DE1570812B1 - Process for the production of polymer compositions - Google Patents

Description

1 "- 2 ■■ · ■■■ - ■■

It is known that vinyl chloride polymers contribute to the fact that the additive in the particles of the

tend to become detached or absorbed by heat and / or polymerizate,

Light decompose, which in some cases leads to a while this due to the excess of the monomer

Deterioration in color and properties are swollen. .

the polymer leads. To counteract this effect, if the organotin compound is added

act, it is widely used to some extent after the excess is not reacted

Stabilizers, among other things the monomers removed below, are contained in the obtained

given sulfur-containing organotin compound polymers the addition is not complete and equal-

applications to add to the polymer before it is a moderately or intimately distributed, so that the mass a Mixing, kneading, extrusion or molding operation, io has thermal stability, which is the same or even

all of which require heating of the resin or are too inferior to that of masses passing through

lead to heating. However, it is normal to mix the additive with the polymer

difficult to evenly distribute the stabili- way, for example by mixing the additive

to achieve sators in the polymer. with the polymer powder and grinding at increased

The present invention has for its object the temperature that has been established. Creation of a method for producing a It is already known in principle that one Polyvinyl chloride compound is based on the sulfur-containing stabilizers even before or during the Organotin compounds evenly distributed 'can add vinyl chloride polymerization. Because of contains. However, this prior art could not be the subject of the invention is a method for 20 be foreseen that it would be when using the prior manufacture of polymer compositions, the vinyl chloride lying special stabilizers of particular polymers and sulfur-containing organotin Advantage is, they to the above-mentioned, very specific bonds, in which sulfur atoms covalently at th point in time in the suspension polymerization to -tin atoms are bound, contained that thereby clog. It is essential that the is characterized in that vinyl chloride, used alone or in addition to organotin compounds, is one of the together with one or more other ethylene polymerisation retarding effects, unsaturated monomers in an amount less than than 50 percent by weight, based on the mono-but it is assumed that if the total active polymer weight, in aqueous suspension in a merization catalyst residue, such as a per-reaction vessel in the presence of suspension stabilizing 3 ° oxide groups, in which polymer products are present, Sators and monomer-soluble peroxide catalysts, these subvert the thermal decomposition of the polymer polymerized and support the organotin compounds. When a compound is polymerization fertilization in an amount of 0.01 to 10 percent by weight, retards or withholds, this is based on it based on the weight of the monomer or monomers, so that the polymerization catalyst zerder aqueous suspension in the reaction vessel 35 interferes with or is inactivated, for example by decomposition after the pressure in the reaction or reaction with peroxide groups. if tion vessel from the sum of the vapor pressures of the one that retards the polymerization or Water and the monomer (s) in the poly-retaining compound during the polymerization temperature has started to fall and sation is added or after the pressure drop while a certain amount of not reacted and before the excess of monosettled matter Monomers! If more is drained off in the reaction vessel, then this is counteracted to the catalyst is. Deactivate the catalyst, so that there are no active catalysts during the suspension polymerization or any residues of the mixer in the final polymer product of vinyl chloride will or will remain, so that this thermal decomposition cannot favor the monomers with other additives in the 45, so that actually Autoclave filled, which then to the desired the heat resistance of the polymerization product polymerization temperature is heated. The car-tes is improved. Compounds that increase the polyclave pressure Do not hold back demmerization at the polymerization temperature and accordingly also essentially speaks of the sum of the saturated does not deactivate the polymerization catalyst, Vapor pressures of water and the monomer 5 ° therefore do not have an improved heat resistance or the monomers at the relevant temperature result.

temperature, and the autoclave remains under this pressure, the organotin compounds containing sulfur

Provided that the temperature remains constant, genes are used primarily as heat stabilizers

throughout the polymerization until the largest added, but they can vinyl chloride polymers

Amount of the monomer or monomers polymerized for purposes other than pigments, for example

are. If no liquid monomer in the autoclave or lubricant, "are added,

more is present, but only gaseous monomer, In the following formulas the following

so the steam is no longer used with the monomer abbreviations: The groups R, R ¹ and R "

saturated, and the pressure begins to decrease. A we- are monovalent aliphatic or aromatic carbon

