Expanded halogen-free flame-retardant ABS material and preparation method thereof

Abstract

The application relates to the technical field of high-molecular compounds, and particularly discloses an intumescent halogen-free flame-retardant ABS material and a preparation method thereof. The preparation method of the intumescent halogen-free flame-retardant ABS material comprises the following steps: S1, flame-retardant slurry preparation, S2, ABS surface treatment, and S3, halogen-free flame-retardant ABS material preparation. A novel solid polysiloxane is prepared, ammonium polyphosphate is modified, and then the modified ammonium polyphosphate is compounded with melamine in a certain proportion to form a high-efficiency intumescent halogen-free flame retardant. After the surface treatment of ABS samples, the ABS samples are placed in the flame-retardant coating slurry, and the ABS samples with the compounded flame-retardant coating are obtained through a pulling method. The flame retardant is coated on the surface of the ABS sample in the form of the flame-retardant slurry, so that the problems of halogen-containing flame retardant toxicity and poor effect of traditional halogen-free flame retardants can be solved, and the problem of obvious decrease of the impact performance of the material after the addition of the flame retardant in the traditional flame-retardant method can be solved.

Description

Technical Field

[0001] This invention relates to the field of polymer compound technology, specifically disclosing an intumescent halogen-free flame-retardant ABS material and its preparation method. Background Technology

[0002] With the improvement of people's living standards and the enhancement of safety and environmental awareness, both domestic and international authorities have imposed stricter fire-retardant and environmental protection requirements on plastic materials used in automobiles, construction, household appliances, and office supplies. Therefore, the research and development of efficient and environmentally friendly flame-retardant technologies is crucial for the application and development of ABS resin, and has become a matter of great concern and urgent need for resolution within the industry.

[0003] Adding flame retardants is currently the most common method for flame-retardant modification of ABS, including halogenated and halogen-free flame retardants. Halogenated flame retardants are usually compounded with other substances to form synergistic systems to enhance the flame-retardant effect. While bromine-based synergistic systems have advantages such as high flame-retardant efficiency and moderate price, their thermal decomposition products have certain toxic effects on humans and the environment. In addition, halogen-free flame retardants for ABS have been developed using metal hydroxides, phosphorus-based agents, and intumescent flame retardants containing multiple flame-retardant elements, but most current research is limited to literature reports and theoretical analyses. On the other hand, the addition of flame retardants inevitably leads to a decrease in the thermal stability and mechanical properties of ABS resin, especially its impact strength.

[0004] Therefore, it is necessary to develop and prepare an environmentally friendly flame-retardant ABS resin with high flame retardancy efficiency and minimal impact on mechanical properties to solve the problems existing in the current technology. Summary of the Invention

[0005] The technical solution adopted in this invention is as follows:

[0006] In a first aspect, the present invention provides a silicon-nitrogen-phosphorus intumescent halogen-free flame retardant, wherein the silicon-nitrogen-phosphorus intumescent halogen-free flame retardant comprises the following components in parts by weight:

[0007] 15-20 parts of solid polysiloxane

[0008] 55-60 parts of modified ammonium polyphosphate

[0009] 25-30 parts of melamine;

[0010] The preparation method of the solid polysiloxane includes the following steps:

[0011] S1: Mix 25-30 parts by weight of vinyltriethoxysilane, 25-30 parts by weight of phosphorus-containing active material and 0.1-1 parts by weight of azobisisobutyronitrile, react thoroughly at 70-90°C, and filter to obtain flame retardant intermediate product.

[0012] The phosphorus-containing active ingredient is one or two of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethyl methyl phosphite, dialkyl phosphite, and phosphorous acid.

[0013] S2: Mix 15 parts by mass of flame retardant intermediate product, 5-10 parts by mass of ultrapure water and 5-15 parts by mass of anhydrous ethanol, react at room temperature under acidic conditions for 0.2-0.8 h, and then react at 50-60℃ for 2-4 h to obtain system A solution;

[0014] S3: Mix 5-10 parts by weight of hexamethyldisiloxane, 2-10 parts by weight of ultrapure water and 5-25 parts by weight of anhydrous ethanol, and react at 50-70℃ for 1-3 hours to obtain system B solution;

[0015] S4: Add the solution B obtained in step S3 dropwise to the solution A in step S2, and continue the reaction at 50-70℃ for 4-6 hours. After drying the product, a solid polysiloxane is obtained.

