DE1469954A1 - Process for the production of flame-retardant and self-extinguishing plastic objects with low electrical surface and volume resistance - Google Patents

Description

, GERMAN OOLD-ÜIID 3ILBER-SCHEIDE ANSTALT.

Frankfort am Main »Welssfrauenstrasse 9 1469954

process to produce τοη flame-retardant and self-wounding plastic objects with little electrical energy. surface and passage resistance.

The invention relates to objects and a method for the division of objects, such as foils, tubes, plates, profiles or other parts which can be produced from vinyl halogenated polymer-plasticizer mixtures, which are characterized by high flame resistance, low Burning time and an electrical surface bsw, Ourohgangswidefstand, which can be tared between 10 and 10 ohm bsw · Oha χ om (measured according to the * conductor etching for the electrical testing of insulating materials ¹ * according to VDB regulation 0303 part 3).

The rapid advance of all kinds of plastics stood for some areas of application oppose the flammability and also the non-conductivity properties of normal plastics «» One is therefore everywhere »where you can borrow flammable or light flammable materials su work is forced to "prepare" flame-retardant plastics with low burning sides, which often also have a low electrical sound Resistance is required »in order to report dangerous electrostatic charges» which occur during their discharge see B. sur ignition of gases, vapors or other harmful substances can feed.

On the other hand, the electrical resistance of the plastic objects should not come into the area of the electrical conductors. The beer of interest "technically valuable range for the electrical surface bsw · Durohgangswiderstend on the order of about 10 to 1o" .Ohm bsw _o 0hm χ asu Haoh fulfillment of these demands should dtr objects serving plastics jedooh Always the sor manufacturing

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still offer the advantages of normal plastics, e.g. * Resistant

• resistance to weather conditions, moisture and ohemisoh · influences, good mechanical strength and easy preprocessing » in other words they should retain the essential advantages over metals and other conventional materials «

Such requirements »ground ζ» B-. from mining for use of thermoplastics as weather ducts, cladding foils and panels Films and sheets with these properties when handling clay s «Bo explosives or other highly flammable substances Sound of great interest,

Various measures for reducing the electrical resistance of plastics are known, but so far only an unsatisfactory effect has been achieved in any case An attempt has been made, for example, by using antistatic plasticizers to reduce the electrical resistance of articles made of weloh polyvinyl chloride «. Due to the only moderate tolerance However, these plasticizers generally lead to the extent that they are used in amounts that sufficiently reduce the electrical properties

* To induce resistance, to be added, to exhaustion symptoms Previously existing antistatic softeners were mostly a condition for the antistatic effectiveness of the softener disadvantageous for many uses

In addition, such antistatisohe plasticizers often affect very dl · flame resistance, the solvent and chemical resistance, as well as the aeohanisohen Festigkeltswerte ^v erarbeitungs- * properties of the displaced with them Weichpolyvinylchlorids unfavorable. Be trlttVz.T »after a water storage or after a

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certain age of the white polyvinylchloride added with them an increase in the electrical resistance "

The well-known measure of the Oberzlehene of thermoplastics with conductive lacquers causes a considerable reduction in the electrical resistance; However, such plastic articles are not very durable addition, because of the relatively low abrasion resistance of the conductive lacquer is for example of the ^ ergbaubehörden not only a low electric Oberflächer.wiJ.ors country f but also a reduced set Electric Dürchtjangewideretaul between inner and outer surface _Z, B, wherein ventilation ducts , required.

to with finely divided metals or with graphite powder To achieve a significant reduction in the electrical resistance of soft polyvinyl chloride, additional heights are necessary, processing this raw material is very difficult design and also the properties of the soft polyvinyl affect chloride in an undesirable way »

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It is also known to incorporate carbon black into soft polyvinyl chloride for coloring plastics. For this purpose, small amounts of carbon black are sufficient and a carbon black addition of 0.1 to 2 ^, depending on the type of carbon black, usually of only 1 £ is recommended. Certain types of carbon black have already been recommended by the applicant for incorporation into plastic mixtures Antistatic moldings, in particular on the basis of polyethylene to be obtained »The same applies to the production of, in a limited sense, conductive objects from corresponding rubber mixtures Average) of 277 if »the pH value of an aqueous carbon black coating of 8, a specific electrical resistance (measured at 300 atm) of 0.06 ohm χ cm and a surface area according to BBT of 133 m ^2/3 (carbon black Corax iPder DEGUSSA ) used «

