DE1569372B1 - Stabilization of vinyl chloride polymers and chlorinated polyethylene - Google Patents

Description

The stabilization of polyvinyl chloride using organotin compounds is shown in the U.S. Patents 2,883,363, 2,872,468, 2,870,182, 2,870,119, 2,914,506, and 2,801,258. Organotin compounds form a measure of the thermal stability because of their unusually good heat stabilization. However, the organotin compounds have the disadvantage that they are toxic and limit this their use in areas of application where toxicity is not an issue. Moreover, most of them are these compounds are liquids and therefore of limited use for rigid or hard Vinyl chloride polymers.

The invention relates to the use of a mixture of

A. 25 to 40 percent by weight of a magnesium salt of benzoic acid and / or of edible Fatty acids derived from fats and oils,

B. 25 to 40 percent by weight of a zinc salt of benzoic acid and / or of edible fats and Fatty acids derived from oils,

C. 20 to 50 weight percent of a non-toxic polyhydric alcohol

for stabilizing vinyl chloride polymers, post-chlorinated polyvinyl chloride and chlorinated polyethylene.

Since the stabilizer combination to be used is a solid mixture, stabilization can be achieved without any deterioration in any of the other properties of the polymers. The stabilizer mixtures to be used are at high temperatures, e.g. B. 190 ⁰ C, as they are required in the processing of rigid PVC, ie stable for 45 minutes and longer.

The stabilizer composition to be used in the present invention is far more effective than any the ingredients alone or together with a second ingredient, indicating that the combination all three components, d. H. of magnesium and zinc salt and polyhydric alcohol, one gives a synergistic effect.

Combinations example .One magnesium salt and a polyhydric alcohol, a zinc salt and a polyhydric alcohol and a magnesium and a zinc salt are at the elevated processing temperatures, ie, about 19O ⁰ C and above, which are required in the processing of rigid polymers, not sufficiently effective - to be used as stabilizers. In addition, the synergistic combination according to the invention gives better results at lower temperatures than the individual components. Combinations of zinc stearate or magnesium stearate and polyhydric alcohols can be found in U.S. Pat. No. 2,711,401.

Examples of fatty acids derived from edible fats and oils are the mixed fatty acids, those of tallow, lard, sardine oil, olive oil, coconut oil, cottonseed oil, soybean oil, corn oil or peanut oil come. The oils from which the fatty acids originate can, if desired, be hydrogenated. Even distilled, fractionated fatty acids or mixtures of fatty acids derived from such fats and oils, are useful.

Any aliphatic compounds with at least two and preferably no more than ten hydroxyl groups can be used. Particularly preferred Polyhydric alcohols are mannitol, sorbitol and glycerin. Pentaerythritol has also proven to be in the Stabilizer compositions according to the invention proved effective.

The stabilizer mixture is generally used in an amount of about 2 to 6% based on the weight of the polymer used. Adequate resistance to deterioration due to

ίο Heat can be used when using only small amounts the stabilizer composition, e.g. B. about 0.25 percent by weight of the polymer can be achieved. Ever the more stabilizer is used, the better the resistance to heat damage.

Amounts above about 10% are generally unnecessary. When plasticized polymers are stabilized less stabilizer is needed, and usually no more than about 3% of the Polymerisatgewise be used.

The stabilizing effect of the stabilizer compositions to be used according to the invention can be improved by adding small amounts of non-toxic antioxidants. If such antioxidants are used, they should be used in amounts no greater than about 0.5% of the polymer mass. Any known antioxidant can be used provided that it is non-toxic in the amounts employed. Typical examples of antioxidants are 2,6-Ditert. - butyl -A- methylphenol, 2 - tert. - Butyl-4 - methoxyphenol, 3 - tert. - Butyl -A- methoxyphenol, n-propyl gallate, n-dodecyl gallate, dilauryl thiodipropionate and nordihydroguayak acid.

The following antioxidants also appear non-toxic in small amounts: 4,4'-methylene-bis- (2,6 - di - tert. - butylphenol), 4,4 - thio - bis (2-tert.-butyl - 5 - methylphenol), 4,4 '- butylidene - bis (2-tert.-butyl - 5 - methylphenol) j 1,1,3 - tris - (3 - tert. - butyl-4 - hydroxy - 6 - methylphenyl) - butane, 2,2'-methylenebis - [4 - methyl - 6 - (I '- methylcyclohexyl) phenol] - and 2,2'-methylene-bis (4-nonylphenol).

