阅读说明：本技术 低烟无卤阻燃电缆相容剂、马来酸酐接枝改性聚烯烃及其制备方法 (Low-smoke halogen-free flame-retardant cable compatilizer, maleic anhydride grafted modified polyolefin and preparation method thereof ) 是由 张祥洲 余学煌 于 2021-09-17 设计创作，主要内容包括：本发明公开了一种低烟无卤阻燃电缆相容剂、马来酸酐接枝改性聚烯烃,属于马来酸酐接枝改性聚烯烃相容剂技术领域。本发明使用甲基丙烯酸缩水甘油酯对乙烯-丁烯嵌段共聚物或丙烯-乙烯嵌段共聚物接枝改性,然后用马来酸酐对制备得到的聚烯烃共聚物接枝改性,再以马来酸酐为连接中间体接枝本发明所选有机锡化合物,制得一种多元嵌段共聚物。该多元嵌段共聚物作为相容剂应用于电缆制造,可以大幅度提升非卤素阻燃剂与电缆基体树脂的界面相容性,有效提高了非卤素阻燃剂与电缆基体树脂的共混分散比例,从而大幅度提高了电缆在干燥环境中的耐热性阻燃性,所制电缆具有很好的拉伸强度及加工性能。本发明制备工艺简单,低烟低毒,具有很好的市场前景。(The invention discloses a low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride grafted modified polyolefin, and belongs to the technical field of maleic anhydride grafted modified polyolefin compatilizers. The invention uses glycidyl methacrylate to graft and modify ethylene-butylene block copolymer or propylene-ethylene block copolymer, then uses maleic anhydride to graft and modify the prepared polyolefin copolymer, and uses maleic anhydride as a connecting intermediate to graft the selected organic tin compound of the invention, thus preparing the multi-element block copolymer. The multi-element block copolymer is applied to cable manufacture as a compatilizer, so that the interface compatibility of a non-halogen flame retardant and cable matrix resin can be greatly improved, the blending dispersion ratio of the non-halogen flame retardant and the cable matrix resin is effectively improved, the heat resistance and the flame retardance of the cable in a dry environment are greatly improved, and the manufactured cable has good tensile strength and processability. The invention has simple preparation process, low smoke and low toxicity, and has good market prospect.)

1. The low-smoke halogen-free flame-retardant cable compatilizer and the maleic anhydride grafted modified polyolefin are characterized in that the preparation raw materials comprise the following components in parts by mass: 150 parts of polyolefin copolymer, 12-18 parts of maleic anhydride, 25-32 parts of organic tin compound, 1-2 parts of antioxidant and 3-5 parts of initiator;

wherein, the polyolefin copolymer is one or two of ethylene-butylene syndiotactic copolymer modified by glycidyl methacrylate and propylene-ethylene syndiotactic copolymer modified by glycidyl methacrylate.

2. The low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin according to claim 1, wherein the preparation method of the polyolefin copolymer comprises the following steps: mixing ethylene-butylene block copolymer or propylene-ethylene block copolymer, glycidyl methacrylate and dibenzoyl peroxide, adding diethyl ether which is 9-12 times of the weight of the ethylene-butylene block copolymer or the propylene-ethylene block copolymer, heating to 240 ℃, magnetically stirring at constant temperature for 12h, washing and drying a reaction product to obtain the polyolefin copolymer.

3. The low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin according to claim 2, wherein the addition amount of the glycidyl methacrylate is 0.6-2.5 parts and the addition amount of the dibenzoyl peroxide is 0.8-1.6 parts per 100 parts of the ethylene-butylene block copolymer or the propylene-ethylene block copolymer in parts by weight.

4. The low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin according to claim 1, wherein the organic tin compound is prepared by mixing dioctyltin and triphenyltin according to a mass ratio of 3: 1, proportioning.

5. The low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin according to claim 1, wherein the initiator is dibenzoyl peroxide or di-tert-butyl peroxide.

