direct dye), direct burgundy NS (direct dye), brilliant scarlet 3R (acid dye), sour alizarin red B (acid stain dye), direct turquoise blue GL (direct dye), cibacron blue 3G

(reaction dye), blankophor B (acid dye), nigrosine (acid dye), sirius G (direct dye), chrysamine G (direct dye), direct solid 150524 - 4 -

yellow GG (direct dye), chrome yellow G (acid pickle dye), chrome yellow ME (acid pickle dye), eosin G (acid dye), basic flavin 8G (basic dye), astrazon yellow 3G (basic dye-5), rhodamine 6GCP (basic dye), safranin T

(basic dye), rhodamine B (basic dye), daitophor AN (basic dye), auramin conc (basic dye), chrysoidin (basic dye) and bismarck brown BG (basic dye).

The above-mentioned polar organic compounds and organic dyes can be used alone or in combination.

Further, the compounds (b) useful in the process of the invention are selected, on the one hand, from halides, oxides, hydroxides and low molecular weight carboxylates of metallic elements, such as e.g. are alkali metals such as sodium and potassium, alkaline earth metals such as magnesium, calcium and barium, metals of the zinc group such as zinc, metals of the aluminum group such as aluminum, metals of the tin group such as titanium and tin, metals of the iron group such as iron and nickel, metals of the chromium group such as chromium and molybdenum, metals of the manganese group such as manganese, metals of the copper group such as copper and silver, and metals of the platinum group such as platinum. Examples of these compounds are sodium fluoride, sodium acetate, ferrochloride, calcium chloride, sodium tartrate, sodium chloride, calcium acetate, titanium dioxide, sodium oxalate, aluminum chloride, cuprichloride, manganese dioxide, iron octoate and stannous chloride.

Compounds (b), on the other hand, are selected from oxo acids of zinc, boron, aluminum, carbon, silicon, tin, titanium, nitrogen, phosphorus, sulfur, chromium, molybdenum, tungsten, chlorine and manganese.

Illustrative examples of oxo acids and their salts are the following: zinc acid, boric acid, aluminum acid, carboxylic acid, silicic acid, tin acid, titanoic acid, phosphoric acids (including dewatered and condensed phosphoric acids such as methaphosphoric acid, pyrophosphoric acid and tripolyphosphoric acid), nitric acid, sulfuric acid, chromic acid, molybdenic acid, tungstenic acid, manganic acid, chloric acid and permanganic acid and dichromic acid in the higher oxidation states;

In carrying out the process of the invention, it is advantageous for compounds (a) and (b) to be dissolved or dispersed separately or in combination with a solvent prior to use. As the solvent, water, alcoholic solutions, ester solutions, ketone solvents, hydrocarbon solvents and chlorinated hydrocarbon solutions are usually used.

The following are the three possible embodiments of the method according to the invention.

In the first embodiment, (a) the compound is dissolved or dispensed in one of the above solvents, and the resulting solution or dispersion is applied to the surface of the inner wall or other parts of the polymerization reactor which come into contact with monomer. Then, the coating surfaces are contacted and treated with compound (b), introducing its solution or dispersion into the reactor and heating the solution or dispersion to preferably 50-100 ° C for 10 minutes or more and then removing the solution or the dispersion from the reactor, followed by a conventional polymerization procedure with the same reactor. In this case, however, it is the case that if the polymerization mixture is aqueous, as with e.g. suspension or emulsion polymerization, and if the solvent used to form the solution or dispersion of compound (b) is water, then it is not always necessary to remove the heated aqueous solution or dispersion.

In the second embodiment, compound (a) is dissolved or dispersed in a suitable solvent, while compound (b) is dissolved or dispersed in the same or -

15052A

clay another solvent. The solution or dispersion of compound (a) is added dropwise to the solution or dispersion of compound (b) and then heated to preferably 5G-100 ° C. The resulting mixture 5 is applied to the surfaces of the inner wall and other parts of the polymerization reactor which come into contact with monomer. The surfaces thus coated are washed with water if necessary. Then, the polymerization is started by a conventional procedure.

