Low-smoke halogen-free flame-retardant polyolefin composite material for energy storage connecting line

Abstract

The invention relates to a low-smoke halogen-free flame-retardant polyolefin composite material for an energy storage connecting line, and belongs to the technical field of preparation of polyolefin composite materials. Comprising the following raw materials in parts by weight: 100 parts of polyolefin resin, 20-45 parts of flame-retardant resin, 4-12 parts of a compatilizer, 2-5 parts of an antioxidant and 2-5 parts of a lubricant, the flame-retardant resin is generated by carrying out hydrosilylation polymerization reaction on a binary flame-retardant monomer and N-isobornyl acrylamide in a first organic solvent and a first catalyst. The flame-retardant resin is a comprehensive flame retardant integrating a nitrogen flame retardant, a silicon flame retardant and a phosphorus flame retardant, and has excellent thermal stability, carbon forming property, smoke suppression property and molten drop prevention property, and by introducing the flame-retardant resin, the obtained polyolefin composite material is endowed with high flame-retardant property and thermal stability.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of polyolefin composite materials, and in particular relates to a low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wires. Background Art

[0002] Polyolefins are widely used in energy storage cables due to their excellent mechanical properties, chemical stability and easy processing. However, since polyolefins are composed of two elements, carbon and hydrogen, they are not heat-resistant, easy to burn, and have no flame retardant properties. As a result, when used in energy storage cables, their flame retardant safety is far lower than that of traditional energy storage cables made of polyvinyl chloride. Although polyvinyl chloride itself has certain flame retardancy, it is easy to release toxic fumes containing hydrogen halides when it burns, which is not environmentally friendly, and is gradually replaced by energy storage cables made of polyolefins. Therefore, when energy storage cables are prepared from polyolefins, flame retardants are generally added to the polyolefin base material to improve its flame retardant properties. However, in the existing domestic flame retardant system, halogen flame retardants (decabromodiphenyl ether, chlorinated paraffin, etc.) are mainly used, but this type of flame retardant has poor compatibility with the polymer matrix when used, releases toxic gases and smoke when burned, and has a serious impact on the environment. Foreign flame retardant systems are mainly based on inorganic flame retardants (magnesium hydroxide, aluminum hydroxide, etc.), which often require a higher addition amount to achieve the flame retardant effect. However, the high addition amount has a negative impact on the mechanical properties of the material.

[0003] Therefore, it is necessary to provide a low-smoke, halogen-free, flame-retardant polyolefin composite material with good mechanical properties for energy storage connecting wires. Summary of the invention

[0004] The object of the present invention is to provide a low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wires.

[0005] The technical problem to be solved by the present invention is that when the existing energy storage connecting wire is prepared from polyolefin, the flame retardant property thereof is improved by introducing halogen flame retardants, which causes the combustion of the obtained flame retardant polyolefin composite material to be environmentally unfriendly.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A low-smoke, halogen-free, flame-retardant polyolefin composite material for an energy storage connecting line comprises the following raw materials in parts by weight: 100 parts of polyolefin resin, 20-45 parts of flame-retardant resin, 4-12 parts of compatibilizer, 2-5 parts of antioxidant, and 2-5 parts of lubricant.

[0008] Furthermore, the flame retardant resin is produced by a hydrosilylation polymerization reaction of a binary flame retardant monomer and N-isobornyl acrylamide in a first organic solvent and a first catalyst.

[0009] Furthermore, the first organic solvent is one of N,N-dimethylformamide and N,N-dimethylacetamide.

[0010] Furthermore, the first catalyst is one of a platinum-supported catalyst and a palladium-supported catalyst.

[0011] Furthermore, the molar ratio of the binary flame retardant monomer to N-isobornyl acrylamide is 1:1.

[0012] Preferably, the hydrosilylation polymerization reaction comprises:

[0013] The binary flame retardant monomer, N-isobornyl acrylamide, the first catalyst and the first organic solvent are mixed uniformly, and heated to 70-85° C. under nitrogen protection, stirred for reaction for 6-12 hours, heated to 100-110° C., kept warm and stirred for 10-20 hours, rotary evaporated, washed and dried to obtain a flame retardant resin.

[0014] Furthermore, the molecular formula of the N-isobornyl acrylamide is shown below.

[0015]

[0016] Furthermore, the preparation of N-isobornyl acrylamide is well known in the art, and the present invention does not limit its preparation process.