6. The preparation method of the low-smoke halogen-free flame-retardant cable compatilizer and the maleic anhydride graft modified polyolefin as claimed in any one of claims 1 to 5, characterized by comprising the following steps:

1) weighing the raw materials according to the formula ratio for later use;

2) taking the polyolefin copolymer in a reaction kettle, adding an organic solvent for dissolving, replacing air in the reaction kettle with inert gas, then adding maleic anhydride, heating to 180-class 200 ℃, and slowly stirring overnight;

3) spin-drying the solvent of the mixture obtained in the step 2), placing the mixture in a stirrer, adding 1/6 mass of initiator and antioxidant, and fully stirring and mixing;

4) and (3) transferring the mixture obtained in the step 3) into a double-screw extruder from a main feeding port, adding the organic tin compound and the rest of the initiator through side feeding, and carrying out melt extrusion and granulation at the temperature of 225 ℃ and 250 ℃ to obtain the cable compatilizer.

7. The preparation method of the low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride grafted modified polyolefin according to claim 6, wherein the organic solvent in the step 2) is tetrahydrofuran, and the addition amount of the organic solvent is 1: and (4) taking the powder 40.

8. The low smoke zero halogen flame retardant cable compatilizer and the maleic anhydride grafted modified polyolefin as claimed in any one of claims 1 to 7 are used for manufacturing a low smoke zero halogen flame retardant cable.

9. The application of the low-smoke halogen-free flame-retardant cable compatilizer and the maleic anhydride grafted modified polyolefin in the low-smoke halogen-free flame-retardant cable according to claim 8 is characterized in that the preparation method of the low-smoke halogen-free flame-retardant cable comprises the following steps:

1) taking 100 parts of matrix resin, 10-12 parts of cable compatilizer, 30-40 parts of non-halogen flame retardant and 2-4 parts of antioxidant according to the mass parts;

2) adding the raw materials into a stirrer, stirring at a high speed of 1000r/min for 5-10min at 800-.

10. The low smoke zero halogen flame retardant cable compatilizer and maleic anhydride grafted modified polyolefin applied to a low smoke zero halogen flame retardant cable according to claim 9, wherein the non-halogen flame retardant is a mixture of nano montmorillonite, magnesium hydroxide, aluminum hydroxide and organic tin compound in equal mass ratio.

Technical Field

The invention belongs to the technical field of maleic anhydride grafted modified polyolefin compatilizers, and particularly relates to a low-smoke halogen-free flame-retardant cable compatilizer, maleic anhydride grafted modified polyolefin and a preparation method thereof.

Background

In recent years, the fire hazard duty ratio caused by cables is high, so that the requirements of cables on low smoke, fire resistance, flame retardance and the like are higher and higher. Since a halogen flame retardant such as organic chloride or organic bromide is added to a common flame-retardant cable, a large amount of smoke is released due to combustion in a fire, for example, hydrogen chloride causes a secondary disaster, and the danger of the cable is greater than that of the fire, so research and development of low-smoke halogen-free flame-retardant cables are devoted at home and abroad for many years.

At present, people usually adopt non-halogen flame retardants to overcome the problem that halogen flame retardants generate a large amount of harmful smoke when burning, such as hydroxide flame retardants, phosphorus nitrogen compound flame retardants, and the like. The flame retardant has the advantages of small addition amount, high flame retardant efficiency, low smoke and low toxicity, but the compatibility of the flame retardant with a high polymer material is poor, so that the mechanical properties of the prepared cable can be reduced to different degrees. For example, application No. 201611118073.6 discloses a B-type flame-retardant irradiation crosslinking halogen-free low-smoke insulating cable material, or application No. 201611023052.6 discloses a low-smoke halogen-free flame-retardant cable material and a preparation method thereof. The higher the content of the flame retardant in the cable material components is, the poorer the interfacial compatibility of the flame retardant and the matrix resin is, so that the uniform dispersion of the flame retardant in the matrix resin is seriously influenced, and the finally prepared cable has better flame retardant property but has reduced mechanical properties to different degrees.

