DE2164560B2 - Process for deforming and vulcanizing a vulcanizable material - Google Patents

Description

The invention relates to a method for deforming and vulcanizing rubbers or synthetic polymers mixed with an organic peroxide (this mixture is referred to below referred to as "vulcanizable material"). The invention specifically provides an excellent one Method for producing elongated molded bodies from a vulcanizable material accessible, in which the material flows through a nozzle with a long flow path, which causes the deformation and vulcanization to be led.

It is a common method to make elongated articles of vulcanized material by the vulcanizable material through a nozzle with a short flow path (which is only used to deform the Material is used) is pressed and the extrudate obtained by a high-pressure steam filled, elongated vulcanization chamber is performed.

A method for producing vulcanized elongated molded bodies has already been proposed, like vulcanized rods, pipes or

insulating bucket with a vulcanized layer '.'cm a vulcanizable ;; Material such as a vulcanizing agent Polyethylene containing, is extruded and vulcanized by passing through a; on the Vulcanization temperature of the material heated nozzle is pressed with a long flow path. This method will hereinafter referred to as vulcanization in a nozzle with a long flow path.

Vulcanization in a nozzle with a long flow path has the following advantages over the conventional method of steam vulcanization:

1) The vulcanizate has exact dimensions and shows Uniform dimensions in the longitudinal direction because the material in the nozzle has a long flow path is tightly enclosed during the entire deformation and vulcanization stage.

2) The outer surface of the vulcanizate thus obtained is glossy and smooth because it is during vulcanization the surface of the product does not come into contact with water droplets, which often hit the surfaces affect the product.

3) When the vulcanization temperature is increased in steam vulcanization, the vulcanization pressure also increases. It is therefore difficult to steam vulcanize at a temperature higher than 20 [! ⁰ C because a vulcanization chamber must be designed to withstand considerably high pressures at these high temperatures. In contrast, in vulcanization with the aid of a nozzle with a long flow path, vulcanization at a high temperature, for example at 250 ° C., can be easily carried out because the vulcanization temperature is set independently of the vulcanization pressure. The vulcanization time can therefore be shortened considerably.

4) The deforming and vulcanizing apparatus can be made remarkably small and simple will.

Despite the expected, described advantages, the vulcanization was carried out with the help of a nozzle long flow path not used industrially. One of the difficulties which the industrial application of the Having prevented vulcanization iiri a nozzle with a long flow path, the difficulty is the molded To feed product smoothly through a nozzle with a long flow path.

To overcome these problems, numerous proposals have been made to improve the smooth passage of the to enable molded product through a closed narrow channel. It was using a Proposed channel whose inner wall is provided with a polished surface. An other suggestion consisted in the use of a passage or channel, the inner wall of which with a thin Layer of a perfluorocarbon resin is coated. Another possibility was mixing a molding aid, such as chlorinated hydrocarbon lubricants, Silicone oil or other lubricating fluids to deir vulcanizable mass (US patent 29 72 780). Another suggestion is to apply a liquid lubricant, such as oil, to the inside surface of the Apply through the passage (US Pat. No. 3,054,142). The liquid lubricant acts as a release agent and avoids scorching and sticking of the molded product on the nozzle surface and serves also as a lubricant that facilitates the passage of the molded product.

However, it has been found that even when used a nozzle with a long flow path and having a polished surface, only vulcanized products can be obtained that have rough or cracked surfaces, ts has also been shown that the Problem not solved by using a long-throw nozzle coated with perfluorocarbon resin because the coating layer is easily damaged in a short period of time. It was

in also found that when using lubricants or molding aids commonly used for molding plastics and rubber like silicone oil and other oils, are vulcanized in a nozzle with a long flow path inside

π a relatively short time after the start of the process the surface of the vulcanizate became rough or cracked, although the molding aid was continuously fed onto the surface of the product. It was found that surprisingly this phenomenon

_ »Ii by the loss of the lubricating and separating Properties of the molding aid is caused by gelatinization as a result of the action of the organic Peroxide is caused to leak from the vulcanizable material. The resulting CJeI sticks to the

2> Surface of the molded product or penetrates into it molded product, creating a rough or cracked surface.

The invention is based on the discovery that, through the use of a very specific class of

κι Form auxiliaries with specific, critical physical Properties for the first time is given the opportunity to deform and vulcanize in one Long flow path nozzle in a continuous industrial process.

The invention relates to a method / to deform and vulcanize a vulcanizable Material in which a mixture of a polymer vulcanizable with the aid of organic peroxide and of an organic peroxide through a nozzle with long

■ to flow path is performed, which has a molding zone and a subsequent Vulkanisationsy.one, while at the same time a molding aid on the inner surface of the Long flow path nozzle is fed in such a way that an uninterrupted film between the

π inner surface of the nozzle and the polymer product is maintained, which is characterized in that the molding aid used
a) a viscosity of at least 1.1 centistokes and not more than 3000 centistokes at 235 " C,

-, (i b) an absorption ratio in the polymer of has less than 100 mg / cm- at 150 "C for 45 hours,

c) is not gelatinized in contact with the organic peroxide during vulcanization

■ j-) and

d) does not boil during vulcanization.

In the practical implementation of the method according to the invention, the molding aid has the effect of the inner surface of the nozzle with a long flow path

ho and the molded product, the chemical and physical properties of which change during vulcanization with the help of the mixed in organic peroxide constantly changing, separating from each other. The molding tool that is on the inside surface of the nozzle

to be provided with a long flow path and on this Way the nozzle separates from the deformed product, should be distributed over the entire interface and form an uninterrupted movie. That on the

Norm auxiliaries transferred to the surface of the molded product should not be missing anywhere as the molded product moves through the nozzle.

The F used for the purposes of the ^invention: ormhilfsmitlcl must have a viscosity of at least ί 1.1 centistokes at 235 ° C, preferably about 5 Centistokcs having.

If the viscosity of the molding aid is less than 1.1 Cenlislokcs, the molding aid tends to flow locally, and it is difficult to cause the molding aid to spread evenly over the entire interface between the inner surface of the long-travel nozzle and the surface of the molded product, so that a non-continuous film is not easily formed. A viscosity ii of 3000 centistokes is a practical upper limit. If the viscosity of the molding aid is more than 3000 centistokes, the molding aid cannot easily be supplied to a nozzle having a long flow path. In addition, the molding aid used for the purposes of the invention must have an absorption ratio of less than 100 mg / cm ² , preferably less than 30 mg / cm ² , with regard to the vulcanizable material to be used. This absorbance ratio is determined for the purposes of the invention in the following manner: One of the prepared to be used vulcanizable material vulcanized sheet (30 mm χ 30 mm χ 1 mm) is dipped for 45 hours at a temperature of 150 ⁰ C in the to be used molding assistants. The plate is weighed before and after immersion. The weight difference divided by the total surface area of the plate before immersion gives the absorption ratio.

When the absorption ratio of the molding aid r> is too high, it is also difficult to form an uninterrupted film of the molding agent and maintain. In general, the molding aid layer can be distributed more evenly Thickness not expected. Especially when the long-travel nozzle is set horizontally, the molding die tends to flow predominantly in the upper region of the interface. if Therefore, if a molding aid with too high an absorption ratio is used, then in the range in since it flows relatively little, the molding aid is absorbed by the molded product, resulting in a partial Drying of the molding aid leads. This partial drying is not switched off even if the supply of the molding aid is increased because ϊο the additional molding aid does not come into the dried-up area, but predominantly into the Enters area in which the flow of the molding agent takes place more easily. It also tends excess molding aid added to the area where flow occurs more easily, tends to spoil the surface of the molded product.