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It is also known to incorporate carbon black into polyvinyl chloride-Weiehmacher mixtures in larger quantities as a filler » With regard to their electrical conductivity, objects produced from such mixtures by the customary methods generally only meet the practical requirements with very high levels of carbon black additions, but are then subject to severe stresses of any kind, as they occur e.g. when used in mining » no longer grown

There has now been a method of making articles found the basis of vinyl halide polymers by customary molding methods, in which. Applying one objects of high flame resistance, low afterburning time, an electrical surface and volume resistance of between 10 and 10 ohms or ohms χ cm can be chosen and with good Tensile strength, tear strength and elongation at break values can get. *

The property of the soft polyvinyl halide, etc. to conduct electricity is - as the applicant has found - influenced by several factors. Za These factors include the I * selected polymer type itself, further the plasticizer type and their Sehalt in the starting mixture, and also the type of black and the amount used, the stabilizer type, the Gleitmitteltype and their content and finally in the manufacture of the moldings according to the conditions under where the mixture of * various components and the thermoplastic deformation "o takes place" the inventive method is characterized gekennzeich-φ net that for the production of flame-resistant or · eelbstverlösohen- • ux the plastic articles with a low electrical surface and Durchjan ^ swiderstand

_ »A) the mixture of vinyl halide polymer and Weioh-J * macher, gjf" von antistatic softeners, In Ver

»A ratio of 75t25 to 55» 45 is set,

b) conductive carbon blacks, plasticizers and possibly antimony trioxyr ¹ in c? »: r Ki ^ chutv, '^ .li * icliefißlg are distributed and BAO ORfGtNAL.

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ο) when processing the well-mixed components only a minimum of shear forces act on the mixture.

With regard to the selection of the starting polymers, the use of a compatible emulsion polymer of vinyl chloride, which is not pre-stabilized with alkaline and which has a regular grain distribution, is of particular advantage, both for proper processing and for the desired electrical resistance values of the moldings. According to the invention, the usable Auagan ^ copolymers, the vinyl halide polymers include not only the polyvinyl halides, but also the copolymers with a predominant proportion of vinyl halide and polymer mixture thereof. Among the vinyl halide polymers, the various polyvinyl chlorides, especially the emulsion polymers, as well as the corresponding fluorides and bromides, count primarily and with outstanding technical success. Suitable copolymers include all polymers without vinyl halides and all of the vinyl halides, insofar as and to the extent that these latter do not significantly reduce the desired effects, such as flame resistance and low electrical surface and passage resistance, from the starting material side. Vinyl chloride, vinyl esters such as acetate and propionate, vinyl ethers, acrilonitrile, acrylic and methacrylic acid and their esters with, in particular, lower aliphatic alcohols, and also butadiene, chloroprene, isoprene, ethylene, propylene, and the like are reckoned with successfully usable co-monomers. Erfindunjs ^ are emäß also polymer mixtures of the listed polymers and copolymers with other known polymers, polycondensates and polyadducts as Aasgangspolymere used, again under the constraint that the desired effects daroh the admixture of other polymers are not degraded weaentlloh} in general I believe that these polymeric minor components cannot be used in predominant amounts.

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The selection of the plasticizer type is important for the conductivity of the plastic object and ζ.To also for the flame retardancy deaeelbeno There are plasticizers that particularly reduce the flammability. These include, for example? the known phosphoric acid esters; also chlorinated paraffins are "here mentioned," As far as antistatic softener as sole plasticizer or as a partial replacement of a primary plasticizer used in stamping, is a particularly strict standard in terms of a very small Weionmaoherwanderungi good flame resistance and good aging ₉ solvent and chemical resistance when selecting of the corresponding antistatic plasticizer in order to prevent a deterioration in the properties of the moldings produced by the process according to the invention .

The amount and type of carbon black used is very important for the properties of the end product. Since there are types of carbon black which give the objects that contain this carbon black a certain conductivity, these so-called highly conductive types of carbon black are recommended for use. greater than 100 m / g iotn They include, for example, the types of carbon black produced by the furnace process, with the properties specified in the introduction (carbon black Corax Ji & der DEGUSSA) finished molded body, the carbon black content must be kept within certain limits according to the invention. The lower limit of about 10 percent by weight of carbon black, based on the polymer, with which a significant reduction in the electrical resistance is possible, depends heavily on the ingredients used in the initial mixture, its additional amount, the degree of distribution of the carbon black and the processing requirements of the mixture. The carbon black additives must depend on the