[0017] Furthermore, the molecular formula of the binary flame retardant monomer is as follows.

[0018]

[0019] Furthermore, the binary flame retardant monomer is produced by a substitution reaction of a 3-hydroxy-2-(hydroxymethyl) propionic acid derivative and a mixture in a molar ratio of 1:2-2.5 in a second organic solvent.

[0020] Preferably, the substitution reaction occurs under the action of an acidifying agent and / or a second catalyst.

[0021] Furthermore, the second organic solvent is one of toluene, acetonitrile, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0022] Furthermore, the acid dressing agent is one of potassium carbonate, sodium carbonate and aluminum oxide.

[0023] Furthermore, the second catalyst is potassium iodide.

[0024] Furthermore, the reaction temperature of the substitution reaction is 70-95°C, and the reaction time is 6-24h.

[0025] Preferably, the substitution reaction comprises:

[0026] After uniformly mixing 3-hydroxy-2-(hydroxymethyl)propionic acid derivative, dimethylchlorosilane and the second organic solvent, adding an acid coating agent and a second catalyst under stirring, heating to 70-95° C. under reflux of condensed water, reacting for 6-24 hours, stopping the reaction, vacuum rotary evaporation, washing with water, and drying to obtain a binary flame retardant monomer;

[0027] The amount of the acid coating agent added is an equivalent or excess amount of the hydrogen chloride generated by the substitution reaction of glycerol and dimethylchlorosilane, and the amount of the second catalyst added is 1-3% of the total mass of glycerol and dimethylchlorosilane.

[0028] Furthermore, the molecular structural formula of the 3-hydroxy-2-(hydroxymethyl)propionic acid derivative is shown below.

[0029]

[0030] Furthermore, the 3-hydroxy-2-(hydroxymethyl)propionic acid derivative is formed by mixing 3-hydroxy-2-(hydroxymethyl)propionic acid and hydroxy caged phosphate in a molar ratio of 1-1.3:1, and undergoing an esterification reaction in a third organic solvent and a third catalyst.

[0031] Furthermore, the third organic solvent is one of toluene, acetonitrile and 1,4-dioxane.

[0032] Furthermore, the third catalyst is an esterification catalyst, such as concentrated sulfuric acid (mass fraction 98%).

[0033] Furthermore, the temperature of the esterification reaction is 65-95° C., and the reaction time is 2-8 hours.

[0034] Furthermore, the molecular structure of the hydroxy caged phosphate is as follows.

[0035]

[0036] The hydroxy caged phosphate is produced by the reaction of pentaerythritol and phosphorus oxychloride of the resin in the technical field, which will not be described in detail in the present invention.

[0037] Furthermore, the polyolefin resin is polyethylene or polypropylene.

[0038] Furthermore, the compatibilizer is a maleic anhydride grafted compatibilizer, such as maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, and the like.

[0039] Beneficial effects of the present invention:

[0040] The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire provided by the present invention introduces a flame-retardant resin into a polyolefin base material, thereby obtaining a highly flame-retardant and smokeless polyolefin composite material;

[0041] Significantly, the flame retardant resin contains nitrogen, silicon and phosphorus in its molecular chain, and is a comprehensive flame retardant that combines nitrogen flame retardants, silicon flame retardants and phosphorus flame retardants. The cage-like phosphate structure and N-isoborneol ring structure contained therein have excellent thermal stability and carbonization, and act as an intumescent flame retardant. The two can form a dense carbon layer when burning, which not only isolates oxygen and heat, but also reduces the generation of smoke and corrosive gases, and prevents dripping. The silicon-oxygen bonds contained in its molecules form a silicon-oxygen layer during the combustion process, playing the role of a silicon flame retardant. Therefore, the flame retardant resin has excellent flame retardancy, smoke suppression and anti-drip effects. Through its introduction, the phenomenon of easy dripping and easy smoke generation during combustion of polyolefin materials can be significantly modified, giving the obtained polyolefin composite material high flame retardant properties, and at the same time, giving the obtained polyolefin composite material good thermal stability. DETAILED DESCRIPTION

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example 1

[0044] Flame retardant resin:

