DE2633833A1 - PROCESS FOR THE PRODUCTION OF POLYVINYL CHLORIDE SUITABLE FOR CALANDER PROCESSING - Google Patents

Description

Process for the production of polyvinyl chloride suitable for calender processing

The vinyl chloride polymers suitable for calendering to form films should have good flow properties and good running properties show on the calender. Furthermore, the lowest possible intrinsic color and high transparency of the polymers result demands.

Finally, the films made from the polymers should have good antistatic properties because they are electrical charged foils attract dust particles and thus tend to get dirty quickly.

Polyvinyl chloride obtained by emulsion polymerization shows good antistatic properties because of its emulsifier content Properties and, in this regard, fulfills the requirements that are made of a suitable for calender processing Polymer represents. However, the emulsifier content has a disadvantageous effect on the inherent color and transparency during calender processing from (see. Table, Comparative Examples 1 and 2).

It is already known in the manufacture of calender processing suitable polyvinyl chloride to use an emulsifier system consisting of alkyl sulfonate and alkyl aryl sulfonate in a weight ratio of 0.25 to 1.0 (DT-OS 2 429 326). So made Polymers show good antistatic properties and adequate heat resistance; in terms of However, their own color and, above all, transparency still need to be improved.

There has now become a method of being suitable for ICalander processing Polyvinyl chloride found that polymers are better

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Heat resistance, lower inherent color and significantly improved Transparency can be obtained by polymerization in an emulsion containing at least 45 percent by weight of monomers in the presence of emulsifiers and water-soluble catalysts and spray-drying the latex obtained, which is characterized is that the sodium salts of an isomer mixture as an emulsifier alkyl disulfonic acid diaryl ester containing sulfonic acid groups the formula

^R i - CII
I. ^R 3 - 3 ^Well CH
I. S.
I. = O ^R 2 O = S =
I. O I.
O
JL I.
O
JL Xso 6th (J ₃ Well = O -SO

are used in the -

R-. , R_ and R straight-chain saturated hydrocarbon residues with 0 to 16 carbon atoms, R + R_ + R at least 8 and at most 16 carbon atoms and contain one statistical distribution of the sulfonic acid groups on the hydrocarbon chain is present.

The process according to the invention is expediently carried out in the presence of the sodium salts of an isomer mixture of sulfonic acid group-containing alkyl disulfonic acid diaryl esters, which was prepared by sulfochlorinating an n-paraffin fraction of the corresponding carbon number and esterifying the sulfochlorides formed with phenol and sodium hydroxide to form the phenyl alkyl monosulfonate, sulfochlorinating the alkyl monosulfonate. Esterifying the sulfonyl chlorides formed with phenol and sodium hydroxide as well as treating the diester with oleum or sulfur trioxide in liquid sulfur dioxide at temperatures below 30 ⁰ C. ■

A preferred embodiment of the method according to the invention is that the addition of the emulsifier continuously in Dependence on sales in such a way that with one

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Conversion of 0 % the emulsifier concentrate 0.006 to 0.01 percent by weight, with a conversion of 20 % the jümulgator concentration 0.012 to 0.03 percent by weight, with a conversion of 30 % the emulsifier concentrate 0.03 to 0.05 percent by weight, with a conversion of 35 % the emulsifier concentration 0.05 to 0.15 percent by weight, with a conversion of 40 % the emulsifier concentration 0.15 to 0.35, with a conversion of 60 % the emulsifier concentrate 0.35 to 0.5 percent by weight and with a conversion of 95 % the emulsifier concentration is 0.7 to 2.0 percent by weight, the percent by weight of emulsifier being based on the amount of polyvinyl chloride.

According to a further preferred embodiment of the egg according to the invention In the process, the polymerization is carried out in an acidic or neutral medium and, after the polymerization, the pH value set to 8.0 to 9.0.

This preferred embodiment has the advantage of a certain one Improvement of the heat resistance and inherent color of the polymer obtained, as shown in the table below can be seen (Example 1-3: Polymerization in an acidic medium, Example 5: Polymerization in an alkaline medium).