The essential feature of the process is that 60 lenhydrogen residues, which can be substituted, and

that the organometallic compounds added they can be the same or different. If in

after the pressure drop has taken place, the groups R, R ¹ and R "

and before the excess monomer drained occur more than once, they can occur for each

will. Occurrences can be the same or different. The rest

It has been found that by making ^{the item 6} 5 R _{5 pj and} d R "are preferably made of those

of the invention forming method selected the dispersion of the hydrocarbon residues, the 3 to 15 carbon

The additive in the polymer has substantial carbon atoms, such as butyl,

is improved. This is likely due to- hexyl, octyl, nonyl, decyl, lauryl, and benzyl

Phenyl. They can be substituted, for example by hydroxyl, amino or nitro groups. if a radical is bonded to the metal atom, this should preferably be a lower alkyl radical, for example Butyl, as such compounds are generally more effective heat stabilizers. In some Cases, however, the higher alkyls, such as those containing more than 8 carbon atoms, and the aromatic radicals are preferred because they have a lower tendency to consist of polymer masses migrate out and are therefore more useful if non-toxic formulations are made will.

R ¹ ", R ^IV and R ^v are divalent aliphatic or aromatic hydrocarbon radicals which may be substituted and they can be the same or different. If in any compound the groups R ^m , R ^IV or R ^{v occur} more than once, they can R ¹¹¹ , R ^IV and R ^v are preferably selected from the hydrocarbon radicals containing 1 to 15 carbon atoms, such as methylene, ethylene, propylene, butylene, hexylene and phenylene radicals, and although they are preferably unsubstituted, they can optionally be substituted, for example by hydroxyl, amino or nitro groups.

η is equal to or greater than 1, and m is an integer that is greater than 0 or equal to 0, m and η can be the same or different, p, q and f are the integers 0 or 1 and can be the same or different be.

n + m + 1 is equal to the valence of the tin.

The preferred compounds have the general formula

(R) "- Sn [-S- (R ⁿ % -X] _{m + I}

wherein X is the group - R ¹ , --OR ¹ , - M (R '), _{1 + m} ,

- C —Υ —R ¹

be used, d. H. those of the general formula

(R) _n Sn

iii + l 2

wherein W - S - - O - or - S - (R ^IV ) _p - V - ίο, where V

-C-Y- (R ^ -Y-C-Z Z

or -YC- (R ^V ) _P -CY-

Z Z

denotes, where Y and Z have the meanings given above and where W, V, Y or Z, if they occur more than once in the connection, they can be the same or different.

Examples of sulfur-containing organotin compounds of the general formula

(R) _n - Sn [- S - (R "\ - X] _{n + 1}

where q = 0 and X = - M - (R ') " _{+ m} are the simple organotin sulfides, such as bis (tributyltin) sulfide

(C ₄ Hg) ₃ Sn - S - Sn (C ₄ Hg) ₃

Other examples of the sulfur-containing organotin compounds of the first class (a) are: I. the simple mercaptides, d. H. Compounds of the general formula

40 (R) _n -Sn - (- S -R ¹ L ₊₁
such as dibutyltin dilauryl mercaptide

(C ₄ Hc,) ₂ Sn (- S - C ₁₂ H ₂₅ ) ₂ ,
II. Substituted mercaptides of the general formula

- Y — C —R ¹

Il ζ

means, where Y - O, —S— or —NH—, and Z represents = O, = S or = NR ".

However, if m is an odd integer greater than 1 or equal to 1, cyclic compounds (R) _n -Sn-

or (R) _n -Sn-

(R ¹¹¹ LCYR ¹

S- (R ¹¹¹ J ₄ -YCR "

Examples in which Y and Z are oxygen are as follows:

Dibutyltin-S.S'-bis - ^ - ethylhexyl mercaptoacetate)

C-S-CH ₂ -CO-O-CH ₂ -CH (C ₂ H ₅ ) ■ (CH ₂ J ₃ CH ₃ ] ₂

Dibutyltin-S, S'-bis - (/ 3-mercaptoethylbenzoate)

(C ₄ H ₉ ), Sn (- S - CH ₂ - CH ₂ - OCO - QH ₅ ) ₂ and

Dibutyltin-S, S'-bis- (nonylthioglycolate)

(C ₄ H ₉ J ₂ Sn - (S - CH ₂ - CH ₂ - CO - O - CgH ₁₉ ) ₂

III. Cyclic compounds of the formula / S _x

(R) _n Sn

ß- ^ll \

include in particular those in which W is the group - O -, such as the condensation product of mercaptoethanol and dioctyltin oxide:

,-NS-,

(QH ₁₇ J ₂ Sn

and cyclic compounds of the formula (R) _n Sn V

iit + l

like those in which V the group

- 0-CO- (R ^ -CO- O -

represents.