[0045] A1. After 0.1 mol 3-hydroxy-2-(hydroxymethyl)propionic acid, 0.1 mol hydroxy caged phosphate and 80 mL toluene are uniformly mixed, concentrated sulfuric acid (mass fraction 98%) is added dropwise, and after the addition is complete, the mixture is heated to 95° C. and reacted for 2 h. The reaction is stopped, and the mixture is rotary evaporated, washed with water and dried to obtain a 3-hydroxy-2-(hydroxymethyl)propionic acid derivative;

[0046] A2, after 0.1 mol 3-hydroxy-2-(hydroxymethyl)propionic acid derivative, 0.2 mol dimethylchlorosilane and 100 mL dimethyl sulfoxide are mixed evenly, 0.1 mol potassium carbonate and 0.4 g potassium iodide are added under stirring, and the mixture is heated to 70° C. under reflux of condensed water, stirred for reaction for 24 h, the reaction is stopped, vacuum rotary evaporation is performed, the mixture is washed with water, and dried to obtain a binary flame retardant monomer;

[0047] A3. Evenly mix 0.1 mol binary flame retardant monomer, 0.1 mol N-isobornyl acrylamide, 10 g platinum-supported catalyst and N,N-dimethylformamide, and heat to 70°C under nitrogen protection, stir and react for 12 h, then heat to 110°C, keep stirring for 10 h, rotary evaporate, wash and dry to obtain flame retardant resin.

[0048] Example 2

[0049] Flame retardant resin:

[0050] A1. After 0.13 mol 3-hydroxy-2-(hydroxymethyl)propionic acid, 0.1 mol hydroxy caged phosphate and 80 mL acetonitrile are uniformly mixed, concentrated sulfuric acid (mass fraction 98%) is added dropwise. After the addition is complete, the mixture is heated to 70° C. and reacted for 7 h. The reaction is stopped, and the mixture is rotary evaporated, washed with water and dried to obtain a 3-hydroxy-2-(hydroxymethyl)propionic acid derivative.

[0051] A2, after 0.1 mol 3-hydroxy-2-(hydroxymethyl)propionic acid derivative, 0.25 mol dimethylchlorosilane and 100 mL N, N-dimethylformamide are uniformly mixed, 0.1 mol potassium carbonate and 0.4 g potassium iodide are added under stirring, and the mixture is heated to 95° C. under reflux of condensed water, stirred for reaction for 6 h, the reaction is stopped, vacuum rotary evaporation is performed, water washing is performed, and drying is performed to obtain a binary flame retardant monomer;

[0052] A3. Evenly mix 0.1 mol binary flame retardant monomer, 0.1 mol N-isobornyl acrylamide, 10 g platinum-supported catalyst and 100 mL N,N-dimethylformamide, and heat to 85°C under nitrogen protection, stir and react for 6 h, raise the temperature to 100°C, keep stirring for 20 h, rotary evaporate, wash and dry to obtain flame retardant resin.

[0053] Example 3

[0054] Polyolefin composites:

[0055] The first step is to prepare the following raw materials in parts by weight: 100 parts of polyolefin resin (low-density polyethylene), 20 parts of flame-retardant resin prepared in Example 1, 4 parts of compatibilizer (maleic anhydride grafted polyethylene), 2 parts of antioxidant (a mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 1:1), and 2 parts of lubricant (polyethylene wax);

[0056] The second step is to extrude the above raw materials through a twin-screw extruder and granulate them to obtain a polyolefin composite material at an extrusion temperature of 130-170°C.

[0057] Example 4

[0058] Polyolefin composites:

[0059] The first step is to prepare the following raw materials in parts by weight: 100 parts of polyolefin resin (low-density polyethylene), 35 parts of flame-retardant resin prepared in Example 1, 8 parts of compatibilizer (maleic anhydride grafted polyethylene), 4 parts of antioxidant (a mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 1:1), and 4 parts of lubricant (polyethylene wax);

[0060] The second step is to extrude the above raw materials through a twin-screw extruder and granulate them to obtain a polyolefin composite material at an extrusion temperature of 130-170°C.

[0061] Example 5

[0062] Polyolefin composites:

[0063] The first step is to prepare the following raw materials in parts by weight: 100 parts of polyolefin resin (low-density polyethylene), 45 parts of flame-retardant resin prepared in Example 1, 12 parts of compatibilizer (maleic anhydride grafted polyethylene), 5 parts of antioxidant (a mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 1:1), and 5 parts of lubricant (polyethylene wax);

[0064] The second step is to extrude the above raw materials through a twin-screw extruder and granulate them to obtain a polyolefin composite material at an extrusion temperature of 130-170°C.

