DE1720749A1 - Process for the production of chlorinated polyethylenes - Google Patents

Description

Process for the production of chlorinated polyethylenes

S · 1st known "that high molecular weight by chlorinating polyolefins chlorine contents of 20 -. 60 percent i" results in a material that can be used ssur elastification of polyvinyl chloride (DAS 10 ^ 5 O89). It is also known that the chlorination products of high molecular weight polyolefins, obtainable in aqueous suspension by a 2-stage process, with a degree of chlorination of about 25 to 50% by weight in admixture with polyvinyl chloride are suitable for producing impact-resistant and tear-resistant moldings. The process by which the starting polyolefins were produced is not of decisive importance; The only requirement is a sufficiently high molecular weight, which corresponds to a relative specific viscosity of about 1 to 10. Chlorination products of polyethylenes produced by the low-pressure polymerization process, especially those of Ziegler polyethylene, have a particularly favorable effect.

Both the polyolefins produced by the low-pressure polymerization process (up to 100 atmospheres and 200 ° C.) and those manufactured by the high-pressure processes (over 1000 atmospheres and over 100 ° C.) have a relatively broad molecular weight distribution. The degree of molecular non-uniformity, which according to GV Schulz, J. Makromol. Chemistry 1 (19 ^ 3) 131 as the ratio _v

Mw (Gewlohteglttel) Mn (means of payment;

- 1

is defined. Ee makes sense to assign a value with U »5 above which a degree of great molecular heterogeneity

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- 2 - Ge. 390

and below which a degree of minor molecular non-uniformity is understood. The usual low-pressure and high-pressure polymerization processes lead to a high degree of polyolefins Degree of molecular non-uniformity. A material with a narrow molecular weight distribution generally acquires higher molecular weight through thermal, thermomechanical or oxidative degradation Polyolefins to a desired molecular weight (B. Vollmert, Outline of macromolecular chemistry, Springer-Verlag 1962, I87). According to Vesslau, polyolefins with a relatively narrow molecular weight distribution are also Makromol. Ch. 26 (1958), 102 obtainable by regulating the molecular weight during the polymerization.

The invention now relates to a process for the production of chlorinated polyethylenes and / or dex-en copolymers in chlorine-resistant solvents at temperatures between 60 and 150 ° C., which is characterized in that such polymers and / or copolymers of ethylene are known Way of chlorination 'in solution, which have a degree of molecular non-uniformity of U s 5 and a viscosity of ri spec c from 0.7 to 10, (measured in 0.1% solution at 135 ° C in decahydronaphthalene). The properties of the chlorination products obtainable according to the invention differ substantially from those which are produced from the above-mentioned polyolefins with greater molecular non-uniformity. They show, for example, a better solubility in carbon tetrachloride and toluene and also a different solution behavior Molecular non-uniformity U ^ 5, for example, with a chlorine content of Ύοη 36 ^ t only 10 wt. From a procedural point of view, too, these solubility and solution properties are advantageous because they allow the chlorination to be carried out at higher concentrations.

- 3 - Ge. 3 . 90

The chlorination products are preferably used as elastic if ikatoren for polyvinyl chloride and / or its copolymers. They are also very generally used as high molecular weight plasticizers for plastic compounds, as coating materials, and also in the varnish and paint sector. For the first-mentioned field of application in particular, they are superior to the chloropolyethylenes made from other starting polyethylenes, since the plasticates containing the products according to the invention have particularly favorable values in the key figures "notched impact strength ¹¹ and" smoothness of the rolled skin ¹¹ .

Good measured values In both properties, however, they are of decisive importance for the possible uses of an elasticized polyvinyl chloride or copolymers. However, with the known chlorination products made of polyethylene with high molecular heterogeneity, this requirement can only be met to a limited extent. Although the notched impact strength of the polyvinyl chloride orphaned with the chloric product increases with increasing relative viscosity to spec / c of the starting polyethylenes, at the same time the roughness of the rolled sheets increases due to the lower compatibility of the two chlorine-containing polymers. A possibility for better rolled sheets In this case, the chlorinated polyolefins are only processed together with a polyvinyl chloride with a value of approx. 70 (measured according to DIN 53 726), with which they are more compatible than, for example, a material with a K value approx. 6O. For a number of areas of application, however, mixing with polyvinyl chloride with a K value of approx. 60 is unavoidable.

