DE1494052A1 - Process for the antistatic finishing of high molecular weight compounds - Google Patents

Description

It is known that high molecular weight substances have the disadvantage of becoming electrostatically charged. Due to the electrostatic charge Objects made from them tend to attract more dust. That must be on the surface of plastic objects by the appearance of spots, crow's feet, zigzag patterns, etc., with fibers and fabrics by their faster Pollution. In addition to heavy pollution caused by electrostatic charge, the Occurrence of a possibly very large potential difference must be taken into account, which can lead to spark formation. Due to the electrostatic charge, the use of high molecular weight substances, such as plastics, can be used for many areas of application to be questioned.

Apart from conditioning, there are two principal ways of preventing or reducing the electrostatic Charge known:

1. Subsequent application of a finish by impregnation with solutions or dispersions of antistatic, often somewhat hygroscopic Links. The plastic moldings made conductive on the surface, i.e. the surface resistance is greatly reduced, so that on the surface applied electrical charges can flow away. The disadvantage of this type of antistatic equipment is easy to spot. If the conductive layer is damaged or wiped off, the antistatic goes Equipment lost.

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2. Incorporation of substances that have a static

Prevent charging of the molded plastic parts. This incorporation has significant advantages over impregnation. The antistatic finish is not bound to the surface and cannot be mechanically wiped off, scraped off or removed. In attempts to incorporate the antistatic agents known from impregnation into plastics, it was surprisingly found that the compounds generally lose their effectiveness in the process. For some, this is due to the fact that they decompose completely or partially at the sometimes very high processing temperatures of the plastics. But even compounds that are stable at these temperatures show no antistatic activity after incorporation. Obviously, there is a fundamental difference between the reaction mechanisms of the antistatic finish by incorporation and impregnation.

This can also be proven by measurement. While by the antistatic treatment with impregnation agent the surface resistance is greatly reduced, this is also the case with very good incorporated antistatic agents practically not affected. The discharge of the electrical charge cannot take place here on the surface. Instead, there is usually a slight change in the volume resistance. But this is also by no means a quantitative measure for the antistatic finish.

For subsequent application of a superficial, antistatic Finishing by impregnation a number of substances have been proposed, e.g.

1. Nitrogen containing compounds such as amines and quaternaries Ammonium salts;

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2. sulfonic acids and aryl-alkyl sulfonates;

3 · phosphoric acids, aryl-alkyl-phosphates, phosphoric ester amides;

k. Polymeric polyhydric alcohols and their derivatives.

Highly hygroscopic inorganic salts were initially known as incorporable antistatic agents. But they become general not used because of the associated risk of corrosion for the processing machines. '

In addition, other compounds have recently become known which, when incorporated, give high molecular weight organic compounds an antistatic effect.

For example, the addition of substituted phosphoric acid amides, urea derivatives and dithiocarbamates is known In some cases, connections are difficult to establish or their cleaning requires considerable effort.

In DAS 1 130 16O the use of specially cleaned, essentially pure, dry, powdered Fatty acid amides with 12 to 18 carbon atoms are described as shaping aids for plastics. It should be noted that such fatty acid amides are also antistatic Should have an effect. The antistatic effects achievable with fatty acid amides of this type were, however, less than satisfactory (cf. Table 1%, Example 17 of the present application).

It has now been found that when using 0.1 to 7 wt .- ^, preferably 0.5 to k wt .- ^ at least one substituted fatty acid amide of the general formula

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-e- U94052

whereby

R = alkyl, alkenyl with 1 to 26 carbon atoms or cycloalkyl

R = H or CH

R = alkyl with 2 to 26 carbon atoms, preferably 12 to 26 carbon atoms mean and

the radicals R ₁ and R "can also contain oxy groups or alkoxy groups, for the antistatic treatment of polystyrene, copolymers of styrene, polyvinyl chloride, vinyl chloride copolymers, polyterephthalates, polyolefins, polycarbonates, polyoxymethylenes, polyacrylonitrile, polyacrylic acid esters, polymethacrylic acid esters, polyacetals, or polyvinyl acetanes Cellulose derivatives and polymer blends containing the above polymers, excellent results can be obtained.

