Halogen-free flame-retardant damping type EPDM rubber material

Abstract

The invention discloses a halogen-free flame-retardant damping type EPDM (Ethylene-Propylene-Diene Monomer) rubber material. The halogen-free flame-retardant damping EPDM rubber material is prepared from the following components in parts by weight: 22 to 33 parts of ethylene propylene diene monomer, 2 to 6 parts of modified halogen-free flame retardant, 1 to 4 parts of composite damping filler, 0.8 to 2.1 parts of anti-aging agent and 0.4 to 0.8 part of accelerant, wherein the modified halogen-free flame retardant is obtained by synthesizing o-hydroxy benzaldehyde, phenyl phosphoryl dichloride and 3-amino-1, 2, 4-triazole, and the composite damping filler is obtained by synthesizing palm oil polyol, phthalic anhydride polyester polyol and diphenylmethane diisocyanate. The modified halogen-free flame retardant and the composite damping filler are added into the EPDM rubber at the same time, so that the obtained EPDM rubber material has excellent flame-retardant effect, aging-resistant effect and damping effect.

Description

Technical Field

[0001] The invention belongs to the technical field of EPDM rubber preparation, and in particular relates to a halogen-free, flame-retardant, and shock-absorbing EPDM rubber. Background Art

[0002] EPDM rubber is a synthetic rubber material that is widely used in the automotive, construction, electrical, pipeline and cable fields for its excellent heat resistance, weather resistance, ozone resistance and chemical resistance. However, EPDM is a hydrocarbon material with a low oxygen index, is extremely flammable, and produces a lot of smoke during combustion, which greatly limits its application. Therefore, solving the flammability problem of EPDM and improving its flame retardant properties have become the research focus of the industry.

[0003] The traditional flame retardant method is to add halogen flame retardants to EPDM. The amount of such flame retardants added is small, and the effect on the mechanical properties and processing properties of the material is small. However, when burning, halogen flame retardants will produce a lot of smoke and toxic and corrosive hydrogen halide gas, causing secondary pollution, which does not meet the current requirements of environmental protection and sustainable development. Therefore, the development of halogen-free, non-toxic and environmentally friendly flame retardants has become a new trend in flame retardant technology.

[0004] Patent CN 114516989 B discloses an EPDM halogen-free flame retardant rubber and a preparation method thereof. The halogen-free flame retardant rubber is made of EPDM oil-filled raw rubber and non-oil-filled EPDM raw rubber as the matrix, organic phosphorus-nitrogen flame retardant is selected as the halogen-free flame retardant, and auxiliary agents are added. The prepared halogen-free flame retardant rubber enables the rubber compound to meet the flame retardant requirements of 0.5mm UL94-V0 level under the requirement of lower hardness, and the rubber compound itself also has good processing performance and physical properties. However, the flame retardant performance, seismic performance and aging resistance of the EPDM rubber compound obtained by this method still have room for improvement. Summary of the invention

[0005] The object of the present invention is to provide a halogen-free flame-retardant shock-absorbing EPDM rubber material, which is used to solve the technical problems of poor flame retardancy, shock resistance and aging resistance of EPDM rubber materials in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The invention provides a halogen-free flame-retardant shock-absorbing EPDM rubber material, which is composed of the following components in parts by weight: 22-33 parts of ethylene propylene diene monomer rubber, 2-6 parts of modified halogen-free flame retardant, 1-4 parts of composite shock-absorbing filler, 0.8-2.1 parts of antioxidant, and 0.4-0.8 parts of accelerator; wherein the modified halogen-free flame retardant is compounded by o-hydroxybenzaldehyde, phenyl phosphoryl dichloride and 3-amino-1,2,4-triazole, and the composite shock-absorbing filler is compounded by palm oil polyol, phthalic anhydride polyester polyol and diphenylmethane diisocyanate.

[0008] Preferably, the preparation method of the modified halogen-free flame retardant comprises the following steps:

[0009] Q1: o-hydroxybenzaldehyde, triethylamine and ethyl acetate are added to a container connected to a reflux tube, stirred at room temperature until o-hydroxybenzaldehyde is completely dissolved, phenylphosphoryl dichloride and ethyl acetate are mixed, and then dripped into the container. After the dripping is completed, the temperature is raised to react. After the reaction is completed, the precipitate is removed by filtration, and the filtrate is washed, dried, concentrated, and recrystallized to obtain product 1;

[0010] Q2: Dissolve the product 1 and 3-amino-1,2,4-triazole in anhydrous ethanol, transfer to a container connected to a reflux tube, heat to react, dissolve 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in anhydrous ethanol, add to the container after the heating reaction is completed, then heat to react, and after the reaction is completed, rotary evaporate, wash, and dry to obtain a modified halogen-free flame retardant.

