A powder flame retardant treating agent, a preparation method and application thereof

Abstract

The application provides a powder flame retardant treating agent, a preparation method and application thereof. The preparation method of the powder flame retardant treating agent comprises the following steps: S1, dimethyl dimethoxysilane and methyl vinyl dimethoxysilane are hydrolyzed and condensed under the action of a hydrolysis catalyst to obtain a hydroxyl-terminated silicone oil; S2, the hydroxyl-terminated silicone oil obtained in step S1 is reacted with alkyl trialkoxysilane under the catalysis of ammonia alkyl silane at 60-80 DEG C under the protection of nitrogen until the viscosity of the reaction system does not change any more. The powder flame retardant treating agent obtained by the preparation method can treat powder flame retardants such as aluminum hydroxide and magnesium hydroxide, and the modified powder flame retardant can be fully dispersed in resin, the powder loading capacity and oxygen index of the resin modification are improved, and good tensile strength and excellent elongation at break are simultaneously achieved.

Description

Technical Field

[0001] This invention relates to the field of flame retardant treatment agent synthesis technology, and more specifically, to a powder flame retardant treatment agent, its preparation method and application. Background Technology

[0002] Flame retardants are functional additives that help polymers achieve flame retardancy. There are various types of flame retardants, which can be classified into additive flame retardants and reactive flame retardants according to their application method. Additive flame retardants are typically added to polymers to impart flame retardancy. Additive flame retardants mainly include organic flame retardants, inorganic flame retardants, halogenated flame retardants, and halogen-free flame retardants. Inorganic flame retardants can include aluminum hydroxide, magnesium hydroxide, etc. These flame retardants can be well dispersed in resins and have advantages such as being environmentally friendly, having low toxicity, low cost, and stable performance.

[0003] One of the key research projects in the wire and cable industry is to achieve low-smoke, halogen-free, flame-retardant, safe, and environmentally friendly effects for wire and cable materials. Current technologies typically use treatment agents to process powdered flame retardants such as aluminum hydroxide and magnesium hydroxide before mixing the treated powdered flame retardants with resins and other substances to ensure the processing performance and various electrical properties of the cable material. Existing treatment agents include silane coupling agents, hydroxyl silicone oils, and epoxy-based silicone titanates. However, existing powdered flame retardant treatment agents suffer from poor dispersibility and low powder filling capacity, and cannot simultaneously achieve good tensile strength, good oxygen index, and excellent elongation at break. Summary of the Invention

[0004] The first objective of this invention is to provide a method for preparing a powder flame retardant treatment agent. The powder flame retardant treatment agent obtained by this method can treat powder flame retardants such as aluminum hydroxide and magnesium hydroxide. The resulting modified powder flame retardant can effectively improve the oxygen index of cable materials while also having good tensile strength and excellent elongation at break.

[0005] The preparation method of the powder flame retardant treatment agent provided by the present invention includes the following steps:

[0006] S1, dimethyldimethoxysilane and methylvinyldimethoxysilane are hydrolyzed and condensed in the presence of a hydrolysis catalyst to obtain hydroxyl-terminated silicone oil;

[0007] S2, under nitrogen protection, the hydroxyl-terminated silicone oil obtained in step S1 is reacted with alkyltrialkoxysilane at 60-80°C under the catalysis of aminoalkylsilane until the viscosity of the reaction system no longer changes.

[0008] In a preferred embodiment of the present invention, in order to improve the effect of the obtained treatment agent, in step S1, the molar ratio of dimethyldimethoxysilane to methylvinyldimethoxysilane is (2-8):1, preferably (3-6):1.

[0009] In a preferred embodiment of the present invention, in step S1, the hydrolysis catalyst can be an alkali metal oxide or a hydroxide, including but not limited to calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide or zinc oxide, preferably magnesium oxide.

[0010] In a preferred embodiment of the present invention, in order to improve the effect of the obtained treatment agent, in step S1, the hydrolysis catalyst is 0.05wt% to 0.1wt% of the total amount of dimethyldimethoxysilane and methylvinyldimethoxysilane.

[0011] In a preferred embodiment of the present invention, step S1 specifically includes the following steps:

[0012] Dimethyldimethoxysilane and methylvinyldimethoxysilane were added dropwise to an aqueous solution of the hydrolysis catalyst at 10–30 °C over a period of 0.5–2 h. The reaction was continued for another 1–2 h. After standing, the lower layer was removed, and low-boiling-point impurities and the catalyst were removed to obtain hydroxyl-terminated silicone oil.

