CN103524853A - Formula of cable insulation material excellent in performance - Google Patents

Abstract

The invention provides a formula of a cable insulation material excellent in performance. The cable insulation material is characterized by consisting of the following materials in parts by weight: 100 parts of a base stock, 20-30 parts of an inorganic filler I, 5-10 parts of an inorganic filler II, 0.5-1.5 parts of carbon black, 3-5 parts of a silane coupling agent, 3-5 parts of an antioxidant, 1-3 parts of a cross-linking agent, 0.2-0.5 part of cross-linking auxiliaries and 0-2 parts of a stripping agent. Through coordination of various components as well as the most appropriate content proportion, the external semi-conductive shielding material produces the novel flame-retardant and water-resistant cable insulation material which is excellent and stable in thermal and mechanical performance.

Description

The formula of material for a kind of cable insulation of excellent performance

Technical field

The present invention relates to technical field of composite materials, the formula of a kind of cable insulation of excellent performance with material is particularly provided.

Background technology

Wires and cables industry is the important supporting industry of electric power and the two large pillar industries in national economy of communicating by letter, in national economy, there is extremely important status, 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 carrying the energy, transmission of information, is " blood vessel " and " nerve " of national economy.

Electric wire normally forms at conductor core wire outer cladding insulation layer, and polyvinyl chloride is simple with its technique manufacture, stable performance, lay conveniently, be not subject to the advantages such as 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 intrinsic dielectric loss of polyvinyl chloride electrical wire and cable is large, working temperature is low, the high not shortcomings of voltage withstand class, and it is replaced by cross-linked polyolefin material emerging, that performance is more excellent gradually.

Yet as not halogen-containing cross-linked polyolefin material, for meeting the needs of cable insulation flame retardant properties, often in polyolefine, add the metal hydroxidess such as magnesium hydroxide, aluminium hydroxide, but the flame retardant effect that adds on the one hand metal hydroxides generation is less, often can not get desired flame retardant resistance, on the other hand, follow as improving the not addition of ever-increasing metal hydroxides of flame retardant properties, the mechanical propertys such as the unit elongation of cross-linked polyolefin material, tensile strength and resistance toheat etc. all can reduce significantly.

Moreover, the limitation of cross-linked polyolefin is also to exist due to the impurity such as linking agent residue decomposition in its system, micropore or the defect such as inhomogeneous, it tends to produce shrub shape defect under the effect of water or highfield, also be that the so-called water shadow of the trees rings, thereby cause disruptive strength to reduce, and finally cause electrical accident.

Therefore, develop and a kind ofly there is the excellent fire-retardant novel cable insulation simultaneously with excellent stable heat, mechanical property that blocks water and use cross-linked polyolefin material, there is important Research Significance and application prospect widely.

Summary of the invention

Object of the present invention is to provide a kind of fire-retardant blocking water with excellence to have the novel cable insulation cross-linked polyolefin material prescription of excellent stable heat, mechanical property simultaneously.

Cable insulation in the present invention is as follows with the formula of cross-linked polyolefin material: in weight part, 100 parts of base-materials, mineral filler one 20-30 part, mineral filler two 5-10 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 0-2 part.

Described base-material is mixed by polyethylene, polypropylene and vinyl-vinyl acetate copolymer, the weight percent of therein ethylene-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 μ m;

Described mineral filler two is four acicular type zinc oxide crystal whisker, and whisker is long 5-10 μ m 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.

Further preferred, described sintering kaolin is 25 weight parts;

Further preferred, described four acicular type zinc oxide crystal whisker is 7 weight parts

Further preferred, described carbon black is 1 weight part;

Further preferred, described silane coupling agent is 4 weight parts;

Further preferred, described antioxidant is 4 weight parts;

Further preferred, described dicumyl peroxide is 2 weight parts;

Further preferred, described cyanacrylate is 0.4 weight part.

Reasonable design of the present invention the formula of cable insulation with cross-linked polyolefin material, by the coordinative role of each component and the most suitable content proportioning, obtained and there is fire-retardant blocking water and there is excellent stable heat, the novel cable insulation material of mechanical property simultaneously.

Embodiment

Embodiment 1.