Examples of this type of compound include the hydrocarbon metal compounds, the on esters of mercapto alcohols with dibasic ones Acids are bound, for example di-n-butyltin-S, S'-di (mercaptoethanol) adipate

/ S - (CH ₂ J ₂ -O-CO (C ₄ H ₉ J ₂ Sn (CH ₂ J ₄

\ S (CH ₂ ) ₂ - O - CO IV. Compounds of the general formula

(R) _n Sn

-S- (R ¹¹¹ LC-YR ¹

m + l

where Z = 0, = S or = NR "and Y = NH or S means such as amides, thiocarbamates, isothiocarbamates, dithiocarbamates and isodithiocarbamates. Examples of this type are:

Dibutyltin-S, S-bis (thioglycoic acid amylamide) (C ₄ Hg) ₂ SnC-S-CH ₂ -CO-NH

Dibutyltin-S-bis- (N-benzyl-S'-benzylisodithiocarbamate)

-SC = N- CH ₂ C ₆ H ₅ S-CH ₂ -

(C ₄ Hg) ₂ Sn

and dibutyltin S-bis (N-butyldithiocarbamate) (C ₄ Hg) ₂ Sn [- S - C - NH - C ₄ Hg] ₂ .

The amount of sulfur-containing organotin compound used is 0.01 to 10 percent by weight of the polymerizable monomer (s) and is preferably in the range from 0.5 to 3 percent by weight.

Other ingredients such as lubricants and other stabilizers, for example lead stearate, dibasic Lead stearate, calcium stearate, cadmium stearate and cadmium laurate and waxes can be used in the Mixture can be introduced and can in many cases simultaneously with or before the sulfur-containing Organotin compound are added. Alternatively, the other additives can be mixed with the polymer mixed in the normal way, and pigments such as titanium dioxide and carbon black can also be added will.

To other ingredients added either to the dispersion or to the polymer obtained include processing aids such as methyl methacrylate-ethyl acrylate copolymers, styrene-acrylonitrile copolymers, chlorinated polyethylene and agents that improve impact resistance, such as calcium carbonate, preferably with a Fatty acid, such as stearic acid, is coated, acrylonitrile-butadiene-styrene copolymers and ethylene-vinyl acetate copolymers.

Plasticizers can be added to the polymer if a plasticized product is required is.

To monomers copolymerized with vinyl chloride Include vinyl esters such as vinyl acetate, vinylidene chloride, alkyl esters of unsaturated Mono- or dicarboxylic acids, such as acrylic acid, methacrylic acid, maleic acid and fumaric acid, in particular the methyl and ethyl esters of such acids, acrylonitrile and methacrylonitrile. The whole amount of comonomers used is less than 50 percent by weight of the total weight of the monomers and is especially less than 20 percent by weight of the total weight of the monomers.

Suitable oil-soluble peroxide catalysts include benzoyl peroxide, lauryl peroxide and the peroxide dicarbonates.

Mixtures of catalysts can also be used. The amount of catalyst used depends on the kind of the catalyst and the polymerization temperature, but generally lies in the range from 0.005 to 2 percent by weight of the monomer (s).

The polymerization is normally carried out at a temperature in the range of 30 to 8O ⁰ C, in particular 40 to 75 ° C.

As suspension stabilizers, gelatine,. Methy! Cellulose or completely or partially hydrolyzed polyvinyl acetates are used.

The amounts of suspension stabilizer are those normally used in the polymerization of vinyl chloride used, for example 0.001 to 5%, preferably 0.004 to 1%, based based on the weight of the monomers. The compositions obtainable according to the invention are special valuable for the production of bars, tubes and other profiles by extrusion processes.

In the following examples, all parts and percentages are based on weight.

