Highly flame retardant insulating material and method for its production

Abstract

The application relates to a high-flame-retardant insulating material and a preparation method thereof, and belongs to the technical field of flame-retardant insulating materials. The material comprises the following raw materials in parts by weight: 60-80 parts of a base resin, 10-30 parts of modified phenyl hydrogen-containing silicon resin, 10-20 parts of a nitrogen-based flame retardant, 4-10 parts of ethylene-acrylic acid copolymer, and 2-6 parts of a crosslinking agent; the modified phenyl hydrogen-containing silicon resin is prepared through a silicon hydrogen addition reaction of phenyl hydrogen-containing silicon resin and a modifier; and the modifier is prepared through a reaction of hexamethylol melamine and acrylic acid and an epoxy silane coupling agent. The polyolefin resin is used as the base resin, the modified phenyl hydrogen-containing silicon resin is used as the filler resin, the ethylene-acrylic acid copolymer and the crosslinking agent are simultaneously introduced, the overall performance of the finally obtained composite material is further improved, the heat resistance, water resistance and high flame retardance of the composite material are endowed, and the insulating performance of the composite material under high temperature is ensured.

Description

Technical Field

[0001] This invention belongs to the technical field of flame-retardant insulating materials, specifically, it relates to a highly flame-retardant insulating material and its preparation method. Background Technology

[0002] High flame-retardant insulating materials refer to materials that can maintain their insulating properties under high temperatures or fire conditions. They are widely used in fields requiring high safety standards, such as wires and cables and electronic equipment. Existing high flame-retardant materials are generally composite materials formed by processing base materials, flame retardants, and other auxiliary materials. However, the insulating properties of composite materials are affected by both temperature and humidity. When composite materials are exposed to high temperatures, the chemical bonds within the material change (e.g., break), leading to a decrease in their insulating properties.

[0003] Therefore, while obtaining highly flame-retardant materials, it is also necessary to take into account the high-temperature resistance of the resulting composite materials. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide a highly flame-retardant insulating material and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] The first objective of this invention can be achieved through the following technical solution:

[0007] A highly flame-retardant insulating material comprises the following raw materials in parts by weight: 60-80 parts matrix resin, 10-30 parts modified phenyl hydrogen-containing silicone resin, 10-20 parts nitrogen-based flame retardant, 4-10 parts ethylene-acrylic acid copolymer, and 2-6 parts crosslinking agent.

[0008] The modified phenyl hydrogen-containing silicone resin is prepared by a hydrosilylation reaction of phenyl hydrogen-containing silicone resin and a modifier;

[0009] The modifier is prepared by reacting hexamethylolmelamine with acrylic acid and an epoxy silane coupling agent.

[0010] Based on the excellent high-temperature resistance, flame retardancy, water resistance, chemical resistance, and insulation properties of phenyl-hydrosilicone resin, the inventors introduced it into the matrix resin (olefin resin). However, considering that the flame retardant properties of phenyl-hydrosilicone resin are insufficient to impart high flame retardant properties to the composite material, this invention addresses the issue of enhancing the flame retardancy of phenyl-hydrosilicone resin by using a modifier to modify it. This modifier introduces a high-nitrogen structure (from hexamethylolmelamine) and a flexible chain (from an epoxy silane coupling agent) into its molecular chain, resulting in a modified phenyl-hydrosilicone resin that possesses the characteristics of a composite flame retardant material combining silicon-based and nitrogen-based flame retardants. Furthermore, the grafted flexible chain improves its interfacial properties with the matrix resin.

[0011] Furthermore, the matrix resin is polyethylene resin or polypropylene resin, preferably polyethylene resin.

[0012] Furthermore, the mass ratio of the phenyl hydrogen-containing silicone resin to the modifier is 100:20-40.

[0013] Furthermore, the catalyst used in the hydrosilylation reaction is a Karstedt catalyst.

[0014] Furthermore, the reaction temperature of the hydrosilylation reaction is 80-100℃, and the reaction time is 12-24h.

[0015] Furthermore, the viscosity of the phenyl hydrogen-containing silicone resin is 50-300 mPa·s.

[0016] Further, the preparation of the modified phenyl hydrogen-containing silicone resin includes:

[0017] The phenyl-containing hydrogen silicone resin, modifier, and dimethyl sulfoxide were heated and mixed evenly. Karstedt catalyst was added, and the mixture was stirred and heated to the reaction temperature. The reaction was stirred to obtain the modified phenyl-containing hydrogen silicone resin.

