A low-smoke, halogen-free flame-retardant polyolefin composite material for energy storage connecting wires

Abstract

The present invention relates to a low-smoke and halogen-free flame-retardant polyolefin composite material for energy storage connecting wires, belonging to the technical field of polyolefin composite material preparation. It 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 formed by hydrosilylation polymerization reaction of 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 nitrogen-based flame retardants, silicon-based flame retardants and phosphorus-based flame retardants, having excellent thermal stability, char-forming property, smoke suppression property and preventing melt dripping property. Through its introduction, the obtained polyolefin composite material is endowed with high flame-retardant property and thermal stability.

Description

Technical Field

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

[0002] Due to its excellent mechanical properties, chemical stability, and easy processability, polyolefin is widely used in energy storage connection wires. However, since polyolefin is composed of only carbon and hydrogen elements, it is not heat-resistant and is easy to burn without flame-retardant properties, resulting in far lower flame-retardant safety when used in energy storage connection wires than those made of traditional polyvinyl chloride. Although polyvinyl chloride itself has certain flame-retardant properties, when it burns, it is easy to release toxic smoke containing hydrogen halide, which is not environmentally friendly, and thus it is gradually replaced by energy storage connection wires made of polyolefin. Therefore, when preparing energy storage connection wires from polyolefin, a flame retardant is generally added to the polyolefin base material to improve its flame-retardant performance. However, in the existing domestic flame retardant systems, halogen-based flame retardants (such as decabromodiphenyl ether, chlorinated paraffin, etc.) are mainly used. However, when these flame retardants are used, they have poor compatibility with the polymer matrix, release toxic gases and produce a large amount of smoke when burning, which has a serious impact on the environment. While foreign flame retardant systems are mainly based on inorganic flame retardants (such as magnesium hydroxide, aluminum hydroxide, etc.). To achieve the flame-retardant effect, a relatively high addition amount is often required, but a high addition amount has a negative impact on the mechanical properties of the material.

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

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

[0005] The technical problem to be solved by the present invention is that when preparing energy storage connection wires from existing polyolefin, the introduction of halogen-based flame retardants is used to improve its flame-retardant performance, resulting in the obtained flame-retardant polyolefin composite material being non-environmentally friendly when burned.

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

[0007] A low-smoke and halogen-free flame-retardant polyolefin composite material for energy storage connection wires, 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 compatibilizer, 2 - 5 parts of antioxidant, and 2 - 5 parts of lubricant.

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

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

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

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

[0012] Preferably, the hydrosilylation polymerization reaction includes:

[0013] Mix the binary flame retardant monomer, N-isobornyl acrylamide, the first catalyst and the first organic solvent evenly, and under nitrogen protection, heat to 70 - 85 °C, stir and react for 6 - 12 h, then raise the temperature to 100 - 110 °C, keep warm and stir for 10 - 20 h, perform rotary evaporation, washing, and drying to obtain the flame retardant resin.

[0014] Further, the molecular formula of N-isobornyl acrylamide is shown as follows.

[0015]

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

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

[0018]

[0019] Further, the binary flame retardant monomer is formed by the substitution reaction of a 3-hydroxy-2-(hydroxymethyl)propionic acid derivative and a compound 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 acid-binding agent and / or a second catalyst.

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

[0022] Further, the acid-binding agent is one of potassium carbonate, sodium carbonate, and aluminum oxide.

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

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

[0025] Preferably, the substitution reaction includes:

[0026] After uniformly mixing a 3-hydroxy-2-(hydroxymethyl)propionic acid derivative, dimethylchlorosilane, and a second organic solvent, an acid-binding agent and a second catalyst are added under stirring, and the mixture is heated to 70-95 °C under reflux of condensed water, reacted for 6-24 h, the reaction is stopped, rotary evaporation is carried out under reduced pressure, washed with water, and dried to obtain a binary flame retardant monomer;

[0027] Wherein, the addition amount of the acid-binding agent is equivalent to or in excess of the hydrogen chloride generated by the substitution reaction of glycerol and dimethylchlorosilane, and the addition amount of the second catalyst is 1-3% of the total mass of glycerol and dimethylchlorosilane.

[0028] Further, the molecular structural formula of the 3-hydroxy-2-(hydroxymethyl)propionic acid derivative is as follows.

[0029]

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

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

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

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

[0034] Further, the molecular structural formula of the hydroxy cage-like phosphate is as follows.

[0035]

[0036] The hydroxy cage-like phosphate is formed by the reaction of pentaerythritol and phosphorus oxychloride in the resin of the present technical field, and the present invention will not elaborate on this.

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

[0038] Further, the compatibilizer is a maleic anhydride grafted compatibilizer, such as maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, etc.

