HU201104B - Electric insulating, thermoplastic or curable mixture apt for granulation, having semi-conducting properties, particularly for utilization in cable industry - Google Patents

Abstract

An electrically insulating or semi-conducting type, thermoplastic or vulcanisable granulating mix, specially used in the cable industry contains (all pts. wt.): 10-50 rubber, 5-50 polyolefin, 0-50 plasticiser, 0-5 graftable silane cpes. 0-10 organic peroxide, and 2-300 known additives. - Polyolefin is of amorphous-crystalline type in (1:10)-(10:1) ratio. The amorphous polymer is atactic polypropylene and contains more than 5x10power 3 mols. by number and has a greater mol. wt. than 8x10power 4. A misture of carbon blocks is used comprising conductive acetylene and general rubber types in 1: (10-30):

Description

BACKGROUND OF THE INVENTION The present invention relates to an electrically insulating and semiconducting, thermoplastic or vulcanizable granular elastomer / plastomer-based composition, particularly for use in the cable industry, which can be processed on plastics, rubber and cable equipment, extruders.

At present, in the cable industry, in addition to thermoplastic insulators, electrically insulating materials are mainly ethylene / propylene co- (EPM) and ethylene / propylene / diene terpolymer (EPDM) rubber-based (hereinafter EP / D / M) and vulcanizable types and polyethylene of different densities - in crosslinkable form - are employed.

The development of EP / D / M cable insulation materials is aimed at the simultaneous improvement of physical-mechanical and electrical properties. Nos. 77,142,300 and 83,216,304. according to the Japanese disclosure, this is achieved by using high crystallinity and polydispersed EP / D / M types. However, because of their extremely high melt viscosity, the blends made with them cannot be processed on equipment for the application of PVC and polyethylene (PE) insulating materials.

In the case of PE insulated cables, the electrical characteristics, the breakage resistance of the low-density type of polydispersity (Japanese Patent Publication No. 84 99 611) are linear low-density polyethylene formed by the butene-1 comonomer (Japanese Patent Publication No. 81 147 838), superimposed PE layers of different densities (Japanese Patent Publication No. 84,101,708), low-density copolymer of PE and polypropylene (hereinafter "PP") (Japanese Patent Publication No. 72,23,440), PE and ethylene / vinyl acetate copolymer ( hereinafter referred to as E / VAC) (Japanese Patent Publication No. 83 225 504), polyolefin and low melting point polyamide (Japanese Patent Publication No. 81 123 607), and PE (Japanese Patent Publication No. 84 89 345) with styrene derivatives ).

Although the methods described improve electrical breakdown strength and .treeing resistance from a range of electrical characteristics, they have the common drawback that they require a high L / D ratio, a special screw-shaped extruder, which is standard in the rubber and cable industry EP / D / Its M-based mixture cannot be applied by the crosshead technique. The semiconductor is thermoplastic and can be vulcanized as a batch! The conductor or insulation shielding filler sheath, and even some special cable designs for the outer sheath, have a very diverse composition of compositions which are common to almost all conductive carbon black. Extremely expensive and very difficult to incorporate conductive carbon black is characterized by an average particle size, high iodine adsorption value, and dibutyl phthalate binding capacity and high specific surface area (RA Swor; DR Harris, F. Lyon, Kautschuk, Gummi, Kunststoffe 37, 1981). (1984).

In their thermoplastic and vulcanizable types, the plastomeric additive is chlorinated PE (hereinafter "CPE") (Japanese Patent Publication No. 73 55 228) CPE + ethylene / ethyl acrylate (hereinafter "E / EA") (3 735 025 and

No. 836,482; US Patent Specifications), E / VAC (Japanese Patent Publication Nos. 83,7704 and 8340,707), Co / Graft Polymer with E / VAC (U.S. Pat. No. 3,684,821). , Japanese Patent Publication Nos. 82 50 325, 82 54 881 and 82 134 807), E / VAC + ethylene / vinyl chloride copolymer (74 87 943, Japanese Patent Publication) E / VAC + Polyestyrene (81 61 440) Japanese Patent Publication No. E / VAC + Styrene / Vinyl Acetate Block Copolymer (Japanese Patent Publication No. 82 103 211), Polyolefin grafted with E / VAC + Vinyl or Vinylidene Compounds (Japanese Patent Publication No. 82 82 904). ), E / VAC (Japanese Patent Laid-open Nos. 81 62 846 and 81 73 812) grafted with aromatic vinyl compounds, E / VAC + butyl methacrylate / styrene copolymer (Japanese Patent Laid-open No. 81 168 302) , PVC + + CPE + ethylene copolymer (Japanese Patent Publication No. 80 35 806), polyolefin (French Patent No. 2,440,128) patent specification,

79,140; 80,62,610; 80 102 112; 81,106,938; Nos. 81,120,004 and 82,34,607. Japanese Patent Laid-Open), Polyethylene or Ethylene Copolymer + Polystyrene (Japanese Laid-Open No. 74 33 939), Polycaprolactone (Japanese Laid-Open No. 83 85 215), Poly (ethylene terephthalate) (82 105 904) disclosure document).