[0018] Furthermore, the modifier is prepared by reacting hexamethylol melamine with acrylic acid and an epoxy silane coupling agent.

[0019] Furthermore, the preparation of the modifier includes:

[0020] After mixing acrylic acid and water evenly, a condensing agent is added and stirred to activate the mixture. Then, an aqueous solution of hexamethylol melamine is added, and the mixture is kept at 20-50°C with stirring to obtain the first product.

[0021] After the first product, epoxy silane coupling agent and dimethyl sulfoxide are mixed evenly, the pH of the solution is adjusted, heated to 50-80℃, and stirred to obtain the modifier.

[0022] Further, the condensing agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide; the molar ratio of acrylic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide and hexamethylolmelamine is 1.2-2:1.2-2:0.03-0.1:1, the stirring activation time is 10-40 min, and the stirring reaction time of acrylic acid and hexamethylolmelamine is 4-24 h.

[0023] Furthermore, the pH of the solution is adjusted to 10-11, the molar ratio of hexamethylolmelamine to the epoxy silane coupling agent is 1:1-1.5, and the stirring reaction time of the first product and the epoxy silane coupling agent is 4-24 h.

[0024] Furthermore, the crosslinking agent is dicumyl peroxide.

[0025] The second objective of this invention can be achieved through the following technical solution:

[0026] A method for preparing a highly flame-retardant insulating material, characterized in that it includes:

[0027] The raw materials for insulating materials are mixed evenly, melt-blended, and then extruded and granulated to obtain a highly flame-retardant insulating material.

[0028] The beneficial effects of this invention are:

[0029] This invention provides a high flame-retardant insulating material and its preparation method. It uses a polyolefin resin as the matrix resin and a modified phenyl hydrogen-containing silicone resin as the filler resin. It utilizes the excellent elastic and machinability properties of the polyolefin resin, combined with the high flame-retardant properties, high-temperature resistance, water resistance, and chemical resistance of the modified phenyl hydrogen-containing silicone resin. Furthermore, it introduces an ethylene-acrylic acid copolymer and a crosslinking agent to further improve the overall performance of the final composite material, endowing it with heat resistance, water resistance, and high flame-retardant properties, thus ensuring the insulation performance of the composite material under high temperature and high humidity environments. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Modifier:

[0033] 1. Mix 0.12 mol of acrylic acid and 100 mL of water thoroughly, then add 0.12 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.03 mol of N-hydroxysuccinimide. Stir and activate for 30 min, then add 50 mL of an aqueous solution of hexamethylolmelamine (0.1 mol). Keep the mixture at 30 °C and stir for 12 h. Rotary evaporate, wash with ethanol, and dry to obtain the first product.

[0034] 2. After thoroughly mixing the first product obtained above, 0.1 mol of epoxysilane coupling agent and 150 mL of dimethyl sulfoxide, adjust the pH of the solution to 10-11, heat to 65℃, keep warm and stir for 8 hours, rotary evaporate, wash, and dry to obtain the modifier.

[0035] Example 2

[0036] 1. Mix 0.15 mol of acrylic acid and 100 mL of water thoroughly, then add 0.15 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.08 mol of N-hydroxysuccinimide. Stir and activate for 10 min, then add 50 mL of an aqueous solution of hexamethylol melamine (0.1 mol). Keep the mixture at 20 °C and stir for 24 h. Rotary evaporate, wash with ethanol, and dry to obtain the first product.

[0037] 2. After thoroughly mixing the first product obtained above, 0.1 mol of epoxysilane coupling agent and 150 mL of dimethyl sulfoxide, adjust the pH of the solution to 10-11, heat to 80℃, keep warm and stir for 4 hours, rotary evaporate, wash and dry to obtain the modifier.

[0038] Example 3

[0039] Modified phenyl hydrogen-containing silicone resin:

[0040] 100g of phenyl hydrogen-containing silicone resin (viscosity 50-300mpa.s), 20g of the modifier obtained in Example 1, and 100mL of dimethyl sulfoxide were heated and mixed evenly. 5g of Karstedt catalyst was added, and the mixture was stirred and heated to 100°C. The mixture was stirred and reacted for 12h. The mixture was then rotary evaporated, washed, and dried to obtain the modified phenyl hydrogen-containing silicone resin.