[0039] The beneficial effects of the present invention:

[0040] The low-smoke, halogen-free flame-retardant polyolefin composite material for energy storage connection wires 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] Remarkably, the molecular chain of the flame-retardant resin contains nitrogen, silicon, and phosphorus, and it is a comprehensive flame retardant integrating nitrogen-based flame retardants, silicon-based flame retardants, and phosphorus-based flame retardants. Moreover, the cage-like phosphate ester structure and the N-isobornyl ring structure contained therein both have excellent thermal stability, char-forming properties, and play the role of an intumescent flame retardant. During combustion, the two can form a dense carbon layer, which not only isolates oxygen and heat but also reduces the generation of smoke and corrosive gases and prevents the phenomenon of dripping. The silicon-oxygen bond contained in its molecule forms a silicon-oxygen layer during the combustion process, playing the role of a silicon-based flame retardant. Therefore, the flame-retardant resin has excellent flame-retardant, smoke-suppressing, and anti-dripping effects. Through its introduction, the phenomenon that the polyolefin material is prone to dripping and generating smoke during combustion can be significantly modified, endowing the obtained polyolefin composite material with high flame-retardant properties. Moreover, at the same time, the obtained polyolefin composite material is endowed with good thermal stability. Detailed implementation manners

[0042] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0043] Example 1

[0044] Flame-retardant resin:

[0045] A1. Mix 0.1 mol of 3-hydroxy-2-(hydroxymethyl)propionic acid, 0.1 mol of hydroxy cage-like phosphate ester, and 80 mL of toluene evenly, then dropwise add concentrated sulfuric acid (mass fraction 98%), and after complete dropping, heat to 95 °C, react for 2 h, stop the reaction, rotary evaporate, wash with water, and dry to obtain a 3-hydroxy-2-(hydroxymethyl)propionic acid derivative;

[0046] A2. Mix 0.1 mol of 3-hydroxy-2-(hydroxymethyl)propionic acid derivative, 0.2 mol of dimethylchlorosilane, and 100 mL of dimethyl sulfoxide evenly, then add 0.1 mol of potassium carbonate and 0.4 g of potassium iodide under stirring, and heat to 70 °C under reflux of condensed water, stir and react for 24 h, stop the reaction, rotary evaporate under reduced pressure, wash with water, and dry to obtain a binary flame-retardant monomer;

[0047] A3. Mix 0.1 mol of a binary flame retardant monomer, 0.1 mol of N-isobornyl acrylamide, 10 g of a platinum-loaded catalyst, and N,N-dimethylformamide uniformly. Under nitrogen protection, heat the mixture to 70 °C, stir and react for 12 h, then raise the temperature to 110 °C, keep the temperature and stir for 10 h, perform rotary evaporation, washing, and drying to obtain a flame retardant resin.

[0048] Example 2

[0049] Flame retardant resin:

[0050] A1. Mix 0.13 mol of 3-hydroxy-2-(hydroxymethyl)propionic acid, 0.1 mol of a hydroxy cage-like phosphate ester, and 80 mL of acetonitrile uniformly. Then, dropwise add concentrated sulfuric acid (mass fraction 98%). After complete addition, heat the mixture to 70 °C, react for 7 h, stop the reaction, perform rotary evaporation, wash with water, and dry to obtain a 3-hydroxy-2-(hydroxymethyl)propionic acid derivative.

[0051] A2. Mix 0.1 mol of the 3-hydroxy-2-(hydroxymethyl)propionic acid derivative, 0.25 mol of dimethylchlorosilane, and 100 mL of N,N-dimethylformamide uniformly. Under stirring, add 0.1 mol of potassium carbonate and 0.4 g of potassium iodide, and heat the mixture to 95 °C under reflux of condensed water, stir and react for 6 h, stop the reaction, perform rotary evaporation under reduced pressure, wash with water, and dry to obtain a binary flame retardant monomer.

[0052] A3. Mix 0.1 mol of the binary flame retardant monomer, 0.1 mol of N-isobornyl acrylamide, 10 g of a platinum-loaded catalyst, and 100 mL of N,N-dimethylformamide uniformly. Under nitrogen protection, heat the mixture to 85 °C, stir and react for 6 h, then raise the temperature to 100 °C, keep the temperature and stir for 20 h, perform rotary evaporation, washing, and drying to obtain a flame retardant resin.

[0053] Example 3

[0054] Polyolefin composite material:

[0055] First step. Prepare raw materials including the following parts by weight: 100 parts of a polyolefin resin (low-density polyethylene), 20 parts of the flame retardant resin prepared in Example 1, 4 parts of a compatibilizer (maleic anhydride grafted polyethylene), 2 parts of an antioxidant (a mixture of antioxidant 168 and antioxidant 1010 mixed in a mass ratio of 1:1), and 2 parts of a lubricant (polyethylene wax).

[0056] Second step. Extrude and pelletize the above raw materials through a twin-screw extruder to obtain a polyolefin composite material, and the extrusion temperature is 130 - 170 °C.