The absorption ratio of some molding auxiliaries increases to values of more than 100 mg / cm ² as a result of the chemical changes wi under the conditions of molding and vulcanization. These molding aids cannot be used for the purposes of the invention even if the original absorption ratio is within the required limits. In addition, the molding aid to be used for the invention must not gelatinize in the course of a continuous process.

Gelatinization of the molding aid under normal process conditions is determined by the following test determined: A mixture of 10 parts by weight of a standard auxiliary substance and 1 part by weight of an organic Peroxide is poured into a closed vessel equipped with a stirrer at a rate of about 10 "C per Minute heated to 235 "C and held at this temperature for 5 minutes. Then the viscosity (1/1) of the obtained liquid measured at 235 "C. The original Viscosity (// u) of the molding aid even at 235 ° C is also measured. If the form tool has a ratio of "/ 1/7;" of less than 30, so it is considered to be non-gelatinizing for the purposes of the invention, and it is expected that it will no gelatinized in a continuous process carried out for at least several hours Film forms on the inner surface of a nozzle with a long flow path. If that used organic Peroxide is not volatile, the heat treatment can be carried out in an open vessel. at In the test described it is not always necessary to use the organic peroxide that is actually used is mixed with the vulcanizable material. Other typical peroxides, for example dicumyl peroxide, can be used without causing an error in the determination.

In addition, the molding aid used for the purposes of the invention should be used under vulcanization conditions not boiling.

When the molding aid boils, bubbles appear on the surface of the vulcanized product generated pockmarks. When heavy boiling occurs, the lubricating and separating properties go of the molding aid is lost and the surface of the vulcanized product therefore becomes rough and in in extreme cases cracking occurs. However, a slightly boiling molding aid can be tolerated because gentle boiling does not significantly affect the surface of the product.

The following classes of compounds are suitable and exemplary for use as molding auxiliaries:

1) Polyoxyalkylenes and their derivatives, random, block or graft copolymers of two or several alkylene oxides and their derivatives, the molecular weight of which is more than 120 and less is more than 100,000,

2) polyhydric alcohols (including their corresponding dehydrated products) from 4 to 50 Carbon atoms, their alkyl esters or ethers,

3) Fatty acid alcohol amides with a total of more than 8 carbon atoms, derived from fatty acids with 2 to 30 Carbon atoms and alcohol amines with 1 to 30 carbon atoms were obtained,

4) fatty acid amides with 8 to 90 carbon atoms,

5) fatty acids with 8 to 90 carbon atoms and their metal salts,

6) Esters of polycarboxylic acids with 6 to 22 carbon atoms and monoalcohols with 1 to 2C Carbon atoms,

7) Phosphoric acid esters of alkyl alcohols with 3 to 30 carbon atoms,

8) Polyester with a molecular weight of flour more than 200 and less than 30,000,

9) metal nitrates and metal halides,

10) masses of polysiloxanes, the molecular weight of which is more than 2000 and less than 100,000 ( is, and Gclatiniemngsinhibitorcn (the irr each to be described later),

11) Polysiloxane masses, their molecular weight is more than 2,000 and less than 100,000, and an alkali or alkaline earth metal hydroxide or oxide.

These compounds are because of their · -, physical, less because of their chemical Properties selected based on their ability to meet the stringent physical requirements described to meet. Typical examples of these compounds are given below:

1) Polyoxyalkylenes and their derivatives, random, block or graft copolymers of two or more Alkylene oxides and their derivatives, the molecular weight of which is more than 120 and less than 100,000 amounts to; of the alkyl ether type, such as

Polyäthy lenglykollaury la t her, Alkylary lather,

how

Polyoxyethylene nonylphenyl ether,

Alkylthioethers, such as polyethylene glycol stearylthioether,

Alkyl esters, such as

Polyoxyethylene tail oil ester,

Polyoxyethylene rosin ester,

Sorbitan alkyl esters, such as polyoxyethylene sorbitan monopalmitate,

Polyoxyethylene sorbitan tristearal,

Polyoxyethylene sorbitan monooleate,

Phosphoric acid esters, such as

Polyoxyethylene dicresyl phosphate, j <>

Condensation products with amines, such as

N, N-di (pe! Yoxyethylene) stearylamine,

Condensation products with amides, such as

Polyoxyethylene stearylamide,

Polyoxyethylene nonylbenzenesulfonamide, and the like;

2) polyhydric alcohols (including their dehydration products) having 4 to 50 carbon atoms and their alkyl esters or ethers;
polyhydric alcohols, such as sorbitan and saccharides, alkyl esters or ethers of polyhydric alcohols (including their dehydration products), such as dehydrated sorbitan palmitate, esters of polyhydric alcohols and fatty acids, such as mono- or diglyceride, of linear fatty acids, such as palmitic acid, stearic acid, or resin acids, such as rhodic acid, naphthenic acid, caproic acid esters of pentaerythritol and alkyl esters of sucrose, myristyl galactose ether and the like;

3) fatty acid alcohol amides with a total of more than 8 carbon atoms, which are formed from fatty acids with 2 to 30 carbon atoms and alcohols with 1 to 30 carbon atoms;
Laurylethanolamide, stearylmethylolamide, palmhyloxymethylalhanolamide and the like;

4) Fetal acid amides with 8 to 90 carbon atoms, such as

Stearic acid amide, oleic acid amide and the like;

5) fatty acids with 8 to 30 carbon atoms and bo their metal salts.like

Fatty acids such as stearic acid, oleic acid, palmitic acid and the like, metal salts of fatty acids such as stearic acid, oleic acid, palmitic acid, lauric acid, 12-hydroxystearic acid and naphthenic acid and _b 5 a metal such as Li, Cu, Be, Mg, Ca, Sr, Ba, Zn, Cd, Al, Ce, Ti, Zr, Pb, Cr, Mn, Co, Ni, Fc, Hg, Ag. Tl, Sn and the like;

6) Esters of polycarboxylic acids with b to 22 carbon atoms and monoalcohols with 1 to 20 carbon atoms, such as

Diallyl phthalate, di-2-ethylhexyl phthalate,
Dinonyl phthalate, di-n-octyl phthalate,
Dibutyl sebacate, di-2-ethylhexyl adipate,
Tri-n-butyl citrate, tri-2-ethylxyltrimclilate,
Tri-n-octyl trimellitate,
Tctra-2-ethylxylpyromellitate
and the same;

7) Phosphoric acid esters of alkyl alcohols having 3 to 30 carbon atoms, such as

Tributyl phosphate, tri-2-ethylhexyl phosphate and like;

8) Polyesters with a molecular weight of more than 200 and less than 30,000, such as
Polyethylene succinate, polypropylene adipate,
Polyethylene azelate,

Poly (1,3-butanediol) sebacate,
Poly (diethylene glycol) adipal,
Poly (1,6-hexanediol) adipate,
Polypropyl phthalate and the like;

9) metal nitrates and metal halides, such as

BiCl ₃ , BiBr ₃ , AgNO ₃ , TlNO ₃ , mixtures of NaNO ₃ , KNO ₃ and Ca (NO ₃ ) ₂ and the like;