[0011] In the above process, o-hydroxybenzaldehyde is used as a functional unit to react with phenylphosphoryl dichloride to introduce phosphorus into the flame retardant monomer. If 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added to the EPDM rubber alone, a higher amount of addition is required to meet the flame retardant requirements. Therefore, it is first reacted with product 1 and 3-amino-1,2,4-triazole to prepare a modified halogen-free flame retardant, which is then added to EPDM to obtain a rubber with a flame retardant effect. The preparation process of the modified halogen-free flame retardant is as follows:

[0012]

[0013] The results of mass spectrometry analysis were: m / z: 932.22 (100.0%), 933.22 (52.6%), 934.22 (16.3%), 933.21 (3.0%), 935.23 (2.3%), 935.22 (1.2%).

[0014] Preferably, in Q1, the mass ratio of o-hydroxybenzaldehyde, triethylamine and phenylphosphoryl chloride is (11.41-13.75) g: (10-10.26) g: (9.5-9.9) g, the dosage ratio of o-hydroxybenzaldehyde to ethyl acetate is (11.41-13.75) g: 100 mL, and the dosage ratio of phenylphosphoryl chloride to ethyl acetate is (9.5-9.9) g: 40 mL. Nitrogen protection is provided during the dropwise addition process, and the temperature during the dropwise addition process is 0-1°C, the temperature of the temperature rise reaction is 60-70°C, the time is 24-30h, a saturated sodium chloride solution is used during the washing process, the number of washings is 3-5 times, and the product is dried using anhydrous sodium sulfate.

[0015] Preferably, in Q2, the mass ratio of product 1, 3-amino-1,2,4-triazole and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is (7.1-8.28) g: (3-3.72) g: (8-9.28) g, the dosage ratio of product 1 and anhydrous ethanol is (7.1-8.28) g: 50 mL, the dosage ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and anhydrous ethanol is (8-9.28) g: 50 mL, the heating reaction temperature is 50-70°C, the heating reaction time is 8-10 h, the temperature rise reaction temperature is 80-90°C, the temperature rise reaction time is 12-14 h, anhydrous ethanol is used in the washing process, and the number of washing times is 3-5 times.

[0016] Preferably, the preparation method of the composite shock-absorbing filler comprises the following steps:

[0017] S1: After removing water from palm oil by rotary evaporation, place the palm oil in a container, stir, preheat, add diethanolamine and sodium methoxide, mix well, take a sample, and obtain palm oil alcohol amide;

[0018] S2: transferring the palm oil alcohol amide to a container containing a magnetic rotor, adding dichloromethane, stirring, then adding sodium bicarbonate solution, continuing stirring, washing after the stirring is completed, standing, separating, collecting the lower organic phase, repeating the washing, mixing the collected organic phases, vacuum rotary evaporation, heating rotary evaporation, and obtaining palm oil polyol;

[0019] S3: Add palm oil polyol, phthalic anhydride polyester polyol, N,N-dimethylcyclohexylamine, dodecyl dimethyl benzyl ammonium chloride and deionized water into a container, mix and stir, add diphenylmethane diisocyanate after sufficient mixing, continue stirring, stop stirring after sufficient mixing to allow free foaming, and solidify after foaming to obtain a composite shock-absorbing filler.

[0020] In the above process, polyols are used as the soft segment structure and isocyanate is used as the hard segment structure in the preparation of the composite shock-absorbing filler. Palm oil is used as the raw material for amidation reaction, and difunctional hydroxyl palm oil polyol is obtained in one step to replace part of the phthalic anhydride polyester polyol. The composite shock-absorbing filler is synthesized by a one-step foaming method.

[0021] Preferably, in S1, the temperature for rotary evaporation to remove water is 100-110°C, the time is 10-12h, the dosage ratio of palm oil, diethanolamine and sodium methoxide is (198-202)g:(84-86)g:4mL, the preheating temperature is 60-70°C, the sampling interval is once every two hours, and the change of absorption peak is observed by infrared to control the reaction progress.

[0022] Preferably, in S2, the stirring time is 5-8 min, the volume ratio of dichloromethane to sodium bicarbonate solution is 2:1, the volume concentration of sodium bicarbonate solution is 10vt%, the stirring time is continued for 4-10 min, the washing is repeated 3-5 times, the vacuum rotary evaporation temperature is 40-60°C, the time is 4-6h, and the heating rotary evaporation temperature is 100-110°C, and the time is 12-14h.