It has been shown that even small amounts of such substituted fatty acid amides after their incorporation give high molecular weight organic compounds give an excellent antistatic effect, so that from such mixtures manufactured objects no longer charge themselves superficially and no longer show any tendency to attract dust. Connections of this type can be produced in a simple manner. Amides, the acid component of which has a low number of carbon atoms, can be easily purified by distillation; Amides, their Acid component has a high number of carbon atoms, usually do not require cleaning, as small amounts of e.g. stearic acid impurities in most cases do not bother.

The concentration of the substituted substances incorporated in the plastic

coated fatty acid amides can advantageously 0.1 to 7 % by weight,

C _{0 is} preferably 0.5 to k % by weight.

"^ It is also an advantage that you are in the high molecular weight - »Compounds also mixtures of 2 or more of the antistatic

J ₀ can incorporate active substances. An increase in

^fJ1 antistatic effectiveness through synergistic effects is possible.

BATH ORIGINAL

Substances having an antistatic effect according to the invention are e.g. to name the following compounds, without the process being restricted to these compounds:

Acetic acid-N-stearylamide Propionic acid-N-methyl-N-staarylamide Butyric acid N-dodecylamide Stearic acid-N-methyl-N-stearylamide Oleic acid-N-stearylamide

Oxyacetic acid-N-methyl-N-stearylamide 9,1O-dioxystearic acid-N-methyl-N-stearylamide Methoxyacetic acid-N-stearylamide

The mechanical and thermal properties, the thermal stability as well as the color and transparency of the polymers are practically not reduced by the addition of the substances mentioned changes. The processing conditions and the temperature range in which the plastics can be thermoplastically deformed remain unchanged. It's just on it care must be taken that the antistatic agents used, with regard to their thermal stability, correspond to those used for processing temperatures required for the respective plastic can be selected.

Furthermore, the products are well compatible with all polymers. The achievable antistatic effect is independent of the humidity of the environment and has a practically unlimited duration, Exudation is not observed. The surface does not become hygroscopic either, but remains unchanged.

By adding substances of the specified class, all high-molecular substances that, as a result of their Electrostatic charges tend to pollute by attracting dust. These show a particularly good effectiveness Compounds e.g. in polystyrene and the copolymers of styrene with butadiene, acrylonitrile and / or vinyl carbazole, in Polyvinyl chloride and vinyl chloride copolymersJeaten, polytere-

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phthalates, polyolefins, such as polymers and copolymers from Ethylene, propylene, butene- (i), pentene- (i), 4-methylpentene- (1), Hexene (1), 5,5-dimethylhexene (1), octadecene (1), 4-phenylpentene (i) as well as vinylcyclohexene, polycarbonates, polyoxymethylenes, Polyacrylonitrile, polyacrylic acid esters ^ polyinethacrylic acid esters, Polyacetals, polyvinyl acetates, polyamides, polyurethanes, Cellulose derivatives and polymer blends containing the above Contain polymers. Unsaturated polyesters and base-hardened epoxy resins as well as paint raw materials can also be preceded or equip them with antistatic properties without difficulty by adding the above-mentioned antistatic agents during processing. the High molecular weight substances can also contain the usual additives such as stabilizers, fillers and dyes.

The compounds according to the invention can be added before or during the polymerization, as well as the pulverulent high polymer later as well as the granules. Depending on the nature of the plastics, mixing in the melt, in the solution or by being absorbed onto the powdery or granulated high polymer. It'll be best before or performed during processing. It has been found that the method of incorporation is not very important. On the other hand, it is important that the substances acting as antistatic agents are distributed as well as possible in the plastic.

