CN103554634B - A kind of High-voltage cable structure with the insulation layer of excellent performance - Google Patents

Abstract

The invention provides a kind of High-voltage cable structure with the insulation layer of excellent performance, High-voltage cable structure by core conductor and be coated on the semiconduction internal shield of conductor periphery from inside to outside successively, insulation layer, semiconduction external shielding layer form.Its insulation layer has following composition: with parts by weight, base-material 100 parts, mineral filler one 20-30 part, mineral filler two 5-10 part, carbon black 0.5-1.5 part, silane coupling agent 3-5 part, antioxidant 3-5 part, linking agent 1-3 part, crosslinking coagent 0.2-0.5 part, stripper 0-2 part.

Description

A kind of High-voltage cable structure with the insulation layer of excellent performance

Technical field

The present invention relates to technical field of composite materials, a kind of High-voltage cable structure with the insulation layer of excellent performance is particularly provided.

Background technology

Wires and cables industry is electric power and the important supporting industry of the two large pillar industries in national economy that communicate, extremely important status is had in national economy, wherein industry production total amount accounts for 4 ‰ to 5 ‰ of the total GDP in the whole nation, electric wire product plays the vital role of the conveying energy, transmission of information, is national economy " blood vessel " and " nerve ".

Electric wire is normally formed at conductor core wire outer cladding insulation layer, and polyvinyl chloride is simple with its manufacture technics, stable performance, lay conveniently, be not subject to the advantages such as the restriction of high low head to be widely used in the insulating material of electric wire always, but along with people's environmental consciousness ground constantly strengthens, restriction for content of halogen in material is day by day harsh, in addition the dielectric loss that polyvinyl chloride electrical wire and cable is intrinsic is large, working temperature is low, the high not shortcomings of voltage withstand class, its gradually replace by emerging, that performance is more excellent crosslinked polyolefin materials.

But as not halogen-containing crosslinked polyolefin materials, for meeting the needs of cable insulation flame retardant properties, often to add the metal hydroxides such as magnesium hydroxide, aluminium hydroxide in polyolefine, but the flame retardant effect adding metal hydroxides generation is on the one hand less, often can not get required flame retardant resistance, on the other hand, with the addition for improving the not ever-increasing metal hydroxides of flame retardant properties, mechanical property and the resistance toheat etc. such as unit elongation, tensile strength of crosslinked polyolefin materials all can reduce significantly.

Moreover, the limitation of cross-linked polyolefin is also because the impurity such as linking agent residue decomposition in its system, micropore or the defect such as uneven exist, it often produces shrub shape defect under the effect of water or highfield, also namely the so-called water shadow of the trees rings, thus cause disruptive strength to reduce, and finally cause electrical accident.

Therefore, develop and a kind ofly there is excellent fire-retardant blocking water there is the novel cable insulation crosslinked polyolefin materials of excellent stable heat, mechanical property simultaneously, there is important Research Significance and application prospect widely.

Summary of the invention

Object of the present invention be namely to provide a kind of have excellent fire-retardant block water have simultaneously excellent stable heat, mechanical property novel cable insulation crosslinked polyolefin materials formula and by its obtained High-voltage cable structure.

Medium and high voltage cable structure of the present invention by core conductor and be coated on the semiconduction internal shield of conductor periphery from inside to outside successively, insulation layer, semiconduction external shielding layer form.

The formula of the cable insulation crosslinked polyolefin materials in the present invention is as follows: with parts by weight, base-material 100 parts, mineral filler one 20-30 part, mineral filler two 5-10 part, carbon black 0.5-1.5 part, silane coupling agent 3-5 part, antioxidant 3-5 part, linking agent 1-3 part, crosslinking coagent 0.2-0.5 part, stripper 0-2 part.

Described base-material is mixed by polyethylene, polypropylene and vinyl-vinyl acetate copolymer, wherein the weight percent of vinyl-vinyl acetate copolymer is 50-55%, polyacrylic weight percent is 15-20%, and in described vinyl-vinyl acetate copolymer, the content of vinyl-acetic ester is 45-50%;

Described mineral filler one is sintering kaolin, and median size is 1-2 μm;

Described mineral filler two is four acicular type zinc oxide crystal whisker, and whisker is long 5-10 μm on average;

The carbon content of described carbon black is at least 98%, and median size is 50-100nm, and maximum particle diameter is less than 250nm, and DBP is 100-150cc/100g;

Described silane coupling agent is vinyl three ('beta '-methoxy oxyethyl group) silane;

Described antioxidant is four-[3-(3,5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol esters and poly-two (2-methyl-4-hydroxyl-5-tert.-butylbenzene) thioether, and the mass ratio of the two is 1:1;

Described linking agent is dicumyl peroxide;

Described crosslinking coagent is cyanacrylate;

Described stripper is silicone adhesive.