[0023] Preferably, in S3, the dosage ratio of palm oil polyol, phthalic anhydride polyester polyol, N,N-dimethylcyclohexylamine, dodecyl dimethyl benzyl ammonium chloride, deionized water and diphenylmethane diisocyanate is (78-82) g: (18-22) g: (1-1.1) mL: 2.5 g: 3 mL: (130-130.28) mL, the mixing time is 1-2 min, the stirring speed is 500-700 rpm, the continued stirring time is 20-40 s, and the curing time is 7-10 days.

[0024] Preferably, a method for preparing a halogen-free flame-retardant shock-absorbing EPDM rubber material comprises the following steps:

[0025] Step (1): adding EPDM rubber into an open mill, and then adding a modified halogen-free flame retardant and a composite shock-absorbing filler, mixing and kneading uniformly and then thinning;

[0026] Step (2): After thinning, adding antioxidant and accelerator, mixing, and obtaining halogen-free flame retardant shock-absorbing EPDM rubber.

[0027] Preferably, in the step (1), the mixing time is 5-8 min, the mixing temperature is 50-70° C., and the number of thin passes is 3-5 times; in the step (2), the mixing time is 4-7 min.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. The present invention obtains a modified halogen-free flame retardant by compounding o-hydroxybenzaldehyde, phenylphosphoryl dichloride and 3-amino-1,2,4-triazole, and obtains a composite shock-absorbing filler by compounding palm oil polyol, phthalic anhydride polyester polyol and diphenylmethane diisocyanate. The modified halogen-free flame retardant and the composite shock-absorbing filler are simultaneously added to ethylene propylene diene monomer rubber for mixing, thereby obtaining an EPDM rubber material with excellent flame retardant effect, aging resistance effect and shock-absorbing effect.

[0030] 2. The present invention reacts o-hydroxybenzaldehyde with phenylphosphoryl dichloride to introduce phosphorus, which is then reacted with 3-amino-1,2,4-triazole and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a modified halogen-free flame retardant. The introduction of phosphorus causes phosphoric acid, metaphosphoric acid, polyphosphoric acid and other compounds to form during combustion, thereby covering the surface of the EPDM rubber material to form a dense protective film, effectively isolating oxygen and heat, and inhibiting the combustion process; the nitrogen element in 3-amino-1,2,4-triazole releases non-combustible gases such as nitrogen during combustion, which can dilute the oxygen concentration in the air and reduce the combustion rate, and the protective film formed by the phosphorus element and the non-combustible gas released by the nitrogen element can enhance each other and jointly improve the flame retardant performance; at the same time, the flame retardant does not contain halogen elements, and does not generate toxic and harmful gases such as hydrogen halides during use, and has excellent environmental protection performance.

[0031] 3. The present invention uses palm oil as a raw material for amidation reaction, and obtains palm oil polyol with difunctional hydroxyl group in one step, which replaces part of phthalic anhydride polyester polyol, and synthesizes composite shock-absorbing filler with diphenylmethane diisocyanate through a one-step foaming method. The palm oil used is an abundant renewable resource, and the preparation process is simple. The bio-based polyol obtained from palm oil replaces the petroleum-based polyol, which is beneficial to environmental protection. The palm oil polyol has good compatibility with EPDM, so that the composite shock-absorbing filler can be evenly dispersed in the EPDM matrix to form a uniform structure, thereby reducing stress concentration and crack generation. It helps to improve the overall shock-absorbing performance of the rubber; polyols react with polyisocyanates to form a composite shock-absorbing filler with a specific microstructure. The formed cross-linked network can increase the elasticity and toughness of the rubber, so that it can better absorb and disperse the impact energy when subjected to external impact; and the large number of tiny bubbles formed can absorb and disperse external impact, reduce vibration and noise transmission, and enhance the shock-absorbing effect; and the composite shock-absorbing filler has antioxidant properties, can capture and neutralize free radicals, slow down the degradation rate of EPDM during the oxidation process, help maintain the physical properties and chemical stability of the rubber, and extend its service life. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0033] EPDM rubber was purchased from Shanghai Beidaer New Materials Co., Ltd.;

[0034] Antioxidant RD was purchased from Shanghai Chengjin Chemical Co., Ltd., CAS No.: 26780-96-1;

[0035] Accelerator CZ was purchased from Handan Yingzi Renewable Resources Recycling Co., Ltd., CAS No.: 95-33-0;

[0036] o-Hydroxybenzaldehyde was purchased from Chiping County Jinshun Chemical Co., Ltd., CAS No.: 90-02-8;