Vinyl chloride polymers are understood to be those which are at least partially made up of repeating group

- CH-C -

II
α χ

are formed and have a chlorine content of more than 40%. In this group, the radicals X each represent hydrogen or chlorine. In the case of vinyl chloride homopolymers each of the radicals X is hydrogen. Therefore, the term does not only include Vinyl chloride homopolymers, but the post-chlorinated polyvinyl chlorides and copolymers of vinyl chloride in a larger proportion and other copolymerizable monomers in a smaller proportion, such as copolymers of vinyl chloride and vinyl acetate, copolymers of vinyl chloride with maleic or fumaric acid or esters and copolymers of vinyl chloride with Styrene. The invention is also applicable to mixtures of polyvinyl chloride in a larger proportion with a smaller proportion of other polymers, such as chlorinated polyethylene or a

Copolymer of acrylonitrile, butadiene and styrene, applicable.

The stabilized polymer composition can easily be prepared by customary processes. The selected stabilizer system is usually mixed with the polymer to be stabilized using, for example, plastic mixing rollers at a temperature at which the mixture is flowable and thorough mixing is facilitated, the stabilizer system with the polymer on a two-roll mixer at about 150 to about 205 ⁰ C is mixed for a time sufficient to form a homogeneous skin. The plasticizer used, if any, can be incorporated with the stabilizer. Rolling for 5 minutes is usually sufficient. After the mass is uniform, it is formed into a skin or sheet material in a conventional manner.

The following examples illustrate preferred embodiments of the invention without restricting it.

example 1

A number of Polymerisatmassen were prepared each containing 150 parts of stabilizers as indicated in Table I, containing on a two-roll mixer until mixed to 191 ⁰ C Vinylchloridhomopolymerisat. Each sample was then divided into two parts; one part each was heated at 177 ° C and the second part at 191 ° C in an air oven. The discoloration was noted and is reported in Table I.

Table I.

Stabilizer composition

Magnetic

sium-

benzoate

Zinc salts

from
Tallow fatty acids
Parts by weight

Mannitol

Heat discoloration at 177 ⁰ C (minutes heating time)

0 30th 60 White dark black Brown yellow yellow yellow Brown orange Red dark Red yellow yellow yellow Brown orange Red Brown White yellow yellow

Heat discoloration at 191 ° C
(Minutes heating time)

15th

45

60

3.0

1.5
1.5

3.0

1.5

1.5

1.5
1.5

1.5
1.5
1.5

black Black

dark brown black

black yellow white

yellow-brown
orange

yellow-brown
orange

White

black black black yellow yellow black dark dark black Red Red yellow ver black carbonates dark black black Red yellow yellow yellow

black black black black black charred

The results given in Table I clearly show that when magnesium benzoate and mannitol are added to polyvinyl chloride (samples C and E), discoloration occurs immediately after heating, so that after only 15 minutes of heating at 191 ^° C. the mass takes on a dark red color. The same dark red color (brown in sample E) is observed after only 60 minutes of heating at 177 ° C. When the zinc salts of tallow fatty acids and mannitol are used in a vinyl chloride polymer composition (samples B and D), the composition turns black after heating at 191 ° C for 45 minutes (30 minutes for sample D) or heating at 177 ° C for 120 minutes. In contrast, the mass remains with the use of the stabilizer combination (Sample F) according to the invention when used in combination of magnesium benzoate, zinc salts of tallow fatty acids and mannitol as a stabilizer combination according to 45minutigem heating at 191 ° C and heating at 177 ⁰ C 120minutigem yellow and transparent. This shows the synergistic nature of the combination, since the stabilizer combination when using all three ingredients, a magnesium salt, a zinc salt and a polyhydric alcohol, gave a significant and better stabilizing effect than compositions containing only two of these ingredients.

Example 2

A series of masses were as in Example 1 using a copolymer of 96%

65 vinyl chloride and 4% vinyl acetate. With the three-component systems according to the invention similar benefits were achieved.

Example 3

A series of masses was prepared as in Example 1, with glycerin in place of mannitol was used. Similar advantages have been achieved with the three component systems.

Example4

A stabilizer composition was prepared consisting of 1.5 parts of mannitol, 1.5 parts of magnesium salts of tallow fatty acids, and 1.5 parts of zinc salts of tallow fatty acids. This stabilizer composition was then mixed with 150 parts by weight of polyvinyl chloride on a two roll mixer. The mass was then divided into two parts, one part was maintained in an air oven at 177 ° C and the other in an air oven at 191 ⁰ C. The color found is given in Table II below.

