阅读说明：本技术 一种无卤阻燃物理发泡绝缘料及其制备方法 (Halogen-free flame-retardant physical foaming insulating material and preparation method thereof ) 是由 陈娟 何焯健 梁忠秋 于 2021-05-10 设计创作，主要内容包括：本发明公开了一种无卤阻燃物理发泡绝缘料,包括如下重量份的组分：预辐照的聚烯烃组合物40份-60份；改性多晶莫来石纤维5份-12份；单甘酯3份-8份；含酸酐的低介电树脂1份-5份；聚砜1份-5份；交联剂3份-8份。本发明通过预辐照的方法,对聚烯烃组合物进行改性,以改变其与其他物质的相容性,再通过对多晶莫来石纤维的改性,使得多晶莫来石纤维能够很好地分散在预辐照后的聚烯烃组合物中,以增加绝缘料的阻燃性能,同时,由于聚烯烃组合物由聚丙烯、聚1-丁烯、聚4-甲基-1-戊烯、己内酯改性甲基丙烯酸酯组成,使得聚烯烃组合物具有较好的耐热性能,适用于耐热等级高的电线电缆。(The invention discloses a halogen-free flame-retardant physical foaming insulating material which comprises the following components in parts by weight: 40-60 parts of a pre-irradiated polyolefin composition; 5-12 parts of modified polycrystalline mullite fiber; 3-8 parts of monoglyceride; 1-5 parts of low dielectric resin containing anhydride; 1-5 parts of polysulfone; 3-8 parts of a cross-linking agent. According to the invention, the polyolefin composition is modified by a pre-irradiation method to change the compatibility of the polyolefin composition with other substances, and then the polycrystalline mullite fiber is modified to be well dispersed in the pre-irradiated polyolefin composition to increase the flame retardant property of the insulating material, and meanwhile, the polyolefin composition is composed of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate, so that the polyolefin composition has better heat resistance and is suitable for wires and cables with high heat resistance level.)

1. The halogen-free flame-retardant physical foaming insulating material is characterized by comprising the following components in parts by weight:

40-60 parts of a pre-irradiated polyolefin composition; 5-12 parts of modified polycrystalline mullite fiber; 3-8 parts of monoglyceride; 1-5 parts of low dielectric resin containing anhydride; 1-5 parts of polysulfone; 3-8 parts of a cross-linking agent;

wherein the pre-irradiated polyolefin composition consists of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate.

2. The halogen-free flame-retardant physical foaming insulating material as claimed in claim 1, wherein the mass ratio of the polypropylene, the poly-1-butene, the poly-4-methyl-1-pentene and the caprolactone modified methacrylate is 1: (0.2-0.4): (0.1-0.3): 0.2.

3. the halogen-free, flame retardant, physically foamed insulation according to claim 1, wherein the pre-irradiated polyolefin composition is prepared by: polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate are uniformly mixed, and then pre-irradiation reaction is carried out under the electron irradiation of 20kGy-40kGy, so as to obtain the radiation-resistant polypropylene/butadiene copolymer.

4. The halogen-free, flame-retardant, physically foamed insulation according to claim 1, wherein the modified polycrystalline mullite fiber is a polycrystalline mullite fiber having hydroxyl groups.

5. The halogen-free flame retardant physical foam insulation material as claimed in claim 1, wherein the monoglyceride is a molecular distillation monoglyceride.

6. The halogen-free flame-retardant physical foaming insulating material as claimed in claim 1, wherein the anhydride-containing low dielectric resin is a maleic anhydride graft modified polyimide resin, and the grafting ratio of the maleic anhydride graft modified polyimide resin is 20-40%.

7. The halogen-free flame retardant physical foaming insulation material according to claim 1, wherein the crosslinking agent is one or a combination of trimethylolpropane trimethacrylate and trimethylolpropane triacrylate.

8. The halogen-free flame-retardant physical foaming insulating material according to claim 1, wherein the mass ratio of the pre-irradiated polyolefin composition, the polysulfone and the cross-linking agent is 1: (0.05-0.1): 0.1.