[0016] The preparation method of the modified ammonium polyphosphate includes the following steps:

[0017] S1: Add 16-24 parts by weight of melamine solution, and dissolve 10-15 parts by weight of alkaline lignin in water and add it to melamine, and react at 60-80℃ for 5-15 minutes;

[0018] S2: Add 25-30 parts by mass of formaldehyde solution to the solution in step S1, and continue the reaction at 80-100℃ for 3-7 hours;

[0019] S3: Add 100-150 parts by mass of ammonium polyphosphate to the solution in step S2, continue the reaction for 2-5 hours, and dry the product to obtain modified ammonium polyphosphate.

[0020] Preferably, when two phosphorus-containing active materials are used in step S2 of the preparation of solid polysiloxane, the molar ratio of the two is 1:1.

[0021] Secondly, the present invention provides a method for preparing an intumescent halogen-free flame-retardant ABS material, the method comprising the following steps:

[0022] Preparation of S1 flame retardant slurry: Dissolve 5-7 parts by weight of film-forming agent in anhydrous ethanol, heat to 60-80℃, add 5-15 parts by weight of silane coupling agent, stir for no less than 15 minutes, then add 10-25 parts by weight of the flame retardant described in the first aspect, continue stirring for no less than 15 minutes, add 1-2 parts by weight of wetting agent and raise the temperature to 120-150℃, and continue stirring to evaporate the anhydrous ethanol to obtain the flame retardant slurry;

[0023] The film-forming agent is one or two of polyvinyl alcohol acetal, polyvinyl alcohol formaldehyde, or polyvinyl alcohol acetal.

[0024] The silane coupling agent is one or two of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane or γ-(methacryloyloxy)propyltrimethoxysilane.

[0025] The wetting agent is one or both of sodium dodecyl sulfate or polyethylene oxide alkyl anisole.

[0026] S2 ABS Surface Treatment: The ABS sample is thoroughly cleaned with detergent to remove surface oil and mold release agent. Then, the ABS sample is immersed in sodium hydroxide solution to remove surface impurities. After rinsing with deionized water, it is air-dried. Then, the ABS sample is immersed in a mixed acid solution of potassium dichromate, phosphoric acid, and sulfuric acid for surface acid treatment to improve the surface energy of the sample.

[0027] Preparation of S3 halogen-free flame-retardant ABS material: The treated ABS strip is placed in the flame-retardant coating slurry, and the ABS sample with a compound flame-retardant coating is obtained by the dip-coating method.

[0028] Preferably, when two components of the film-forming agent, silane coupling agent, or wetting agent are selected, the mass ratio of the two film-forming agents, silane coupling agents, or wetting agents is 1:1.

[0029] Preferably, during the preparation of the flame-retardant slurry in step S1, the stirring state is maintained. The stirring rate before adding the wetting agent is 1000 r / min, and the stirring speed is adjusted to 500 r / min during the process after adding the wetting agent.

[0030] Preferably, in the S2 ABS surface treatment, the mass concentration of the sodium hydroxide solution is 1%.

[0031] Preferably, in the S2 ABS surface treatment, the mixed acid solution is prepared by mixing concentrated sulfuric acid and phosphoric acid in a volume ratio of 18:7.

[0032] Thirdly, the present invention provides an intumescent halogen-free flame-retardant ABS material, which is prepared by the method described in the second aspect.