As a third option, separate solutions or dispersions of the compounds (a and b) are prepared in the same or different solvents. The solutions or dispersions of (a) and (b) are applied one or more times to the surfaces that come into contact with monomer. The coated surfaces thus passed are subjected to heat treatment by passing hot water through the jacket or blowing hot air into the reactor. It is preferred to carry out the application of the coating solutions or dispersions while maintaining the inner wall at 50-100 ° C, passing 20 hot water through the jacket. It is further preferred to terminate the application of the solutions or dispersions by passing hot water through the jacket and simultaneously injecting hot air into the reactor at each interval of application or coating. .

In each of the above embodiments, it is too common for compounds (a) and (b) to contact each other at a temperature higher than 50 ° C. If the temperature is lower, no satisfactory result is obtained and more than ten hours are required for treatment.

The ratio of compound (b) to compound (a) used in accordance with the process of the invention may vary depending on the nature of the compounds used and the type of polymerization involved. In the first embodiment described above, where the compound (b) has a low concentration in the aqueous phase, and in the second embodiment, where the compounds (a) and (b) do not mix well with each other, it is preferred. in particular, the ratio of compound (b) to compound (a) is relatively large or generally from 0.1: 1 to 500: 1 by weight. In the second embodiment, where the heated mixture of compound (a) and compound (b) is applied, the ratio of compound (b) to compound (a) may be relatively small, e.g. from 0.01: 1 to 50: 1 by weight.

According to the invention, the amounts of compound (a) or (b) or a mixture thereof to be used for coating the inner wall and other parts of the reactor may be more or less the same as in the case where conventional Conventional coating materials. For example, sufficient prevention of polymer crust deposition with an amount of at least 15 0.001 g / m2 can be achieved.

It may be added in connection with the three embodiments described above that it is of course optional to use any one of them not only alone but in combination. For example, the surfaces are first coated with a mixed solution of compounds (a) and (b), followed by heating as in the second embodiment, and the surfaces thus coated are coated with a solution of compound (a) and a solution of compound (b) in sequence, followed by heating as in the third embodiment.

When two kinds of compound (a) are used in combination, it is sometimes possible to obtain better results by selecting one of the two compounds from the water-soluble and the other from those soluble in organic solvents.

Furthermore, to obtain better crust prevention for the polymerization mixture concerned, it is necessary to add a solution or dispersion of compound (a) or (b) or a mixed and heated mixture or dispersion of the compounds (a and b). In this case, the amounts of such additives should be limited to a range of several parts per minute. million to one hundred parts per million on the basis of monomer since excessive amounts can cause harmful effects on the resulting polymer product.

To further enhance the crust deposit prevention, it is proposed for the polymerization mixture to add an alkaline substance, however not in accordance with the definition of compound (b), such as oxides, hydroxides, carbonates, phosphates, bicarbonates, silicates and acetates of alkali metals, alkaline earth metals and ammonium .

However, it is important that the alkaline substance should be added in such an amount that it will not degrade the resulting polymer. This suitable amount is e.g. up to 1% by weight based on the monomer or monomer mixture.

The process of the present invention 15 can be used for all types of polymerization, i.e. suspension, emulsion, solution and mass polymerization of vinyl chloride or a monomer mixture consisting essentially of vinyl chloride. Furthermore, the process of the invention does not limit the nature of the various additives such as suspending agents, emulsifiers and chain transfer agents, polymerization initiators as well as polymerization temperature and speed of rotation.

The process of the invention can be effectively applied not only to homopolymerization of vinyl chloride, but also to copolymerization of vinyl chloride together with one or more copolymerizable monomers. Of copolymerizable monomers, e.g. mention is made of vinyl esters, vinyl ethers, acrylic acid and methacrylic acid, esters thereof, maleic acid and fumaric acid, esters thereof, maleic anhydride, aromatic vinyl monomers, vinyl halides as well as vinyl chlorides, vinylidene halides, olefins, acrylonitrile and methacrylonitrile.

The following examples illustrate the method 35 of the invention.

