阅读说明：本技术 一种核电站电缆用热塑性耐辐射无卤低烟阻燃护套料 (Thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for nuclear power station cable ) 是由 周才辉 周巍 卢金俊 贾少晋 李国锋 于 2019-11-08 设计创作，主要内容包括：本发明涉及一种核电站电缆用热塑性耐辐射无卤低烟阻燃护套料,属于新型电缆材料技术领域。为了解决现有的护套料无法需足大尺寸时的材料性能要求,提供一种核电站电缆用热塑性耐辐射无卤低烟阻燃护套料包括以下重量份的基料：100,基料至少含有耐高温聚烯烃弹性体；耐高温耐辐射改性母粒：30～40,至少含有缩合多环多核芳烃树脂和耐高温耐辐照树脂；阻燃剂：100～200,至少含有氢氧化铝；抗氧剂：4.0～12,至少含有不对称受阻酚型杯芳烃作为主抗氧剂；抗辐照剂：1.0～12。本发明能够形成协同作用,能够达到90℃/60年的热寿命和耐辐射性能要求,其护层具有均匀性,适用于大口径厚护套层的电缆料,兼具高阻燃性能。(The invention relates to a thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for a nuclear power station cable, belonging to the technical field of novel cable materials. In order to solve the problem that the existing sheath material cannot meet the material performance requirement when the material is large enough, the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable comprises the following base materials in parts by weight: 100, the base material at least contains high-temperature-resistant polyolefin elastomer; high-temperature-resistant radiation-resistant modified master batch: 30-40 parts of condensed polycyclic polynuclear aromatic hydrocarbon resin and high-temperature-resistant and irradiation-resistant resin; flame retardant: 100 to 200 parts by weight of a composition containing at least aluminum hydroxide; antioxidant: 4.0-12, and at least contains asymmetric hindered phenol calixarene as a main antioxidant; an anti-irradiation agent: 1.0 to 12. The invention can form a synergistic effect, can meet the requirements of thermal life and radiation resistance of 90 ℃/60 years, has uniform protective layer, is suitable for cable materials with large-caliber thick sheath layers, and has high flame retardant property.)

1. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable is characterized by comprising the following components in parts by weight:

base material: 100, the base material at least contains high-temperature-resistant polyolefin elastomer;

high-temperature-resistant radiation-resistant modified master batch: 30-40, wherein the high-temperature-resistant and radiation-resistant modified master batch at least contains condensed polycyclic polynuclear aromatic hydrocarbon resin and high-temperature-resistant and radiation-resistant resin;

flame retardant: 100-200, wherein the flame retardant at least contains aluminum hydroxide;

antioxidant: 4.0-12, wherein the antioxidant at least contains asymmetric hindered phenol calixarene as a main antioxidant;

an anti-irradiation agent: 1.0 to 12.

2. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power plant cable according to claim 1, wherein the asymmetric hindered phenol type calixarene is selected from asymmetric hindered phenol type calix [4] arene and/or asymmetric hindered phenol type calix [6] arene.

3. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the cable of the nuclear power station as claimed in claim 1, wherein the high-temperature-resistant polyolefin elastomer is one or more selected from a high-temperature-resistant polyolefin elastomer NOTIO PN-3560, a high-temperature-resistant polyolefin elastomer NOTIO PN-2070 and a high-temperature-resistant polyolefin elastomer NOTIO PN-2060.

4. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable according to claim 1, wherein the antioxidant further comprises phosphite ester auxiliary antioxidant, and the weight ratio of the asymmetric hindered phenol calixarene to the phosphite ester auxiliary antioxidant is 1.0: 0.1 to 0.5.

5. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power plant cable according to claim 3, wherein the base material further comprises an ethylene-methyl methacrylate copolymer and an ethylene-vinyl acetate copolymer, and the base material comprises the following components in parts by weight:

high temperature resistant polyolefin elastomer NOTIO PN-3560: 10;

ethylene-methyl methacrylate copolymer: 1.0 to 2.0;

ethylene-vinyl acetate copolymer: 1.0 to 2.0.

6. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable according to any one of claims 1 to 5, wherein the high-temperature-resistant radiation-resistant modified master batch comprises the following components in parts by weight:

high-temperature resistant and irradiation resistant resin: 30-50, wherein the high-temperature-resistant and radiation-resistant resin is one or more selected from polyether sulfone micro powder, polyphenylene sulfone micro powder, ferrocene and polyphenylene oxide micro powder;

condensed polycyclic polynuclear aromatic hydrocarbon resin: 5.0 to 15;

styrene-ethylene-butylene-styrene block copolymer: 30-50;

ethylene-methyl methacrylate copolymer: 5.0 to 10.

7. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the cables of the nuclear power plants as claimed in any one of claims 1 to 5, wherein the flame retardant further comprises one or more of kaolin, calcium carbonate, magnesium hydroxide and zinc borate.

8. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the cables of the nuclear power plants as claimed in any one of claims 1 to 5, wherein the radiation-resistant agent is selected from one or more of ferrocene, 2-amino-5- (p-methoxyphenyl) -1, 3, 4-thiadiazolidinium complex and 6-benzylaminopurine copper complex.

9. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power plant cable according to claim 8, wherein the radiation-resistant agent comprises the following components in parts by weight:

2-amino-5- (p-methoxyphenyl) -1, 3, 4-thiadiazole lanthanum complex: 1.0 to 2.0; ferrocene: 1.0 to 1.2; 6-benzylaminopurine copper complex: 0.5 to 1.0.

10. The thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power plant cable according to any one of claims 1 to 5, characterized by further comprising 0.5 to 8.0 parts by weight of a mildew preventive.

Technical Field

The invention relates to a thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for a nuclear power station cable, belonging to the technical field of novel cable materials.

Background

The cable sheath material for nuclear power stations is required to have excellent electrical performance, radiation resistance, halogen-free low-smoke low-toxicity and good flame-retardant performance, and most of the existing cable sheath materials for nuclear power stations are formed into thermosetting materials through crosslinking, so that the heat resistance can meet the use requirements of cables for nuclear power stations. However, these products are only suitable for general-caliber sheath materials, and for large-caliber thick-sheath cables, if a crosslinking method is adopted, the potential risk of cracking is generated due to nonuniform crosslinking degree of the sheath. The high heat-resistant and radiation-resistant cable sheath material disclosed in the Chinese patent (No. CN105694192B) applied by the applicant earlier comprises 100 parts by weight of a base material, 30-40 parts by weight of a high temperature-resistant and radiation-resistant resin modified master batch, 1.0-15 parts by weight of an inorganic flame retardant and 1.0-10 parts by weight of a crosslinking sensitizer, wherein the base material at least contains an ethylene-methyl methacrylate copolymer and/or an ethylene-ethyl acetate copolymer, and the flame retardant at least contains aluminum hydroxide. The sheath material has good heat resistance, high radiation resistance, long heat life and high radiation resistance⁶⁰The performance of the Co-gamma ray cumulative dose can meet the requirements of cables of third-generation nuclear power stations.

However, in the above patent documents, thermosetting polymer composite materials have been obtained by crosslinking polymer composite materials to form a three-dimensional network structure by irradiation of an induced radical. The method can greatly improve the heat resistance of the material, but for cables with larger outer diameter or thicker extrusion layers, the irradiation may cause uneven crosslinking degree of the sheath polymer composite material, and the cable sheath is easy to crack under the long-term stress condition. If the crosslinking is carried out by electron beam irradiation, electron residues can be generated, which can reduce the insulating property of the material, so that the irradiation crosslinking process is not suitable for the cable.

At present, the thermoplastic halogen-free low-smoke flame-retardant polyolefin cable sheath material does not need to be crosslinked after being extruded, but the long-term working temperature of the thermoplastic halogen-free low-smoke flame-retardant polyolefin cable sheath material is generally not more than 90 ℃, the thermal life of the thermoplastic halogen-free low-smoke flame-retardant polyolefin cable sheath material cannot reach 90 ℃/60 years, and the thermoplastic halogen-free low-smoke flame-retardant polyolefin cable sheath.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for a nuclear power station cable, and solves the problem of how to realize the halogen-free flame-retardant sheath material suitable for a large-section thick-sheath cable, and the sheath material still has high heat service life and radiation resistance without crosslinking.

The invention aims to realize the following technical scheme that the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable comprises the following components in parts by weight:

base material: 100, the base material at least contains high-temperature-resistant polyolefin elastomer;

high-temperature-resistant radiation-resistant modified master batch: 30-40, wherein the high-temperature-resistant and radiation-resistant modified master batch at least contains condensed polycyclic polynuclear aromatic hydrocarbon resin and high-temperature-resistant and radiation-resistant resin;

flame retardant: 100-200, wherein the flame retardant at least contains aluminum hydroxide;

antioxidant: 4.0-12, wherein the antioxidant at least contains asymmetric hindered phenol calixarene as a main antioxidant;

an anti-irradiation agent: 1.0 to 12.