[0013] The amount of water used in the aqueous solution of the hydrolysis catalyst can be 1 to 3 times the total amount of dimethyldimethoxysilane and methylvinyldimethoxysilane.

[0014] In a preferred embodiment of the present invention, in order to improve the effect of the obtained treatment agent, in step S2, the alkyltrialkoxysilane is propyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane or dodecyltrimethoxysilane, preferably decyltrimethoxysilane.

[0015] In a preferred embodiment of the present invention, in order to improve the effect of the obtained treatment agent, in step S2, the aminoalkylsilane can be a difunctional aminoalkylsilane, including but not limited to N-β-aminoethyl-γ-aminopropyltrimethoxysilane, piperazinepropyltrimethoxysilane, or N,N-dimethylpropanediaminopropyltrimethoxysilane or other difunctional aminoalkylsilanes, preferably N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0016] In a preferred embodiment of the present invention, in order to improve the effect of the obtained treatment agent, in step S2, the alkyltrialkoxysilane is 20wt% to 40wt% of the hydroxyl-terminated silicone oil obtained in step S1.

[0017] In a preferred embodiment of the present invention, in order to improve the effect of the obtained treatment agent, in step S2, the aminoalkylsilane is preferably 1 wt% to 3 wt% of the mass of an alkyltrialkoxysilane.

[0018] In a specific embodiment of the present invention, the standard for the end of the reaction in step S2 is "the viscosity of the reaction system no longer changes", or it can be "no low-boiling substances are produced in the reaction system". In a specific embodiment of the present invention, the reaction usually takes 2 to 4 hours.

[0019] In a specific embodiment of the present invention, in step S2, after the reaction is complete, the low-boiling-point substances are removed by depressurization to obtain the powder flame retardant treatment agent of the present invention.

[0020] The powder flame retardant treatment agent obtained using the above preparation method can modify the powder flame retardant, and the resulting modified powder flame retardant can effectively improve the oxygen index of cable materials. The powder flame retardant may include one or more of aluminum hydroxide, magnesium hydroxide, silicon carbide, calcium carbonate, magnesium oxide, aluminum oxide, and silicon dioxide. In an optional embodiment of the present invention, the powder flame retardant may be aluminum hydroxide and magnesium hydroxide. The mass ratio of aluminum hydroxide to magnesium hydroxide may be (2-15):1. In a specific embodiment of the present invention, this powder flame retardant is used as an example to describe the present invention in detail. The modification effects of other powder flame retardants are not shown in this article due to space limitations in the patent documents.

[0021] In a specific embodiment of the present invention, the modification method can use conventional modification methods in the art. In this embodiment, the modification method may include the following steps: mixing and reacting the powdered flame retardant and the powdered flame retardant treatment agent for 1-2 hours, and then drying at 100-120°C for 2-4 hours to disperse. Preferably, the amount of the powdered flame retardant treatment agent is 0.5 wt% to 0.8 wt% of the powdered flame retardant.

[0022] Another object of the present invention is to provide a powder flame retardant treatment agent obtained by the above preparation method.

[0023] Another object of the present invention is to provide the application of the above-described preparation method or the powdered flame retardant treatment agent obtained by the above-described preparation method in improving the oxygen index of cable materials. Specifically, another object of the present invention is to provide the application of the above-described preparation method or the powdered flame retardant treatment agent obtained by the above-described preparation method in the preparation of cable materials.

[0024] The powder flame retardant treatment agent provided by this invention can be used in the preparation of common cable materials in the art, for example, cable materials prepared using polyethylene base resin. The raw materials for this cable material may include, for example, polyethylene base resin, flame retardant treated with the powder flame retardant treatment agent, dioctyl o-dicarboxylate, paraffin oil, and antioxidants, etc.

[0025] The beneficial effects of this invention are as follows:

[0026] 1) The powder flame retardant treatment agent obtained by the preparation method provided by the present invention can improve the dispersibility of flame retardant powder, increase the amount of powder, and significantly improve the oxygen index and elongation at break of cable material without reducing tensile strength.