[0041] Example 4

[0042] Modified phenyl hydrogen-containing silicone resin:

[0043] 100g of phenyl hydrogen-containing silicone resin (viscosity 50-300mpa.s), 40g of the modifier obtained in Example 2, and 100mL of dimethyl sulfoxide were heated and mixed evenly. 10g of Karstedt catalyst was added, and the mixture was stirred and heated to 80°C for 24h. The mixture was then rotary evaporated, washed, and dried to obtain the modified phenyl hydrogen-containing silicone resin.

[0044] Example 5

[0045] Insulation materials:

[0046] Step 1: Prepare the following raw materials by weight: 60 parts polyethylene resin (LDPE), 30 parts modified phenyl hydrogen-containing silicone resin prepared in Example 3, 10 parts ethylene-acrylic acid copolymer, and 5 parts crosslinking agent;

[0047] The second step is to mix all the raw materials of the insulating material evenly, melt blend, and then extrude and granulate to obtain a high flame-retardant insulating material.

[0048] Example 6

[0049] Insulation materials:

[0050] Step 1: Prepare the following raw materials by weight: 70 parts polyethylene resin (LDPE), 20 parts modified phenyl hydrogen-containing silicone resin prepared in Example 4, 8 parts ethylene-acrylic acid copolymer, and 4 parts crosslinking agent;

[0051] The second step is to mix all the raw materials of the insulating material evenly, melt blend, and then extrude and granulate to obtain a high flame-retardant insulating material.

[0052] Example 7

[0053] Insulation materials:

[0054] Step 1: Prepare the following raw materials by weight: 80 parts polyethylene resin (LDPE), 10 parts modified phenyl hydrogen-containing silicone resin prepared in Example 3, 10 parts ethylene-acrylic acid copolymer, and 3 parts crosslinking agent;

[0055] The second step is to mix all the raw materials of the insulating material evenly, melt blend, and then extrude and granulate to obtain a high flame-retardant insulating material.

[0056] Comparative Example 1

[0057] Insulating material: Compared to Example 5, the modified phenyl-hydrosilicone resin in the raw materials was replaced with an equal amount of phenyl-hydrosilicone resin (viscosity 50-300 mPa·s), all other aspects remained the same. In this comparative example, the raw materials, when mixed, exhibited stratification during subsequent melt extrusion.

[0058] Comparison document 2

[0059] Insulating material: Compared with Example 5, the modified phenyl hydrogen-containing silicone resin in the raw materials is removed, and the rest are the same.

[0060] Comparative Example 3

[0061] Insulating material: Compared with Example 5, the modified phenyl hydrogen-containing silicone resin in the raw materials is replaced with the modified phenyl hydrogen-containing silicone resin prepared as follows, all other aspects are the same:

[0062] Modified phenyl hydrogen-containing silicone resin:

[0063] 100g of phenyl-hydrosilicone resin (viscosity 50-300 mPa·s), 20g of the first product obtained in step 1 of Example 1, and 100mL of dimethyl sulfoxide were heated and mixed evenly. 5g of Karstedt catalyst was added, and the mixture was stirred and heated to 100°C for 12 hours. The mixture was then rotary evaporated, washed, and dried to obtain the modified phenyl-hydrosilicone resin. In this comparative example, the raw materials, when mixed, exhibited stratification during subsequent melt extrusion.

[0064] Experiment 1: The insulating materials obtained in Examples 5-7 and Comparative Example 2 were molded into samples using a molding process. The volume resistivity of the samples at 20℃, 40℃ and 80℃ was measured. The test results are shown in Table 1.

[0065] Test 2: The insulating materials obtained in Examples 5-7 and Comparative Example 2 were molded into samples and subjected to flame retardancy tests (according to UL-94). The test results are shown in Table 1.

[0066] Experiment 3: The insulating materials obtained in Examples 5-7 and Comparative Example 2 were molded into samples and subjected to thermal transformation temperature tests (tested according to ISO 75 standard). The test results are shown in Table 1.

[0067] Experiment 4: The insulating materials obtained in Examples 5-7 and Comparative Example 2 were molded into samples and subjected to chemical resistance tests (according to GB / T 11547, test conditions: 10% sodium chloride by mass, 23±2℃, 168h).