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Example 1

For the purpose of this example, 2 liter stainless steel autoclaves are used, each equipped with a turbine stirrer. The surface of the inner wall of each autoclave and the blades of the stirrer are coated with a 0.1% solution in toluene of each of the various organic dyes listed under the term "Compound A" in Table I of an amount of approx. 0.05 g / m 2 (as dry matter) and the coated surfaces are dried at 70 ° C for 60 minutes, then a 1% aqueous solution of each of the various oxo acids or salts thereof, under the heading "Compound B" in the same table is applied to the coated and dried surfaces in an amount of approx. 0.05 g / m (as dry matter) followed by drying at 70 ° C for 60 minutes.

Then, in each of these autoclaves coated in this way, 900 g of water, 0.4 g of methyl cellulose and 0.8 g of polyvinyl alcohol are introduced. After the autoclave is emptied of air and instead filled with nitrogen, 600 g of vinyl chloride monomer and 0.21 O (, c (-azobis-dimethylvaleronitrile) 20 are introduced and the mixture is subjected to suspension polymerization at a stirring rate of 1000 rpm). and a temperature of 57 ° C for 6 hours The polymerization is repeated for each autoclave only until the crust deposit exceeds 2 g / m, the number of such repeated polymerization cycles being given in Table I under the heading "number of cycles". in other words, crust deposition effectively prevents this number of repeated polymerization cycles. Details and results are shown in Table I.

For comparative purposes, experiments were performed using Compound A or Compound B alone, ie not in combination, and in similar manner and under similar conditions, and the results shown in the same table are obtained.

35 r 150524 - 10 -

Table I

Compounds Compound Compounds A and B__A__B_

For- Number For- Number For- Number Compound Compound search re search re- _A_ _B_ no times no times no times nigrosine sodium black silicate 1 18 13 12 25 2 alcohol potassium black nitrite 2 12 14 9 26 2 oil of boric acid 3 10 15 7 27 1

Threne silicic acid

Gray K 4 5 16 3 28 2

Ainilin potassium black dichromate 5 6 17 4 29 1

Alizarin Tripolyul R phosphoric acid 6 6 18 2 30 2

Solid light- Magnesium yellow G carbonate 7 4 19 3 31 1

Threne tin-

Golden acid yellow EK 8 3 20 2 32 1

Pyrazolone sodium red molybdate 9 3 21 · 2 33 2

Permanent titanium orange GTR acid 10 3 22 2 34 1

Phthalo-Permanganecyanine Blue Acid 11 2 23 1 35 1

Naphthol sodium yellow S borate 12 3 24 2 36 1

Note: Trial numbers 13-36 are control trials.

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Example 2

The same autoclaves as in Example 1 are coated with compounds A and B in combination, as indicated in Table II, and for comparison purposes with compounds A and B 5 alone, as indicated in the same table, all in the same manner and under the same conditions as in Example 1. 1. Into each of the coated autoclaves, 900 g of water, 6 g of sodium lauryl sulfonate, 1 g of potassium persulfate and 600 g of vinyl chloride are introduced for the purpose of performing emulsion polymerization at 10 48 ° C for 10 hours. The details and results of these experiments are shown in Table II.

Table II

Experiment No. Compound A Compound B Number of turns 15 37 higrosine black tripolyphosphoric acid 5 38 alcohol black sodium nitrate 3 39 oil black sodium nitrite 2 40 riigrosine black sodium silicate 5 41 alcohol black boric acid 3 20 42 nigrosine black boric acid 3 43 black sodium borate acid 2 44 alcohol black 46 black phosphoric acid 1 25 -

Note: Trial numbers 42-46 are control trials.

Example 3

The same autoclaves as in Example 1 are coated with Compounds A and B in combination, as indicated in Table III, and 30 for comparative form with Compounds A and B alone, as indicated in the same Table, all in the same manner and under the same conditions as in Example 1. 1. Into each of the coated autoclaves is introduced 900 g of water, 0.4 g of methyl cellulose, 0.8 g of polyvinyl alcohol, 600 g of vinyl chloride and 60 g of a comonomer, ie. vinyl acetate or vinylidene chloride and 0.21 g of isopropyl peroxydicarbonate to carry out suspension polymerization at 52 ° C for approx. 6 hours. The details and results are shown in Table III.