The base material contains the high-temperature-resistant polyolefin elastomer material, so that the base material has good compatibility with various resins, elastomers and flame retardants in the material and is used as the base material, thereby being beneficial to improving the thermal life of the material; meanwhile, the asymmetric hindered phenol calixarene antioxidant is selectively added, the activity is obviously enhanced by considering that hydroxyl in the molecular structure is subjected to the electron repelling action of ortho-tertiary butyl, active hydrogen atoms are easily provided to combine with peroxy radicals, and free radicals formed by phenol have low activity and high stability. And the compatibility of the asymmetric hindered phenol calixarene and a base material is better, and the amount of the asymmetric hindered phenol calixarene can be more than that of a common antioxidant. The addition of the asymmetric hindered phenol calixarene combined with the polyolefin elastomer base material can obviously improve the thermal oxidative aging resistance of the material without crosslinking, so that the material can be suitable for large-size cable sheath materials, the problem that the sheath is easy to crack due to uneven crosslinking when the conventional crosslinking agent is added in large size is avoided, and the requirement of the minimum thermal life of 90 ℃/60 years is still not met. A large number of researches show that the master batch is modified by adding the high-temperature-resistant and radiation-resistant master batch, and at least thermosetting COPNA (condensed polycyclic polynuclear aromatic hydrocarbon resin) resin is contained in the master batch, wherein a benzene ring structure can form a conjugation effect with a benzene ring in asymmetric hindered phenol type calixarene, so that hydrogen on a hindered phenolic hydroxyl group of the master batch is more active, and a peroxy radical is more easily combined, and a free radical formed by phenol is more stable due to the conjugation of the benzene ring, so that the breakthrough improvement of the thermo-oxidative aging resistant effect of the master batch is realized, the thermo-sensitive cross-linking agent is not required to be added, the thermal life of 90 ℃/60 years can be achieved without cross-linking when the master batch is used for a large-section thick sheath cable, and an extrusion sheath of the master batch is not required to be cross-linked, the performance uniformity of each part is. Meanwhile, after the flame retardant is added, other properties can also meet the requirements of the thermoplastic sheath material for the third-generation nuclear power station cable.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable, the asymmetric hindered phenol calixarene preferably takes p-tert-butylphenol and formaldehyde aqueous solution as initial raw materials, and is subjected to three-step reactions of cyclizing polycondensation, tert-butyl removal and chloromethylation, and finally, the reaction is subjected to nucleophilic substitution reaction with 2-methyl-6-tert-butylphenol to synthesize asymmetric phenol calixarene 4a (n is 4) and 4b (n is 6), wherein the benzene ring structure of the asymmetric phenol calixarene is more favorable for absorbing redundant energy and converting the redundant energy into vibration energy to release the vibration energy, so that thermal oxidation of the material is inhibited.

The asymmetric hindered phenol calixarene has the performances of light resistance, heat resistance, oxygen resistance and radiation resistance, has good dispersibility in a base material, is beneficial to improving the addition amount of the calixarene, and can form a more effective conjugation effect with other components.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the cable of the nuclear power station, as a preferable scheme, the high-temperature-resistant polyolefin elastomer is one or more selected from high-temperature-resistant polyolefin elastomers NOTIO PN-3560, NOTIO PN-2070 and NOTIO PN-2060. The high-temperature resistant polyolefin elastomer is a series of alpha-olefin-based elastomers (trade names and brands corresponding to the names) developed by the chemical company of Mitsui Japan, has excellent temperature resistance, high softening point and low hardness, has good compatibility with various resins, elastomers and inorganic flame retardants, and has not been reported to be applied to cable sheath materials at present. Therefore, through a great deal of research, the inventor effectively realizes better thermal life performance by adopting the high-temperature resistant polyolefin elastomer which is not applied in the sheath material and combining the synergistic effect of adding the asymmetric hindered phenol type calixarene and the condensed polycyclic polynuclear aromatic hydrocarbon resin, can achieve the effect of the thermal life of 90 ℃/60 years beyond expectation, and can achieve the thermal life of 90 ℃/60 years beyond expectation of a large-section (the diameter is more than 60mm) or thick-sheath (more than 2 mm) cable material without irradiation crosslinking, and the sheath has the advantage of good uniformity.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable, as a preferred scheme, the antioxidant also contains phosphite ester auxiliary antioxidant, and the weight ratio of the asymmetric hindered phenol calixarene to the phosphite ester auxiliary antioxidant is 1.0: 0.1 to 0.5. The benzene ring in the main antioxidant calixarene can form a conjugated effect with the benzene rings in the COPNA and the SEBS in the material, the addition amount of the main antioxidant is increased, the thermo-oxidative aging resistance of the material can be improved in a breakthrough manner, and meanwhile, a small amount of phosphite auxiliary antioxidant (such as the antioxidant 168) can generate a synergistic effect with the main antioxidant, so that the antioxidant performance of the material can be further improved.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable, as a preferred scheme, the base material further comprises an ethylene-methyl methacrylate copolymer and an ethylene-vinyl acetate copolymer, and the base material comprises the following components in parts by weight:

high temperature resistant polyolefin elastomer NOTIO PN-3560: 10;

ethylene-methyl methacrylate copolymer: 1.0 to 2.0;

ethylene-vinyl acetate copolymer: 1.0 to 2.0.