By each given component proportion of table 1 (wherein base-material meet summation be 100 weight parts) prepare burden and by each raw material all dry to 100 ℃ standby; 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), successively add Banbury mixer to carry out melting mixing each raw material, mixing temperature is 200-220 ℃, and mixing time is 15-20min; After mixing discharging, through twin screw extruder extruding pelletization, described screw diameter is 32mm, and length-to-diameter ratio is 42; After granulation, enter high-speed kneading machine and spray linking agent (I) and crosslinking coagent (J) high-speed mixing, and control temperature at 140-160 ℃, the cooling product that obtains after mixing 10-15min.In wherein said vinyl-vinyl acetate copolymer, the content of vinyl-acetic ester is 48%.

Outside embodiment 2-3 and comparative example 1#-9# place formula are as shown in table 1, 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 at 23 ℃ and 90 ℃ of two temperature, and peeling force is measured respectively at 25 ℃ and 50 ℃ of two temperature.As shown in Table 2:

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

Vinyl-vinyl acetate copolymer can be brought into play well fire retardation in system, in order to reach required fire-retardant requirement, the content of ethane-acetic acid ethyenyl ester in base-material should reach 50%, but flexibility, intensity and thermotolerance that too much interpolation can cause system wretched insufficiency all.In vinyl-vinyl acetate copolymer, the content range of vinyl-acetic ester should be between 45-50%, even if very few content can cause having added enough vinyl-vinyl acetate copolymers and still be difficult to meet fire-retardant needs, but too much content can cause affinity with other components of base-material too poor 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 and block-water performance of material, select the kaolin through oversintering, its block-water performance is especially excellent, the high-intensity effect of proposing has also been played in the interpolation of mineral filler simultaneously 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 as surpassed 30% mobility variation that can cause system, thereby cause 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 collaborative use of the silane coupling agent of sintering kaolin preferably and in system of the present invention, can effectively improve its dispersiveness like this, thereby strengthen its result of use.The kaolinic particle diameter of sintering is that 1-2 μ m has good dispersiveness, and good strengthening effect.

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

The effect of carbon black is mainly that it can effectively be suppressed at the space charge occurring under the effect of water or highfield, thereby effectively solve the sharply destruction of material electrical property, for bringing into play above-mentioned effect, the addition of carbon black at least should reach 0.5 weight part, but too much interpolation is obviously unfavorable for the needs of insulating material integrated electronic performance.The carbon content of carbon black should at least reach 98%, otherwise can be because contain more O₂, H₂, the ash impurity that grades, and become the defect source that causes space charge to occur, be unfavorable on the contrary the improvement of material property.For bringing into play 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 has played obvious dispersion mineral filler and block-water effect in system, for bringing into play 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, so its content should not surpass 5 weight parts.

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

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

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

Table 2

* the condition of I, immersion is 50 ℃ * 100 days; The condition of II, heat aging is 125 ℃ * 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, successively add Banbury mixer to carry out melting mixing each raw material as far as possible, so that mixing more even, mixing abundant for guaranteeing, mixing temperature is 200-220 ℃, and mixing time is 15-20min; After mixing discharging, through twin screw extruder extruding pelletization, described screw diameter is 32mm, and length-to-diameter ratio is 42, to guarantee the effect of extruding of material; After granulation, enter high-speed kneading machine and spray linking agent (I) and crosslinking coagent (J) high-speed mixing, and control temperature at 140-160 ℃, the cooling product that obtains after mixing 10-15min, to guarantee material degree of crosslinking.Through the formula of the present invention design, be aided with described preparation technology parameter, can obtain and there is fire-retardant blocking water and there is excellent stable heat, the novel cable insulation material of mechanical property simultaneously.

Claims (8)

1. the cable insulation material prescription of an excellent performance, it is characterized in that having following composition: in weight part, 100 parts of base-materials, mineral filler one 20-30 part, mineral filler two 5-10 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 0-2 part.

Described base-material is mixed by polyethylene, polypropylene and vinyl-vinyl acetate copolymer, the weight percent of therein ethylene-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 μ m;

Described mineral filler two is four acicular type zinc oxide crystal whisker, and whisker is long 5-10 μ m 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.

2. formula according to claim 1, is characterized in that: described sintering kaolin is 25 weight parts.

3. formula according to claim 1, is characterized in that: described four acicular type zinc oxide crystal whisker is 7 weight parts.

4. formula according to claim 1, is characterized in that: described carbon black is 1 weight part.

5. formula according to claim 1, is characterized in that: described silane coupling agent is 4 weight parts.

6. formula according to claim 1, is characterized in that: described antioxidant is 4 weight parts.

7. formula according to claim 1, is characterized in that: described dicumyl peroxide is 2 weight parts.

8. formula according to claim 1, is characterized in that: described cyanacrylate is 0.4 weight part.