Table III

Experiment No. Comonomer Compound A Compound B Laps 47 Vinyl Nigrosine Black Silicic Acid 8 Acetate 48 Vinyl Oil Black Tripolyphosphorus Acetate Acid 49 Vinyl Nigrosine Black Potassium Nitrite 7 Acetate 50 Vinyl Oil Black Boric Acid 4 Acetate 51 Vinylidene Nigrosine Black Phosphorus Acid 52 vinylidene alcohol black molybdate 5 chloride 53 vinylidene nigrosine black potassium silicate 8 chloride 54 vinyl nigrosine black potassium silicate 5 acetate 55 vinyl oil black potassium silicate 3 acetate 56 vinyl oil spray silicic acid 1 acetate 57 vinyl oil black tripolyphosphorus acid black tripolyphosphorus 5 chloride acid 59 vinylidene alcohol tripolyphosphorus 3 chloride acid 60 vinylidene alcohol sodium molybdate 1 chloride

Note: Trial numbers 54-60 are control trials.

150524 - 13 -

Example 4

The same autoclaves as in Example 1 are coated with a 0.05% solution or dispersion of a mixture of Compound A and Compound B in equal amounts, but in varying combinations as given in Table IV at a 2 amount of 0. 1 g / m as dry matter and the coated surfaces are dried at 70 ° C for 60 minutes. Suspension polymerization of vinyl chloride is then carried out in the same manner and under the same conditions as in Example 1 for examination of crust deposits. Details and results are shown in Table IV.

Table IV

Experiment No. Compound A Compound B. Number of cycles 15 61 nigrosine black sodium borate 16 62 black potassium nitrite 12 63 oil black silica 11 64 Threne Gray K boric acid 5 20 65 aniline black tripolyphosphorus 6 acid 66 alizar yellow R potassium dichromate 5 67 solid pale yellow G tin acid 3 25 68 Threne Golden sodium silicate 3

yellow RK

69 Pyrazolone red titanoic acid 3 70 permanent orange permanganoic acid 2.

3 g 71 phthalocyanine phosphoric acid 4 blue 72 naphthol yellow S sodium molybdate 3

Example 5

The same autoclaves as in Example 1 are coated with compounds A and B in combination as mentioned in Table V in the same manner and under the same conditions as in Example 4.

With each of the coated autoclaves, an emulsion polymerization is performed similar to that of Example 2. The details and results of these experiments are shown in Table V.

Table V

Test No. Compound A Compound B Number of turns 73 Nigrosine black tripolyphosphorus 4 acid 74 alcohol black sodium molybdate 2 75 oil black sodium nitrite 2 15 76 Nigrosine black sodium silicate 4 77 nitric acid boric acid 2

Example 6

The same autoclaves as in Example 1 are used, and they are coated with compounds A and B as set forth in Table VI in the same manner and under the same conditions as in Example 4. With each of the coated autoclaves, a suspension polymerization or copolymerization is practically carried out. taken as in Example 3. Details and results are shown in Table VI.

Table VI

Test No. Compound A Compound B Number of rounds 78 Nigrosine black silicic acid 7 30 79 Oil black tripolyphosphoric acid 5 Nigrosine black potassium nitrite 7 81 Oil black boric acid 4 ^ 82 Nigrosine black phosphoric acid 6 83 Liquid sodium molybdate 5 84 Nigrosine black potassium silicate 6 1505

Note Experiments Nos. 78-81 relate to homopolymerization of vinyl chloride.

Experiments Nos. 82-84 apply to copolymerization of vinyl chloride and vinylidene chloride.

Example 7

The same autoclaves as used in Example 1 are coated with a solution of Nigrosine black in ethanol or toluene in different amounts as indicated in Table VI, then dried at 70 ° C for 60 minutes. Then a 10% aqueous solution of sodium silicate is applied over the 2 coated and dried surfaces in an amount of 0.05 g / m (as dry matter) and dried at 70 ° C for 60 minutes. Thereafter, suspension polymerization of vinyl chloride is performed with each of the coated autoclaves in the same manner and under the same conditions as in Example 1 for the examination of crustal deposition. Details and results are shown in Table VII.

Table VII

2 2q Experiment No. Applied amount Nigrosine black g / m Number of rounds 85 10 2 86 2 3 87 1 4 88 0.5 5 25 89 0.05 5 90 0.005 3 91 0.0005 2 92 0.5 2 93 0.5 6 30 94 0.01 3

Notes: 1) The solutions of Nigrosine variety in Experiments Nos. 85-91 are in ethanol, while in Nos. 92-93 toluene is used.