In purely elastomer-based systems, it is almost exclusively EP / D / M (Japanese Patent Publication Nos. 81 67 350; 82 132 604 and 82 170 404). Such a composition is disclosed in U.S. Pat. According to Japanese Patent Specification, it can only be granulated if the weight ratio of ethylene: propylene in EP / D / M rubber is 72:27 to 92: 8. However, its rheological properties make it impossible to process on cross-linked PE insulating equipment.

Presumably, methods and compositions containing both a plastomer and an elastomer as a polymer component have been developed to overcome the difficulties outlined above. Liquid nitrile rubber used in conjunction with CPE is intended to facilitate the mixing of electrically conductive carbon black (Japanese Publication Nos. 80 15 054 and 80 15 055). Polyisobutylene (GDR 158 070) plays a similar role

HU 201104 Β patent). Alternatively, the role of the elastomer, due to its high compatibility, is to soften the grafted plastomer (Japanese Patent Publication Nos. 82 61 041 and 83 222 140), or to improve the compatibility of 5 different constituents based on their chemical structure (Japanese Patent Publication No. 81 62 846). import document).

Of the elastomers, styrene / butadiene block copolymers are used to adjust theological properties (82,165,902, Japanese Patent Publication). Also known is a composition which employs PE at a given density in addition to EP / D / M to increase treeing resistance (German Patent Publication No. 2,712,618) and to increase adhesion to PE ( Japanese Patent Publication No. 83,212,007).

The presence of the plastomeric constituent used in the methods described herein is intended to provide a peeling strength when used as an insulating shade, i.e. as an extruded layer for insulation, and to improve granulation, sometimes with other characteristics. The major disadvantage of plastomer bulk compositions 25 is that they can only be processed on plastics processing equipment. In addition, they are only suitable for the formation of curing layers in the case of vulcanizing materials which are strongly bonded to PE or crosslinked PE (XLPE) insulation, although in many cases the cable industry requires an easily peelable, peelable layer in addition to the non-detachable semiconductor layer. 35

In contrast, elastomeric bulk compositions may not be processed on plastics crosslinked PE coating equipment. The addition of these thermoplastic styrene / butadiene block copolymers 40 also does not help due to their extremely poor resistance to heat aging.

The internal phase conductor of the cables is usually twisted stranded copper or aluminum conductor. This conductor is provided with an inner semiconductor layer 45, which serves to smooth out or smooth the field strength differences caused by the conductor surface irregularities.

This inner semiconductor layer is surrounded by a crosslinked EP / D / M or PE insulating layer and 50 is applied to the outer semiconductor layer. The role of this outer semiconductor layer is primarily to delimit the electric field. The requirements for the adhesion of these layers to one another depend on the particular shell design and stress 55.

In addition to the various elastomers described, other additives, e.g. 60 colloidal sulfur (Japanese Patent Application Laid-Open No. 83 30 001), metal salts (Japanese Patent Laid-open Nos. 76 79 140; 82 34 607 and 82 134 807) are known for this purpose. However, these additives have a detrimental effect on the life of the cable insulation, especially when moisture is present in the conductor and insulation.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks of the disclosed processes by providing a thermoplastic or vulcanizable composition having a color, gelatine or semiconductor properties, particularly suitable for use in the cable industry.

- granulate,

- can be processed on both PE and EP / D / M processing (extrusion) equipment

- its detachability can be adjusted to the requirements, including very high adhesion.

These latter two requirements mean that the composition has a torque (denoted by M1) of less than 10 dN.m, measured by Monsanto rheometer, at a displacement angle of 130 ° at 130 ° C, and Wallace's plasticity according to TGVSZ 302-76. Peel or tear strength between -70 and less than 100 N / cm measured on finished cable.

An elastomer / plastomer-based composition meeting all the above requirements is obtained according to the following formula:

10-50 parts by weight of rubber 5-50 parts by weight of polyolefin 0-50 parts by weight of plasticizer 0-5 parts by weight of graftable silane compound 0-10 parts by weight of organic peroxide

2-300 parts by weight of other additives, if applicable. polyolefin is composed of amorphous and crystalline types, the latter being atactic polypropylene having a numerical average molecular weight (Mn) of greater than 5x10 ³ g, an average molecular weight of Μ · 8x10 ⁴ g and a semiconductor composition in which the following electrically conductive: acetylene the weight ratio of carbon black is 1: (10-30) :( 1-30).