10) Mixtures of polysiloxanes with a molecular weight of more than 2,000 and less than 100,000 and gelatinization inhibitors (to be described in detail below), how

a composition of matter consisting of liquid organopolysiloxane, such as polydimethylsiloxane, Polymethylphenylsiloxane, and an inhibitor. If polysiloxane is used alone as a molding aid is, the gelatinization of the polysiloxane occurs in a short time during vulcanization. However, polysiloxane can be used as a satisfactory molding aid if it is a Inhibitor is added, which reacts with the organic peroxide and the crosslinking of the polysiloxane prevented by the peroxide. Examples of these inhibitors include phenols and amines, such as a-naphthol, ^ -naphthol, pyrogallol, catechol, 4,4'-thio-bis (6-t-butyl-m-cresol), 1,2-dihydro-2,2,4-trimethylquinoline (and its polymerization products), bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, Dinaphthyl-p-phenylenediamine hydroquinone and the like. The amount of the dem Polysiloxane to be added inhibitor is generally in the range of 5 to 30 parts by weight, preferably 10 to 20 parts by weight per 100 parts by weight of the polysiloxane.

11) Compositions of substances consisting of polysiloxanes having a molecular weight of more than 2,000 and less than 100,000 and an alkali or Alkaline earth metal hydroxide or oxide, such as

a mixture of polysiloxane and a metal oxide, such as calcium oxide, or metal hydroxides, such as Potassium hydroxide, sodium hydroxide, lithium hydroxide and the like. The form tool mixed metal hydroxide or oxide has the function of the degree of polymerization of the polysiloxane to be reduced by hydrolysis. In this way, the crosslinking is acted upon of the organic peroxide caused increase in the degree of polymerization of polysiloxane compensated. Such a composition can be used in a satisfactory manner for the purposes of

Invention can be used as a molding aid. The amount of to be added to the polysiloxane Metal hydroxide or oxide generally ranges from 1 to 10 parts by weight, preferably from 3 to 7 parts by weight, per 100 parts by weight of the polysiloxane. Among the numerous molding auxiliaries used in the present invention, polyoxyalkylenes are preferred and their derivatives, random, block or graft copolymers of 2 or more alkylene oxides in and their derivatives, and aliphatic polyesters are used.

A molding aid which is a solid or a highly viscous liquid can be used in the form of the melt or in the form of a mixture with a suitable liquid, for example alkylbenzoi. [£ in such mixture must of course fulfill the above-mentioned physical requirements for the molding aid.

Are addition polymers for the purposes of the invention, suitable synthetic 2 »polymers such as homo- or copolymers of olefins, diolefins, Vinylestern, vinyl ethers, vinyl ketones and other vinyl or vinylidene monomers. Further examples of synthetic polymers are polyamides, thermoplastic poly- 2; esters and polyorganosiloxanes. Polymers such as

Polyethylene, ethylene-propylene copolymers, ethylene-propylene-diene terpolymer, Ethylene vinyl acetate copolymer,

Ethylene-ethyl acrylate copolymer, styrene-butadiene copolymer,
Polycis-1,4-isoprene, polychloroprene, polybutadiene, polydimethylsiloxane or polyphenylmethylsiloxane.

However, any synthetic polymer can be used to carry out the method according to the invention can be used, which can be vulcanized with the help of an organic peroxide.

Examples of suitable organic peroxides are dialkyl hydroxides such as

Dimethyl peroxide, methyl ethyl peroxide, Diethyl peroxide, 1,1-dihydroxydiethyl peroxide,

Ethyl cyclohexyl peroxide, propylhexyl peroxide, Di-tert-butyl peroxide, di-n-butyl peroxide, tert-butyl-tert-amyl peroxide,

tert-butyl-phenol-methyl peroxide, tert-butyl vinyl peroxide,

lert-butylcumyl peroxide,

Dichloro-tert-butyl peroxide, in

Di-tert-pentyl peroxide,

tert.-Pentyi-terl.-hexyl peroxide, di-n-hexyl peroxide, di-iert.-hexyl peroxide, Dicyclohexyl peroxide, di-n-heptyl peroxide,

Diphenyl-methyl-9-xarithenyl peroxide, -, ->

Dicumyl peroxide, Ι, Γ-di-tert-butyl peroxyethane, 2,2-bis (tert-butylperoxy) butane, 1,4-bis (cumylperoxy) butane,

l, IO-bis (ctimylperoxy) decane,

2,5-dimethyl-2,5-di (tert-butylpcroxy) hexane, <, n

2,5-dimethyl-2,5-di (tert-butylperoxy) -3-hexyne, 1,3-bis (t <: rt.-butylpcroxy) diisopropylbeny.ol, 1,4-bis (tert-butylproxy) diisopropylbcn / .ol and the like,

Hydropcroxydc, like (, 'S.

2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-diniethylhexine-2,5-dihydroperoxide and the same;

Peroxy acids and their esters, such as
tert-butyl peroxybenzoate,
Di-tert-butyl diperoxyphthalate,
2,5-di (benzoylperoxy) hexane and the like.

Mixtures of the organic peroxides mentioned can also be used in the process according to the invention will.

The specified organic peroxides can be added to the vulcanizable material in an amount of 0.05 to 10 parts by weight per 100 parts by weight of the synthetic polymer. The vulcanizable materials used for the process according to the invention can contain various additives, such as antioxidants, vulcanization accelerators, vulcanization retarders, other vulcanization auxiliaries, tension stabilizers, plasticizers, colored pigments, carbon black or dyes. Examples of antioxidants that can be used are 4,4'-bis (3-methyl-6-lert.-butylphenol), N, N'-di-2-naphthy! -P-phenylenedianiine. Examples of suitable vulcanization accelerators are ρ, ρ'-dibenzoylquinone dioxime, tetramethylthiuram disulfide. Examples of vulcanization retarders are 2,6-di-tert-butyl-p-cresol, phthalic anhydride. Examples of other vulcanization auxiliaries are triallyl isocyanurate and diallyl phthalate. Examples of voltage stabilizers are 9,10-dibromanthracene, diphenyl disulfide, N ₁ N'-dialkyl copper dithiocarbamate.

The accompanying drawings are intended to provide a better understanding of the method according to the invention, which represent schematic representations of particular embodiments of the invention. In these drawings shows

Fig. 1 is a longitudinal section of a device for producing an electrical cable with vulcanized Insulation layer and

2 shows a longitudinal section of a device for producing a tube from vulcanized polymer!

In Fig. I a nozzle 3 is shown with a long flow path, which is connected to the cross-head 1 of an extruder with the aid of a nozzle holding device 7 and which consists of the nozzle parts 31, 32 and 33, which are connected to one another in a row by flanges and therefore can be broken down into individual parts.

The flange 4, which is screwed onto the end of the nozzle part 31, forms an annular recess 47 and an annular projection 46. This annular recess 47 results in a step 48. In a porous tube 41 is inserted into this recess 47. The inner diameter of the nozzle part 31, des The protrusion 46 and the porous tube 41 are the same. An annular chamber 42 surrounds the porous tube 41. This chamber 42 is connected to a bore 44 in the flange 45, and the bore 44 is via a Connecting part 45 connected to a line 43.