On the other hand, it is known that when chlorination products are used that are obtained by chlorination of polyolefins with a high relative specific viscosity had been obtained in aqueous suspension, achieved a very good notched impact strength of the mixtures with polyvinyl chloride, but here, too, form again, in this Probably because the compatibility is not sufficient due to the high molecular weight of the Auagangspolyäthylens. By chlorination of the polyethylene in an organic medium, for example Carbon tetrachloride, the smoothness of the mill heads can be improved somewhat, but the impact strength decreases again away. So it was not possible until now to use an as an ETA for

* rough rolled heads

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ORIGINAL INSPECTED

- * - Ge. 390

Polyvinyl chloride or its copolymers fully satisfactory, chlorinated polyethylene, which gives the thermoplastic at the same time high notched impact strength and good pellet properties receive.

Among polymers and copolymers of ethylene with a degree of molecular disparity of U * 5 # which are used as starting materials for the Process according to the invention are used, ethylene polymers or copolymers with a narrow molecular weight distribution, such as stated above, by the ratio U «" ^Ί · ^aitedrüic ken, understood that a specific viscosity η spec / c of 0.7 to 10, preferably 0.7 to 5 »in particular 0.9 to 2, measured in 0, 1% solution in decahydronaphthalene in iron at 135 ° C. The ethylene copolymers to be used are those polymers which are formed in the copolymerization of ethylene with C "to C" - (^ - olefins, the polymers in particular in question come in which the higher olefins are no longer included as IO wt. $.

The polyolefins to be chlorinated according to the invention are prepared, for. B. by known methods by thermomechanical degradation of higher molecular weight polymers with relative specific viscosities vi spec / c of, for example, 2.5 (measured in 0.1 ^ long solution) up to 35 (measured in a 0.01 solution) to a value of 0.7 to 10, preferred.'0.9 to 2 (measured in 0.1% solution) in the extruder. Oa the higher molecular weight polymers mentioned can be prepared with such small amounts of catalysts that their removal prior to further processing can be dispensed with, and they also make them more economical A very suitable Auegangematerial. Furthermore, those obtained by direct polymerization with molecular weight regulation to the desired relative specific viscosity according to Wesslau are also suitable reproducible polyolefins, provided that they meet the condition U «5, although we should give preference to thermomechanically degraded products.

The chlorination of ethylene polymers or copolymers is carried out in known manner at temperatures between about 60 and 150 ⁰ C, preferably 70 to 120 ⁰ C in the presence of organic chlorine-resistant solvent, optionally in mixtures of chlorreslstentem solvent and water. The preferred solvent used is carbon tetrachloride, but chloroform,

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Use methylene chloride, chlorobenzene or hybrids of the chlorinated hydrocarbons mentioned. Is chlorinated at a temperature below 8O ⁰ C, then the presence of a free radical catalyst acting "as benzoyl peroxide or azodiisobutyronitrile beneficial.

The polyethylenes or their copolymers can be chlorinated to any desired chlorine content up to about 70 wt. #. Are products with 20 to 50 preferred for the proposed use as Elastifikatoren for Kunetstoffmaseen, preferably 30 to kO wt. Ήα particularly suitable.

The products produced according to the invention are used for elasticization of vinyl chloride polymers or copolymers mixed with these in amounts of 5 to 60, preferably 10 to 50 wt. #. With a 10 to 2 Ö # addition you get particularly cheap Effects in notched impact strength, coat smoothness, tear strength and Elongation at break.

In the following, the production process is based on examples Chlorination products explained and shown which advantages are less when using chlorinated polyethylene from polyethylene molecular inhomogeneity when they are used as elasticizers for polyvinyl chloride masses. Parts are always parts by weight Understood.

example 1

Α) A low-pressure polyethylene with the relative specific viscosity eta / c (measured in 0.01 # iger solution at 135 ° C in decahydronaphthalene) »35 was thermomechanically in the extruder to the viscosity eta / c (measured in 0.1 ^ iger Solution) = 1.1 and the flowability i- (at 190 ° C and 5 kg load) «65 g / 10.

j mxn

reduced. The degree of molecular non-uniformity was U - 2.5.

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Parts of the granules, 20 parts of carbon tetrachloride and 0.01 Parts of azodilsobutyroniltrile were then enamelled in a Boiler at 90-105 ° C and 6 * 8 atm with 2.5 parts of chlorine on one Chlorine content of 37 »4% chlorinated. After blowing out the dissolved hydrogen chloride with nitrogen and stripping off the solvent at 60 ° C. under reduced pressure, 3.2 parts of a clear, colorless, rubber-elastic paste remained.