2) In Experiment # 93, surfaces of the Nigrosinsort coatings were lightly wiped with a piece of ethanol-soaked cotton gauze after drying.

150524 - 16 -

Example 8

The same coating and polymerization procedure is used as in Experiment No. 88 of Example 7, except that 5% by weight, 0.1% by weight or 5,0001% by weight of vinyl chloride, sodium silicate is added to the polymerization mixture before the beginning of the polymerization reaction. The result is that the number of polymerization rounds where crust deposition is prevented is 9, 7 and 5, respectively.

Example 9

The same procedure is used as in Experiment No. 61 in Example 4, except that the coated surfaces are further coated with Nigrosine Black and Sodium Silicate in the same manner and under the same conditions as in Experiment No. 1 in Example 1. of polymerization cycles where crust formation is prevented is 25.

Example 10 In this example, 1000 liter stainless steel polymerization containers are equipped with a propeller type stirrer 20 with 600 mm diameter blades. The surfaces of the inner wall of the containers and agitator blades and the shaft are coated with a 0.5% solution in methanol of a mixture of

Sudan B and Nigrosine in various mixing ratios by 2 weight, as indicated in Table VIIIi, an amount of 0.05 g / m 25 (dry matter), the coated surfaces totaling 2 4 m. In each of the polymerization containers thus coated, 500 kg of water is introduced into which one of the various metal salts listed in Table VIII is dissolved, after which treatment at the temperature indicated in the same table follows with stirring at a rate of 110 rpm. . minutes for 30 minutes as well as cooling. Thereafter, 2.2 kg of sodium lauryl sulfate, 3 kg of cetyl alcohol, 200 g of dimethylvaleronitrile and 200 kg of vinyl chloride are introduced to perform suspension polymerization at 50 ° C for 7 hours by a conventional method. After completion of the reaction, the coated surfaces are washed with water and dried, and then the amount of crust deposition determined in Table VIII is determined.

fS & 524 - 17 -

For comparison purposes, similar experiments are performed with Sudan B or nigrosine alone and not in combination or without any metal salt. The results are also shown in the table.

Table VIII

Mixing conditions

Test Sudan B / Quantity No. Nigrosine Temperature _ Metal Salt_ (g / in) 95 * 100/0 90 ° C Sodium Silicate 10 g 520 96 100/10 90 ° C Sodium Silicate 10 g 5 97 100/50 90 ° C Sodium Silicate 10 g 0 98 100/100 90 ° C sodium silicate 10 g 0 99 100/500 90 ° C sodium silicate 10 g 0 100 100/1000 90 ° C sodium silicate 10 g 20 101 * 0/100 90 ° C sodium silicate 10 g 780 102 100/100 70 ° C sodium silicate 10 g 3 103 100/100 50 ° C sodium silicate 10 g 10 104 100/100 90 ° C sodium bicarbonate 0 20 g 105 100/100 90 ° C primary calcium-0 phosphate 20 g 106 100/100 90 ° C sodium acetate 20 g 0 107 100/100 90 ° C ferrochloride 20 g 0 108 100/100 90 ° C calcium chloride 20 g 0 109 100/100 90 ° C potassium sulfate 20 g 0 110 100/100 90 ° C alum 20 g 0 111 100 / 100 90 ° C sodium carbonate 10 g 0 112 0/0 ** (none) 1,800 113 100/0 ** (none) 960 114 0/100 ** (none) 1,250

Notes: * control ** no heat treatment 150524 - 18 -

Example 11

The same polymerization containers as in Example 10 are similarly coated with a 1% solution or dispersion in one of the solvents of Table IX of 5 a polar organic compound or organic dye alone or in combination and a metal salt as indicated in the same table. , which is heated to 90 ° C for 30 minutes. After the coated surfaces are washed with water, 100 kg of vinyl chloride, 200 g of water, 0.05 g of diisopropyl peroxydicarbonate, 1 kg of sodium dodecylbenzenesulfonate and 1.5 kg of ethyl alcohol are introduced into each polymerization vessel and an emulsion polymerization is carried out at an elevated level. temperature of e.g. 45 ° C with stirring at 110 rpm. per minute for 8 hours. After completion of reaction, the amount of crustal deposition is investigated and determined. The results are shown in Table IX.