It will be surprising to those skilled in the art that the addition of the commonly known tackifier APP may produce a granular composition that does not adhere to the granules during storage. In the case of vulcanizable variants, it is extremely surprising that these compositions can be vulcanized at all, since they are known to be degraded by polypropylene peroxide. This is used during manufacturing and certain processing operations to adjust the average molecular weight and the required molecular weight distribution. It is also surprising that the resulting volatile impurities can be used at all in APP cable containing insulating and semiconducting compositions containing hexane and polymerization belt catalyst traces: metal alkyls and their decomposition products, since their impurities would be the opposite. It is also surprising that the semiconductor composition has a conductivity of less than 300 ohms.cm and is required for acetylene and rubber

HU 201104 Β results from the combined use of carbon black, while maintaining plasticity and viscosity (M1) within processing limits. Due to the different size of the carbon black, the processability would be impaired.

Accordingly, the present invention can be granulated in a thermoplastic or vulcanizable form

10-50 parts by weight of rubber 5-50 parts by weight of polyolefin 0-50 parts by weight of plasticizer 0-5 parts by weight of graftable silane compound

0 to 10 parts by weight of an organic peroxide and 2 to 300 parts by weight of an insulating or semiconducting composition based on other known additives, mainly for use in the cable industry, in which the polyolefin (1:10) to (10: 1) by weight of amorphous crystalline type stands and larger more amorphous type 5xl0 than ³ g average number of and 8xl0 ⁴ g per an average weight molecular weight atactic polypropylene, and semiconductor properties will the composition of the carbon black used other additives as conductive acetylene: Distribution of rubber types 1: (10-30) : (1-30).

EP / D / M, butyl rubber, polyisobutylene and the combination thereof are preferably used as rubbers according to the invention.

Preferred crystalline polyolefins are low density polyethylene, ethylene / vinyl acetate, ethylene / ethyl acrylate, ethylene / butyl acrylate copolymers according to the invention.

Suitable plasticizers are oils, waxes, beverage type plasticizers.

Preferably the graftable silane compound is vinyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane.

Among the organic peroxides, dicumyl peroxide, tert-butyl perbenzoate, 1,3-bis-tert-butyl peroxyisopropyl / benzene and the combination thereof are preferred.

Among the other additives, the activator is fatty acids, triaryl cyanurate, glycols; kaolin, dolomite, colloidal silica, chalk, among the known fillers in the insulating compositions; in the semiconductor compositions, carbon black as well as anti-aging agents, flame retardants, and lubricants may be advantageously used in both compositions.

The main advantages of the composition according to the invention are as follows:

- retains granular and granular forms without the use of any dusting agent;

- thermoplastic or vulcanizable compositions can be prepared;

Due to its granular form and suitably adjusted theological properties, it can be processed on cross-linked polyethylene cable insulation equipment as well as on rubber insulated cables;

- its characteristics allow it to meet the requirements of international standards adopted by the cable industry;

- the peel strength of the composition measured on the finished cable can be adjusted as required;

- it is easy to produce and relatively inexpensive due to the use of atactic polypropylene at a relatively low cost;

The composition of the present invention is illustrated but not limited to the following examples:

Example 1

According to the vulcanizable AD formulations and thermoplastic E-F formulations of the composition and properties shown in Table 1, semiconductor compositions were prepared:

HU 201104 Β Composition: Recipe, portion of tomato!

A B C D E F

Xaucsuk

EPIM (Dutral Square 334 Ex,

Montedison product) 20 20 - - 3 3 EPM (Dutral Co. 054, Montedison product) - - 10 10 5 5 Butyl rubber (BK 1675, Soviet type) - - - - 2 2 polyolefin Low density polyethylene (Tipolen 40019, Tisza Chemical Combinator Product) 10 10 20 20 20 Polypropylene copolymer (Tipolen K 823, Tisza Chemical Combinator Product) 15 15 Ethylene / vinyl acetate (Evathane 2805, product of ICI) 20 5 10 10 Ethylene / ethyl acrylate - - 5 - - - Atactic polypropylene Mn = 6x10 ³ g Μ · = 1χ10 ⁵ g 10 - 5 45 5 - Mn = 3.4x10 ³ g M «= 4.8x10 ⁴ g - 10 - - - 5 emollient oil 5 5 10 10 - - di-isooctyl-f bowl - - - - 3 3 Organic peroxide dicumyl peroxide (Di-Cup 40C, Hercules product) 1.4 1.4 - - - - 1,3-bis / tert-butyl peroxyoxyisopropyl / benzene (Perkadox 14/40, Noury Term. · 6.7 6.7 activator Star insav 1 1 - ZnO 1 1 1.3 1.3 -. Nail guide wire (Ketjenblack) EC, Degussa company term.) 2 2 1 1 1.5 1.5 acetylene (P 1250, GDR product) 20 20 30 30 35 35 rubber industry (PGM 33, Soviet type) 30.1 30.1 30 30 1.5 1.5