A flange 4 'of the nozzle part 32 is hermetically on the with the help of bolts 49 and nuts iiO Flange 4 attached. The molding aid is extracted from a molding aid container through line 43 and bore 44 (which is not shown) with the aid of a high pressure pump (not shown), such as a multi-piston pump, in particular a Bosch-type pump, inserted into chamber 42.

The grief 42 serves as a storage container for the molding tool. The molding agent which is filled in the chamber 42 oozes out of the porous tube 41. The molding agent spreads from the inner surface of the porous tube 41 to the entire inner surface of the subsequent part of the lung path nozzle and facilitates

through the smooth passage of a molded product the channel of the nozzle with a long flow path 3.

The molding aid is applied to the inner surface of the nozzle in the area of entry into the nozzle channel supplied, preferably it is supplied within 1 m of the entry into the nozzle channel. The entry area of the nozzle channel of the long flow path nozzle is maintained at a temperature so high that melted a vulcanizable material to be deformed is, but is so low that the κι premature vulcanization is avoided (this Area is hereinafter referred to as the deformation zone). The subsequent area of the nozzle with long flow path is held at a temperature high enough to vulcanize the material, r, This zone is heated with the aid of a belt heater surrounding the nozzle with a long flow path 6 (this area will hereinafter be referred to as the vulcanization zone). The length of the deformation zone is subject no restriction; however, it is preferably less than 1 in. The deformation zone can be on the actual entry of the nozzle channel of the nozzle with a long flow path may be restricted.

A molten vulcanizable material R is extruded by means of an extruder, not shown, on an electric conductor W which is continuously inserted into a cross-head through a guide member 2, and is deformed to form predetermined dimensions while the deformation zone of the nozzle with a long flow path jo happened. The molded layer on the electrical conductor W is heated and vulcanized while passing through the vulcanizing zone of the nozzle with a long flow path, and after exiting the nozzle is fed into a water-cooled device 5 directly connected to j3 of the nozzle part 33. There, water is continuously supplied and discharged under high pressure, for example of about 30 kg / cm ² , in the direction of the arrow shown in FIG. 1.

It has surprisingly been found that the m) formation of cavities or bubbles in the insulating layer is negligibly small if a cable insulation is immediately cooled in pressurized water after the cable has emerged from the nozzle with a long flow path. 4-,

It was found that a vulcanizate obtained by steam distillation shows numerous micro voids when observed under a microscope. It has also been found that in conventional steam vulcanization, which is usually carried out at a pressure of between 15 and 20 kg / cm ² , a cooling water pressure of more than about 10 kg / cm ² has little effect on the number of voids that occur in the insulation.

In contrast, it was found that the vulcanizate obtained according to the invention has no voids when the cooling is carried out at a pressure of more than 10 kg / cm ² .

All of these electrical observations were made under a differential interference microscope to detect hollow wi Clearly distinguish between the rooms and the insulating material.

A hohlrau infreie insulation that was considered ideal for Hochspannungükabel, could be realized by the erfindungsfiemüße process now for the first time h ^r>.

A device for making a pipe cross-linked ^ polymer! is shown in the accompanying Fig.2. In Fig. 2, the vulcanizable material R is extruded with the help of an extruder into the channel of the attachment (adapter) 1 and p;> ch the passage through the passages of the branches 7 of the distributor 3 in the area of the entry of a nozzle with a long flow path 4 deformed cylindrical shape. At this stage, the temperature of the vulcanizable material is still below its vulcanization temperature. The vulcanizable material thus formed is then heated and vulcanized as it moves through the annular channel (vulcanization zone) enclosed by the long flow path nozzle 4 and the long mandrel 5. The molding aid is applied to both the inner surface of the long flow path nozzle 4 through the porous tube 10 in the manner described in connection with FIG. 1 as well as onto the outer surface of the mandrel 5 through the porous tube 11 which is inserted and secured between the distributor 3 and the mandrel 5. This mandrel 5 is screwed onto the distributor 3 and extends as far as the exit of the cooling device 6. To feed the molding aid onto the mandrel 5, this molding aid is passed through the channel 16 and bore 17 in the same way as in FIG. I inserted into the annular chamber 12. The mandrel 5 is heated to the vulcanization temperature with the aid of the heating cartridge 19 inserted into the mandrel. The heating cartridge 19 is connected to a power source via the lead wires 18. After the vulcanized tube has emerged from the outlet of the nozzle with a long flow path 4, it is cooled under pressure in the cooling device 6, which is directly connected to the nozzle with a long flow path 4, for example at about 10 kg / cm ² . The up to the exit of the cooling device 6 in the in F i g. The mandrel 5, which extends in the manner shown in FIG. 2, serves to prevent the tube from being deformed by the pressure of the cooling medium. However, a mandrel 5 can also be used which extends only as far as the exit of the nozzle with long flow path 4, provided that the deformation of the vulcanized pipe by the pressurized cooling medium is permissible or that there is no risk of deformation of the pipe by the pressurized cooling medium exists. To produce a vulcanized product free of bubbles or voids, a pressure of the cooling medium of 5 to 50 kg / cm ² , preferably 5 to 30 kg / cm ² and in particular 20 to 30 kg / cm ^{2 is} recommended. It is also preferred to use a cooling device 5 which is constructed so that it can be easily moved, for example by using wheels attached thereto. With this structure, it is more convenient to decrease or increase the number of nozzle parts or to replace the nozzle parts, and moreover, the cooling device itself can be shifted depending on the thermal expansion of the long flow path nozzle 3 due to temperature changes. In the method according to the invention, depending on the cross-section and size of the desired product, nozzles with a long flow path of different cross-sectional shapes and dimensions are optionally used. It is possible that these nozzles with a long flow path are composed of two or more nozzle parts which are connected to one another in series in the manner shown in FIG. Materials with good thermal conductivity, such as iron, brass, copper or aluminum, are preferably used as the material for the nozzle with a long flow path. The nozzle with a long flow toilet; can after

can be heated in numerous ways, for example with the help of an electric one placed around the nozzle Heating band, with the help of tines arranged around the nozzle and heated with hot oil, through direct supply of electrical current to the wall the nozzle or induction heating. The long flow path nozzle is usually 1 to 20 meters long or longer if necessary.

The term "nozzle with a long flow path" is used for a nozzle with a long nozzle channel that is used in the English as »longland die«.

The method of applying molding aid to the inner surface of the nozzle with long flow path can be freely may be selected provided that the molding aid supplied extends over the entire inner surface of the nozzle is distributed with a long flow path or at least over the entire inner surface of its vulcanization zone. It It is believed that the use of a porous tube as shown in FIG. 1 shown is the best Possibility of supplying the molding aid; however, it can also be the application of another Method may be possible, such as supplying the molding aid through an in the nozzle with a long flow path provided slot.

The molding aid is usually supplied in the deformation zone with a long flow path, however, the deformation zone is extremely short, see above it takes place at the inlet opening of the nozzle with a long flow path. Additional feeding is also possible. For example, the additional introduction can take place at a predetermined point in the vulcanization zone. This additional introduction of molding aids is preferably carried out in the bottom part of the horizontal arranged nozzle with a long flow path, because this area tends to dry out.

With the kind of the molding aid, the size of the molded products, and the molding and vulcanization conditions, the rate of supply of the molding aid varies; however, it is usually in the range of about 0.001 to 0.04 cm ³ per 1 cm ^{2 of} the surface of the molded product.