20 15052Λ

- 19 -Table IX

Polar Organic Compound / Crust

Test Dye / Mixture Solution Formation No. Metal Salt Ratio Medium (g / m) 115 * (None) - (None) 1,600 116 * Sudan B - Toluene 550 117 * Diaminonaph - Methanol 630 Thalen 118 * Nigrosine Base - Mixed ** 480 119 * EDTA, 2 Na - water 1,100 120 * phytic acid - methanol 980 121 * methylene blue - methanol 690 122 * nigrosine - water 1,300 123 Sudan B / nigro-100/5/100 ethanol 23 sin Na2SiC> 4 124 Sudan B / nigro - 100/50/100 ethanol 0 sin Na2Si04 125 Sudan B / nigro- 100 / 100/100 ethanol 0 sin Na2Si04 126 Sudan B / nigro- 100/1000/100 ethanol 10 sin Na2Si04 127 diaminonaph- 100/100/100 ethanol 0 thalen nigrosine / NaHCOg 128 nigrosine base 100 / 100/100 ethanol 0 nigrosine / NaHCOg 129 methylene blue 100 / 100/100 ethanol 30 nigrosine / FeCl2 130 Sudan B / phytin-100 / 100/100 ethanol 63 acid NaHCO 100/100/100 water 81 EDTA, 2 Na2 SO4 132 indoline 100/100/100 mixed *** 53 p-toluenesulfinic acid NaCl 133 oil black BB / 100 / 100/100 mixed *** 49

Daitophor AN / CaCO3 134 alcohol 100 / 100/100 mixed *** 0 potassium / sodium tartrate / Na2 SiC> 4 150524 - 20 -

Notes: * control ** toluene and methanol *** ethanol and methylene chloride.

Example 12 The same polymerization containers as in Example 10 are similarly coated with the same material as in Experiment No. 126 in Example 11 in an amount of 0.1 g / m (as dry matter). In each of the coated containers 100 kg of vinyl chloride, 200 kg of water are introduced together with the various initiators, suspending agents or other additives or co-monomers according to Table X, after which a suspension polymerization is carried out at an elevated temperature of e.g.

57 ° C with stirring at 100 rpm. per minute for 10 hours. After completion of the reaction, the amount of crustal deposition is examined and determined. The results are shown in Table X.

As a control, similar polymerization is performed using the same additives or comonomers with polymerization containers coated with a single dye, such as e.g. nigrosine base, or not at all coated. The resulting crustal deposition is shown in the same Table X.

In Table X, PVA denotes polyvinyl acetate, HPMC denotes hydroxypropyl methyl cellulose, ΪΡΡ denotes diisopropyl peroxydicarbonate, LPO denotes lauryl peroxide, and BPO denotes benzoyl peroxide.

30 150524

- 21 -Table X

Quantity of crust According to

Experiment Polymerization Suspension Additive / Inventor Initiator Agent Comonomer Control 135 dimethyl valeryl hydrovinyl acetate 0 190 nitrile 0.03 kg lysed PVA 15 kg 0.1 kg 136 dimethyl valeryl hydrovinyl acetate 0 130 nitrile 0.03 kg of lysed PVA 5 kg 0.1 kg 137 dimethylvalero-HPMC 0.1 kg sorbitan 0 230 nitrile 0.03 kg monolaurate 0.1 kg 138 dimethylvalero-HPMC 0.1 kg sodium 0 290 nitrile 0.03 kg 2-ethyl hexylsulfo-succinate 0.1 kg 139 IPP 0.02 kg partially hydro (nothing) 0 210 lysed PVA 0.1 kg 140 LPO 0.5 kg partially hydro (nothing) 0 330 lysed PVA 0.1 kg 141 BPO 0 , 7 kg partially hydro- (nothing) 0 310 lysed PVA 0.1 kg 142 * dimethylvalero- partially hydro- (nothing) - 1,200 nitrile 0.3 kg lysed PVA 0.1 kg

Notes: * check. No coating.