The materials have better compatibility, excellent heat resistance and good compatibility, and meanwhile, the base material still takes the high-temperature-resistant polyolefin elastomer NOTIO PN-3560 as a main material, so that the heat resistance of the materials can be better ensured. Its thermal life and resistance⁶⁰The accumulated dose of Co-gamma rays has better effect.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable, as a preferred scheme, the high-temperature-resistant radiation-resistant modified master batch comprises the following components in parts by weight:

high-temperature resistant and irradiation resistant resin: 30-50, wherein the high-temperature-resistant and radiation-resistant resin is one or more selected from polyether sulfone micro powder, polyphenylene sulfone micro powder, ferrocene and polyphenylene oxide micro powder;

condensed polycyclic polynuclear aromatic hydrocarbon resin: 5.0 to 15;

styrene-ethylene-butylene-styrene block copolymer: 30-50;

ethylene-methyl methacrylate copolymer: 5.0 to 10.

By simultaneously containing the condensed polycyclic polynuclear aromatic hydrocarbon resin and the styrene-ethylene-butylene-styrene block copolymer, the benzene ring and the benzene ring in the asymmetric hindered phenol calixarene can be more effectively conjugated, better thermo-oxidative aging resistance is realized, the thermal life of 90 ℃/60 years is reached, and better radiation resistance can be achieved.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable, the high-temperature-resistant irradiation-resistant resin is firstly prepared into the corresponding master batch at high temperature, so that the master batch can be blended with the inorganic flame retardant aluminum hydroxide and the base material at lower temperature, the defect of decomposition failure caused by blending of the inorganic flame retardant aluminum hydroxide at high temperature is effectively overcome, the aluminum hydroxide is decomposed at high temperature, a large amount of heat is absorbed in the decomposition process, the surface temperature of the composite material is reduced, the generated metal oxide forms a compact carbon layer (the surface of an adhesive material), the further combustion of the material can be prevented, the generated water vapor can dilute the combustible gas, and the flame-retardant effect can be achieved. Preferably, the flame retardant further comprises one or more of kaolin, calcium carbonate, magnesium hydroxide and zinc borate. The flame retardant property is ensured, and simultaneously, the insulating property of the material can be favorably improved, for example, the water absorption of the cable sheath material can be reduced by kaolin, and the insulating property is improved.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the nuclear power station cable, as a preferred scheme, the anti-irradiation agent is selected from one or more of ferrocene, 2-amino-5- (p-methoxyphenyl) -1, 3, 4-thiadiazole lanthanum complex and 6-benzylaminopurine copper complex. The aging resistance and the irradiation resistance of the material can be more effectively improved. As a further preferable scheme, the radiation-resistant agent comprises the following components in parts by weight:

2-amino-5- (p-methoxyphenyl) -1, 3, 4-thiadiazole lanthanum complex: 1.0 to 2.0; ferrocene: 1.0 to 1.2; 6-benzylaminopurine copper complex: 0.5 to 1.0.

In the thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for the cable, as a preferred scheme, the sheath material further comprises 0.5-8.0 parts by weight of a mildew preventive. The material has better mildew-proof performance. Further preferably, the mildewcide is selected from tributyltin oxide and derivatives thereof and/or tributyltin derivatives.

And putting the uniformly mixed mixture and master batch into a double-stage double-screw extrusion granulator, and carrying out extrusion granulation under the conditions that the temperature is controlled to be 150-200 ℃ and the rotating speed is 200-500 r/min to obtain the corresponding radiation-resistant thermoplastic halogen-free low-smoke flame-retardant sheath material for the cable.

In summary, compared with the prior art, the invention has the following advantages:

by adopting a high-temperature-resistant polyolefin elastomer and asymmetric hindered phenol calixarene as main antioxidants and adopting a material common system containing condensed polycyclic polynuclear aromatic resin, a good synergistic effect can be formed, so that a conjugate effect is formed, the thermo-oxidative aging resistance of the cable is remarkably improved, the requirements on the thermal life and the radiation resistance of the cable can reach 90 ℃/60 years, the sheath layer has uniformity, the cable is suitable for a cable material with a large-caliber thick sheath layer, the cable has high flame retardant property, and other properties also meet the requirements of sheath materials for cables of third-generation nuclear power plants.

Detailed Description

The technical solution of the present invention is further specifically described below by way of specific examples, but the present invention is not limited to these examples.