The temperature conditions during deformation and vulcanization and the cooling conditions with regard to the pressure of the cooling medium depend on the vulcanizable materials to be used. For example, when using low density polyethylene with a content of dicumyl peroxide, the pressure of the cooling medium is in the range of about 5 to 50 kg / cm ² , the temperature of the deformation zone in the temperature range of about 110 to 140 ⁰ C and the temperature of the vulcanization zone in the range of about 150 to 300 ° C selected. In general, the pressure of the cooling medium, the temperature of the deformation zone and the temperature of the vulcanization zone are in the range from 5 to 50 kg / cm ² , 100 to 150 ^° C. and 140 to 300 ^° C., respectively.

In the method according to the invention, the deformed product can before it enters the vulcanization zone occurs, mi 'are coated with a layer that does not contain any organic peroxide. This can be done by suitable means, for example with the aid of an extruder, take place. The applied layer prevents that direct contact of the molding agent with the organic peroxide emerging from the molded product and therefore reduces the risk of the molding agent being destroyed by the organic peroxide.

The preferred coating materials are polyethylene. Masses on the basis of polyethylene and other thermoplastic polymers are used. For making an electrical cable with a vulcanized Coating layer, this coating layer can be a semiconducting layer. Coating layers of a

ι Thickness of 0.5 to 1 mm are usually sufficient to to prevent the molding aid from coming into contact with the organic peroxide.

The invention makes it possible to use vulcanization with the aid of a nozzle with a long flow path

ic applicable for the first time and it can be vuikanized Manufactured articles with good surface finish in a more efficient and economical manner will. In addition, the method according to the invention is particularly suitable for producing

Ij insulated high voltage cables because the manufactured vulcanized insulation is free of voids and bubbles.

The process according to the invention is described below using examples.

B e i s ρ i e I 1

A vulcanizable polyethylene, consisting of 100 parts by weight of F > Low density ethylene with a

2-, density of 0.920 and a melt index of 0.5 (according to ASTM D 1238-1970, Method A, Condition E), 2.0 parts by weight dicumyl peroxide, 0.5 parts by weight 4,4'-thio-bis (3-methyl-6-t-buty! Phenol) and 0.25 parts by weight of diallyl phthalate., Was in an electric

jo heated extruder (cylinder channel: 120 mm, L / D: 14, Compression ratio: 2) inserted and extruded onto a cable core that is continuously with -> iner linear speed of 3.5 m / min was introduced into the crosshead of the extruder. Of the

The j5 cable core had a vulcanizable, semiconducting polyethylene layer with a thickness of 1 mm on a strand (diameter 600 mm ² ) made of 91 copper wires, the outer diameter was 2.9 mm.

A long flow path nozzle with a length of 6000 mm and an inner diameter of 69.9 mm was attached directly to the exit of the crosshead, and the deformation zone (500 mm) was at 130 ° C, the vulcanization zone (remaining 5500 mm) was at 250 . kept ⁰ C. a delivery füt the molding aid of the nozzle was with a long flow path arranged that the crosshead was adjacent in 100 mm distance from the end as a molding aid was an ethylene oxide-propylene oxide block copolymer (a molding aid 1), the following data was. density (ρ) 1.05 at 20 ° C, refractive Are "{ηΐ): 1.459, viscosity: 5.76 centistokes at 235 ° C boiling point: more than 300 ⁰ C, ηι / τ / ο: below 2, absorption ratio: - 0.15 mg / cm ² (Note 1). These; Molding aid was continuously fed through

5 ^r ) feeding device at a rate of 1.5 ^{cm 3} / me (0.012 cm ³ on 1 cm ^{2 of} the surface of the extruded product) using a high pressure piston pump. The non-vulcanizable polyethylene was extruded onto the cable core and leg

bo passage through the deformation zone deformed unc then heated and vulcanized as it passes through the vulcanization zone. The one with vulcanized Polyethylene insulated cable was made with the help of a long float after passing through the nozzle

b5 high pressure cooling water of 25 kg / cm ² cooled. In this way, a vulcanized polyethylene-coated cable (Dicki

18 mm), which had a glossy surface (Grade No. 1, Note 2). In no area of Cable insulation voids were found (Note 3).

Examples 2 to 24

The deforming and vulcanization of insulating materials on a cable core was carried out according to the invention Procedure carried out under the conditions shown in Table 1. the number of Voids in the insulating layer were determined according to the method of Example 1 (Note 3). No voids were found in the cable insulation made according to each example became. The duration of the continuous implementation of the process and the nature of the surface of the insulating layer of the cable according to each of the examples are shown in Table 1.

Remarks:

1. It is believed that the negative value of the absorption ratio is caused by the extraction of certain additives from the polyethylene into the molding aid.

2. The surface of the vulcanizate is evaluated in the following way: Evaluation

No. 1: Shiny

No. 2: Shiny, but unmistakable

No. 3: Not shiny, but with a smooth handle

No.4: Honeycomb-shaped fine cracks

3. The number of voids in the insulating layer was determined as follows: a test piece cut from the insulating layer is cooled in liquid nitrogen for 30 minutes, then the piece is cut into slices approximately 10 microns thick using a microtome. The number of voids in the disk is counted under an optical microscope (differential interference type microscope, magnification 300 times).

At- Structure of the electric cable b
mm C.
el c2 c 3 Molding aid e
cSt f
⁰ C G H
mg / cm ² /
cc / crn ^s • si K)
H-fc a 18th LDPE
(o: 0.920,
MI: 0.5) DCP
2.0 parts 4,4'-thiobis- (3-me-
ethyl-6-t-butyl-
phenol) 0.5 parts
Diallyl phthalate
0.25 parts d 28-0 300 < 2> -0.82 0.01 r 560 2 Copper strand (91/2.9 mm, diam
diameter: 600 m ² covered) with
vulcanized semi-conductive
Polyethylene layer (1 mm thick) 18th LDPE
(ρ: 0.920,
MI: 1.0) TBCP
2.5 parts 4,4'-thiobis- (3-me-
ethyl-6-t-butyl-
phenol) 0.3 parts
ρ, ρ'-dibenzoylquinone-
dioxime 0.5 parts Molding aid 2 8.96 300 < 2> -1.03 0.011 3 dito 18th EVA
(ο: 0.93,
MI: 3.5,
VAc content:
14% weight%) TBCP
2.5 parts 4,4'-thiobis- (3-me-
ethyl-6-t-butyl-
phenol) 0.3 parts
ρ, ρ'-dibenzoylquinone-
dioxime 0.5 parts Molding aid 2 4.42 300 < 2> -1.08 0.015 4th dito 18th LDPE
(ρ: 0.920,
MI: 0.5) BBPB
3.0 parts N.N'-Dinaphthyl-
p-phenylene diamine
0.5 parts
ρ, ρ'-dibenzoylquinone-
dioxime 0.2 parts Molding aid 2 1.98 245 < 2> 0.35 0.65 5 Copper strand (91/2.9 mm, diam
knife: 600mm ² ) covered with
vulcanized semi-conductive
Polyethylene layer (1 mm thick) 17th LDPE
(ο: 0.920,
MI: 0.3) TBCP
2.0 parts Triallyl iso-
cyanurate 1.0 parts
Phthalic acid
anhydride 0.8 parts Nonylphenyl
polyoxyethylene *) 1.17 350 < 2> 0.85 1.65 6th Copper strand (37 / 2.6 mm, diam
diameter: 600 m ² covered) with
vulcanized semi-conductive
Polyethylene layer (1 mm thick) 17th dito dito dito Oleic acid amide **) 1.13 360 < 2> 0.92 1.86 7th dito 16 LDPE
(ο: 0.920,
MI: 1.0) BBPB
2.0 parts Triallyl iso-
cyanurate 2.0 parts
2,6-di-t-butyl-
paracresol 0.5 parts Stearic acid ***) 141 400 < 3.5 1.18 3.2 8th Copper strand (19 / 2.6 mm. Dia
knife: 100mm ² ) covered with
vulcanized semi-conductive
Polyethylene layer (1 mm thick) 16 LDPE
(ο: 0.920,
MI: 1.0) DCP
2.0 parts Triallyl iso-
cyanurate 2.0 parts
ρ, ρ'-dibenzoylquinone-
dioxim 0.7 parts Polydimethyl
siloxane
(200OcSt at 3O ⁰ C)
100 parts
Pyrogallol 20 parts 132 400 < 3.8 3.56 6.4 9 Copper strand (19 / 2.6 mm, diam
knife: 100mm ² ) covered with
vulcanized semi-conductive
Polyethylene layer (1 mm thick) Polydimethyl
siloxane
(200OcSt at 30 ° C)
100 parts
KOH 5 parts