The hydrocarbon chain of the emulsifiers to be used in the process according to the invention contains 10 to 18 carbon atoms. Hydrocarbon mixtures can also be used to produce the emulsifiers. The sulfonic acid groups are statistical (as formed by sulfochlorination of hydrocarbons) distributed along the hydrocarbon chain. A typical preparation example of the process according to the invention The emulsifiers to be used are specified below;

A. Preparation of an alkyl disulfonic acid diaryl ester containing sulfonic acid groups:

300 g of one obtained by sulfochlorinating phenyl alkyl monosulfonate (produced by sulfochlorinating a C, C, o-n ~ paraffin fraction and esterification of the sulfochlorides formed with phenol and sodium hydroxide solution) and by subsequent

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Esterification The diesters obtained with phenol and sodium hydroxide solution are dissolved in 450 g of liquid sulfur dioxide at -15.degree. 141 g of a. Mixture of 75 g of gaseous SO ₀ and 60 g of gaseous S0 "introduced. After that, the S0 “at

a temperature of 0-5 C distilled off. The remaining sulfonates are dissolved in 900 g of water and treated with 20 percent strength Sodium hydroxide solution neutralized. A description of the manufacture of the devices to be used according to the invention Emulsifiers can be found in DT-OS 1 938 958.

The final concentration of emulsifier should, based on polyvinyl chloride, not less than 0.7 and not more than 2.0 percent by weight. Above 1.5 percent by weight emulsifier the inherent color and heat resistance of the polymer with undiminished excellent transparency - a little worsened v / ground, however, an emulsifier concentration of up to 2.0 percent by weight because of the better running properties of the product on the calender may be an advantage.

The water-soluble compounds usually used in the emulsion polymerization of vinyl chloride are used as catalysts in question, such as water-soluble persulphate, water-soluble persulphate combined with a reducing component, such as water-soluble bisulfate, hydrosulfite, hydrazine, thiosulfate, formaldehyde, sulfoxylates, hydrogen peroxide combined with reducing Components such as bisulfite, hydrazine, hydroxylamine or ascorbic acid, also combined water-soluble persulfate with hydrogen peroxide and an activating component such as copper salts.

As Polyraerisationsternperatur should the usual temperatures between 50 and 80 ⁰ C, corresponding to a pressure of 5-12 bar, selected v / ground.

The dispersions obtained should contain at least 45 percent by weight of polymer. High polynierlion concentrations guarantee one high space-time yield during the polymerization and decrease

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South the energy expenditure with regard to the spray drying process. The spray drying is carried out in such a way that a free-flowing powder is obtained. Polymers with a good flowability should contain at least 90% grain content with a particle diameter of> 63 ° and less than 50% grain size with a particle diameter of> 160 °.

The spray drying can be carried out in customary spray drying devices / such as, for example, in Ullmcinns Encyclopadie der technical chemistry, 1951, 1st volume, page 602 are described.

For a two-component atomization to a coarse powder, the one in the
DT-PS 1 263 619 described nozzle is suitable. In order to get to grain fractions with 90% ^> 63 ρ grain fraction, the
After the drying process, the finer grains are screened off.

Grain fractions that are equal in the atomization in the correct
Order of magnitude, but can be obtained by atomization by means of single-fluid nozzles. With this type of atomization
the dispersion is forced through a nozzle with a diameter of 1.5 to 3.0 mm under a pressure of 5 to 30 atmospheres.

Using the atomizing disc atomization method, too, grain fractions suitable for coarse atomization are obtained.
To further explain the method of operation according to the invention
the following examples and comparative examples serve:

Comparative example 1

3
In a 6 m pressure vessel with a reflux condenser and

is provided with a stirrer, with exclusion of atmospheric oxygen

-. 1 510kg of water submitted, furthermore

5 1 of a 3.5% emulsifier solution, which is 1.4 %

of a sodium alkyl sulfonate and 2.1 % of a sodium

alkylarylsulfonates -contained,

3.0 kg of mono-, sodium phosphate and

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1,000 kg of vinyl chloride.

The speed of the stirrer is set to 55 revolutions per minute and the reaction mixture is heated to 66.degree. With achievement the temperature will be equal volumes of a 2% Hydrogen peroxide solution and a 0.8% ascorbic acid solution dosed into the reaction vessel, 20 l of each solution within the first hour.

Then the metering speed of the hydrogen peroxide solution and the ascorbic acid solution adapted to the reaction. in the in general, 3 to 8 liters of solution are required per hour. The reaction rate should be such that the Polymeriscition finished after 5 hours.

As soon as the reaction starts, v / ground vinyl chloride and emulsifier solution further dosed. The amount of vinyl chloride is adjusted so that 1,200 kg of vinyl chloride are introduced in about 3 hours v / earth. The 3.5% emulsifier solution is depending on retracted according to the following program:

Time (h) 3.5% emulsifier solution (1) Emulsifier conversion {%)

concentration wt.%

0 begin 0.009 0 0.5 5 0.009 5 1.0 12th 0.019 15th 1.5 44 0.030 25th 2.0 144 0.086 35 2.5 260 0.260 50 3.0 380 0.45 - 3.5 500 0.67 65 4, Q • 629 0.88 - 4.5 End of reaction 1.05 80 5.0

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After completion of the polymerization, 0.3 % sodium carbonate,

based on PVC, added to the polymerization batch.