[0057] Example 4

[0058] Polyolefin composite material:

[0059] Step 1: Prepare raw materials including the following parts by weight: 100 parts of polyolefin resin (low-density polyethylene), 35 parts of the 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 mixed in a mass ratio of 1:1), and 4 parts of lubricant (polyethylene wax);

[0060] Step 2: Extrude and pelletize the above raw materials through a twin-screw extruder to obtain a polyolefin composite material, with an extrusion temperature of 130 - 170 °C.

[0061] Example 5

[0062] Polyolefin composite material:

[0063] Step 1: Prepare raw materials including the following parts by weight: 100 parts of polyolefin resin (low-density polyethylene), 45 parts of the 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 mixed in a mass ratio of 1:1), and 5 parts of lubricant (polyethylene wax);

[0064] Step 2: Extrude and pelletize the above raw materials through a twin-screw extruder to obtain a polyolefin composite material, with an extrusion temperature of 130 - 170 °C.

[0065] Comparative Example 1

[0066] Polyolefin composite material:

[0067] Compared with Example 3, the flame retardant resin is replaced with an equal amount of resin prepared by the following steps, and the rest is the same:

[0068] Mix 0.1 mol of the binary flame retardant monomer prepared in Step A2 of the example, 0.1 mol of styrene, 10 g of platinum-loaded catalyst, and 100 mL of N,N-dimethylformamide uniformly, and under nitrogen protection, heat to 70 °C, stir and react for 12 h, raise the temperature to 110 °C, keep warm and stir for 10 h, perform rotary evaporation, washing, and drying to obtain the flame retardant resin.

[0069] Comparative Example 2

[0070] Polyolefin composite material:

[0071] Compared with Example 3, the flame retardant resin is replaced with an equal amount of resin prepared by the following steps, and the rest is the same:

[0072] Mix 0.1 mol of styrene, 0.1 mol of N-isobornyl acrylamide, 10 g of platinum-loaded catalyst, and N,N-dimethylformamide uniformly, and under nitrogen protection, heat to 70 °C, stir and react for 6 h, raise the temperature to 110 °C, keep warm and stir for 10 h, perform rotary evaporation, washing, and drying to obtain the flame retardant resin.

[0073] Comparative Example 3

[0074] Polyolefin composite material:

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

[0076] The pellets obtained in Examples 3-5 and Comparative Examples 1-3 were molded into specimens for physical property testing. The test results are shown in Table 1. Among them, the smoke generation rate was measured by a smoke density tester with a set radiation intensity of 25 kW·m -2 , and the sample size was 75x75x2.5 mm 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 performance and heat resistance.

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

[0082] The above content is only an example and explanation of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should all belong to the protection scope of the present invention.

Claims

1. A low-smoke, halogen-free, flame-retardant polyolefin composite material for energy storage connection wires, characterized in that: It 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 formed by hydrosilylation polymerization reaction of a binary flame retardant monomer and N - isobornyl acrylamide in a first organic solvent and a first catalyst; The molecular structural formula of the binary flame retardant monomer is as follows: The binary flame retardant monomer is formed by substituting reaction of a 3 - hydroxy - 2 - (hydroxymethyl)propionic acid derivative and dimethylchlorosilane in a molar ratio of 1:2 - 2.5 in a second organic solvent; the 3 - hydroxy - 2 - (hydroxymethyl)propionic acid derivative is formed by esterification reaction of 3 - hydroxy - 2 - (hydroxymethyl)propionic acid and hydroxy - cage - like phosphate in a molar ratio of 1 - 1.3:1 in a third organic solvent and a third catalyst; The reaction temperature of the substitution reaction is 70 - 95 °C, and the reaction time is 6 - 24 h.

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

3. The low-smoke, halogen-free, flame-retardant polyolefin composite material for an energy storage connection line according to claim 1, wherein, 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 an energy storage connection line according to claim 1, wherein The hydrosilylation polymerization reaction includes: Mix the binary flame retardant monomer, N - isobornyl acrylamide, the first catalyst and the first organic solvent evenly, and under nitrogen protection, heat to 70 - 85 °C, stir and react for 6 - 12 h, then raise the temperature to 100 - 110 °C, keep warm and stir for 10 - 20 h, and after post - treatment, obtain the flame retardant resin.

5. The low-smoke and halogen-free flame-retardant polyolefin composite material for an energy storage connecting wire according to claim 1, wherein The substitution reaction occurs under the action of an acid - binding agent and / or a second catalyst.

6. The low-smoke and halogen-free flame-retardant polyolefin composite material for an energy storage connection wire according to claim 5, 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 acid - binding agent is one of potassium carbonate, sodium carbonate, and aluminum oxide; the second catalyst is potassium iodide.

7. The low-smoke, halogen-free and flame-retardant polyolefin composite material for an energy storage connecting wire according to claim 1, wherein, The temperature of the esterification reaction is 65 - 95 °C, and the reaction time is 2 - 8 h.

8. The low-smoke and halogen-free flame-retardant polyolefin composite material for an energy storage connecting wire according to claim 1, wherein The polyolefin resin is polyethylene or polypropylene.

Images