Structure of the electric cable b C. c2 c3 Molding aid e ³ C G H i 0.69 At- a mm c \ TBCP Triallyl iso- d cSt 270 < mg / cm- cc / cm- 0.73 game
No. 17th LDPE 2.5Tsile cyanurate 2.0 parts 12.8 2> 0.78 0.32 Copper strand (37 / 2.6 mm, diam (ρ: 0.920, Tetramethylthiuram Poly (1,6-hexane 0.012 10 knife: 200 mm ² ) covered with MI: 0.3) dilsufid 0.7 parts diol adipate) vulcanized semi-conductive DCP Triallyl iso- 260 < Polyethylene layer (1 mm thick) 13th dito 2.5 parts cyanurate 2.0 parts 2.13 2> 3.62 1.43 Copper strand (7 / 2.0 mm, diam 4,4'-thiobis (3-methyl- Sorbitan 11 knife: 22mm ² ) covered with 6-t-butyl- monolaurate vulcanized semi-conductive phenol) 0.5 parts Polyethylene layer (1 mm thick) DCP Triallyl iso- 27O < 13th LDPE 2.5 parts cyanurate 2.0 parts 3.62 2> -0.20 0.32 ¹ ^ Copper strand (7 / 2.0 mm, diam (o: 0.920, 4,4'-thiobis (3-methyl- Polyoxyethylene 12th knife: 22mm ² ) covered with MI: 0.3 6-t-butyI- sorbitan monolaurate vulcanized semi-conductive phenol) 0.5 parts cn Polyethylene layer (1 mm thick) dito dito 260 < O 13th dito dito dito 1.26 250 < 2> 1.61 dito 13th dito Laurylethanolamide 1.67 2> 25.2 13th dito DCP Zinc white 5.0 parts Tetra-n-octyl 300 < 14th 16 EPDM 3.0 parts Poly (2,2,4-trimethyl- pyromelitat 5.73 2> -0.15 Copper strand (19 / 2.6 mm, diam 1,2-dihydro- Molding aid 1 15th knife: 100mm ² ) covered with quinone) 1.5 parts vulcanized semi-conductive MT carbon Polyethylene layer (1 mm thick) 12.5 parts chemically prepared traded clay 125 pieces P-200 paraffin oil 2.0 parts Minimum of 5.0 parts Paraffin wax 5.0 parts

continuation

example
No. a

Structure of the electric cable

b mm

Molding aid d

c2

c3

Hi

mg / cm ² cc / cm ^:

Head strand (19 / 2.6 mm, diameter: 100 mm ² ) covered with a vulcanized semi-conductive polyethylene layer (1 mm thick)

Copper strand (19 / 2.6 mm, diameter: 100 mm ² ) covered with a vulcanized, semi-conductive polyethylene layer (1 mm thick)

dito

Copper strand (19 / 2.6 mm, diameter: 100 mm ² ) covered with a vulcanized, semi-conductive polyethylene layer (1 mm thick)

dito

16

16

16

16

16

SBR DCP Zinc white 5.0 parts Molding auxiliary 1 Molding aid 3 3.0 parts Poly (2,2,4-trimethyl- 1,2-dihydro- quinone) 1.0 part Stearic acid 2.0 parts MT Carbon 50 parts Dibenzothiazyl disulfide 1.25 parts Calcium carbonate 37.5 parts Paraffin wax 3.0 parts Polycis DCP Zinc white 3.0 parts Mixture of 1,4-isoprene 2.0 parts Poly (2,2,4-trimethyl- Glycerine and poly- 1,2-dihydro- propylene adipate quinone 0.75 parts (1: 1) Stearic acid 1.0 part N-phenyl-N'-iso- Mixture of propyl-p-phenylene- Molding aid 1 diamine 0.75 parts and dioctyl sebacate Lead dimethyl (1: 1) dithiocarbamate 0.3 parts Mixture of LDPE dito 4,4'-thiobis (3-methyl- Sorbitan mono- (ρ: 0.92. 6-t-butyl- laurate and MI: 1.0) phenol) 0.5 parts Stearic acid (1: 1) Diallyl phthalate 0.25 parts LDPE DCP 4,4'-thiobis (3-methyl- (ρ: 0.92, 2.0 parts 6-t-butyl- MI: 1.0) phenol) 0.5 parts Diallyl phthalate 0.25 parts dito dito dito

5.73 300 <2> -3.18

0.012

8.96

300 <2> -1.07 0.012

3.52

290 <2>

250 <2>

1.83 0.36

64 20.5

N) N)

1.8

260 <2>

3.3

0.74

continuation

example
No. a

Structure of the electric cable

b mm

c el

Molding aid d

el

e cSt

/ 7

niL''cni ^:

Copper strand (19 / 2.6 mm. Diameter Ib LDPE knife: 100 mm-) covered with (<j: 0.92.

vulcanized semi-conductive Ml: 1.0)

Polyethylene layer (1 mm thick)

Copper strand (19 / 2.6 mm. Diameter 16 LDPE diameter: 100 mm ² ) covered with (ρ: 0.92.

vulcanized semi-conductive Ml: 1.0)

Polyethylene layer (1 mm thick)

DCP 4.4'-thiobis (3-methyl-

2.0 parts 6-t-butyl-

phenol) 0.5 part diallyl phthalate 0.25 part

DCP 4,4'-thiobis (3-methyl-

2.0 parts 6-t-butyl-

phenol) 0.5 part diallyl phthalate 0.25 part

80% solution of 0.65 255 <2> oleic acid amide in alkylbenzene viscosity 13cSt at 30 ⁰ C and ηϊ : 1.487