[0065] Comparative Example 1

[0066] Polyolefin composites:

[0067] Compared with Example 3, the flame retardant resin was replaced by the following resin prepared in the following steps, and the rest was the same:

[0068] 0.1 mol of the binary flame retardant monomer prepared in step A2 of Example, 0.1 mol of styrene, 10 g of a platinum-supported catalyst and 100 mL of N,N-dimethylformamide were mixed evenly, and heated to 70°C under nitrogen protection, stirred for reaction for 12 h, heated to 110°C, stirred for 10 h, rotary evaporated, washed and dried to obtain a flame retardant resin.

[0069] Comparative Example 2

[0070] Polyolefin composites:

[0071] Compared with Example 3, the flame retardant resin was replaced by the following resin prepared in the following steps, and the rest was the same:

[0072] 0.1 mol styrene, 0.1 mol N-isobornyl acrylamide, 10 g platinum-supported catalyst and N,N-dimethylformamide were mixed evenly, heated to 70°C under nitrogen protection, stirred for reaction for 6 hours, heated to 110°C, stirred for 10 hours, rotary evaporated, washed and dried to obtain flame retardant resin.

[0073] Comparative Example 3

[0074] Polyolefin composites:

[0075] Compared with Example 3, the flame retardant resin is deleted, and the rest is the same.

[0076] The pellets obtained in Examples 3-5 and Comparative Examples 1-3 were molded into samples and tested for physical properties. The test results are shown in Table 1. The smoke generation rate was tested using a smoke density tester, with the radiation intensity set at 25 kW·m -2 , sample size is 75x75x2.5mm 3 .

[0077] Table 1

[0078]

[0079]

[0080] It can be seen from the data in Table 1 that the polyolefin composite materials obtained in Examples 3-5 of the present invention have excellent flame retardancy, smoke suppression and heat resistance.

[0081] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0082] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wires, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of polyolefin resin, 20-45 parts of flame retardant resin, 4-12 parts of compatibilizer, 2-5 parts of antioxidant and 2-5 parts of lubricant; The flame retardant resin is produced by a hydrosilylation polymerization reaction of a binary flame retardant monomer and N-isobornyl acrylamide in a first organic solvent and a first catalyst; The molecular structure of the binary flame retardant monomer is as follows:

2. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 1, characterized in that: The first organic solvent is one of N,N-dimethylformamide and N,N-dimethylacetamide; the first catalyst is one of a platinum-supported catalyst and a palladium-supported catalyst.

3. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 1, characterized in that: The molar ratio of the binary flame retardant monomer to N-isobornyl acrylamide is 1:

1.

4. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 1, characterized in that: The hydrosilylation polymerization reaction comprises: The binary flame retardant monomer, N-isobornyl acrylamide, the first catalyst and the first organic solvent are uniformly mixed, and heated to 70-85° C. under nitrogen protection, stirred for reaction for 6-12 hours, heated to 100-110° C., kept warm and stirred for 10-20 hours, and post-treated to obtain a flame retardant resin.

5. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 1, characterized in that: The binary flame retardant monomer is formed by a substitution reaction in a second organic solvent, wherein a 3-hydroxy-2-(hydroxymethyl) propionic acid derivative, a hydroxy caged phosphate and a dimethylchlorosilane are mixed in a molar ratio of 1:2-2.5; and the 3-hydroxy-2-(hydroxymethyl) propionic acid derivative is formed by an esterification reaction in a third organic solvent and a third catalyst, wherein the 3-hydroxy-2-(hydroxymethyl) propionic acid derivative is mixed in a molar ratio of 1-1.3:1 and a hydroxy caged phosphate is mixed.

6. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 5, characterized in that: The substitution reaction occurs under the action of an acidifying agent and / or a second catalyst.

7. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 6, characterized in that: The second organic solvent is one of toluene, acetonitrile, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; the acidifying agent is one of potassium carbonate, sodium carbonate, and aluminum oxide; and the second catalyst is potassium iodide.

8. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 5, characterized in that: The reaction temperature of the substitution reaction is 70-95° C., and the reaction time is 6-24 h.

9. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 5, characterized in that: The temperature of the esterification reaction is 65-95° C., and the reaction time is 2-8 hours.

10. The low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connecting wire according to claim 1, characterized in that: The polyolefin resin is polyethylene or polypropylene.

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