CN1996502A - Low-smoke halogen-free combustion-preventing cable insulation and jacket material for nuclear power plant - Google Patents

Abstract

This invention relates to one nuclear power station with low smoke without chimney cable insulation protection materials, which uses ethene-vinyl acetate polymer or silicon resin as base resin interfacing polyolefin, wherein, it uses aluminum hydroxide, magnesium hydrate, earth silicon or silicon resin as combustion inhibitor with aid of antiager, photographic sensitizer and process aid agent; the sensitizer is for cyanoacrylate, 1,1,1-trimethylolpropane methyl methacrylate, organic silicon resin, phenylene silica gel or formaldehyde-phenol resin; The aid process agent is for aliphatic acid salt and organic silicon.

Description

Used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material

Technical field

The present invention relates to a kind of used in nuclear power station 1E level K1 class cable.Especially relate to a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material.Belong to the cable technology field.

Background technology

Nuclear power has become the more and more countries common recognition as a kind of technology maturation, the clean energy resource that can utilize on a large scale, and particularly current oil price is high, fewer and feweri urgency and the importance that develops nuclear power of especially showing of available resources.The construction of nuclear power station be unable to do without supporting with it electric wire, particularly 1E level K1 class cable.

Because K1 class cable is to be used in the nuclear power plant containment shell; might be subjected to the effect of harsh and unforgiving environments factors such as high temperature, high-pressure water vapor and chemical agent and the radiation of high dose gamma-rays, so K1 class cable should still can keep its transfer function under the home condition or under earthquake and the accident condition He after the accident.Thereby in loss of fluid test, the high temperature that cable bore (reaching 160 ℃) high-vapor-pressure (reaching 0.56MPa) and high dose radiation (reaching 850kGy) are very harsh, use conventional material definitely through so harsh environmental condition of daring not accept, its result shows as the cable embrittlement, cracking even collapse lose conduction function fully.So, development K1 class cable, primary problem is to locate cable insulation and the protective cover material that is appropriate to environment in the nuclear power plant containment shell, and they must possess following four conditions:

1, is bittern-free flame-proof material, must has low cigarette (concentration), low toxicity, low-corrosiveness during burning.

2, the thermal ageing life desired value should be greater than 40 years, and have favorable mechanical physical property and electrical property.

3, ability gamma-ray irradiation.

4, good technology extrusion performance and cross-linking radiation performance are arranged.

Prior cable insulation and sheath all are to be base resin with the polyolefin with the halogen-free flameproof material, are fire retardant with the hydroxide hydrate, are equipped with other auxiliary agent and combine.Because the flame retarding efficiency of fire retardant is lower, in order to guarantee the anti-flammability of material, adds fire retardant in a large number, makes the mechanical performance of material and technology extrusion performance greatly worsen.

Summary of the invention

The objective of the invention is to overcome above-mentioned deficiency, a kind of high mechanical properties, long-life, radioresistance, used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material that extrusion performance is good are provided.

The object of the present invention is achieved like this: a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material, it is characterized in that: it is to be base resin with ethylene-vinyl acetate copolymer or silicones, inserting polyolefin graft polymerization thing strengthens, with aluminium hydroxide, magnesium hydroxide,hydrated SiO 2 or silicones is fire retardant, being equipped with age resistor, irradiation sensitizer and processing aid combines

Described age resistor adopts four-(3,5-di-tert-butyl-hydroxy phenyl propionic acid) pentaerythritol ester, 1,3,5 trimethyls-2,4,6-three (3, the 5-di-tert-butyl-4-hydroxyl benzyl) benzene or 4,4 ' thiobis (the 6-tert-butyl group-3-methylphenol) are main age resistor, select phosphorous acid-benzene dioctyl ester and three (2 simultaneously for use, the 4-di-tert-butyl-phenyl) phosphite ester is as auxiliary age resistor