Disclosure of Invention

Aiming at the problems that in the prior art, when a halogen flame retardant is added, toxic dense smoke is generated during combustion, and when a non-halogen flame retardant is added, the mechanical property of the cable is affected, the invention provides a low-smoke halogen-free flame-retardant cable compatilizer, maleic anhydride grafted modified polyolefin and a preparation method thereof. The compatilizer is prepared by block copolymerization of glycidyl methacrylate-ethylene-butylene, maleic anhydride and an organic tin compound, not only ensures the flame retardant property of the cable, but also can obviously improve the tensile strength and the processability of the cable.

The invention is realized by the following technical scheme:

a low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin comprise the following preparation raw materials in parts by mass: 150 parts of polyolefin copolymer, 12-18 parts of maleic anhydride, 25-32 parts of organic tin compound, 1-2 parts of antioxidant and 3-5 parts of initiator.

Further, the polyolefin copolymer is one or two of ethylene-butylene syndiotactic copolymer modified by glycidyl methacrylate and propylene-ethylene syndiotactic copolymer modified by glycidyl methacrylate.

Further, the preparation method of the polyolefin copolymer comprises the following steps: mixing ethylene-butylene block copolymer or propylene-ethylene block copolymer, glycidyl methacrylate and dibenzoyl peroxide, adding diethyl ether which is 9-12 times of the weight of the ethylene-butylene block copolymer or the propylene-ethylene block copolymer, heating to 240 ℃, magnetically stirring at constant temperature for 12h, washing and drying a reaction product to obtain the polyolefin copolymer.

Further, the addition amount of the glycidyl methacrylate is 0.6 to 2.5 parts and the addition amount of the dibenzoyl peroxide is 0.8 to 1.6 parts by weight per 100 parts of the ethylene-butene block copolymer or the propylene-ethylene block copolymer.

The glycidyl methacrylate has high-activity acrylate double bonds and epoxy groups, and can react with various functional groups to form a diversified polymer.

Further, the organic tin compound is prepared from dioctyl tin and triphenyl tin according to a mass ratio of 3: 1, proportioning.

The inventor finds that the polyolefin copolymer prepared by the invention is grafted and modified by maleic anhydride, and then the organotin compound selected by the invention is grafted by taking the maleic anhydride as a connecting intermediate, so that the prepared multi-block copolymer can be used as a compatilizer of cable matrix resin and a non-halogen flame retardant in the preparation process of the low-smoke halogen-free flame-retardant cable. Compared with the common maleic anhydride grafted polyolefin compatilizer, the compatilizer can obviously improve the blending dispersion ratio of the selected non-halogen flame retardant and the cable matrix resin, and effectively solves the problem of the dispersibility of a large proportion of non-halogen flame retardant in the cable matrix resin.

Further, the initiator is dibenzoyl peroxide or di-tert-butyl peroxide.

A preparation method of a low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin comprises the following steps:

1) weighing the raw materials according to the formula ratio for later use;

2) taking the polyolefin copolymer in a reaction kettle, adding an organic solvent for dissolving, replacing air in the reaction kettle with inert gas, then adding maleic anhydride, heating to 180-class 200 ℃, and slowly stirring overnight;

3) spin-drying the solvent of the mixture obtained in the step 2), placing the mixture in a stirrer, adding 1/6 mass of initiator and antioxidant, and fully stirring and mixing;

4) and (3) transferring the mixture obtained in the step 3) into a double-screw extruder from a main feeding port, adding the organic tin compound and the rest of the initiator through side feeding, and carrying out melt extrusion and granulation at the temperature of 225 ℃ and 250 ℃ to obtain the cable compatilizer.

Further, the organic solvent in the step 2) is tetrahydrofuran, and the adding amount is that the volume ratio (g/mL) of the polyolefin copolymer to the organic solvent is 1: and (4) taking the powder 40.