A latex with 48 % solids is obtained. The K value according to Fikentscher (Lunge-Berl 1934/5, page 945) is 60, the emulsifier content based on PVG is 1 %. The dispersion is free from

Sieve residue.

The dispersion thus obtained becomes more common in a spray tower Type with a volume of around 200 m atomized. The spray tower contains 10 single-fluid nozzles with a mouth diameter of 2.0 mm. By 110 l of dispersion are forced through each nozzle every hour. The air tower inlet temperature is 165 C, the air tower outlet temperature 80 C, the warning air volume .22,000 Nm / h.

The dispersion is kept under a pressure of 8 atmospheres. The PVC powder coming out of the tower and separated in a filter has the following particle size distribution:

_: 94 % of the powder has a larger diameter

than 63 u and 36 percent by weight of the powder has a diameter - "." ■ "■" ■ - knives of more than 160 u.

The inherent color, transparency and heat resistance of the powder, which are determined as described below are in the Table compiled.

Comparative example · 2

As in Comparative Example 1, in the 6 m container under Exclusion of atmospheric oxygen except

1 510 kg of water a solution of

60 g copper nitrate and
1 0Ö0 g sodium pyrophosphate in ^ ■ 5 1 H _? 0 _? submitted, furthermore

5 1 of a 3.5% emulsifier solution, which 1.4 % -; of a sodium alkyl sulfonate and 2.1 % of a -. NatriuKalkylarylsulfönrtes contains, 1 000 kg vinyl chloride and,

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5 1 of a 3% potassium persulfate solution

The speed of the stirrer is set to 55 revolutions> ro minute and the reactor vessel is heated to 66 c. When this temperature is reached, a 1.5% ELO “solution is poured into the The reaction vessel is metered in and the rate of reaction is controlled with the amount of hydrogen peroxide. In the first hour of the The reaction requires more than 5 liters of hydrogen peroxide, later about 5 liters per hour. The reaction is adjusted so that the polymerization is completed in 5 hours. With the beginning of the reaction, the further addition of takes place

1,200 kg of vinyl chloride in 3 hours and the running-in of the 3.5? Igen emulsifier solution according to the program of the Comparative example 1.

At the end of the reaction, when the pressure begins to drop, 0.3 % soda, based on PVC, is added again. A dispersion with 48 % solids is obtained, the K value of which is 60 and which is worked up in a manner similar to that in Comparative Example 1. After spray drying, a powder is obtained which has a particle size distribution as in Comparative Example 1. The inherent color, transparency and heat resistance of the powder are listed in the table.

example 1

The procedure is as in Comparative Example 1, but instead of the emulsifier mixture consisting of alkyl sulfonate and alkyl aryl sulfonate, a 3.5 % value is used. Solution of an alkyl disulfonate di-aryl ester sulfonated on the aryl group used, prepared according to A. (page 3).

The dispersion obtained has: 48 % solids, the polymer has a K value of 60 and an emulsifier content of 1 %.

After spray drying under the conditions of the comparative example The grain distribution is the same as in the comparative examples obtain.

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The inherent color, transparency and heat resistance are in the Table compared to the comparative examples.

Example 2

The procedure is as in Example 1. After the polymerization, however, 1 % of the emulsifier, based on. PVC added to the dispersion. The transparency and heat resistance of the powder obtained after spray-drying are again compared to the comparative examples in the table.

Example 3

The procedure is as in Example 1, but the emulsifier solution has a concentration of 2.8% of the sulfonated alkyl disulfonic acid diaryl ester. The latex obtained has a solids content of 48 %, a K value of 6.0 and an emulsifier concentration of 0.8 %. It is sprayed as described in the preceding examples, and the inherent color, transparency and heat resistance of the powder obtained are listed in the table. ·

Example 4 .- ■■■ - '

It is polymerized and worked up as in Comparative Example 2. Instead of the mixture of alkyl sulfonate and alkyl aryl sulfonate, however, the alkyl disulfonic acid diaryl ester sulfonated on the aryl groups, the preparation of which is described under A., is used as a 3.5% solution. The inherent color, transparency and heat resistance of the powder containing 1% emulsifier has a K value 60 are listed in the table.