Table II
Heat discoloration at 177 ^° C

Initially pale yellow

Yellow after 30 minutes of heating

Yellow after 60 minutes of heating

Yellow after 120 minutes of heating

Heat discoloration at 191 ° C

Initially pale yellow

Yellow after 15 minutes of heating

Yellow after 30 minutes of heating

After 45 minutes of heating ..... yellow

Example 5

The procedure of Example 4 was carried out using a stabilizer composition 1.5 parts of sorbitol, 1.5 parts of magnesium benzoate and 1.5 parts of zinc salts of tallow fatty acids are repeated. The results obtained are shown in Table III below.

Table III Heat discoloration at 177 ° C

Initially white

Yellow after 30 minutes of heating

Yellow after 60 minutes of heating

After 120 minutes of heating .... yellow

Heat discoloration at 191 ° C

~ Initially ...; White

Yellow after 15 minutes of heating

* Yellow after 30 minutes of heating

.. Yellow after 45 minutes of heating

The results of Examples 4 and 5 show that other stabilizer compositions described in fall within the scope of the invention, to stabilize at about 190 ° C for at least 45 minutes and to Stabilization at 177 ° C for at least 2 hours are satisfactory.

Example 6

Example 5 was repeated using pentaerythritol as the polyhydric alcohol. It equivalent results were obtained. Hence, pentaerythritol is polyvalent to the other non-toxic ones Equivalent to alcohol.

Example7

Three stabilizer compositions were prepared. Each contained 1.5 parts of mannitol, 1.5 parts of magnesium benzoate and 1.5 parts of zinc salts of tallow fatty acids. 0.15 part of a non-toxic antioxidant in the proportions used was added to each of the stabilizer compositions. Each stabilizer composition was then mixed with 150 parts by weight of a vinyl chloride homopolymer in a two roll mixer. The antioxidant used in each case and the results obtained upon heating the Polymerisatmasse in an air oven at 177 ⁰ C and 191 ⁰ C are given in Table IV. Samples A and F from Table I are also included in Table IV for comparison.

• Antioxidant Tabel 0 30th 60 120 IV 15th Heat discoloration at 191 ° C irrigation time) 60 75 Heat discoloration at 177 ° C White yellow yellow yellow gdb (Minutes] 45 yellow ver 's 2,6-di-tert-butyl (Minutes heating time) 30th yellow carbonates 4-methylphenol White yellow yellow yellow 0 yellow yellow yellow ver G 4,4'-methylene White yellow carbonates bis- (2,6-di-tert-
butylphenol
4,4'-thiobis White yellow yellow yellow yellow yellow yellow black H (2-tert-butyl- White yellow 5-methylphenol) yellow J Control attempt White dark black black White black black black (no stabilizer Brown black and no anti black A. oxydans) White none White yellow yellow yellow yellow ver black yellow carbonates yellow F. White

From the above values it can be seen that the use of a small amount of antioxidant does the Stabilizing effect of the combination increases, thereby increasing the useful life of the polymer 191 ° C is increased by at least 15 minutes, which is an important factor in many processing conditions Characteristic represents. The test temperature of 177 ° C was not sharp enough for the synergistic To show the effect that the antioxidant has on the stabilizer composition.

Example 8

A stabilizer composition was prepared by mixing 5 parts of mannitol, 2.5 parts of magnesium benzoate, 4 parts of zinc salts of tallow fatty acids and 0.4 parts of 2,6-di-tert-butyl-4-methylphenol 4.65 parts of this stabilizer composition were then mixed with 150 parts by weight of a vinyl chloride homopolymer mixed on a two-roll mixer, and the resulting polymer mass was heated in an air oven at 191 ° C. The results obtained are shown in Table V.

Table V

Initially

After 15 minutes of heating
After heating for 30 minutes
After 45 minutes of heating
After 100 minutes of heating
After 75 minutes of heating

White

yellow

yellow

yellow

yellow

dirty yellow

The use of this stabilizer composition in polyvinyl chloride therefore resulted in good resistance to damage from heat at 191 ^° C. for at least 1 hour.

Example 9

The procedure of Example 8 was followed using zinc benzoate in place of zinc tallow fatty acid salts and of magnesium salts of coconut fatty acids in place of magnesium benzoate. Equivalent results were obtained.