The high polymers treated with the compounds described antistatic can be processed by all customary processing methods, for example on presses, injection molding machines
or extruders. It can accordingly be pressed or injection molded bodies, semifinished products, foils, blown hollow bodies, pipes, fibers, threads, monofilaments iisw. produce. The resins mixed with the compounds mentioned can
as coating or casting resins or in combination with glass fibers

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and / or fillers are processed in the usual way. The high polymers finished in this way are special interesting for packaging purposes (packaging, canisters, bottles, cups), vacuum cleaner accessories, conveyor belts, exhibits and models, housing parts (e.g. for radio and television sets, vacuum cleaners) electrical systems, such as lighting fixtures, Cable insulation, plugs, switches or fittings, air conditioning and ventilation systems, plastic dishes, Kitchen machines, threads, fibers, fabrics, foils, lacquers, i.e. wherever antistatic equipment is important will. |

The antistatic effect of inorganic or organic substances in high molecular weight substances is the simplest determine by means of cigarette ash. For the test, fuel, Extruder or press plates with a woolen cloth vigorously for about 15 seconds. rubbed and about 2mm over a layer of Cigarette ash held. If the plastic plates are well antistatic, no cigarette ash will be attracted. Since cigarette ash is somewhat hygroscopic and moist cigarette ash has other electrical properties, the ash used for the test should be older than 6 hours.

A number of other methods for determining the electrostatic charge are known, but it has been found that practically only the listed test method delivers real, practical values.

Table 1 shows the results of the investigation. It can be seen that an excellent antistatic effect is achieved with all of the substances listed became.

139 b

Examples

Some antistatic compounds similar to those in the description correspond to the empirical formula, have been incorporated into various high-polymer substances. 'A compilation Table 1 contains the antistatic agents used, the amount added and the test results.

The incorporation of the antistatic was done in the following manner carried out:

Examples 1, 3 to 6, 8 to 17

Polymer powder (see Table 1) was in a high-speed mixer mixed with the amounts of the corresponding substituted fatty acid amides listed in the table for 5 to 10 minutes. then the mixtures were granulated on the extruder and injected into sheets 1 mm thick on an injection molding machine.

The antistatic agents of Examples 1, 3 to 6, 8 to 15 were if they were not liquid, injected into the samples in a molten state. The antistatic agents of Examples 16 and 17 were mixed in as a powder. Comparative Examples 12 to 15 and 17 show that 6arboxamides, not fall under the formula given for the compounds according to the invention, have no antistatic effect.

Example 2

Low-pressure polyethylene powder was mixed with a 1Oxigen warm ethanolic solution of acetic acid-N-stearylamide in the mixer well mixed. After the solvent had evaporated, granulation and then processing took place of the material to injection molded sheets.

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U94052

Example 7

200 g of a commercially available unsaturated polyester resin, which by condensation of 5 moles of ethylene glycol with 3 moles Maleic anhydride and 2 moles of phthalic anhydride and then dissolving the condensation product in 30 Wt .- ^ styrene had been obtained after the addition of 2% methyl ethyl ketone peroxide, 0.1% cobalt naphthenate and 1.0% of a fatty acid amide (see table) for plates encapsulated and cured at room temperature in the absence of air.

Of course, the examples described can only represent a small selection of the available options. The antistatic effect that can be achieved is not due to the substances listed or to those described in Table 1 Combination bound with plastics. Other antistatic agents can be used with the same success Substances that correspond to the empirical formula in the description, be used. When combining with plastics, care must only be taken that the decomposition point of the compounds used as antistatic agents is not lower than the processing temperature of the plastics.

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Tabel

When used
play plastic
No.