Described irradiation sensitizer is a triallyl isocyanurate, 1,1,1-trimethylolpropene trimethyl acrylic ester, organic siliconresin, penylene silica gel or phenolic resins,

Described processing aid is soap and organosilicon,

The weight portion of each component is in described insulation and the protective cover material:

70 ~ 90 parts of base resins

10 ~ 30 parts of polyolefin graft polymerization things

90 ~ 150 parts of fire retardants

0.3 ~ 3 part in main age resistor

1 ~ 2 part in age resistor phosphorous acid-benzene dioctyl ester

1 ~ 2 part of age resistor three (2, the 4-di-tert-butyl-phenyl) phosphite ester

2 ~ 3 parts of irradiation sensitizers

1 ~ 2 part of soap

1 ~ 2 part of organosilicon polymer

Pigment is an amount of.

The amount of being fuming was little when the advantage of base resin ethylene-vinyl acetate copolymer (EVA) or silicones was burning, and toxicity is low, and the processing characteristics excellence, and material source is wide, and price is low.The ethylene-vinyl acetate copolymer resin trade mark requires as follows: vinyl acetate (VA) content: 15 ~ 28%, and melt index: 0.8 ~ 6.

In order to guarantee that material has higher mechanical strength, must strengthen the binding ability of resin and fire retardant, its approach is the polarity that increases base resin.At present feasible is to insert strong polar group such as ester group or amide groups.What the present invention adopted is polyolefin graft polymers, maleic anhydride grafted polyethylene for example, maleic anhydride grafted ethene-acetate ethylene copolymer, acid amide-grafted ethylene-vinyl acetate copolymer etc.Can improve the mechanical strength of material like this.

Because used in nuclear power station cable insulation and protective cover material require to have requirements such as low cigarette, Halogen, low toxicity, so fire retardant is selected aluminium hydroxide, magnesium hydroxide,hydrated SiO 2 or silicones for use.But the flame retarding efficiency of these several fire retardants is lower, and combine with base resin not firm.So when selection, must select for use surface treatment good, fineness reaches micron-sized powder.

Because the life expectancy of used in nuclear power station cable required greater than 40 years, its operational environment should be able to stand the effect of high-energy radiation, high temperature, high humidity, thus in other auxiliary agent preventing aging system determine it is core technology of the present invention.The present invention selects the Hinered phenols antioxidant of without pollution as main age resistor, selects for use two kinds of phosphite esters as auxiliary age resistor simultaneously, plays cooperative effect, adds these age resistor and can guarantee that the useful life of cable was greater than 40 years.

In order to reduce irradiation dose, improve the production efficiency of electric wire cross-linking radiation, should in material, add an amount of irradiation sensitizer, this based sensitisers belongs to multi-functional two key ester classes that contain.In addition, test shows, adds some and contain the radiation resistance that polymer phenyl ring, that contain siloxanes can improve compound greatly in prescription on strand.

Because the fire retardant of selecting for use among the present invention is hydroxide hydrate,hydrated SiO 2 or silicones, the amount of adding could satisfy the fire-retardant requirement of cables of nuclear power during only greater than base resin.But its result sharply increases the viscosity of formula mixture, finally causes to be difficult to extrude, or extrudes the material rough surface.Therefore must add suitable processing aid,, improve processing performance, increase gel quantity to reduce viscosity.Selected fatty acid salt of the present invention and organosilicon polymer are collaborative, to improve the extrusion performance of material.