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desired electrical resistance can be dea finished article or "varies according to the ^PROCESSING conditions," The upper limit of Hußzusatzes is ZcTo determined by the required mechanical properties, wherein there are ^ e on the processing method and on the formulation together dividing a boundary of the Rußzusatzes above which further Rußzusätze no achieve a substantial reduction in electrical resistance "

It is known per se to reduce the flammability of products made from various more or less easily flammable products Polymers the starting substances or «. - Mixtures Antiiron « add trioxide. It can therefore be advantageous to use the starting mixtures according to the present invention, if appropriate Incorporating antimony trioxide * You add antimony trioxide does not worsen the desired electrical values or only insignificantly when it comes to the non-combustibility or, respectively, flame retardancy the objects do not arrive, the mixing of antimony trioxide in the starting substances can be omitted. Will however, the reduction in flammability or flame resistance of the objects is necessary, but the amount of this additive which reduces or eliminates flammability should not more than 10 percent by weight, based on the total mixture, expediently and advantageously between $ 2 and $ 6 » Larger amounts usually have no increasing effect, they worsen possibly even the otherwise good electrical resistance * .verteo

For the manufacture of objects from the described plastic mixture can use the usual processing methods such as calendering, extrusion, injection molding, pressing and centrifuging be applied. However, there are narrow requirements to set the temperature control during processing, In general, in order not to reduce the desired effects, the processing temperature has been kept as low as possible, e.g. a temperature of 165 ° C

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are not exceeded »Compliance is particularly beneficial the temperature in the range between 145 and 160 ° C. So much for the Processing no or only very low shear forces, the temperatures mentioned may be exceeded slightly «,

in order to achieve the goal pursued by the method according to the invention, namely a low electrical surface and volume resistance EU reach, the shear forces acting on the initial dimensions, de ho the shear load of the mixtures, as well as the dwell » time in the processing machine are kept to a minimum »Such minimal working conditions make the ^ enough * ▼ on optimal values, especially with regard to the desired values electrical properties of the final products. So 2.B. for a soft polyvinyl chloride with a 40 weight rose Rufisueatz (based on the polymer) after its processing the following electrical resistances are achieved:

without action with action with action

of shear forces lower middle

(see B »in the case of press-shear forces soher forces th plates)

Spes * electric
Thermosetting resistance
in ohms χ cm 6 χ 10 ² 1 .5 χ 10 ⁵ 7th χ 1Ο ⁹ electrical upper
flea resistance
in ohms 7 χ 10 ² 5 X 10 * 1 χ 1O ⁷

Due to the homogeneous structure of the plastic objects produced by the method according to the invention, the typical characteristics, such as low electrical resistance and flame retardancy, are uniformly present throughout the object: they are not reduced by a mechanical or ohemical surface load. Bew AUOH a Waseerlagerung. A multi-day temperature ^ load of about 70 ⁰ C provide any reduction in these güneti gen properties .. 909813/1449

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Since the material has to be electricity conductive properties _v 1st electric resistance not only by the added amount _f, for example, "a naoh a special process mountains" • presented carbon black, or varied by a variation of the processing conditions "but it is also influenced by the line cross section Bs It is therefore possible to reduce the electrical resistance by increasing the cross-section of the line. Since the electrical conductivity is achieved by adding solid substances that are neither leachable nor chemically alterable in a simple way, "there is no change in the electrical resistance in the course of time". In addition, the electrical conductivity of the material does not depend on the presence of a certain humidity »

The objects produced according to the method according to the invention are released very quickly and are removed from the flame not able to maintain the fire itself (test naoh Oil 53 382) · This property is also not affected by aging nooh changed by other influences (such as water storage).

The high values for tear strength, elongation at break and world maturity are broad areas of application available for the items manufactured using this process.

In addition to the areas of application in mining, there is one use of objects manufactured according to the method according to the invention possible in vehicle, aircraft and shipbuilding »as long as the specific properties are advantageous there · Also let a discharge of electrical charges when using the naoh dem Method of the invention produced articles a.B. ala flooring in laboratories »operating rooms or trees in which Leiohtentzttndliohe fatty substances, liquids or oasis stored become »mOglloh. Particularly favorable for processing soloher Plastic objects have a good ability to be confused 'off, especially naob. the high-frequency or solvent welding process,

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Examples:

For the production of moldings, a mixture of the following Beatand parts is made!

46 parts by weight of emulsion polyrinylochloride with a K value of 70 28 "dioctyl phthalate as plasticizer.