[0027] 2) The preparation method of the powder flame retardant treatment agent provided by the present invention has mild conditions, high yield, and is economical and environmentally friendly. Detailed Implementation

[0028] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0029] Unless otherwise specified in the examples, the conditions should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. In this invention, unless otherwise specified, "%" refers to a percentage by mass.

[0030] Example 1

[0031] This embodiment provides a method for preparing a powder flame retardant treatment agent, including the following steps:

[0032] S1, at 10-30℃, 96.2g of dimethyldimethoxysilane and 26.45g of methylvinyldimethoxysilane were added dropwise to a solution containing 0.082g of industrial magnesium oxide and 200g of water. After the addition was completed in about 1 hour, the mixture was stirred for 80 minutes and allowed to stand for about 30 minutes. The mixture was then separated, and the oil phase was distilled to remove impurities and filtered to obtain 75.3g of a nearly colorless and transparent hydroxyl-terminated silicone oil with a vinyl content of 6.38%.

[0033] S2, under nitrogen protection, the hydroxyl-terminated polymethyl vinyl silicone oil obtained in step S1 is mixed with 19g of decyltrimethoxysilane and 0.27g of N-β-aminoethyl-γ-aminopropyltrimethoxysilane and reacted at 62-66℃ for 3h. At this time, the viscosity of the reaction system no longer changes. Low-boiling substances are removed under reduced pressure to obtain the final product.

[0034] Example 2

[0035] The preparation method provided in this embodiment is the same as that in Example 1, except that:

[0036] In step S1, the amount of dimethyldimethoxysilane added is 72.13 g, and the amount of hydroxyl-terminated silicone oil obtained in step S1 is 59.4 g. The vinyl content of the hydroxyl-terminated silicone oil obtained in step S1 is 7.92%.

[0037] In step S2, the amount of decyltrimethoxysilane used is 20 wt% of the mass of the hydroxyl-terminated silicone oil obtained in step S1, and the amount of N-β-aminoethyl-γ-aminopropyltrimethoxysilane used is 1.0 wt% of the mass of decyltrimethoxysilane.

[0038] Example 3

[0039] The preparation method provided in this embodiment is the same as that in Example 1, except that...

[0040] In step S1, the amount of dimethyldimethoxysilane added was 132.24 g, and the amount of hydroxyl-terminated silicone oil obtained in step S1 was 94.3 g. The vinyl content of the hydroxyl-terminated silicone oil obtained in step S1 was 4.93%.

[0041] In step S2, the amount of decyltrimethoxysilane used is 35 wt% of the mass of the hydroxyl-terminated silicone oil obtained in step S1, and the amount of N-β-aminoethyl-γ-aminopropyltrimethoxysilane used is 2.3 wt% of the mass of decyltrimethoxysilane.

[0042] Example 4

[0043] The preparation method provided in this embodiment is the same as that in Example 1, except that 19g of propyltrimethoxysilane is used instead of 19g of decyltrimethoxysilane in step S2.

[0044] Example 5

[0045] The preparation method provided in this embodiment is the same as that in Example 1, except that: in step S2, hexyltrimethoxysilane is used to replace decyltrimethoxysilane, and piperazinepropyltrimethoxysilane is used to replace N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0046] Example 6

[0047] The preparation method provided in this embodiment is the same as that in Example 1, except that: in step S2, octyltrimethoxysilane is used instead of decyltrimethoxysilane, and N,N-dimethylpropanediaminopropyltrimethoxysilane is used instead of N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

[0048] Example 7

[0049] The preparation method provided in this embodiment is the same as that in Example 1, except that: in step S2, dodecyltrimethoxysilane is used instead of decyltrimethoxysilane.

[0050] Experimental Example

[0051] A104E aluminum hydroxide and magnesium hydroxide were mixed at a mass ratio of 12:1. 0.8% of the treatment agent provided in the example was added to the mixed powder. The mixture was stirred in a mixer at 750-800 r / min for 1.5 h. After the reaction was complete, small molecules such as alcohols were removed. The mixture was then dried at 105-110 °C for about 3 h to disperse the powder and obtain the treated flame retardant.