[0037] Triethylamine was purchased from Shandong Ranxi Chemical Technology Co., Ltd., CAS No.: 121-44-8;

[0038] Ethyl acetate was purchased from Shandong Xinyujia Chemical Co., Ltd., CAS No.: 141-78-6;

[0039] Phenylphosphoryl dichloride was purchased from Hubei Xinghengye Technology Co., Ltd., CAS No.: 824-72-6;

[0040] 3-Amino-1,2,4-triazole was purchased from Hubei Longxin Chemical Industry Co., Ltd., CAS No.: 61-82-5;

[0041] Anhydrous ethanol was purchased from Foshan Changxing New Materials Co., Ltd., CAS No.: 64-17-5;

[0042] 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was purchased from Jinan Jinbang Environmental Protection Technology Co., Ltd., CAS No.: 35948-25-5;

[0043] Palm oil was purchased from Hefeng New Energy Co., Ltd., CAS number: 8002-75-3;

[0044] Diethanolamine was purchased from Shandong Taixi Chemical Co., Ltd., CAS No.: 111-42-2;

[0045] Sodium methoxide was purchased from Jinan Hongju Chemical Co., Ltd., CAS number: 124-41-4;

[0046] Dichloromethane was purchased from Shandong Baihua Chemical Co., Ltd., CAS No.: 75-09-2;

[0047] Sodium bicarbonate was purchased from Henan Yushuifeng Environmental Protection Technology Co., Ltd., CAS No.: 144-55-8;

[0048] Phthalic anhydride polyester polyol was purchased from Haian Petrochemical Plant, Jiangsu Province, CAS No.: 32472-85-8;

[0049] N,N-dimethylcyclohexylamine was purchased from Jinan Hongwang Chemical Co., Ltd., CAS number: 98-94-2;

[0050] Dodecyl dimethyl benzyl ammonium chloride was purchased from Zaozhuang Shibang Biotechnology Co., Ltd., CAS number: 139-07-1;

[0051] Diphenylmethane diisocyanate was purchased from Shandong Xinhe New Materials Co., Ltd., CAS number: 101-68-8.

[0052] Example 1

[0053] This embodiment discloses a method for preparing a modified halogen-free flame retardant, comprising the following steps:

[0054] Q1: 12.58 g of o-hydroxybenzaldehyde, 10.13 g of triethylamine and 100 mL of ethyl acetate were added to a container connected to a reflux tube, and stirred at room temperature until the o-hydroxybenzaldehyde was completely dissolved. 9.7 g of phenylphosphoryl dichloride and 40 mL of ethyl acetate were mixed, and then dripped into the container at 0°C under nitrogen protection. After the addition was completed, the temperature was raised to 60°C for reaction for 24 hours. After the reaction was completed, the precipitate was removed by filtration, and the filtrate was washed 5 times with a saturated sodium chloride solution, dried with anhydrous sodium sulfate, concentrated, and recrystallized to obtain product 1;

[0055] Q2: 7.64 g of product 1 and 3.36 g of 3-amino-1,2,4-triazole were dissolved in 50 mL of anhydrous ethanol, transferred to a container connected to a reflux tube, and heated at 60°C for 10 h. 8.64 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was dissolved in 50 mL of anhydrous ethanol. After the heating reaction was completed, the mixture was added to the container, and then heated at 90°C for 12 h. After the reaction was completed, the mixture was rotary evaporated, washed with anhydrous ethanol for 3 times, and dried to obtain a modified halogen-free flame retardant.

[0056] This embodiment discloses a method for preparing a composite shock-absorbing filler, comprising the following steps:

[0057] S1: 200g of palm oil was placed in a container after being dehydrated by rotary evaporation at 110°C for 12h, stirred, and preheated at 70°C before adding 85g of diethanolamine and 4mL of sodium methoxide, mixed evenly, and the sampling interval was once every two hours. The absorption peak change was observed by infrared to control the reaction process, and palm oil alcohol amide was obtained;

[0058] S2: Transfer the palm oil alcohol amide to a container containing a magnetic rotor, add 600 mL of dichloromethane, stir for 8 min, then add 300 mL of a 10vt% sodium bicarbonate solution, continue stirring for 10 min, wash 3 times after the stirring is completed, let stand, separate the liquids, collect the lower organic phase, repeat the washing, mix the collected organic phases, perform vacuum rotary evaporation at 60°C for 4 h, and then heat and rotary evaporate at 110°C for 12 h to obtain palm oil polyol;

[0059] S3: Add 80g palm oil polyol, 20g phthalic anhydride polyester polyol, 1.05mL N,N-dimethylcyclohexylamine, 2.5g dodecyl dimethyl benzyl ammonium chloride and 3mL deionized water into a container, stir at 700rpm for 2min, add 130.14mL diphenylmethane diisocyanate after thorough mixing, continue stirring for 40s, stop stirring after thorough mixing to allow free foaming, and cure for 8 days after foaming to obtain a composite shock-absorbing filler.