The reasonable design of the present invention formula of cable insulation crosslinked polyolefin materials, by coordinative role and the content proportioning the most suitable of each component, obtain and there is fire-retardant blocking water there is the novel cable insulation material of excellent stable heat, mechanical property simultaneously, and be applied to High-voltage cable structure.

Embodiment

Embodiment 1.

Undertaken preparing burden by each component proportion (wherein base-material meets summation is 100 weight parts) given by table 1 and each raw material is all dried to 100 DEG C for subsequent use; Then by the order of polypropylene (A), ethane-acetic acid ethyenyl ester (B), polyethylene, carbon black (C), mineral filler one (D), mineral filler two (E), silane coupling agent (F), antioxidant (G), stripper (H), each raw material priority is added Banbury mixer and carry out melting mixing, mixing temperature is 200-220 DEG C, and mixing time is 15-20min; Through twin screw extruder extruding pelletization after mixing discharging, described screw diameter is 32mm, and length-to-diameter ratio is 42; Enter high-speed kneading machine after granulation and spray linking agent (I) and crosslinking coagent (J) high-speed mixing, and control temperature is at 140-160 DEG C, after mixing 10-15min, cooling obtains product.In wherein said vinyl-vinyl acetate copolymer, the content of vinyl-acetic ester is 48%.

Embodiment 2-3 and comparative example 1#-9# place formula as shown in table 1 outside, preparation method is all identical with embodiment 1.

Table 1

The performance parameter test of each embodiment is listed in table 2, and wherein volume specific resistance is measured respectively under 23 DEG C and 90 DEG C of two temperature, and peeling force is measured respectively under 25 DEG C and 50 DEG C of two temperature.As shown in Table 2:

The problem that polypropylene makes up on the one hand flexibility that vinyl-vinyl acetate copolymer causes in system, thermotolerance is deteriorated, also play the effect of resistant to damage, heat distortion on the other hand simultaneously, for playing above-mentioned function, the ratio of polypropylene in base-material at least should reach 15%; But too much polypropylene addition is as caused the deficiency of system mobility and bridging property more than 20%, also can reduce the flexibility, elongation, heat-resistant aging etc. of system simultaneously.

Vinyl-vinyl acetate copolymer can play fire retardation well in system, in order to reach required flame-retardancy requirements, the content of ethane-acetic acid ethyenyl ester in base-material should reach 50%, but too much interpolation can cause the flexibility of system, intensity and thermotolerance all wretched insufficiencies.In vinyl-vinyl acetate copolymer, the content range of vinyl-acetic ester should between 45-50%, still be difficult to meet fire-retardant needs even if very few content can cause with the addition of enough vinyl-vinyl acetate copolymers, but too much content then can cause too poor with the affinity of other components of base-material and affect the bridging property of system and follow-up mechanical property.

The mineral filler of sintering kaolin has material impact for the fire-retardant of material and block-water performance, select the kaolin through oversintering, its block-water performance is especially excellent, the interpolation of mineral filler simultaneously also serves the effect improving intensity to a great extent, in order to reach the interpolation effect of this mineral filler, its addition at least should be 20 weight parts, but too much addition is deteriorated as can be caused the mobility of system more than 30%, thus causing the deterioration of the properties such as Tensile strength, heat aging, flexibility, block-water performance also declines to some extent simultaneously.It should be noted that the silane coupling agent of sintering kaolin preferably and in system of the present invention is collaborative to use, effectively can improve its dispersiveness like this, thus strengthen its result of use.Sinter kaolinic particle diameter to be 1-2 μm there is good dispersiveness, and good strengthening effect.

Four acicular type zinc oxide crystal whisker mineral filler improves the effect of intensity except playing, mainly also can there is collaborative flame retardant effect with antioxidant at it, excellent flame retardant properties can be had equally when not adding a large amount of metal hydroxide combustion inhibitor, in addition it also has the effect of raising system thermostability, for playing its effectiveness, its addition at least should reach 5 weight parts, but too much interpolation then may cause the decline of the performances such as tensile strength.The whisker on average long 5-10 μm of four acicular type zinc oxide crystal whisker, this is conducive to it and plays the effect improving intensity.

The effect of carbon black is mainly that it effectively can suppress the space charge occurred under the effect of water or highfield, thus effectively solve the sharply destruction of material electrical property, for playing above-mentioned effect, the addition of carbon black at least should reach 0.5 weight part, but too much interpolation is then obviously unfavorable for the needs of insulating material integrated electronic performance.The carbon content of carbon black at least should reach 98%, otherwise can because containing more O ₂, H ₂, ash to grade impurity, and becomes the defect source causing space charge to occur, is unfavorable for the improvement of material property on the contrary.For playing better effect, it is 50-100nm that the particle diameter of carbon black and DBP meet median size, and maximum particle diameter is less than 250nm, and DBP is that 100-150cc/100g is more suitable.