80% solution of 0.71 250 <2> magnesium stearates in triamylamine

35.5

23 dito Flow path
k
mm 16 dito dito W.
ml
mm dito m2
⁰ C Tri-n-butyl citrate 0.68 P.
kg / cm ² 260 <2> 8.31 4.0 N) N) 24 69.9 18th LDPE
(ρ: 0.920.
Ml: 0.1) dito 5,500 dito 250 Molding Aids 5,348 25th 320 <2> -0.08 0.012 64 56 Tabel Copper strand (91 / 2.9 mm. Dia
knife: 600mm ² ) covered with
vulcanized semi-conductive
Polyethylene layer (1 mm thick) 69.9 5,500 250 25th O example
No. 1 (continued) 69.9 /1
mm / 2
C. 9 500 250 O
cm / min 25th Duration of the
continuous
Procedure
execution
hours Surfaces-
nature 2 Nozzle with long
j
mm 69.9 500 130 9 500 250 35 25th 300 < 1 3 6,000 54.2 500 130 19 700 250 35 25th 250 < 2 4th 6,000 54.2 500 125 19 700 250 55 25th 250 < 2 5 10,000 47.0 500 125 9,990 260 55 25th 200 < 3 6th 10,000 47.0 300 125 9,990 260 112 25th 100 < 3 7th 20,000 54.2 300 125 2,800 270 114 22nd 100 < 3 8th 20,000 X \ Ci 10 130 2,700 250 61 20th 20 < 1 9 10,000 10 130 61 25 < 2 10 10,000 200 125 28 100 < 2 1 1 3,000 300 130 21 70 < 3

continuation

example Long flow path nozzle I. / 2 / 71 / π 2 υ P. Duration of the komi Surface No. Ii C. ml X continuous nature / A- mm mm cm / min kg / cm ^: Statute execution mm mm hours

12 13 14 15 16 17 18 19 20 21 22 23 24

3 3 3 3 3 3 3 3 3 3 3 3 3 6

33.0 33.0 33.0 47.0 47.0 47.0 47.0 47.0 47.0 47.0 47.0 47.0 69.9

300 300 300 200 200 200 200 200 200 200 200 200 500

130 130 130 130 130 130 130 130 130 130 130 130 130

2 2 2 2 2 2 2 2 2 2 2 2 5

Annotation:

The symbols given in the table have the following meanings:

a: cable core

b: Thickness of the insulating layer applied to the cable core (mm)

C- Composition of the vulcanizable to be applied to the cable core

Materials

el: synthetic resin (y: density. Ml: melt index (ASTM D 1238-1970. method A. Condition E). VAc: vinyl acetate)

c2: organic peroxide

c3: other additives

d: Art

e: viscosity (vo) (centistokes at 235 ⁼ C)

f: boiling point (= C)

h: absorption ratio at 150 "C. 45 hours (mg / cm ² )

/ ": Feed rate (cmVcm ^{2 of} the outer surface of the insulating layer)

j: length of the nozzle channel (mm)

k: inner diameter (mm)

/: Deformation zone

Ii: length (mm)

/ 2: temperature ( ⁼ C)

m: vulcanization zone

ml: length (mm)

m 2: temperature ( ^c C)

o: feed speed of the cable core (cm / min)

p-. Pressure of cooling water (kg / cm ² )

250
250
250
210
210
210
210
210
210
210
210
210
250

DDTBH:

21 21 21 48 45 47 47 47 47 47 47 47 47 35

20 20 20 18 18 18 18 18 18 18 18 18 25

80 <

100 <

100 <

50 <

45 <

45 <

150 <

25 <

25 <

25 <

25 <

20 <

600 <

Low density polyethylene

Ethylene vinyl acetate copolymer

Ethylene-propylene-diene terpolymer

Dicumyl peroxide t-butylcumyl peroxide 1,3-bis (t-butvlpeimy) diisopropylbenzene

2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3

Molding aid 1: ethylene oxide-propylene oxide block copolymer (u: 1.05 at 20 ^c C

/ J ---: "! .459) Molding aid 2: ethylene oxide-propylene oxide block copolymersjy: 1.Ofal at 20C.

n ?: 1,462)

Molding aid 3: copolymers!., In which ethylene oxide by graft copolymerization

tion is grafted onto polypropylene oxide (average molecular weight: 3300) "

Molding aid 4: copolymer. in which ethylene oxide by graft copolymerization

is grafted onto polypropylene oxide (average molecular weight: 2200)

Molding aid 5: ethylene oxide-propylene oxide block copolymer (o: 1,095 at 20 ⁼ C.

π ν: 1,466)

*) That which is withdrawn from the interface between the nozzle and the product at the end of the nozzle Mold aid boiled slightly before the cooler hit the nozzle end was connected.

**). ***) These mold auxiliaries were melted by turning the feed device -. 'N for the molding aid at 100 ^; C, and then fed.

Example 25

A vulcanized cable was produced in the manner described in Example 1 with the modification that polyoxyethylene stearylamide instead of molding auxiliary I and di-t-butyl peroxide instead of DCP was used. The process was carried out continuously for 60 hours.

Manufacture of high-density polyethylene rod with an outside diameter of 25.8 mm at a speed of JJ m / min. FormhUfsmittel 1 was at a rate of 0.01 cmVcm- the AuQctifU ^- hc · de: supplied product. Continuous implementation of the process was ensured for 120 hours, with a surface finish of grade no. 1 being obtained.

Example 26

An insulated cable was manufactured in the same manner as in Example 11 except that sorbitan was used in place of sorbitan monolaurate. Sorbitan molten was fed by the feeder was maintained for the molding aid at 160 ⁰ C. Continuous operation was achieved for 60 hours with Grade 3 surface finish.

Example 27

An insulated cable was manufactured in the same manner as in Example 14 except that Dibutyl phthalate instead of tetra-n-octyl pyromellitate was used. The process could be carried out continuously for 40 hours, with a surface finish corresponding to Grade No. 3 was obtained.

Example 28

A 3000 mm long nozzle with a long flow path and an inner diameter of 25.8 mm was connected to the outlet of the longitudinal head of a piston extruder. The 300 mm long forming zone was maintained at 150 ⁰ C and the subsequent 2700 mm long vulcanization zone was heated to 200 ⁰ C. A mixture of 1.0 part by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 1.0 part by weight of N, N'-di-2-naphthyl-p-phenylenediamine and 100 was fed to this extruder Parts by weight of high-density polyethylene (ρ: 0.965, melt index Ml: 0.2 [ASTM D 1238-1970, method A, condition F]) fed to a vulcanized

Example 29

Using an apparatus shown in Fig. 2, a vulcanizable polyethylene consisting of 100 parts by weight of high density polyethylene of density 0.96 and 2 parts by weight of dicumyl peroxide was extruded from the extruder into a nozzle with long flow path 4 (5000 mm long). At the entrance of the nozzle 4, molding aid 1 was fed to both the inner surface of the nozzle 4 and the outer surface of the mandrel 5 ^{at a rate of 0.015 cmVcm 2 of the surface of the molded product.} While the molded product moved through the die with long flow path 4, it was vulcanized at a temperature of 23O ⁰ C lur. The vulcanized product was then cooled in the cooling device 6 (length 5000 mm) under a pressure of 15 kg / cm ^2. An excellent vulcanized polyethylene pipe was formed, the wall thickness of which was 4 mm and the outside diameter of which was 400 mm.

Comparative Examples 1 to 6

The deformation and vulcanization of insulation materials on cable cores was carried out under the conditions shown in Table 2 conditions shown. In Comparative Example I was for 3 hours after the start of An insulated cable with a good surface finish (grade no. 1) was obtained, after which it was made however, the surface of the cable gradually became rough and finely cracked about 10 minutes later. Pieces of gelled film of the molding aid (silicone oil) were on the cracked surface of the Product. In the comparative examples 2 to 6, only products with heavily cracked surfaces were achieved.