A low-smoke halogen-free flame-retardant cable compatilizer and maleic anhydride graft modified polyolefin are applied to manufacturing of a low-smoke halogen-free flame-retardant cable, and the preparation method of the low-smoke halogen-free flame-retardant cable comprises the following steps:

1) taking 100 parts of matrix resin, 10-12 parts of cable compatilizer, 30-40 parts of non-halogen flame retardant and 2-4 parts of antioxidant according to the mass parts;

2) adding the raw materials into a stirrer, stirring at a high speed of 800-1000r/min at 220 ℃ for 5-10min, and then transferring the mixture to a double-screw extruder for melt extrusion and granulation to obtain the low-smoke halogen-free flame-retardant cable.

Further, the matrix resin is one or two of metallocene polyethylene and medium density polyethylene.

Further, the antioxidant is antioxidant 1010.

Further, the non-halogen flame retardant is a mixture of nano montmorillonite, magnesium hydroxide, aluminum hydroxide and organic tin compound according to equal mass ratio.

The basic requirements of flame retardants are: the flame-retardant efficiency is high, and the dosage required for obtaining the unit flame-retardant efficiency is less; the fuel is low in toxicity or non-toxic, and the amount of toxic and corrosive gas and smoke generated during combustion are as small as possible, so that the fuel is environment-friendly; the flame-retardant coating has good compatibility with a flame-retardant base material, is not easy to migrate and seep, and does not excessively deteriorate the processing performance and mechanical property of the base material; low price and the like. Thus, the conventional flame retardants have more or less some disadvantages, such as a large amount of toxic fumes generated during the combustion of the halogen-based flame retardants, poor compatibility of the hydroxide flame retardants with the substrate, and the like. The flame retardant is compounded by selecting nano montmorillonite, magnesium hydroxide and aluminum hydroxide according to equal mass ratio, the nano inorganic mineral can improve the heat resistance of the material, the aluminum hydroxide can improve the heat capacity of the polymer, and the magnesium hydroxide can play a certain smoke abatement role; dioctyltin and triphenyltin have certain flame retardance and smoke suppression but are less effective. The inventor researches and discovers that when the multi-component copolymer prepared by the invention and grafted with the organotin compound (composed of dioctyltin and triphenyltin according to the mass ratio of 3: 1) is used as a compatilizer, and the mixture composed of nano montmorillonite, magnesium hydroxide, aluminum hydroxide, organotin compound and the like in the mass ratio is used as a composite flame retardant, the flame retardant performance of the prepared cable can be greatly improved, and the dispersibility of the composite flame retardant in the cable can also be improved.

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

the invention uses glycidyl methacrylate to graft and modify ethylene-butylene block copolymer or propylene-ethylene block copolymer, then uses maleic anhydride to graft and modify the prepared ethylene-butylene syndiotactic copolymer modified by glycidyl methacrylate or propylene-ethylene syndiotactic copolymer modified by glycidyl methacrylate, and uses maleic anhydride as a connecting intermediate to graft the selected organic tin compound, thus preparing the multi-element block copolymer. The multi-element block copolymer can be used as a compatilizer for cable manufacture, can obviously improve the interface compatibility of the non-halogen flame retardant selected by the invention and the cable matrix resin, effectively improves the blending dispersion ratio of the non-halogen flame retardant and the cable matrix resin, greatly improves the heat resistance and flame retardance of the cable in a dry environment, and leads the manufactured cable to have good tensile strength and processing performance. The cable can effectively replace the existing high-toxicity halogen flame-retardant cable, and the invention has the advantages of simple preparation process, low smoke and low toxicity, and has good market prospect.

Detailed Description

The present invention will be further described with reference to specific examples, but the present invention is not limited to the following examples. The process is conventional unless otherwise specified, and the starting materials are commercially available from the open literature.

Example 1

Taking 100 parts of ethylene-butylene block copolymer, 1.6 parts of glycidyl methacrylate and 0.8 part of dibenzoyl peroxide according to parts by weight; and (2) mixing and adding diethyl ether with the weight 10 times that of the ethylene-butylene block copolymer, heating to 230 ℃, magnetically stirring at a constant temperature for 12 hours, and washing and drying a reaction product to obtain the polyolefin copolymer.