[0033] The beneficial effects achieved by this invention are as follows:

[0034] This invention provides a silicon-nitrogen-phosphorus intumescent halogen-free flame retardant. By selecting and proportioning different film-forming agents, silane coupling agents, and this flame retardant, a flame-retardant slurry is prepared and coated onto the surface of an ABS sample to produce a flame-retardant ABS resin. This is intended to meet market requirements for flame-retardant ABS resin. The product performance indicators simultaneously meet the following requirements: limiting oxygen index: ≥27.8, vertical burning flame retardancy rating: UL94 V-0, impact strength: ≥13.5kJ / m. 2 This preparation method can only enable the material to achieve a better flame retardant effect and reduce the impact on impact strength. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the following embodiments. It should be noted that this invention is not limited to the following embodiments.

[0036] Example 1

[0037] Weigh 25 parts of vinyltriethoxysilane, 25 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 0.5 parts of azobisisobutyronitrile and place them in a three-necked flask. Mix thoroughly and heat to 80°C for 12 hours. Filter to obtain the intermediate product. Weigh 15 parts of the intermediate product, 7 parts of ultrapure water, and 10 parts of anhydrous ethanol. React at room temperature under acidic conditions for 0.5 hours and then continue to react at 55°C for 3 hours. Weigh 5 parts of hexamethyldisiloxane, 3 parts of ultrapure water, and 20 parts of anhydrous ethanol. Mix thoroughly and react at 60°C for 2 hours. Then, slowly add the obtained substance dropwise to the second step system and continue to react at 60°C for 5 hours. After rotary evaporation and drying, obtain the self-made solid polysiloxane.

[0038] 16 parts of melamine were dissolved in water and placed in a flask. 10 parts of alkaline lignin were dissolved in water and added to the flask in several batches. The mixture was reacted at 70°C for 10 minutes. 25 parts of formaldehyde solution were slowly added dropwise, and the mixture was reacted at 90°C for 5 hours. 100 parts of ammonium polyphosphate were added, and the mixture was reacted for 4 hours. The product was filtered, dried, and thoroughly ground to obtain modified ammonium polyphosphate.

[0039] 15 parts of solid polysiloxane, 55 parts of modified ammonium polyphosphate, and 30 parts of melamine were thoroughly mixed in a high-speed mixer to obtain a self-made silicon-nitrogen-phosphorus intumescent halogen-free flame retardant.

[0040] Weigh 70 parts of anhydrous ethanol into a beaker, and stir the magnetically at 1000 r / min. Slowly add 5 parts of polyvinyl methyl acetal and continue stirring for 30 min. Then, raise the temperature to 70°C and slowly add 5 parts of γ-aminopropyltriethoxysilane and stir for 20 min. Add 10 parts of the self-made flame retardant and continue stirring for 20 min. Then, adjust the stirring speed to 500 r / min, add 1 part of sodium dodecyl sulfate, and raise the temperature to 130°C. Continue stirring until the anhydrous ethanol evaporates and the solution becomes viscous.

[0041] The ABS sample was thoroughly cleaned with detergent to remove surface oil and mold release agent. Then, the ABS sample was immersed in sodium hydroxide solution to remove surface impurities. After rinsing with deionized water, it was air-dried. 2.0g of potassium dichromate was added to a mixed acid solution of 17mL of 98% concentrated sulfuric acid and 6.5mL of phosphoric acid. The ABS sample was then immersed in the mixed acid solution for surface acid treatment to improve the surface energy of the sample.

[0042] The treated ABS sample is placed in it to obtain flame-retardant ABS.

[0043] Example 2

[0044] Keeping the other steps in Example 1 unchanged, the ratio of the three materials in the self-made silicon-nitrogen-phosphorus intumescent halogen-free flame retardant is changed to 20 parts solid polysiloxane, 55 parts modified ammonium polyphosphate, and 25 parts melamine.

[0045] Example 3

[0046] Keeping the other steps in Example 1 unchanged, the amount of the self-made silicon-nitrogen-phosphorus intumescent halogen-free flame retardant added to the flame retardant slurry was adjusted to 25 parts.