9. the halogen-free flame-retardant physically foamed insulation material according to any one of claims 1 to 8, characterized by comprising the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and putting the second premix into an extruder, and performing extrusion granulation to obtain the halogen-free flame-retardant physical foaming insulating material.

10. The halogen-free flame-retardant physically foamed insulation material according to claim 1, wherein in step S3, the extrusion temperature is 150 ℃ to 180 ℃.

Technical Field

The invention relates to the technical field of plastics, in particular to a halogen-free flame-retardant physical foaming insulating material and a preparation method thereof.

Background

With the rapid development of economy, electric wires and cables are widely applied in various industrial fields. With the frequent occurrence of electrical fire accidents, the fire-retardant problem of the electric wires and cables gradually attracts attention of all countries in the world. In recent years, more than 80% of the causes of death of people in fire accidents are related to dense smoke and toxic gas generated by materials, and in order to reduce potential safety hazards, at present, in many large public places, wires and cables specially used for transmitting electric energy and communication signals are required to be capable of preventing flame from spreading, and also to be capable of maintaining the cables to continuously transmit electric energy and communication signals, and the cables also have low smoke generation amount and low gas corrosion during combustion, so that workers can safely leave the site, namely the cables are required to have the performances of no halogen, low smoke, flame retardance and the like.

Polyolefins are polymers of olefins, and are a general term for thermoplastic resins obtained by the single polymerization or copolymerization of alpha-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and the like, as well as certain cyclic olefins, each of which has its own unique performance advantages and application fields. However, the compatibility between polymers and other components is very poor due to differences in chemical structure, crystallization behavior, and the like between the materials.

Patent CN106519409B discloses an irradiation crosslinking low-smoke halogen-free flame-retardant cable material, which adopts ethylene-vinyl acetate copolymer, polyethylene, compatilizer, inorganic flame retardant, metal oxide, modifier, silicone powder, ethylene bis stearamide and antioxidant, and patent CN107722439A discloses an environment-friendly cable insulation layer, the outer insulation layer of which adopts ethylene-vinyl acetate copolymer, linear low-density polyethylene, ethylene propylene diene monomer, scratch-resistant agent, sensitizer, silicon nitrogen flame retardant, compound anti-aging agent, reinforcing filler and compound compatilizer. The compatibility of the polyolefin with other ingredients is increased by adding a compatibilizer in each of the above patents.

Disclosure of Invention

In order to overcome the defects of the prior art, one of the purposes of the invention is to provide a halogen-free flame-retardant physical foaming insulating material which has better flame retardance and heat resistance and is suitable for wires and cables with high heat resistance.

The invention also aims to provide a preparation method of the halogen-free flame-retardant physical foaming insulating material, which is simple and easy to control and can be applied to large-scale production.

One of the purposes of the invention is realized by adopting the following technical scheme:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

40-60 parts of a pre-irradiated polyolefin composition; 5-12 parts of modified polycrystalline mullite fiber; 3-8 parts of monoglyceride; 1-5 parts of low dielectric resin containing anhydride; 1-5 parts of polysulfone; 3-8 parts of a cross-linking agent;

wherein the pre-irradiated polyolefin composition consists of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate.

Further, the mass ratio of the polypropylene, the poly-1-butene, the poly-4-methyl-1-pentene and the caprolactone modified methacrylate is 1: (0.2-0.4): (0.1-0.3): 0.2. the preparation method comprises the following steps: the preparation method comprises the following steps of uniformly mixing polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate according to the formula amount, and then carrying out pre-irradiation reaction under the electron irradiation of 20-40 kGy to obtain the modified polypropylene. Polypropylene is a crystalline material with higher strength and better heat resistance; the chemical resistance, the aging resistance and the electrical insulation of the poly-1-butene are similar to those of polypropylene; the poly-4-methyl-1-pentene is thermoplastic resin with the minimum density, has excellent heat resistance, a melting point of 240 ℃, and has better electrical insulation and chemical resistance; the caprolactone modified methacrylate is a macromonomer which is polymerized by taking hydroxyethyl methacrylate as an initiator at a temperature of 130-150 ℃ and caprolactone monomers in a mass ratio of 1 (0.5-0.8), has the characteristics of good scratch resistance, wear resistance, low-temperature toughness and high elasticity, and is added into the radiation crosslinking reaction of polyolefin to modify the polyolefin so that the surface of the product has an ester group and can be compatible with other components. Preferably, the mass ratio of the polypropylene, the poly-1-butene, the poly-4-methyl-1-pentene and the caprolactone modified methacrylate is 1: 0.3: 0.1: 0.2.