Example 2

Taking 100 parts of propylene-ethylene block copolymer, 1.8 parts of glycidyl methacrylate and 1.0 part of dibenzoyl peroxide according to parts by weight; and (2) mixing and adding diethyl ether with the weight being 12 times that of the propylene-ethylene segmented copolymer, heating to 230 ℃, magnetically stirring at constant temperature for 12 hours, and washing and drying a reaction product to obtain the polyolefin copolymer.

Example 3

A low-smoke halogen-free flame-retardant cable compatilizer, maleic anhydride graft modified polyolefin:

1) 150 parts by mass of the polyolefin copolymer obtained in example 1, 15 parts by mass of maleic anhydride, and 30 parts by mass of an organotin compound (prepared by reacting dioctyltin and triphenyltin in a mass ratio of 3: 1 component), 2 parts of antioxidant 1010 and 4 parts of dibenzoyl peroxide for later use;

2) and (2) putting the polyolefin copolymer into a reaction kettle, and adding tetrahydrofuran for dissolution (the mass-volume ratio of the polyolefin copolymer to the tetrahydrofuran is 1: 40 g: mL), replacing air in the reaction kettle with inert gas, then adding maleic anhydride, heating to 195 ℃, and slowly stirring overnight;

3) spin-drying the solvent of the mixture obtained in the step 2), placing the mixture in a stirrer, adding 1/6 mass of dibenzoyl peroxide and 1010 mass of antioxidant, and fully stirring and mixing;

4) and (3) transferring the mixture obtained in the step 3) into a double-screw extruder from a main feeding port, adding the organic tin compound and the residual dibenzoyl peroxide through side feeding, and carrying out melt extrusion and granulation at 240 ℃ to obtain the cable compatilizer.

Preparation examples 4 to 7 were prepared in the same manner as in example 3 by adjusting the preparation raw materials, and the raw material settings are shown in table 1.

TABLE 1

The cable compatibilizers prepared in examples 3 to 7 were subjected to performance tests, and the results are shown in table 2.

TABLE 2

Note: [1]190 ℃ and 2.16kg

Comparative examples 1-3 were prepared according to the procedure parameters of example 3:

comparative example 1

1) Weighing 150 parts of ethylene-butylene block copolymer, 15 parts of maleic anhydride and 30 parts of organic tin compound (prepared by mixing dioctyltin and triphenyltin according to a mass ratio of 3: 1 component), 2 parts of antioxidant 1010 and 4 parts of dibenzoyl peroxide for later use;

2) putting the ethylene-butylene block copolymer into a reaction kettle, and adding tetrahydrofuran to dissolve (mass-volume ratio of ethylene-butylene block copolymer to tetrahydrofuran is 1: 40 g: mL), replacing air in the reaction kettle with inert gas, then adding maleic anhydride, heating to 195 ℃, and slowly stirring overnight;

3) spin-drying the solvent of the mixture obtained in the step 2), placing the mixture in a stirrer, adding 1/6 mass of dibenzoyl peroxide and 1010 mass of antioxidant, and fully stirring and mixing;

4) and (3) transferring the mixture obtained in the step 3) into a double-screw extruder from a main feeding port, adding the organic tin compound and the residual dibenzoyl peroxide through side feeding, and carrying out melt extrusion and granulation at 240 ℃ to obtain the compatilizer.

Comparative example 2

1) Weighing 150 parts by mass of the polyolefin copolymer prepared in example 1, 15 parts by mass of maleic anhydride, 2 parts by mass of antioxidant 1010 and 4 parts by mass of dibenzoyl peroxide for later use;

2) and (2) putting the polyolefin copolymer into a reaction kettle, and adding tetrahydrofuran for dissolution (the mass-volume ratio of the polyolefin copolymer to the tetrahydrofuran is 1: 40 g: mL), replacing air in the reaction kettle with inert gas, then adding maleic anhydride, heating to 195 ℃, and slowly stirring overnight;

3) spin-drying the solvent of the mixture obtained in the step 2), placing the mixture in a stirrer, adding 1/6 mass of dibenzoyl peroxide and 1010 mass of antioxidant, and fully stirring and mixing;

4) and (3) transferring the mixture obtained in the step 3) into a double-screw extruder from a main feeding port, adding the residual dibenzoyl peroxide through side feeding, and carrying out melt extrusion and granulation at 240 ℃ to obtain the compatilizer.