Example 10

The procedure of Example 8 was followed using magnesium salts of corn oil fatty acids repeated as the magnesium salt and of zinc salts of corn oil fatty acids as zinc salts. There were equals Results achieved.

Example 11

A stabilizer combination was made using 3 parts magnesium benzoate, 5 parts Zinc salts of tallow fatty acids, 4 parts of mannitol and 0.4 parts of 2,6-di-tert-butyl-4-methylphenol are produced. 2 parts of this stabilizer combination were then mixed with 100 parts of vinyl chloride homopolymer, which is plasticized with 45 parts of dioctyl phthalate and 5 parts of epoxidized soybean oil, mixed. It Good stabilization was achieved for 2 hours heating at 177 ° C.

Example 12

The procedure of Example 8 was repeated using zinc salts of hydrogenated peanut oil fatty acid in place of the tallow fatty acid salts. A Polyvinylchloridmasse containing this stabilizer composition remained yellow after 45minutigem heating at 191 ⁰ C.

Example 13

The procedure of Example 12 was followed using hydrogenated cottonseed oil fatty acids repeated in place of the fatty acids of hydrogenated peanut oil. The results were equivalent achieved.

Example 14

Three stabilizer compositions were prepared. Each contained 1.5 parts of mannitol, 1.5 parts Magnesium benzoate and 1.5 parts of zinc salts of tallow fatty acids. 0.15 part of 2,6-di-tert-butyl-p-cresol, the is non-toxic in the amounts used, were then used with each of the stabilizer compositions mixed. Each stabilizer composition was made up of 127.5 parts by weight of a vinyl chloride homopolymer and 22.5 parts of each of the extender resins identified in Table VI. It a two roll mixer at 177 ° C was used. After heating the polymer mass in one Air oven at 177 ° C and results obtained at 191 ° C are given in Table VI.

Waste resin Tabel 0 30th White bright 60 120 VI Heat discoloration at 191 ° C 15th Minutes heating time) 45 60 I. 75 U Heat discoloration at 177 ° C White yellow orange yellow dark ( yellow 30th yellow yellow black O (Acrylonitrile buta- (Minutes heating time) yellow yellow diene styrene poly 0 K merisat) bright bright White bright bright ver ver (Graft copoly- White pale yellow orange orange orange bright orange carbonates carbonates merisat from Bu orange L. tadien with meth White acrylic acid methyl ester) pale yellow pale yellow yellow black black (chlorinated poly pale yellow! pale yellow ethylene, 38% M. Chlorine) White

From the above data it can be seen that the stabilizer compositions according to the invention are as equally effective in Polyvinylchloridmischungen at the homopolymer alone at 177 ° C and 191 ⁰ C.

Example 15

The procedure of Example 14 was a post-chlorinated polyvinyl chloride as a polymer and mixing repeated using the stabilizer combination in the polymer at 193 ⁰ C.

Heat discoloration at 191 ° C

Initially

After 15 minutes of heating.
After heating for 30 minutes.
After 45 minutes of heating.
After heating for 120 minutes

.. yellow-brown

,. dark yellow brown

.. dark yellow-brown

.. dark yellow-brown

.. dark yellow-brown

Table VII
Heat discoloration at 177 ° C

Initially

After heating for 30 minutes.
After heating for 60 minutes.
After heating for 120 minutes

.. yellow-brown

.. yellow-brown

.. dark yellow-brown

. dark yellow brown

65 This example shows that the stabilizer compositions according to the invention in post-chlorinated Polyvinyl chloride give satisfactory stabilization.

Example 16

The procedure of Example 12 was followed using of olive oil fatty acids in place of peanut oil fatty acids. There were equals Get results.

109514/381

Example 17

The procedure of Example 12 was followed using of lard fatty acids in place of peanut oil fatty acids. There were equals Get results.

Example 18

The procedure of Example 12 was followed using sardine oil fatty acids in place of Peanut oil fatty acids repeatedly. Equivalent results were obtained.

Claims (2)

Patent claims: 1. Use a mixture of A. 25 to 40 percent by weight of a magnesium salts of benzoic acid and / or fatty acids derived from edible fats and oils, B. 25 to 40 percent by weight of a zinc salt of benzoic acid and / or of edible fats fatty acids derived from oils, C. 20 to 50 percent by weight of a non-toxic polyhydric alcohol for stabilizing vinyl chloride polymers, post-chlorinated polyvinyl chloride and chlorinated Polyethylene. 2. Training according to claim 1, characterized in that the stabilizer mixture to be used additionally contains a non-toxic antioxidant.