Table 2

Comparative structure of the electric cable
example

; f b

1 Copper braid (19 / 2.0 mm, cross 12th LDPE TBCP Triallyl isocyanate 1.0 part cut 60 mm ² ); covered with (o: 0.920 3.0 parts Triamethylthiuriinulisulfil vulcanized, semiconducting cr Ml: 0.5) 0.5 parts Polyethylene layer (1 mm thick) 2 dito 12th dito dito dito 3 Copper pigtail (19 / 2.0 mm, cross 12th LDPE TBCP Triallyl isocyanurai 1.0 part cut 60 mm ² ), coated with (»: 0.920 3.0 parts Tetniinethylihiuriimdisulfid vulcanized, semiconducting cr Ml: 0.5) 0.5 parts Polyethylene layer (1 mm thick) 4th dito dito dito dilo dito 5 dito dito dito dito dito 6th dito dito dito dito dilo

29 ■ continuation) aqueous with a long flow path / 2 21 64 - 2.55 - ro 560 A. O 30th OO H cc / cm- Form Aid Cl Solution of potassium soap from k 1 ° C ml "C mg / cm- ' 1.36 Tabel d Soybean oil) Il 125 mm 400 < cm / min 2> 2.39 2 (continued) mm mm 125 2800 41 2> 30.5 jet 36.0 200 125 ₍ , 2800 300 < 41 2> 200 10.8 • 2 (I j 36.0 200 125 cSi 2800 250 < 41 5t 17th 1.2 Comparative 36.0 200 125 168.5 2800 100 41 2> -0.32 7.5 example mm 36.0 200 125 2800 300 < 41 120 1.25 3000 36.0 200 2.56 2800 110 41 1.8 1 3000 36.0 200 0.38 Polydimethylsiloxane (2000 cSt 3000 2 at 30 ° C) 3000 P. con- 3 castor oil 3000 Duration of Ver 4th Eugenol 3000 kg / cm- natural driving guide 5 water 25th hours 6th Paraffin oil 25th 3 Soap solution (25% 25th - 25th - Tabel ml 25th - Comp.- ° C 25th - Ex. 250 250 250 1 250 2 250 3 250 4th 5 6th

Comparative example 7

Using the same vulcanizable polyethylene, an extruder of the same size and the same cable core as in Example 1, a vulcanized polyethylene insulated cable was produced using a conventional vertical steam vulcanizer at a speed of 0.28 m / min. The length of the Dampfvulkanisationskanimer was 12 m, m is the length of the water cooling chamber. 11, the steam had a temperature of 205 ⁰ C and a pressure of 18 kg / cm ^2. The resulting cable holds a 4 grade surface. The number of voids in the insulating layer was determined according to the method described in Example 1 (Note 3) and there were approximately 100 voids greater than 1 micron in diameter in a range of 170 χ 120 microns ² in one of the middle layer of the Cable insulation removed disc found.

Comparative example 8

A vulcanized cable was used in the example ί described manner produced with the modification that the molding aid (molding aid 1) not durcr a feeding device for the molding aid was fed, but with the one made of polyethylene low density existing vulcanizable base material in an amount of 2.0 parts by weight per 10 ( Parts by weight of the material was mixed. The extrusion of a vulcanized product was acceptable not possible because the material stares at the inner surface of the nozzle with a long flow path! vulcanized and stuck.

For this purpose 2 sheets of drawings

Claims (11)

Patent claims: 1. A method for deforming and vulcanizing a vulcanizable material, in which a Mixture of a polymer vulcanizable with the aid of organic peroxide and an organic one Peroxide is passed through a nozzle with a long flow path, which is a forming zone and an adjoining one Has vulcanization zone, while at the same time a molding aid on the inner surface of the Long flow path nozzle is fed in such a way that an uninterrupted film is between the inner surface of the nozzle and the polymer product is maintained, characterized in that that the molding aid used a) a viscosity of at least 1.1 centistokes and not more than 3000 centistokes at 235 ° C, b) has an absorption ratio in the polymer of less than 100 mg / cm- at 150 ^° C. for 45 hours, c) does not gelatinize in contact with the organic peroxide during vulcanization will and d) does not boil during vulcanization. 2. The method according to claim 1, characterized in that one of the following as molding aid Connections is used: 1) Polyoxyalkylenes and their derivatives, statistical. Block or graft copolymers of at least two alkylene oxides or their derivatives, with a molecular weight of more than 120 and less than 100,000, 2) polyhydric alcohols, including dehydration products c of these compounds, having 4 to 50 carbon atoms and their alkyl esters or -ether, 3) Fatty acid alcohol amides with a total of more than 8 carbon atoms obtained from Fatty acids with 2 to JO carbon atoms and alcohols with 1 to 30 carbon atoms, 4) fatty acid amides with 8 to 90 carbon atoms, 5) fatty acids with 8 to 30 carbon atoms and their metal salts, 6) Esters of polycarboxylic acids with 6 to 22 carbon atoms and monoalcohols with I. up to 20 carbon atoms, 7) phosphoric acid esters of alkyl alcohols with 3 to 30 carbon atoms, 8) polyesters with a molecular weight of more than 200 and less than 30,000, 9) metal nitrates and metal halides, 10) Mixtures of polysiloxanes with a molecular weight of more than 2,000 and less than 100,000 and gelation inhibitors, 11) Mixtures of polysiloxanes with a molecular weight of more than 2,000 and less than 100,000 and an alkali metal hydroxide, alkali octal oxide, Alkaline earth metal hydroxide or alkaline earth metal oxide, and that the molding aid used as a continuous film between the inner surface of the Nozzle and the polymer product is arranged. 3. The method according to claims 1 or 2, characterized in that the deformed and vulcanized Polymeric polyethylene having a sea melt index of 0.1 to 2 is. 4. The method me claims 1 to i, thereby characterized in that for manufacturing an electrical cable with a vulcanized coating a) a molten vulcanizable material consisting of a with the help of organic ■) Peroxide vulcanizable polymers and one organic peroxide, continuously extruded onto an electrical conductor, b) the material is deformed and vulcanized by being exposed to elevated temperature and Hi tem pressure through a nozzle with long Flow path is guided, which has a molding zone and a subsequent vulcanization zone, while simultaneously applying a molding aid to the inner surface of the nozzle with a long ι "> flow path is applied, which 1) a viscosity of at least 1.1 cenlislokes and at most 3000 centistokes 235 ° C, 2) an absorption ratio in the polymer ren of less than 30 mg / etr.- during 45 Hours at 150 ⁰ C, 3) not gelatinized in contact with the organic peroxide during vulcanization will and r> 4) does not boil during vulcanization, and c) the coated conductor after exiting the end of the nozzle with a long flow path with the aid from under pressure from 15 to 30 kg / cm- ' ίο standing cooling water is cooled. 5. The method according to claim 4, characterized in that the polymer is polyethylene with a Schinel / index from 0.1 to 2.0 is used, the Vulcanization zone of the nozzle with a long flow path π is kept at a temperature between 200 ⁰ C and 300 ⁰ C and that the molding aid is selected from the following compounds: polyoxyalkylenes and their derivatives, random, block or graft copolymers of at least 2 alkylene oxides mi and their derivatives, the molecular weight of which is more than 120 and less than 100,000, or a Mixture of these materials.