Silane coupling agent vinyl three ('beta '-methoxy oxyethyl group) silane serves obvious dispersed inorganic filler and block-water effect in system, for playing above-mentioned effect, silane coupling agent should at least add 3 weight parts, but its excessive interpolation can make the unit elongation of material and heat aging property decline, and therefore its content should not more than 5 weight parts.

Antioxidant four-[3-(3,5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester and poly-two (2-methyl-4-hydroxyl-5-tert.-butylbenzene) thioether be that selecting of 1:1 mainly considers that it can play cooperative flame retardant effect well with four acicular type zinc oxide crystal whisker, and certain prevent the effect extruding precrosslink, in order to play this effect, its content at least should be 3 weight parts, when more than 5 weight part, flame retardant effect does not increase significantly, and seriously may suppress follow-up being cross-linked simultaneously.

Linking agent is obviously important for the interpolation of cross-linked polyolefin, but as known, its residue decomposition can become the defect source that space charge produces, therefore its content is unsuitable too high, but in order to being cross-linked of guarantee system, with the addition of necessary crosslinking coagent cyanacrylate in system of the present invention, thus can rationally solve the problem.

In order to improve the stripping performance of insulation layer and inside and outside screen layer etc., a certain amount of silicone adhesive effect stripper can be added in system, but its content more than 2%, otherwise can not can reduce plasticity, the mechanical property of material.

Table 2

* I, the condition of immersion is 50 DEG C × 100 days; II, the condition of heat aging is 125 DEG C × 7 days

For formula system of the present invention, according to the order of polypropylene, ethane-acetic acid ethyenyl ester, polyethylene, carbon black, mineral filler one, mineral filler two, silane coupling agent, antioxidant, stripper, each raw material priority is added Banbury mixer as far as possible and carry out melting mixing, mixing more even to make, fully mixing for ensureing, mixing temperature is 200-220 DEG C, and mixing time is 15-20min; Through twin screw extruder extruding pelletization after mixing discharging, described screw diameter is 32mm, and length-to-diameter ratio is 42, extrudes effect with what ensure material; Enter high-speed kneading machine after granulation and spray linking agent (I) and crosslinking coagent (J) high-speed mixing, and control temperature is at 140-160 DEG C, after mixing 10-15min, cooling obtains product, to ensure crosslink material degree.Through the formula of the present invention's design, be aided with described preparation technology parameter, can obtain and there is fire-retardant blocking water there is the novel cable insulation material of excellent stable heat, mechanical property simultaneously.

By the cable insulation material in the present invention by coextrusion processes, prepare by the conductor of core and be coated on the semiconduction internal shield of conductor periphery from inside to outside successively, High-voltage cable structure that insulation layer, semiconduction external shielding layer are formed.

Claims (1)

1. there is a High-voltage cable structure for the insulation layer of excellent performance, described High-voltage cable structure by core conductor and be coated on the semiconduction internal shield of conductor periphery from inside to outside successively, insulation layer, semiconduction external shielding layer form,

It is characterized in that the insulation layer of described excellent performance has following composition: with parts by weight, base-material 100 parts, mineral filler one 25 parts, mineral filler 27 parts, carbon black 0.5-1.5 part, silane coupling agent 3-5 part, antioxidant 3-5 part, linking agent 1-3 part, crosslinking coagent 0.2-0.5 part, stripper 1 part;

Described base-material is mixed by polyethylene, polypropylene and vinyl-vinyl acetate copolymer, wherein the weight percent of vinyl-vinyl acetate copolymer is 50-55%, polyacrylic weight percent is 15-20%, and in described vinyl-vinyl acetate copolymer, the content of vinyl-acetic ester is 45-50%;

Described mineral filler one is sintering kaolin, and median size is 1-2 μm;

Described mineral filler two is four acicular type zinc oxide crystal whisker, and whisker is long 5-10 μm on average;

The carbon content of described carbon black is at least 98%, and median size is 50-100nm, and maximum particle diameter is less than 250nm, and DBP is 100-150cc/100g;

Described silane coupling agent is vinyl three ('beta '-methoxy oxyethyl group) silane;

Described antioxidant is four-[3-(3,5-di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol esters and poly-two (2-methyl-4-hydroxyl-5-tert.-butylbenzene) thioether, and the mass ratio of the two is 1:1;

Described linking agent is dicumyl peroxide;

Described crosslinking coagent is cyanacrylate;

Described stripper is silicone adhesive.