further, the modified polycrystalline mullite fiber is a polycrystalline mullite fiber with hydroxyl groups, the diameter of the polycrystalline mullite fiber is 1-3 mu m, the length of the polycrystalline mullite fiber is 20mm-40mm, and the polycrystalline mullite fiber has good compatibility with the pre-irradiated polyolefin composition due to the hydroxyl groups on the surface of the polycrystalline mullite fiber. The modification method of the modified polycrystalline mullite fiber comprises the following steps: the mass ratio is 1: 2, carrying out hydroxylation treatment on the polycrystalline mullite fiber by using a strong oxidation solution composed of potassium permanganate and hydrogen peroxide to enable the surface of the polycrystalline mullite fiber to have hydroxyl functional groups, wherein the mass ratio of the strong oxidation solution to the polycrystalline mullite fiber is 1 (50-80). The polycrystalline mullite fiber is an excellent reinforcing material for ultra-light high-temperature refractory fiber and composite material, and is the whole Al₂O₃-SiO₂The ceramic fiber is one of ceramic fibers, is composed of mullite microcrystal, integrates the characteristics of a crystal material and a fiber material into a whole, has the use temperature of 1500-1700 ℃ which is 200-400 ℃ higher than that of a glass fiber, and has the advantages of high temperature resistance, corrosion resistance, small specific gravity, high melting point, good thermal shock resistance, low thermal conductivity, high-temperature strength and the like.

Furthermore, the monoglyceride is molecular distillation monoglyceride which is obtained by purifying by a molecular distillation technology, and the monoglyceride has the advantages of quick migration in resin, long effect, reduced surface resistance and reduced formation and accumulation of static electricity.

Further, the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin, and the dielectric constant of the resin is less than 3 at the frequency of 10 GHz. The polyimide resin has the characteristics of heat resistance, low temperature resistance, excellent mechanical property, good processing property, no toxicity and the like, but has poor compatibility with polar polymers, and after the maleic anhydride is grafted and modified, the compatibility of the polyimide resin with the polar polymers can be increased, so that the polyimide resin can be better dispersed, and is convenient for further reaction in the later electronic irradiation process. Preferably, the grafting ratio of the maleic anhydride graft-modified polyimide resin is 20 to 40%.

Further, the cross-linking agent is one or a combination of trimethylolpropane trimethacrylate and trimethylolpropane triacrylate.

Further, the mass ratio of the pre-irradiated polyolefin composition, the polysulfone and the cross-linking agent is 1: (0.05-0.1): 0.1. polysulfone has a heat distortion temperature of 175 ℃, can be used for a long period of time at temperatures between-100 ℃ and 150 ℃, has excellent resistance to aging at high temperatures, and can react with polyolefin compositions to improve their thermal stability. Preferably, the mass ratio of the pre-irradiated polyolefin composition, polysulfone and cross-linking agent is 1: 0.08: 0.1.

one of the purposes of the invention is realized by adopting the following technical scheme:

a halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and putting the second premix into an extruder, and performing extrusion granulation to obtain the halogen-free flame-retardant physical foaming insulating material.

Further, in step S3, the extrusion temperature is 150 ℃ to 180 ℃.

When in use, the halogen-free flame-retardant physical foaming insulating material can be subjected to cross-linking under the irradiation of electrons with the irradiation dose of 130kGy-180 kGy.