B) The polyethylene described above was thermomechanically degraded to the viscosity eta .c (measured in 0.1 iger solution) a 1.3 and the flowability 1 = 41. The U-Vert was 3.

2 parts of the granulate and 6 parts of carbon tetrachloride were chlorinated to a chlorine content of 35.5 H with 2.3 parts of chlorine in an enamelled kettle at 90-100 ° C. and T> - 8 atm. After working up as described above, 3.1 parts of a colorless, rubber-elastic composition were obtained.

For comparison purposes, the following chlorination products were prepared from polyethylenes with a broad molecular weight distribution:

C) A low-pressure polyethylene, through polymerization under molecular weight control with hydrogen to the relative specific viscosity eta / c (measured in 0.1% solution) »1.5»

sp

U-Vert 8 was chlorinated as described under B). The chlorine content was 3518 #. After working up under the above conditions 3.1 parts of an almost colorless, rubber-elastic mass were obtained obtain.

D) 1 part of a low-pressure polyethylene, as described under C) produced, eta / c «1.4, U = 10, 38 parts of carbon tetrachloride were added and at 105-115 ° C / 7-8 atm 1 part of chlorine is chlorinated to a chlorine content of 33 * 6 Jt. Work-up and appearance of the product were as described under A). The yield was 1.4 parts.

K) 1.8 part of the low-pressure polyethylene described under C), 38 parts of carbon tetrachloride and 0.01 part of aaodiisobutyronitrile were at 80-100 ° C and 6-8 ktü with 2.8 parts of chlorine. · 1η · η chlorine content of 43 »5 Jt colored. Work-up and appearance J wmr as described under 0), the yield was 3.1 parts.

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Γ) 2 parts of a low-pressure polyethylene with the relative specific viscosity eta / c (measured in 0.1 # solution) β 3.0

*! ■■
and the U-value 8.5 was mixed with kO parts carbon tetrachloride and O ₁ OI parts azodiisobutyronitrile, then chlorinated at 90-95 ° C and 5-8 atmospheres to a chlorine content of 3315 % . The yield after work-up by Ublichur was 2.8 parts.

G) The polyethylene described under F) was made in an analogous manner

at 100 - 115 ° C catalyst-free to a chlorine content of 39 # O £ chlorinated.

To measure the smoothness of the skin, molding compounds made of polyvinyl chloride and the chlorination products A-O were produced on a laboratory roller mill with polished steel rollers according to the following approach

* Weight 8 parts

Suspension polyvinyl chloride from K-Vert 60 (measured according to DIN 53 726) 90

Chlorination product according to tests A to G 10 Stabilizer Marl ^ C * 1

(metal-free organic compound)

Stabilizer MarltW S X * 3

(Ba / Cd complex of higher fatty acids)

♦ Manufacture of Argus Chemicals.

At a roller temperature of 175 C, after rolling times of

5 »15 and 25 minutes, a sample of the rolled head is taken and the Surface quality assessed visually.

The following mixtures were produced to measure the mechanical properties!

Parts by weight of a) suspension polyvinyl chloride with a K value of 70

(measured according to DXN 53 726) 80

Chlorination product according to A to G 20 Stabilizer Mark C

(metal-free organic compound) 1

Stabilizer Mark WSX

(Ba / Cd complex) 3

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b) Sueponsionepolyvinylohlorid from K-Word 70 Chlorination product according to A to G Stabilizer Mark C Stabilizer Mark VSX

Ge. 390

Part by weight

90 10

The mixtures were each rolled for 15 minutes at 175 C Wa las tempera door, then samples from them at 175 ° ^C with a pressure of

120 kg / cm pressed.

1.) Smoothness of the coat

Test results

Mixture with chlorination product

Rolling time minutes

Obor curse texture of the hide

5 smooth 15th smooth 25th smooth

5 15 25

smooth smooth smooth

5 15

rough

very rough structure

Orange peels "

25th very rough,
structure Orange peel D. 5 smooth 15th smooth 25th smooth E. 5 rough 15th
25th rough
very rough. /structure
Orange peel F. Ui Ui very rough
very rough, /structure
Orange peel 25th very rough. N N HN G 5 very rough, ti Il NN 15th very rough, N N NN 25th very rough. N N NW

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As can be seen, only the connection results from the comparison products after D a smooth roller head. As can be seen from the following table, however, the chlorination product according to D has a significant lower notched impact strength than the products according to A and B, which are much more compatible with polyvinyl chloride.