18 ^M conductive carbon black (Corax L® from DEGUSSA) 5 "antimony trioxide

2.5 "barium-Cqdmium-Laarat as stabilizer .0.5 ^M fatty acid ester as lubricant (ester of closer

* fatty acids with higher alcohols,

mostly chemical ones of a waxy consistency.

This mixture is processed as follows: either: a) with a pitting pressure of approx. 300 kg / cm and a pressing temperature of 165 ⁰ O with a pressing time of about 4 minutes

or _; · - ·· ■ b) with an extruder using a round or slot die at a cylinder temperature which rises ^{from 135 0} C to 155 ^{0 C and at}

a shower temperature between 160 and The dwell time in the extruder should be 5 to 10 minutes not or not significantly exceed.,

The two: listed processing methods are clear Deviations from the specified temperature programs do not occur without major changes in the properties of the manufactured items enter "

Will there be other properties, e.g. higher or lower softness for the objects to be manufactured, aind opposite the conditions of the example deviations possible «

The possible different soot contents essentially depend from the required values for the electrical surface and Durohge resistance as well as from the type of processing from «- when extruded under the conditions listed under b) Foil were B.B. with a thickness of 0.25 mm, the following physical data was determined: 9098 ί 3/1 A 4 9

~ 11

Tensile strength 170 kg / cm

Elongation at break 225 #

Tear strength 6.4 kg / omega

Cold break temperature -30 C

Electrical surface resistance 1.0x10 ohm

Electrical continuity resistance 1.5x10 Ohm χ cm

Afterburn time Less than 1 second.

With the exception of the values FLIR the electrical resistance, these figures were also on films that had been prepared according to the listed under a) method is obtained., The surface electrical bzwo resistance was the foils at 3 '10 ohm or "Ohm χ cm.

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Claims (1)

U69954 PATENT CLAIMS 1.) Method Bam Manufacture of flame-retardant objects with an electrical surface or Durohgangewlderatand of 1O ⁵ to 10 ohms or ohms χ om on the Baele of "vinyl halide polymers in Miachungen with Weiohmaohern and RuQ using the usual deformation process, characterized» that a mixture of the vinyl halide polymer with plasticizer, optionally with anti-static plasticizers, in a ratio of 75/25 to 55/45 is used, conductive types of carbon black, Weiohmaohar and optionally antimony trioxide are uniformly distributed in the mixture and when the mixture is processed, the lowest possible forces act 2.) The method according to claim 1, characterized in that «a soot with a mean particle size according to BET of at least 100 m / g in amounts of 10 to 20 percent by weight, based on the total mixture, is used as the conductive carbon black. _t ■ · 3.) A process NaOH claims 1 and 2, characterized in that ale Vinylhalogenidpolymerieat a verpa & tbaree Bmulsionspolymerieat that is not pre-stabilized alkaline and f has a regular particle size distribution "is preferably a \ _i Vinylohloridpolymeriaat or-mieohpolymerieat, is used. 4 ») Method according to the requirements 1 to 3» characterized by that old plasticizer is an antistatic Weiohmaoher "Hein or is used proportionally » f.) The method according to the tests 1 to 4 "marked by means of the notification of a phosphoric acid tester" waA / oUr "ines Ohlorp * ra # fine in quantities of 3 pale ae« ioh | «px« i «B% · based on the aeaaata odor 'as a further addition.' BATH ORIGINAL ÖÖ9813 / 1M9 H69954 6.) A process NaOH AnaprUohen the 1 bit 5, characterized in that during Here Tellen the Qegenstände a too Verarbeltungstemperatar 165 ⁰ O nioht substantially Uberaohritten is and the Terweilzeit the Auagangamieohang in the ^v erarbeitungsmasohino is at a minimum at said temperature. 7 ·) Objects including vinyl halide polymer, plasticizers, carbon black and other known additives, in particular pollen, soles and plates for use as weather ducts, deco foils and plates, weather doors, water columns and the like, of high flame resistance, very low heat resistance and low electrical surfaces? - or Thermoset resistance, characterized in that all essentially consist of at least one vinyl halide polymer, in particular a dnulsion polymer, and, if necessary, an antistatic, resistance in a ratio of 75-25 to 5345 " as a highly conductive carbon black" in particular a carbon black of at least 100 m / g epeiifia naoh BBT gemeeaeo) In amounts of 10 to 20 percent by weight, based on the oil solution, and optionally from antimony trioxide. Pfm.1o.1o.62
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