" _Λ Example 1

2000 parts of distilled water, 1.4 parts of hydrolyzed polyvinyl acetate and 0.35 parts of diisopropyl

peroxydicarbonate were placed in a stainless steel autoclave. The autoclave became continuous stirred and evacuated, then flushed with nitrogen and evacuated again. 1000 parts of vinyl chloride were added and the autoclave was then kept at a temperature of 65 ° C. After the Autoclave pressure had fallen to 6.3 atmospheres, a solution of 16 parts of dibutyltin-S, S'-bis- (nonylthioglycolate),

(QH ₁₇ J ₂ Sn

,NS,

- CH,

IO

dissolved in 40 parts of ethylene dichloride, injected. The mixture was stirred and cooled for an additional half hour, and then the autoclave was blown against the atmosphere. The polymer was filtered from the aqueous medium and then in an oven at 5O ⁰ C for 24 hours. The yield of polymer was 683 parts and analysis showed it to contain 1.4% dibutyltin S, S'-bis (nonyl thioglycolate) which corresponds to a retention of about 60%.

The polymer was then maintained without further additives in a crepe 5minutiges by rolling on a two-roll mill, in which a roll at 160 ⁰ C and the other roll at 170 ⁰ C, placed. The crepe was clear and almost pale in color.

For comparison, a polymer was prepared according to the above procedure, omitting the addition of dibutyltin - S, S '- bis - (nonylthioglycolate). 2.34 parts of dibutyltin S, S'-bis (nonylthioglycolate) was added to 100 parts of the dried polymerizate powder and the mixture was rolled for 5 minutes as above to give a clear pale brown cre "pe. The color difference between the two samples remained after were pressed from the crepes cut samples for 2 minutes at 190 ⁰ C.

Example 2

40

The procedure of Example 1 was repeated, using a condensation product of mercaptoethanol and dioctyltin oxide, i.e. a compound of formula ■

was used in place of the dibutyltin-S, S'-bis- (nonylthioglycolate). 813 parts of polymer were formed and analysis showed that it contained 1.4% of the dioctyltin oxide-mercaptoethanol condensation product, which corresponds to a retention of about 71%. This polymer was rolled as in Example 1 to provide a clear CrSpe of a very pale yellow color. A control polymer was prepared by polymerizing vinyl chloride according to the above procedure, but omitting the step of adding dioctyltin oxide-mercaptoethanol condensate product. 1.97 parts of the condensation product was added to 100 parts of the control polymer and the mixture was rolled as in Example 1 to give a clear, pale brown crepe. The color difference was also seen after samples of the crepe for 2 minutes had been pressed at 19O ⁰ C.

Comparative experiments A

The following experiments show that dibutyltin-S, S'-bis- (nonylthioglycolate) acts as an inhibitor for the polymerization of vinyl chloride.

The polymerization recipe and procedure were the same as in Example 1, and around one Curve of conversion at various times after the start of the polymerization was obtained in a series of attempts the autoclave was blown off against atmospheric pressure to initiate the reaction cancel at different times. In this series of experiments no dibutyltin-S, S-bis- (nonylthioglycolate) used.

In a second series of experiments, 16 parts of dibutyltin-S, S'-bis (nonylthioglycolate) in The autoclave was injected at various times, and the autoclave was on for a total of 4 hours kept at the polymerization temperature from the beginning of the polymerization before the blowing off.

The results are given in the table below.

No dibutyltin-S, S'-bis- (nonylthioglycolate) present conversion
% Dibutyltin-S, S'-bis- (nonylthioglycolate) injected conversion
•% elapsed time between
Reaching the reaction temperature
and blowing off
(Hours.) 7.5 elapsed time between
Reaching the reaction temperature
and injecting
Dibutyltin-S, S'-bis- (nonylthioglycolate)
(Hours.) 8.5 0.50 25.5 0.50 26.5 1.00 · 42.5 1.00 44.5 1.50 57.0 1.50 58.5 " 2.00 71.0 2.00 - 2.33 - - 75.0 - 80.0 2.40 - 4.00 -

'' These results are in graphical form in the Drawing shown.

Another attempt in which dibutyltin-S, S'-bis- (nonylthioglycolate) was added to the aqueous medium before the addition of vinyl chloride gave no polymer at all; i.e., the conversion was zero.

It can be seen that the addition of dibutyltin-SmS'-bis- (nonylthioglycolate) causes the polymerization to slow down during the polymerization.

009525/280

Comparative experiments B

These experiments show that the addition of non-inhibiting or only slightly retarding organotin Thermal stabilizers that do not contain sulfur do not provide the improvement that with dibutyltin-S, S'-bis (nonylthioglycolate) (Example 1) and the condensation product of mercaptoethanol and dioctyltin oxide (Example 2).