Antistatic agents

S t ruk t ur'f ο rme 1

additive

Ash test after 1 and 21 tapes

Low pressure polyethylene acetic acid-N-dodecylamide CH ^ -C-NH-

Low pressure polyethylene acetic acid-N-stearylamide CH ₃ -C-NH-C ₁₈ H

0.5

Polystyrene

Acetic acid-N-methyl-N-stearylamide

0 CH,

CH ₃ -CN

1.5

CO
O
CD

Acrylonitrile styrene copolymer

Propionic acid-N-methyl-N stearylamide

CH,

* ^C 18 ^H 37

Butadiene styrene copolymer

Butyric acid-N-methyl-N-stearylamide

CH

C ₃ H ₇ -CN:

* ^C 18 ^H 37

polyamide

Lauric acid-N-methyl-N-stearylamide

C ₁₁ H ₂₃ -CN

CH,

Polyester resin
(hardened)

Steeric acid-N-methyl-N-S te arylami d

CH

C ₁₇ H ₃₅ -CN:

C ₁₈ H ₃₇

1..0

Polyethylene glycol

terephthalate

Oxyacetic acid-N-methyl-N-stearylamide

HO-CH ₂ -CN

.CH,

C ₁₈ H ₃₇

1.5

Polyacrylonitrile

9,1O-dioxystearic acid-N-methyl-N-stearylamide OH OH

C ₈ H ₁₇ -CH-CH-C ₇ H ₁₄ -C

1.0

High pressure polyethylene methco -acetic acid-N-

Polycarbonate Stearyxamide CH ₃ -O-CH ₂ -C-NH-C ₁₈ H 3 1 1 Polypropylene Butyric acid-N-methyl-
N-stearylamide 0
C ₃ H ₇ -CN ^ ^ CH ₃
^ ° ΐβ ^Η 37 1.5 12th Polypropylene Acetic acid n-butyl
N-S tearylamide D.
G ¹ H ₃ -CNC ^ " ^C 18 ^H 37 1.5 ■ »■ 13th Polypropylene Acetic acid-N-octyl-N-
Dodecylamide B /
CH ₃ -CN ^ ' ^C 12 ^H 25 1.5 + 14th Polypropylene Easetic acid-N-dibutyl- ■
amide CH ₃ -CN <^ ^ _{0 H} 1.5 + 15th Formic acid-N-methyl-
N-stearylamide H I N ^{/ CH3
C} 18 ^H 37 1.5 + ^

Polypropylene

01 acid-N-dodecylamide

C ₈ H ₁₇ -CH = CH-C ₇ H ₁₄ -C

NH

^C 12 ^H 25

y 1 7 polypropylene

Oleic acid amide, purified according to DAS 1 130 I60

CgH ₁₇ -CH = CH-C

- no attraction
+ Attraction

Claims (3)

Patent claims: R alkyl, alkenyl with 1 to 26 carbon atoms or cycloalkyl, R ₂ H or CH- R- denote alkyl with 2 to 26 carbon atoms and the radicals R and R- can also contain oxy groups or alkoxy groups, for the antistatic treatment of polystyrene, copolymers of styrene, polyvinyl chloride, Vinyl chloride copolymers, polyterephthalates, polyolefins, polycarbonates, polyoxymethylenes, polyacrylonitrile, Polyacrylic acid esters, polymethacrylic acid esters ^ polyacetals, Polyvinyl acetates, polyamides, polyurethanes or cellulose derivatives and polymer mixtures that comprise the above polymers contain, 2. Use a mixture of two or more antistatic effective substituted fatty acid amides of the general formula mentioned in claim for finishing the in claim 1 mentioned high molecular weight compounds. 909827/1395 New documents (Art. 7 Paragraph 2 No. 1 sau 3 of the amendment · * v. 4. ·. 3. Antistatic mixtures, consisting of organic, high molecular weight compounds, which may also be customary
May contain additives, and 0.1-7 wt .- ^, preferably 0.5- ^ wt .- $ of one or more substituted fatty acid amides of the general formula R, - C - ^R 3 whereby Alkyl, alkenyl (with 1 to 26 carbon atoms) or cycloalkyl, R ₂ H or CH, R “alkyl with 2-26 carbon atoms, preferably with 12-26 Carbon atoms, mean and the radicals R ₁ and R_ can also contain oxy groups or alkoxy groups. 90982 7/1396