HU 201104 Β

Ingredients:

Recipe, mass roses

THE B C D E F anti-aging Conoline Derivative (Flectol H, Monsanto product) 0.5 0.5 - 0.5 0.5 Features: Specific volume resistance ohm. cm. 300 7450 58 120 100 290 Ml (Monsanto) 8 10.5 5.5 6 9 11 Wallace plasticity 60 85 45 50 50 70 Peeling strength N / cm 80 70 25 70 50 75 Table 1 features very perspective- Second example

show that the compositions of the formulations B and F using comparative formulations using a molecular weight of less than APP according to the invention do not allow their use in crosslinked PE cable insulation equipment and furthermore their conductivity is less favorable.

creative

caoutchouc

EPDM (Vistalon 719, product of Esso)

polyolefin

Low Density PE (Example 1)

Atactic Polypropylene Mn = 6x10 ³ g, M »= 1x10 ⁵ g Mn = 2.5x10 ³ g, Mm = 1.5x10 ⁴ g

Organic peroxide

Dicumyl peroxide

Injectable silane compound

Vinyl trimethoxysilane

3-methacryloxy-propyl-trimethoxysilane

Moisture-cured masterbatch grafted with a silane compound was prepared according to the following formulas:

Recipe, parts by weight

50 50

40

40-4

0.2

0.2 0.2 0.2

1.9 1.9

2.5 2.5

-611

HU 201104 Β

To 95% by weight of the grafted mixture prepared according to the above formula, 5% by weight of the activator-containing masterbatch having the following composition was added:

di-n-butyltin dilaurate 1 part by weight phenolic antioxidant 5 parts by weight ethylene / vinyl acetate (Example 1) 54 parts by weight kaolin 20 parts by weight dolomite 20 parts by weight

followed by cross-head extrusion cable insulation, which was cured by heat treatment in hot water for 3 hours. Although mixtures of formulas based on formulas A and B were suitable for theology, they had low average molecular weight and isotactic polypropylene.

Formulation mixture B using highly contaminated constituent APP was not vulcanized. The volumetric resistance of the product vulcanized from mixture C was less than 1 x ^{10 7} Mohm-cm, while that of D was less than 1x10 ⁶ Mohm-cm. In addition, for the latter mixture, the average value of the physical-mechanical properties required by the standards was 10-15% below the specification.

Example 3

Electrically insulating, vulcanizable A and B and thermoplastic C-D insulating compositions were prepared according to the following formulas:

Recipe, parts by weight

A B C D

caoutchouc EPDM (Vista 7000, Esso product) 30 30 10 10 polyolefin Low Density Polyethylene (Example 1) 5 5 0.5 0.5 Atactic polypropylene Mn = 6x10 ³ g, M «= 1x10 ⁵ g 8 4.5 4.5 Mn = 2.5x10 ³ g, Me = 1.5x10 ⁴ g - 8 - - emollient oil 2 2 10 10 Organic peroxide Dicumyl peroxide (Example 1) 2.1 2.1 - - activator ZnO 1.5 1.5 - - extender kaolin 41.4 41.4 80 colloidal diatomaceous earth 10 10 - - dolomitic - - - 70 Flame retardant decabromodiphenyl ether, - - - 30 SbzOa - - - 20

-713

HU 201104 Β

Mixture A and B had the following characteristics after vulcanization at 155 ° C for 30 minutes:

specific volumetric resistance: (Mohm.cm.) tensile strength (MPa) elongation at break (%) M1, dN.m Wallace plasticity

8x10® or lxl0 less than ⁶

8.2 or 7.7

280, respectively. 310 10

8.5 and 11.5 and 75 respectively.

Mixtures C and D were used as fillers because of their excellent extrudability, they could be processed on both plastic and rubber extruders.

Claims (1)

Patent Claim Point A thermoplastic or vulcanizable, granular insulating or semiconductor-based elastomer / plastomer-based composition, particularly for use in the cable industry, characterized in that 10-50 parts by weight of rubber, 5-50 parts by weight of polyolefin, 0-50 parts by weight of plasticizer, 0-5 parts by weight silane compound, 0 to 10 parts by weight of organic peroxide and 2 to 300 parts by weight of other additives known per se, and the polyolefin (1:10) to (10: 1) by weight is amorphous: crystalline type and the amorphous type is greater than 5x10 ³ g average numerical and atactic polypropylene having a weight average molecular weight greater than 8 x ^{10 1} , and the other carbon black used as an additive in the weight distribution of 1: (10-30) :( 1-30).