150524 - 22 -

Example 13

The same coating materials as in Experiment No. 129 of Example 11 are applied to the interior wall surfaces and other parts of the combined mass polymerization containers, the first container being of stainless steel and 2 liters vertical, while the second container being a 4 liter stainless steel container of horizontal type. Then wash all the coated surfaces with water and dry. In the first container, 800 g of vinyl chloride and 0.4 g of dimethylvaleronitrile are introduced and a mass polymerization is carried out at 60 ° C with stirring at 900 rpm. minute for 2 hours. The reaction mixture is transferred to the second vessel loaded with 800 g of vinyl chloride and 0.4 g of dimethyl-valeronitrile. Polymerization is carried out at 57 ° C under stirring at 100 rpm. per minute for 10 hours. After polymerization is completed, the polymer crust deposit is examined in each polymerization container.

In comparison, an experiment is performed without any coating treatment or with a coating of ordinary nigro's base.

The results of the above experiments are shown in Table XI.

Table XI

25 Crust Quantity First Second

Test Container Container No. Coating Material (g / no) (g / in) 148 Same as Sample No. 125 0 0 149 Same as Sample No. 129 0 0 30 145 Same as Sample No. 136 0 0 146 * (none) 1,400 2,040 147 * nigrosine base 70 180

Note: * control.

Example 14

With the same coating polymerization container and application as in Experiment No. 126 in Example 11, suspension polymerization is carried out in the same manner and with the same additives as in Experiment No. 137 in Example 12 for 10 hours only with the difference that in some experiments, separately the coating material from test # 126 is added to the polymerization mixture in the varied amounts shown in Table XII, and in other experiments an alkaline substance, e.g. sodium hydroxide, calcium hydroxide or sodium acetate as indicated in the table. This cycle of polymerization is repeated to observe the crustal deposit with the naked eye, or in the same manner as in Example 1.

The results are shown in Table XII.

Table XII

Added amount of Alkaline coating

Attempt Material Added Quantity Time of Number 15 (parts per million) (%) _ addition * laps 148 (nothing) (nothing) - 3 149 10 (nothing) - 4 150 50 (nothing) - 6 151 100 ( none) - 8 20 152 (none) NaOH 0.01 0 8 153 (none) NaOH 0.01 1 hour 6 154 (none) NaOH 0.01 2 hours 5 155 (none) NaOH 0.01 3 hours 4 156 (none) none) NaOH 0.05 0 10 25 157 (none) NaOH 0.1 0 13 158 (none) Ca (OH) 2 0.05 1 hour 8 159 50 CH3 C00Na 0.1 1 hour 16

Notes: The quantities in parts per million or 30 percent is based on the weight of vinyl chloride monomer.

* Number of hours elapsed from the start of each polymerization cycle.

35

Claims (1)

A process for polymerizing vinyl chloride monomer alone or in admixture with one or more copolymerizable monomers in the presence of a polymerization initiator, subjecting the surfaces of the inner walls and other portions of the polymerization reactor prior to polymerization. in contact with a monomer, a treatment with at least one crust preventive compound which may be an organic dye or a polar organic compound, characterized in that one is treated with (a) at least one organic compound selected from polar compounds. organic compounds and organic dyes, the polar organic compound being selected from nitrogen-containing organic compounds, sulfur-containing organic compounds, oxygen-containing organic compounds, phosphorus-containing organic compounds, tar, pitches, resins and waxes, and the organic dye being selected from azo -color-20 fabrics, anthraquinone dyes, indigo dyes, sulphide dyes tufts, phthalocyanine dyes, diphenyl raethane dyes, triphenylmethane dyes, nitro dyes, thiazole dyes, xanthene dyes, nitroso dyes, acridine dyes, azin dyes, oxazine dyes, thiazine dyes dyes, naphthoquinone dyes and cyanine dyes, and (b) at least one compound selected between halides, hydroxides, oxides and carboxylates of metals and oxo acids of zinc, boron, aluminum, carbon , silicon, tin, titanium, nitrogen, phosphorus, sulfur, chromium, molybdenum, tungsten, chlorine and manganese and inorganic salts of these oxo acids, the treatment comprising, 35