Compared with the prior art, the invention has the beneficial effects that:

the halogen-free flame-retardant physical foaming insulating material provided by the invention modifies the polyolefin composition by a pre-irradiation method so as to change the compatibility of the polyolefin composition with other substances, and then modifies the polycrystalline mullite fiber, so that the polycrystalline mullite fiber can be well dispersed in the pre-irradiated polyolefin composition so as to increase the flame retardant property of the insulating material.

The preparation method is simple and easy to control, and can be applied to large-scale production.

Detailed Description

The present invention is further described below with reference to specific embodiments, and it should be noted that, without conflict, any combination between the embodiments or technical features described below may form a new embodiment. The following are specific examples of the present invention, and raw materials, equipments and the like used in the following examples can be obtained by purchasing them unless otherwise specified. In the following examples, the modified polycrystalline mullite fiber is a polycrystalline mullite fiber having a hydroxyl group obtained by the method of the present invention, unless otherwise specified; the monoglyceride is molecular distillation monoglyceride.

Example 1:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

40 parts of a pre-irradiated polyolefin composition; 5 parts of modified polycrystalline mullite fiber; 3 parts of monoglyceride; 1 part of low dielectric resin containing acid anhydride; 1 part of polysulfone; 3 parts of a crosslinking agent;

wherein the pre-irradiated polyolefin composition is prepared by mixing the components in a mass ratio of 1: 0.3: 0.1: 0.2 of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate; the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin with the grafting rate of 20 percent; the cross-linking agent is trimethylolpropane trimethacrylate.

The halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and (3) putting the second premix into an extruder, and performing extrusion granulation at the extrusion temperature of 160 ℃ to obtain the halogen-free flame-retardant physical foaming insulating material.

Example 2:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

50 parts of a pre-irradiated polyolefin composition; 8 parts of modified polycrystalline mullite fiber; 5 parts of monoglyceride; 3 parts of low dielectric resin containing anhydride; 3 parts of polysulfone; 5 parts of a crosslinking agent;

wherein the pre-irradiated polyolefin composition is prepared by mixing the components in a mass ratio of 1: 0.3: 0.1: 0.2 of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate; the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin with the grafting rate of 20 percent; the cross-linking agent is trimethylolpropane trimethacrylate.

The halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and (3) putting the second premix into an extruder, and performing extrusion granulation at the extrusion temperature of 160 ℃ to obtain the halogen-free flame-retardant physical foaming insulating material.

Example 3:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

60 parts of a pre-irradiated polyolefin composition; 12 parts of modified polycrystalline mullite fiber; 8 parts of monoglyceride; 5 parts of low dielectric resin containing anhydride; 5 parts of polysulfone; 8 parts of a crosslinking agent;

wherein the pre-irradiated polyolefin composition is prepared by mixing the components in a mass ratio of 1: 0.3: 0.1: 0.2 of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate; the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin with the grafting rate of 20 percent; the cross-linking agent is trimethylolpropane trimethacrylate.

The halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and (3) putting the second premix into an extruder, and performing extrusion granulation at the extrusion temperature of 160 ℃ to obtain the halogen-free flame-retardant physical foaming insulating material.

Example 4:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

55 parts of a pre-irradiated polyolefin composition; 6 parts of modified polycrystalline mullite fiber; 3 parts of monoglyceride; 2 parts of low dielectric resin containing anhydride; 4.4 parts of polysulfone; 5.5 parts of a crosslinking agent;

wherein the pre-irradiated polyolefin composition is prepared by mixing the components in a mass ratio of 1: 0.3: 0.1: 0.2 of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate; the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin with the grafting rate of 20 percent; the cross-linking agent is trimethylolpropane trimethacrylate.

The halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and (3) putting the second premix into an extruder, and performing extrusion granulation at the extrusion temperature of 160 ℃ to obtain the halogen-free flame-retardant physical foaming insulating material.