[0047] Example 4

[0048] Weigh 30 parts of vinyltriethoxysilane, 30 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 1 part of azobisisobutyronitrile and place them in a three-necked flask. Mix thoroughly and heat to 80°C for 12 hours. Filter to obtain the intermediate product. Weigh 15 parts of the intermediate product, 5 parts of ultrapure water, and 15 parts of anhydrous ethanol. React at room temperature for 0.5 hours under acidic conditions and then continue to react at 55°C for 3 hours. Weigh 10 parts of hexamethyldisiloxane, 5 parts of ultrapure water, and 15 parts of anhydrous ethanol. Mix thoroughly and react at 60°C for 2 hours. Then, slowly add the obtained substance dropwise to the second step system and continue to react at 60°C for 5 hours. After rotary evaporation and drying, obtain the self-made solid polysiloxane.

[0049] 24 parts of melamine were dissolved in water and placed in a flask. 15 parts of alkaline lignin were dissolved in water and added to the flask in several batches. The mixture was reacted at 70°C for 10 minutes. 30 parts of formaldehyde solution were slowly added dropwise, and the mixture was reacted at 90°C for 5 hours. 100 parts of ammonium polyphosphate were added, and the mixture was reacted for 4 hours. The product was filtered, dried, and thoroughly ground to obtain modified ammonium polyphosphate.

[0050] 15 parts of solid polysiloxane, 55 parts of modified ammonium polyphosphate, and 30 parts of melamine were thoroughly mixed in a high-speed mixer to obtain a self-made silicon-nitrogen-phosphorus intumescent halogen-free flame retardant.

[0051] Weigh 70 parts of anhydrous ethanol into a beaker, and stir magnetically at 1000 r / min. Slowly add 7 parts of polyvinyl methyl acetal and continue stirring for 30 min. Then, raise the temperature to 70°C and slowly add 15 parts of γ-aminopropyltriethoxysilane and stir for 20 min. Add 10 parts of homemade flame retardant and continue stirring for 20 min. Then, adjust the stirring speed to 500 r / min, add 2 parts of sodium dodecyl sulfate, and raise the temperature to 130°C. Continue stirring until the anhydrous ethanol evaporates and the solution becomes viscous.

[0052] The ABS sample was thoroughly cleaned with detergent to remove surface oil and mold release agent. Then, the ABS sample was immersed in sodium hydroxide solution to remove surface impurities. After rinsing with deionized water, it was air-dried. 2.0g of potassium dichromate was added to a mixed acid solution of 17mL of 98% concentrated sulfuric acid and 6.5mL of phosphoric acid. The ABS sample was then immersed in the mixed acid solution for surface acid treatment to improve the surface energy of the sample.

[0053] The treated ABS sample is placed in it to obtain flame-retardant ABS.

[0054] Example 5

[0055] Keeping the other steps in Example 4 unchanged, the ratio of the three materials in the self-made silicon-nitrogen-phosphorus intumescent halogen-free flame retardant is changed to 20 parts solid polysiloxane, 55 parts modified ammonium polyphosphate, and 25 parts melamine.

[0056] Example 6

[0057] Keeping the other steps in Example 4 unchanged, the amount of the self-made silicon-nitrogen-phosphorus intumescent halogen-free flame retardant added to the flame retardant slurry was adjusted to 25 parts.

[0058] Test Results

[0059] The performance test results of the examples and comparative examples are shown in Table 1 below:

[0060] Table 1 Performance Test Results

[0061]