2. Mechanical values

The measurement of the notched impact strength was carried out ^{in accordance with DIN 53 453 at 0 ° C.}

Mix with
Chlorination product
after approach Notched impact strength
at 0 ⁰ C ₂
cm kp / cm Λ 80/20
90/10 49
15th B. 80/20 without break C. 80/20 40 D. 80/20 18th E. 80/20 16 F. 80/20 26th G 80/20 31

A comparison of the values in both tables shows that a smooth rolled head with simultaneously high notch impact strength only with achieve the chlorination products according to the invention according to A and B. leaves.

Example 2

A) A low pressure polyethylene with the relative specific viscosity eta __ / c (measured in 0, T #iger solution) »2.8, the flow lock

hold i_ »1.5 and the degree of molecular non-uniformity U ■ 8.5 was thermomechanically on the flow behavior 1_» 21.4 and the viscosity eta _e _ / c (measured in 0.1 # solution) »1, 5 dismantled. The U-value was now k,

- 10 -

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2 parts of the granules were In 30 parts carbon tetrachloride chlorinated with 2.2 parts of chlorine to a chlorine content of 33.7 #. Oils work-up was carried out as described in Example 1 A). The yield was 3 * 1 parts of a colorless rubber-like one Dimensions.

B) For comparison purposes, the information in DAS 1 236 774, column 2, Line 51 to column 3 »line 11, the chlorination product described re-enacted. The low-pressure polyethylene used had the U-Vert 10.

The smoothness of the coat was determined on a mixture as in Example 1 described. At a roller temperature of 175 ° C, after the initial formation of a smooth Rolled skin with a continuation of the rolling time up to 15 minutes the rolled head with a content of the bond according to B) a Orange peel structure, while the fur with the compound according to A is still completely smooth after 25 minutes (end of the experiment) Surface and a lighter color.

ν
The notched impact strength was determined on moldings which, as in

Example 1 were prepared.

Mix with
Chlorination product
after approach Notched impact strength
at OC ₂
cm kp / cm A. 80/20
90/10 48
16 B. 80/20
90/10 41
11th

Example 3

A low pressure polyethylene with the relative specific viscosity eta / c (measured in 0.03 £ strength solution) "20 was obtained in the RSV eta / c (measured in 0.1 £ strength solution) ■ thermo-mechanically built from 1.25. The degree of molecular non-uniformity U was 2.5, the flowability I ₅ - 35

- 11 - ■

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k pieces of the granules and 38 parts of carbon tetrachloride were mixed with 4.8 parts of chlorine at 90 - chlorinated I30 ⁰ C and 6 to 8 atm to a chlorine content of 36.6 $. The work-up was carried out as in the preceding examples. The bulge was 6.4 parts of a colorless, rubber-elastic measure.

The surface quality of the rolled head was as in the example 1 described determined. The rolled sheet was completely smooth after 25 minutes of rolling.

The notched impact strength in the 80/20 batch (see Example 1) was 53 cm kp / cm.

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Claims (6)

Patent claims: 1.) Process for the production of chlorinated polyethylenes and / or their copolymers in chlorine-resistant solvents Temperatures between 60 and 150 ° C, characterized in that that such polymers or copolymers of ethylene are subjected to chlorination in solution in a known manner a degree of molecular non-uniformity of U = 3 and a viscosity of µ spec / c from 0.7 to 10 (measured in 0.1 ^ iger Solution in decahydronaphthalene). 2.) Process according to A1, characterized in that the ethylene polymers or copolymers to be chlorinated were obtained by thermomechanical degradation of higher molecular weight polymers. 3.) Verfaliren according to A 1, characterized in that carbon tetrachloride is used as the clilorrcsistentcs solvent. k.) Process according to A1, characterized in that chlorination is carried out in the presence of a mixture of a chlorine-resistant solvent and water. 3 ·) Chloropolylithylenes with chlorine contents up to 7U Gow. V '· durcii obtained chlorination of such polyethylenes or their copolymers, which have a degree of molecular non-uniformity U of * 5 and a viscosity of Vjspez / c from 0.7 to 10, in chlorbestündigen solvents at T- oraturen between 60 and 150 ⁰ C. 6.) Chlorination products according to A 5, with a chlorine concentration of 30 to k0 wt. $. 009S20 / 1723