Comparative example 3

1) Weighing 150 parts of ethylene-butylene block copolymer, 15 parts of maleic anhydride, 2 parts of antioxidant 1010 and 4 parts of dibenzoyl peroxide for later use;

2) putting the ethylene-butylene block copolymer into a reaction kettle, and adding tetrahydrofuran to dissolve (mass-volume ratio of ethylene-butylene block copolymer to tetrahydrofuran is 1: 40 g: mL), replacing air in the reaction kettle with inert gas, then adding maleic anhydride, heating to 195 ℃, and slowly stirring overnight;

3) spin-drying the solvent of the mixture obtained in the step 2), placing the mixture in a stirrer, adding 1/6 mass of dibenzoyl peroxide and 1010 mass of antioxidant, and fully stirring and mixing;

4) and (3) transferring the mixture obtained in the step 3) into a double-screw extruder from a main feeding port, adding the residual dibenzoyl peroxide through side feeding, and carrying out melt extrusion and granulation at 240 ℃ to obtain the compatilizer.

The compatibilizers prepared in examples 3 to 7 and comparative examples 1 to 3 were used to manufacture cables by the following methods, respectively:

1) taking 100 parts of metallocene polyethylene, 12 parts of compatilizer, 35 parts of non-halogen flame retardant (nano montmorillonite, magnesium hydroxide, aluminum hydroxide, organic tin compound (composed of dioctyltin and triphenyltin according to the mass ratio of 3: 1) according to the equal mass ratio) and 10103 parts of antioxidant according to the mass parts;

2) adding the raw materials into a stirrer, stirring at a high speed of 1000r/min for 10min at 220 ℃, and then transferring the mixture to a double-screw extruder for melt extrusion and granulation to obtain the cable.

The performance of the prepared cable was measured, and the results are shown in table 3.

TABLE 3

Wherein the detection standard of the tensile strength is GB/T1040.1; the detection standard of vertical combustion is GB/T2408; the detection standard of the limit oxygen index is GB/T2406.

As can be seen from the data of examples 3-7 in the table, the cable prepared by using the compatilizer prepared by the invention has excellent tensile strength and flame retardant property; the data of the comparative example 3 and the comparative example 1 show that the tensile strength of the compatilizer prepared from the ethylene-butylene block copolymer which is not modified by the glycidyl methacrylate is greatly reduced, and the flame retardant property of the cable is also reduced, which is probably because the compatilizer lacks acrylate double bonds and epoxy groups with high activity of the glycidyl methacrylate, the subsequent block copolymerization of maleic anhydride and organic tin compounds is difficult, and the multi-block copolymer cannot be effectively formed, so that the compatilizer has poor compatibility effect, the non-halogen flame retardant is unevenly dispersed and not fine in the cable matrix resin, the mechanical property is greatly reduced, and the flame retardant property of the cable is also influenced to a certain extent; the data of the comparative example 3 and the comparative example 2 show that the cable prepared by the compatilizer which is not modified by the organic tin compound has greatly reduced flame retardant property and small reduced tensile strength, which probably results from disappearance of the synergistic effect of the compatilizer which lacks an organic tin block and the flame retardant containing the organic tin component, thus seriously influencing the flame retardant effect of the flame retardant, and also limits the blending ratio of the flame retardant and the cable matrix resin, so that part of the flame retardant can not be uniformly dispersed, thereby reducing the mechanical property of the cable.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will understand that: modifications to the embodiments of the present application or equivalent replacements of some technical features may still be made, which should all be covered by the scope of the technical solution claimed in the present application.