By adopting above-mentioned measure, insulation of the present invention and protective cover material meet the high strength that K1 class cable uses (15＞MPa), long-life (40＞40 years), anti-high dose radiation, the requirement of extrusion performance good (can produce) with Universal screw rod.Following table is cable insulation of the present invention and protective cover material performance:

Performance				Standard-required	Insulation Material	Protective cover material	Inserts
								The prescription test piece	Tensile strength (Mpa)			(12.5 insulation) 11.0 (sheath)	17.7	16.5	9.0
Elongation at break (%)			170	254	240	60
							Heat ageing		Temperature * time		135℃×168h 120℃×168h	158× 168	158× 268
Tensile strength rate of change (%)		±25	-7	-9
						Elongation at break rate of change (%)			±25	-2	-5
Durometer A hardness			-	94	93								96
						Proportion (g/cm3)			-	1.40	1.40	1.60
Thermal deformation (%)			50	12	15
						Heat is extended	Maximum elongation rate (%) under the load		175	50	50
Cooling back maximum permanent elongation (%)		15	5	5
							ρ20(Ω.cm)			1.0×1012	3.5×1013	1.5×1013
Brittle temperature ℃				-60	-53
							Oxygen index (%)				38	37	44
Than smoke density Dm		Flame is arranged	200	43	50
							Nonflame	100	91	86
		PH value			≥4.3	5.2						5.4
Conductivity r (μ s/mm)							10	1	0.8
			Poison exponent			5					1	0.9
Halogen content (%)							0.5	0	0
			The finished cable test	Thermal life (year)							＞40	40.6	40.6
Insulation resistance constant K i							≥3.67	15.8
				Insulate heat is shunk (%)							≤4.0	1.5
Sheath thermal contraction (%)							≤4.0		0.5
				Ozone resistance test							Do not chap	Qualified	Qualified
Thermal ageing test							150℃×720h	By	By
				Irradiation test							950kGy	By	By
The LOGA test							By	By	By
				Low-temperature impact test							-15℃	By	By
Sheath scraped finish test							〉=30 times		1791
				The particular curve test							3500V/5min does not puncture	By	By

Description of drawings

Fig. 1 is a used in nuclear power station 1E level K1 class cable cross-section structural representation of the present invention.

Among the figure: tin-coated copper conductor 1, low cigarette, Halogen, flame retardant insulation (individual layer or bilayer) 2,band 3, fireproofglass ribbon layer 4, tinned copperwire woven shield 5, fireproofglass ribbon layer 6, band 7,oversheath 8, inserts 9.

Embodiment

The present invention is a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material, it is characterized in that: it is to be base resin with ethylene-vinyl acetate copolymer or silicones, inserting polyolefin graft polymerization thing strengthens, with aluminium hydroxide, magnesium hydroxide,hydrated SiO 2 or silicones is fire retardant, be equipped with age resistor, irradiation sensitizer and processing aid through mixing processing, granulation, extrude and cross moulding.The described ethylene-vinyl acetate copolymer resin trade mark is as follows: vinyl acetate content: 15 ~ 28%, and melt index: 0.8 ~ 6.Fire retardant is micron-sized powder.

Embodiment 1:

Step 1, batching and high-speed mixing

Get ethylene-vinyl acetate copolymer 70kg, maleic anhydride grafted polyethylene 30kg, aluminium hydroxide 90kg, four-(3,5-di-tert-butyl-hydroxy phenyl propionic acid) pentaerythritol ester 3kg, phosphorous acid-benzene dioctyl ester 1kg, three (2, the 4-di-tert-butyl-phenyl) phosphite ester 2kg, triallyl isocyanurate 2kg, dolomol, zinc stearate or calcium stearate 2kg, dimethicone 1kg and pigment are an amount of, place in the high speed agitator, high-speed mixing is mixed with compound.

Step 2, extrusion plasticizing granulation

Step 1 is got compound place the granulation of parallel dual-screw extrusion plasticizing.

Step 3,step 2 is got pellet be extruded into cable with other material.

Step 4,step 3 is got cable carry out the electron ray cross-linking radiation and get used in nuclear power station 1E level K1 class cable.

Embodiment 2: the difference of present embodiment and embodiment 1 only is the batching of step 1, and all the other are all with embodiment 1.