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Testing · for iron color, transparency and heat resistance

The powder to be examined is mixed in a bowl with stabilizer and lubricant in the following ratio:

100 parts by weight PVC,

I ₇ O parts by weight of di-n-octyl tin bis (2-ethylhexyl) thioglycolate,

H)

1.0 part by weight of lubricant Loxiol G 10 and

hh) 0.5 weight parts wax E.

The mixture is kneaded on a roller mill at 165 ° C. for 5 minutes.

a) Bigen color and transparency

The thoroughly kneaded, rolled mixture is pressed under a pressure of 200 bar and 170 ^° C. for four minutes. The transparency and inherent color of the 1 mm thick plates are determined visually. High numerical values in the table mean poor intrinsic color.

b) heat resistance

The kneaded, hot mixture is drawn out into a sheet 1.0 mm thick. The fur turns into squares of 18 18 mm punched out and subjected to a temperature load of 190 ° C. in a Karussel-Brabender heating furnace. Samples are in Taken from a time interval of 5 minutes. The thermal load can be recognized by the discoloration. The time that is up immediately passes before blackening is a measure of heat resistance.

Glycerol monooleate
Montanic acid ester

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Emulsifier

lot

Weight%

Heat., ■ Resistance. (Minutes)

Own color

transparency

09385, Comparative
example State of the art
State of the art 1
2 ^ ₁
ο
ro example according to the invention 1 cn example , according to the invention 2 example according to the invention 3 example according to the invention 4th

1/0 1.0

1.0 2.0 0.8

1/0

75
75 1.1 /
1.2 3 opaque,
milky Γ 2633833 4th
Uü
\ 80 1.0 crystal clear 75 1.0 crystal clear 85 1.0 crystal clear 75 1.1 crystal clear

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As can be seen from the table, the inventive Operation compared with that of the relevant prior art in the heat resistance and the The inherent color of the polymers achieve certain improvements, while the transparency is improved to a considerable extent.

701885/0211

Claims (4)

O.Z. 2941 07/26/76 claims 1. A process for the production of polyvinyl chloride suitable for calender processing by polymerization in an aqueous emulsion containing at least 45% monomers in the presence of emulsifiers and water-soluble catalysts and spray-drying of the latex obtained, characterized in that as an emulsifier, the sodium salts of an isora mixture containing sulfonic acid groups Alkyl disulfonic acid diaryl ester of the formula SO ₃ Na can be used in the R, R ₂ and R denote straight-chain saturated hydrocarbon radicals with 0 to 16 carbon atoms, R ₁ + R "+ R- contain at least and at most 16 carbon atoms and a statistical distribution of the sulfonic acid groups on the hydrocarbon chain is present. 2. The method according to claim 1, characterized in that the sodium salts of an isomer mixture containing sulfonic acid groups are used as the emulsifier Alkyldisulfonic acid diaryl ester are used, which was prepared by sulfochlorinating an n-paraffin fraction corresponding carbon number and esterification the sulfochlorides formed with phenol and sodium hydroxide solution to form the phenyl alkyl monosulfonate, Sulfochlorination of the alkylmonosulfonic acid phenyl esters, esterification of the sulfochlorides formed with Phenol and treating the diesters with oxygen or sulfur trioxide in liquid sulfur dioxide at temperatures below 30 C. ORIGINAL INSPECTED 709885/0215 0 ^{R! TriNAU} ZL 07/26/76 3. The method according to claim 1 or 2, characterized in that the emulsifier is added continuously as a function of the conversion in such a way that at a conversion of 0 % the emulsifier concentration is 0.006 to 0.01 percent by weight, at a conversion of 20 % the emulsifier concentration is 0.012 to 0.03 percent by weight, with a conversion of 30% the emulsifier concentration 0.03 to 0.05 percent by weight, with a conversion of 35 % the emulsifier concentration 0.05 to 0.15 percent by weight, with a conversion of 40 % the emulsifier concentration 0.15 to 0.35 percent by weight , at a conversion of 60 % the emulsifier concentration is 0.35 to 0.5 percent by weight and at a conversion of 95 % the emulsifier concentration is 0.7 to 2.0 percent by weight, the percent by weight of the emulsifier being based on the amount of polyvinyl chloride. 4. The method according to claim 1, 2 or 3, d a d Uf r c h marked that the polymerization is carried out in an acidic or neutral medium and, after the polymerization, the pH of the latex obtained is set to 8.0 to 9.0. 709885/0215