[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A silicon-nitrogen-phosphorus intumescent halogen-free flame retardant, characterized by, The silicon-nitrogen-phosphorus intumescent halogen-free flame retardant comprises the following components by mass fraction: Solid polysiloxane 15-20 parts Modified ammonium polyphosphate 55-60 parts Melamine 25-30 parts The preparation method of the solid polysiloxane comprises the following steps: S1: 25-30 parts by mass of vinyl triethoxysilane, 25-30 parts by mass of phosphorus-containing active substance and 0.1-1 part by mass of azobisisobutyronitrile are uniformly mixed, and then fully reacted at 70-90°C, and the flame retardant intermediate product is obtained after filtration; The phosphorus-containing active substance is one or two of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethyl methyl phosphite, dialkyl phosphite and phosphorous acid; S2: 15 parts by mass of the flame retardant intermediate product, 5-10 parts by mass of ultrapure water and 5-15 parts by mass of anhydrous ethanol are uniformly mixed, and then reacted at room temperature under acidic conditions for 0.2-0.8 h and at 50-60°C for 2-4 h to obtain a system A solution; S3: 5-10 parts by mass of hexamethyldisiloxane, 2-10 parts by mass of ultrapure water and 5-25 parts by mass of anhydrous ethanol are uniformly mixed and reacted at 50-70°C for 1-3 h to obtain a system B solution; S4: the system B solution obtained in step S3 is added dropwise into the system A solution obtained in step S2, and the reaction is continued at 50-70°C for 4-6 h, and the obtained product is dried to obtain the solid polysiloxane; When two phosphorus-containing active substances are used in step S1 of the preparation of the solid polysiloxane, the molar ratio of the two is 1:1; The preparation method of the modified ammonium polyphosphate comprises the following steps: S1: a solution of 16-24 parts by mass of melamine is added, and 10-15 parts by mass of alkaline lignin is dissolved in water and added to the melamine, and the reaction is carried out at 60-80°C for 5-15 min; S2: 25-30 parts by mass of a formaldehyde solution is added dropwise to the solution in step S1, and the reaction is continued at 80-100°C for 3-7 h; S3: 100-150 parts by mass of ammonium polyphosphate is added to the solution in step S2, and the reaction is continued for 2-5 h, and the product is dried to obtain the modified ammonium polyphosphate.

2. A process for the preparation of intumescent halogen-free flame-retardant ABS material, characterized in that, The preparation method comprises the following steps: S1: 5-7 parts by mass of a film-forming agent is dissolved in anhydrous ethanol, heated to 60-80°C, 5-15 parts by mass of a silane coupling agent is added, stirred for not less than 15 min, then 10-25 parts by mass of the flame retardant of claim 1 is added, continues to stir for not less than 15 min, 1-2 parts by mass of a wetting agent is added and the temperature is raised to 120-150°C, and the anhydrous ethanol is evaporated under continuous stirring to obtain a flame retardant slurry; The film-forming agent is one or two of polyvinylidene chloride, polyvinyl formal or polyvinyl acetal; The silane coupling agent is one or two of γ-aminopropyl triethoxysilane, γ-(2,3-epoxypropoxy) propyl trimethoxysilane or γ-(methacryloyloxy) propyl trimethoxysilane; The wetting agent is one or two of sodium dodecyl sulfate or polyoxyethylene alkyl benzyl ether; S2 ABS surface treatment: the ABS is washed with detergent to remove surface oil and release agent, then the ABS sample is immersed in sodium hydroxide solution to remove surface impurities, then washed with deionized water and naturally dried; then the ABS sample is immersed in a mixed acid solution of potassium dichromate, phosphoric acid and sulfuric acid for surface acid treatment to improve the surface energy of the sample; S3 Preparation of halogen-free flame-retardant ABS material: the treated ABS sample is placed in a flame-retardant coating slurry, and an ABS sample with a composite flame-retardant coating is obtained by a pulling method; When two components of the film-forming agent, silane coupling agent or wetting agent are selected, the mass ratio of the two film-forming agents, silane coupling agents or wetting agents is 1:

1.

3. A process for the preparation of intumescent halogen-free flame retardant ABS material according to claim 2, characterized in that, In the step S1 flame-retardant slurry preparation process, the stirring state is maintained, the stirring speed before adding the wetting agent is 1000 r / min, and the stirring speed after adding the wetting agent is adjusted to 500 r / min.

4. A process for the preparation of intumescent halogen-free flame retardant ABS material according to claim 2, characterized in that, In the S2 ABS surface treatment, the mass concentration of the sodium hydroxide solution is 1%.

5. A process for the preparation of intumescent halogen-free flame retardant ABS material according to claim 2, characterized in that, In the S2 ABS surface treatment, the mixed acid solution is prepared by mixing concentrated sulfuric acid and phosphoric acid at a volume ratio of 18:

7.

6. An intumescent halogen-free flame-retardant ABS material, characterized in that, Prepared by the method of any one of claims 2-5.

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