Example 5:

different from the embodiment 4, the mass ratio of the polypropylene, the poly-1-butene, the poly-4-methyl-1-pentene and the caprolactone modified methacrylate in the embodiment 5 is 1: 0.3: 0.3: 0.2, specifically as follows:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

40-60 parts of a pre-irradiated polyolefin composition; 5-12 parts of modified polycrystalline mullite fiber; 3-8 parts of monoglyceride; 1-5 parts of low dielectric resin containing anhydride; 1-5 parts of polysulfone; 3-8 parts of a cross-linking agent;

wherein the pre-irradiated polyolefin composition is prepared by mixing the components in a mass ratio of 1: 0.3: 0.3: 0.2 of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate; the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin with the grafting rate of 20 percent; the cross-linking agent is trimethylolpropane trimethacrylate.

The halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and (3) putting the second premix into an extruder, and performing extrusion granulation at the extrusion temperature of 160 ℃ to obtain the halogen-free flame-retardant physical foaming insulating material.

Example 6:

different from the embodiment 4, the mass ratio of the polypropylene, the poly-1-butene, the poly-4-methyl-1-pentene and the caprolactone modified methacrylate in the embodiment 6 is 1: 0.2: 0.1: 0.2, specifically as follows:

a halogen-free flame-retardant physical foaming insulating material comprises the following components in parts by weight:

40-60 parts of a pre-irradiated polyolefin composition; 5-12 parts of modified polycrystalline mullite fiber; 3-8 parts of monoglyceride; 1-5 parts of low dielectric resin containing anhydride; 1-5 parts of polysulfone; 3-8 parts of a cross-linking agent;

wherein the pre-irradiated polyolefin composition is prepared by mixing the components in a mass ratio of 1: 0.2: 0.1: 0.2 of polypropylene, poly-1-butene, poly-4-methyl-1-pentene and caprolactone modified methacrylate; the low dielectric resin containing acid anhydride is maleic anhydride graft modified polyimide resin with the grafting rate of 20 percent; the cross-linking agent is trimethylolpropane trimethacrylate.

The halogen-free flame-retardant physical foaming insulating material comprises the following preparation steps:

s1: firstly, uniformly stirring a pre-irradiated polyolefin composition, modified polycrystalline mullite fiber, anhydride-containing low dielectric resin and polysulfone at normal temperature to obtain a first premix;

s2: adding a cross-linking agent and monoglyceride into the first premix, and uniformly mixing to obtain a second premix;

s3: and (3) putting the second premix into an extruder, and performing extrusion granulation at the extrusion temperature of 160 ℃ to obtain the halogen-free flame-retardant physical foaming insulating material.

In the above embodiments, each material is not limited to the above components, and each material may also be composed of other single components or multiple components described in the present invention, and the component parts of each material are not limited to the above parts, and the component parts of each material may also be a combination of other component parts described in the present invention, and are not described herein again.

Comparative example 1

In contrast to example 4, the polyolefin composition of comparative example 1 was prepared without the addition of caprolactone-modified methacrylate, and the remaining formulation and preparation method were the same as in example 1.

Comparative example 2

In comparison with example 4, the polyolefin composition of comparative example 2 was prepared without adding poly-4-methyl-1-pentene and the remaining formulation and preparation were the same as in example 1.

Comparative example 3

Compared with example 4, in comparative example 3, no modified polycrystalline mullite fiber was added, and the rest of the formulation and the preparation method were the same as those of example 1.

Comparative example 4

In comparison with example 4, in comparative example 4, polysulfone was not added, and the remaining formulation and preparation method were the same as in example 1.

Performance testing

The insulating materials prepared in the above examples 1-6 and comparative examples 1-4 were subjected to foaming crosslinking under electron irradiation with an irradiation dose of 160kGy, and the obtained sheets were subjected to the following performance tests, tensile strength GB/T0403-2006, elongation at break GB/T0403-2006, volume resistivity GB/T3048-2007 at 20 ℃, thermal elongation test GB/T2951-2008, thermal aging test GB/T2951-2008, smoke density test GB8323-2008, and halogen acid gas test GB/T176501-1998, and the results are shown below.

TABLE 1

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.