[0068] Table 1

[0069]

[0070] As can be seen from the data in Table 1, the insulating materials obtained in Examples 5-7 have good high temperature resistance, flame retardancy and insulation properties.

[0071] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high flame retardant insulation material, characterized in that, The insulating material comprises the following raw materials by weight: 60 parts of base resin, 30 parts of modified phenyl hydrogen-containing silicone resin, 10 parts of ethylene-acrylic acid copolymer, and 5 parts of crosslinking agent; or 70 parts of base resin, 20 parts of modified phenyl hydrogen-containing silicone resin, 8 parts of ethylene-acrylic acid copolymer, and 4 parts of crosslinking agent; or 80 parts of base resin, 10 parts of modified phenyl hydrogen-containing silicone resin, 10 parts of ethylene-acrylic acid copolymer, and 3 parts of crosslinking agent. The modified phenyl hydrogen-containing silicone resin is prepared by a hydrosilylation reaction of a phenyl hydrogen-containing silicone resin and a modifier. The modifier is prepared by a reaction of hexamethylol melamine and acrylic acid, and an epoxy silane coupling agent. The viscosity of the phenyl hydrogen-containing silicone resin is 50-300 mpa.s. The preparation of the modifier comprises: After the acrylic acid and water are uniformly mixed, a condensing agent is added, stirring is activated, an aqueous solution of hexamethylol melamine is added, and the solution is stirred and reacted at 20-50°C, to obtain a first product. After the first product, the epoxy silane coupling agent, and dimethyl sulfoxide are uniformly mixed, the pH of the solution is adjusted, the solution is heated to 50-80°C, and the solution is stirred and reacted, to obtain the modifier.

2. A high flame retardant insulation material according to claim 1, characterized in that, The mass ratio of the phenyl hydrogen-containing silicone resin to the modifier is 100:20-40.

3. A high flame retardant insulation material as claimed in claim 1, wherein, The catalyst used in the hydrosilylation reaction is Karstedt catalyst.

4. A high flame retardant insulation material as claimed in claim 1, wherein, The reaction temperature of the hydrosilylation reaction is 80-100°C, and the reaction time is 12-24h.

5. A high flame retardant insulation material as claimed in claim 1, wherein, The condensing agent is 1-ethyl-(3-dimethylaminopropyl) carbonyldiimide hydrochloride and N-hydroxysuccinimide.

6. A high flame retardant insulation material according to claim 5, wherein The molar ratio of the acrylic acid, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimide hydrochloride, N-hydroxysuccinimide, and hexamethylol melamine is 1.2-2:1.2-2:0.03-0.1:1, the stirring activation time is 10-40 min, and the stirring reaction time of the acrylic acid and the hexamethylol melamine is 4-24h.

7. A high flame retardant insulation material as claimed in claim 1, wherein, The solution pH is adjusted to 10-11, the molar ratio of the hexamethylol melamine to the epoxy silane coupling agent is 1:1-1.5, and the stirring reaction time of the first product and the epoxy silane coupling agent is 4-24h.

8. The method of claim 1, wherein the high flame retardant insulation material is prepared by mixing the flame retardant, the binder, the filler, and the reinforcing material. The insulating material comprises the following raw materials by weight: 60 parts of base resin, 30 parts of modified phenyl hydrogen-containing silicone resin, 10 parts of ethylene-acrylic acid copolymer, and 5 parts of crosslinking agent; or 70 parts of base resin, 20 parts of modified phenyl hydrogen-containing silicone resin, 8 parts of ethylene-acrylic acid copolymer, and 4 parts of crosslinking agent; or 80 parts of base resin, 10 parts of modified phenyl hydrogen-containing silicone resin, 10 parts of ethylene-acrylic acid copolymer, and 3 parts of crosslinking agent. The insulating material comprises the following raw materials by weight: 60 parts of base resin, 30 parts of modified phenyl hydrogen-containing silicone resin, 10 parts of ethylene-acrylic acid copolymer, and 5 parts of crosslinking agent; or 70 parts of base resin, 20 parts of modified phenyl hydrogen-containing silicone resin, 8 parts of ethylene-acrylic acid copolymer, and 4 parts of crosslinking agent; or 80 parts of base resin, 10 parts of modified phenyl hydrogen-containing silicone resin, 10 parts of ethylene-acrylic acid copolymer, and 3 parts of crosslinking agent.

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