[0052] The specific performance of the powder flame retardant treatment agent was evaluated by preparing cable material samples: 35 parts of base resin (the base resin is obtained by mixing 75% ethylene-25% vinyl acetate polymer, polyethylene compound, and polyolefin in a mass ratio of 70:15:15), 65 parts of powder flame retardant treated with the treatment agents obtained in Examples 1-7 above (the powder flame retardant in Comparative Example 4 is an untreated flame retardant, i.e., A104E aluminum hydroxide and magnesium hydroxide mixed in a mass ratio of 12:1), 0.5 parts of dioctyl o-dicarboxylate, 2 parts of paraffin oil, and 0.5 parts of antioxidant 1010 were mixed evenly in a mixer (135-145°C) and then extruded and granulated from a twin-screw extruder. The resulting mixture was granulated and injection molded into finished products according to GB / T The oxygen index was tested according to GB / T1040-2008, and the elongation at break and tensile strength were tested according to GB / T1040-2006. At the same time, Dow Corning 11-100, vinyltris(methoxyethoxy)silane, and Hubei Anruike UM-1703 were selected to replace the treatment agents provided in the examples to treat the powder flame retardants respectively. Comparative examples 1 to 3 were set up respectively, and the performance results were summarized as shown in Table 1 below.

[0053] Table 1 Performance Results

[0054] Oxygen Index / % Elongation at break / % Tensile strength / MPa Example 1 42 226 12.8 Example 2 41 220 13.5 Example 3 42 218 12.6 Example 4 40 217 12.5 Example 5 39 207 11.7 Example 6 38 193 11.3 Example 7 40 215 12.9 Comparative Example 1 35 211 12.2 Comparative Example 2 32 194 10.7 Comparative Example 3 35 203 11.1 Comparative Example 4 28 154 9.6

[0055] Finally, the method of this invention is merely a preferred embodiment and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for producing a powder flame retardant treatment agent, characterized by comprising the steps of: Includes the following steps: ​ S1, dimethyldimethoxysilane and methylvinyldimethoxysilane are hydrolyzed and condensed in the presence of a hydrolysis catalyst to obtain hydroxyl-terminated silicone oil; the molar ratio of dimethyldimethoxysilane to methylvinyldimethoxysilane is (2~8):1; S2, under nitrogen protection, the hydroxyl-terminated silicone oil obtained in step S1 is reacted with alkyltrialkoxysilane at 60-80°C under the catalysis of aminoalkylsilane until the viscosity of the reaction system no longer changes; the alkyltrialkoxysilane is 20wt%-40wt% of the mass of the hydroxyl-terminated silicone oil obtained in step S1; the aminoalkylsilane is 1wt%-3wt% of the mass of the alkyltrialkoxysilane.

2. The production method according to claim 1, characterized by, In step S1, the molar ratio of dimethyldimethoxysilane to methylvinyldimethoxysilane is (3~6):

1.

3. The preparation method according to claim 1, characterized in that, In step S1, the hydrolysis catalyst is calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, or zinc oxide; The hydrolysis catalyst is 0.05wt% to 0.1wt% of the total amount of dimethyldimethoxysilane and methylvinyldimethoxysilane.

4. The method of claim 1, wherein, In step S1, the hydrolysis catalyst is magnesium oxide.

5. The production method according to any one of claims 1 to 4, characterized by, The specific steps of step S1 include: Dimethyldimethoxysilane and methylvinyldimethoxysilane are added dropwise to an aqueous solution of the hydrolysis catalyst at 10–30 °C. The addition is completed within 0.5–2 h, and the reaction continues for 1–2 h. After standing, the lower layer is removed to remove low-boiling-point impurities and catalyst, and hydroxyl-terminated silicone oil is obtained.

6. The preparation method according to any one of claims 1 to 4, characterized in that, In step S2, the alkyltrialkoxysilane is propyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, or dodecyltrimethoxysilane.

7. The production method according to claim 6, wherein In step S2, the alkyltrialkoxysilane is decyltrimethoxysilane.

8. The production method according to any one of claims 1 to 4, characterized by, In step S2, the aminoalkylsilane is N-β-aminoethyl-γ-aminopropyltrimethoxysilane, piperazinepropyltrimethoxysilane, or N,N-dimethylpropanediaminopropyltrimethoxysilane.

9. The production method according to claim 8, characterized by, In step S2, the aminoalkylsilane is N-β-aminoethyl-γ-aminopropyltrimethoxysilane.

10. The powder flame retardant treatment agent obtained by the preparation method according to any one of claims 1 to 9.

11. The preparation method according to any one of claims 1 to 9 or the powder flame retardant treatment agent according to claim 10 in improving the oxygen index of cable materials.