The polymerization was carried out as in Example 1 with the exception that 20 parts of a dioctyltin carboxylate stabilizer which does not contain sulfur, was added to the aqueous medium before the vinyl chloride was added.

The reaction time was 4 ¹ Z ₂ hours and the yield 72% · The analysis showed that the polymer contained 2.16% of original stabilizer, which corresponds to a retention of 77.5%.

A control polymerization carried out under the same conditions, but in which the ^{dioctyltin carboxylate was} omitted, gave a conversion of 78.7% after a reaction time of 3V _{2 hours.}

The polymer produced by polymerization in the presence of dioctyltin carboxylate was on rolled a two-roll mixer as in Example 1 and compared the crepe with that through Rolling 100 parts of the polymer obtained in the control polymerization with 2.8 parts of dioctyltin carboxylate was obtained. Both crepes were pale amber, but the one from the Polymers made by polymerization in the presence of dioctyltin carboxylate slightly darker than that made by rolling the control polymer with dioctyl tin carboxylate. Appropriate Results were obtained from an experiment in which the dioctyl tin carboxylate was injected into the autoclave was when the pressure dropped from the average pressure during the polymerization to 6.3 at was.

Another comparison was made by adding 20 parts of dibutyltin di (nonylmaleate),

(C ₄ Hg) ₂ Sn (O-CO-CH = CH-CO-OC ₉ H ₁ S) ₂

were added in place of the dioctyltin carboxylate to add the vinyl chloride. The response time to the A 78% conversion was achieved in 4 hours. The polymer contained 2.34% dibutyltin di (nonylmaleate), which corresponds to a retention of 91% is equivalent to. Both this polymer and one by injecting the dibutyltin di (nonylmaleate) after The pressure in the autoclave had dropped to 6.3 atm and the polymer was produced by rolling as compared in Example 1 to a blend obtained by rolling 100 parts of the control polymer with 2.6 parts of dibutyltin di (nonylmaleate). All three crepes had similar pale browns Colorations. Similarly, films pressed from the crepes were of a similar color.

A third comparison was made using parts of dibutyltin dilaurate instead of dibutyltin di (nonylmaleate) carried out. If the dibutyltin dilaurate was added before the vinyl chloride after a reaction time of 4 hours, the conversion was 78%. The polymer contained 2.03% original stabilizer, which corresponds to a reluctance of about 79%.

Both this polymer and one obtained by injecting the dibutyltin dilaurate after the The pressure in the autoclave to 6.3 at produced polymer was by rolling as in Example 1 with a Compared blend obtained by rolling 100 parts of the control polymer with 2.6 parts of dibutyltin dilaurate was made. Again, all of the crepes were similar pale brown in color, and from the crepes pressed films were of similar color.

Comparative experiment C

This experiment shows that there was no improvement in thermal stability as found in Example 1 is to be rind if the dibutyltin-S, S'-bis- (nonylthioglycolate) is added after the excess monomer is blown off.

The polymerization of Example 1 was repeated, but the 16 parts of dibutyltin-S, S'-bis (nonylthioglycolate) were added after the excess monomer had been blown from the autoclave. The aqueous medium and the polymer were ^{stirred at 50 °} C., with samples being taken at time intervals.

The samples were rolled as in Example 1 and the crepes were compared to crepes made by Rolling 100 parts of the control polymer with 2.34 parts of dibutyltin-S, S'-bis- (nonylthioglycolate) were manufactured. Crepes from samples removed after stirring for 1, 3 and 16 hours all inferior colors compared to the roller mixes.

Claims (1)

Claim: Process for the preparation of polymer compositions, the vinyl chloride polymers and sulfur-containing Organotin compounds in which sulfur atoms are covalently bonded to tin atoms are included, characterized in that vinyl chloride, alone or together with one or more other ethylenically unsaturated monomers in an amount of ■ less than 50 percent by weight, based on the total monomer weight, in aqueous suspension in a reaction vessel in the presence of suspension stabilizers and monomer-soluble Peroxide catalysts and polymerized the organotin compound in an amount of 0.01 to 10 percent by weight, based on the weight of the monomer or monomers, of the aqueous Suspension in the reaction vessel is added after the pressure in the reaction vessel of ' the sum of the vapor pressures of the water and the monomer (s) has started to fall at the polymerization temperature and during still a certain amount of unreacted monomer! is present in the reaction vessel. 1 sheet of drawings