Step 1, batching and high-speed mixing

Get silicones 90kg, maleic anhydride grafted ethene-acetate ethylene copolymer 10kg, magnesium hydroxide 150kg, 1,3,5 trimethyls-2,4,6-three (3, the 5-di-tert-butyl-4-hydroxyl benzyl) benzene 0.3kg, phosphorous acid-benzene dioctyl ester 2kg, three (2, the 4-di-tert-butyl-phenyl) phosphite ester 3kg, 1,1,1-trimethylolpropene trimethyl acrylic ester, organic siliconresin, penylene silica gel or phenolic resins 3kg, dolomol 1kg, hydroxy silicon oil 2kg and pigment are an amount of, place in the high speed agitator, high-speed mixing is mixed with compound.

Embodiment 3: the difference of present embodiment and embodiment 1 only is the batching of step 1, and all the other are all with embodiment 1.

Step 1, batching and high-speed mixing

Get silicones 80kg, acid amide-grafted ethylene-vinyl acetate copolymer 20kg,hydrated SiO 2 120kg, 4,4 ' thiobis (the 6-tert-butyl group-3-methylphenol) 1kg, phosphorous acid-benzene dioctyl ester 1.5, three (2, the 4-di-tert-butyl-phenyl) phosphite ester 1.5kg, 1,1,1-trimethylolpropene trimethyl acrylic ester 2.5kg, zinc stearate 1.5kg, hydroxy silicon oil 1.5kg and pigment are an amount of, place in the high speed agitator, high-speed mixing is mixed with compound.

Claims (5)

1, a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material, it is characterized in that: it is to be base resin with ethylene-vinyl acetate copolymer or silicones, inserting polyolefin graft polymerization thing strengthens, with aluminium hydroxide, magnesium hydroxide, hydrated SiO 2 or silicones is fire retardant, being equipped with age resistor, irradiation sensitizer and processing aid combines

Described age resistor adopts four-(3,5-di-tert-butyl-hydroxy phenyl propionic acid) pentaerythritol ester, 1,3,5 trimethyls-2,4,6-three (3, the 5-di-tert-butyl-4-hydroxyl benzyl) benzene or 4,4 ' thiobis (the 6-tert-butyl group-3-methylphenol) are main age resistor, select phosphorous acid-benzene dioctyl ester and three (2 simultaneously for use, the 4-di-tert-butyl-phenyl) phosphite ester is as auxiliary age resistor

Described irradiation sensitizer is a triallyl isocyanurate, 1,1,1-trimethylolpropene trimethyl acrylic ester, organic siliconresin, penylene silica gel or phenolic resins,

Described processing aid is soap and organosilicon,

The weight portion of each component is in insulation and the protective cover material:

70 ~ 90 parts of base resins

10 ~ 30 parts of polyolefin graft polymerization things

90 ~ 150 parts of fire retardants

0.3 ~ 3 part in main age resistor

1 ~ 2 part in age resistor phosphorous acid-benzene dioctyl ester

1 ~ 2 part of age resistor three (2, the 4-di-tert-butyl-phenyl) phosphite ester

2 ~ 3 parts of irradiation sensitizers

1 ~ 2 part of soap

1 ~ 2 part of organosilicon polymer

Pigment is an amount of.

2, a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation according to claim 1 and 2 and protective cover material is characterized in that: described polyolefin graft polymers is maleic anhydride grafted polyethylene, maleic anhydride grafted ethene-acetate ethylene copolymer or acid amide-grafted ethylene-vinyl acetate copolymer.

3, a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation according to claim 1 and 2 and protective cover material, it is characterized in that: described soap is dolomol, zinc stearate or calcium stearate; Organosilicon polymer is dimethicone or hydroxy silicon oil.

4, a kind of according to claim 1 or 5 used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation and protective cover material is characterized in that: the described ethylene-vinyl acetate copolymer resin trade mark is as follows: vinyl acetate content: 15 ~ 28%, and melt index: 0.8 ~ 6.

5, a kind of used in nuclear power station low-smoke halogen-free combustion-preventing cable insulation according to claim 1 and 2 and protective cover material, it is characterized in that: described fire retardant is micron-sized powder.

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