[0060] The present embodiment discloses a halogen-free flame-retardant shock-absorbing EPDM rubber material, which is composed of the following components in parts by weight: 27.5 parts of ethylene propylene diene monomer rubber, 4 parts of modified halogen-free flame retardant, 2.5 parts of composite shock-absorbing filler, 1.45 parts of antioxidant RD, and 0.6 parts of accelerator CZ.

[0061] This embodiment discloses a method for preparing a halogen-free, flame-retardant, shock-absorbing EPDM rubber material, comprising the following steps:

[0062] Step (1): adding EPDM rubber to an open mill, followed by adding a modified halogen-free flame retardant and a composite shock-absorbing filler, mixing at 60° C. for 8 minutes, and then thinning the mixture for 5 times;

[0063] Step (2): After thinning, add antioxidant RD and accelerator CZ, mix for 6 minutes, and obtain halogen-free flame retardant and shock-absorbing EPDM rubber.

[0064] Example 2

[0065] This embodiment discloses a method for preparing a modified halogen-free flame retardant, comprising the following steps:

[0066] Q1: 11.41 g of o-hydroxybenzaldehyde, 10 g of triethylamine and 100 mL of ethyl acetate were added to a container connected to a reflux tube, stirred at room temperature until o-hydroxybenzaldehyde was completely dissolved, 9.5 g of phenylphosphoryl dichloride and 40 mL of ethyl acetate were mixed, and then dripped into the container at 0°C under nitrogen protection. After the addition was completed, the temperature was raised to 60°C for reaction for 24 hours. After the reaction was completed, the precipitate was removed by filtration, and the filtrate was washed 5 times with a saturated sodium chloride solution, dried with anhydrous sodium sulfate, concentrated, and recrystallized to obtain product 1;

[0067] Q2: 7.1 g of product 1 and 3 g of 3-amino-1,2,4-triazole were dissolved in 50 mL of anhydrous ethanol, transferred to a container connected to a reflux tube, and heated at 60°C for 10 h. 8 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was dissolved in 50 mL of anhydrous ethanol. After the heating reaction was completed, it was added to the container, and then heated to 90°C for 12 h. After the reaction was completed, it was rotary evaporated, washed with anhydrous ethanol 3 times, and dried to obtain a modified halogen-free flame retardant.

[0068] This embodiment discloses a method for preparing a composite shock-absorbing filler, comprising the following steps:

[0069] S1: 198g of palm oil was subjected to rotary evaporation at 110°C for 12h to remove water, then placed in a container, stirred, preheated at 70°C, added with 84g of diethanolamine and 4mL of sodium methoxide, mixed evenly, and sampled once every two hours. The absorption peak change was observed by infrared to control the reaction process, and palm oil alcohol amide was obtained;

[0070] S2: Transfer the palm oil alcohol amide to a container containing a magnetic rotor, add 600 mL of dichloromethane, stir for 8 min, then add 300 mL of a 10vt% sodium bicarbonate solution, continue stirring for 10 min, wash 3 times after the stirring is completed, let stand, separate the liquids, collect the lower organic phase, repeat the washing, mix the collected organic phases, perform vacuum rotary evaporation at 60°C for 4 h, and then heat and rotary evaporate at 110°C for 12 h to obtain palm oil polyol;

[0071] S3: Add 82g palm oil polyol, 22g phthalic anhydride polyester polyol, 1.1mL N,N-dimethylcyclohexylamine, 2.5g dodecyl dimethyl benzyl ammonium chloride and 3mL deionized water into a container, stir at 700rpm for 2min, add 130.28mL diphenylmethane diisocyanate after thorough mixing, continue stirring for 40s, stop stirring after thorough mixing to allow free foaming, and cure for 8 days after foaming to obtain a composite shock-absorbing filler.

[0072] The present embodiment discloses a halogen-free flame-retardant shock-absorbing EPDM rubber material, which is composed of the following components in parts by weight: 22 parts of ethylene propylene diene monomer rubber, 2 parts of modified halogen-free flame retardant, 1 part of composite shock-absorbing filler, 0.8 parts of antioxidant RD, and 0.4 parts of accelerator CZ.

[0073] This embodiment discloses a method for preparing a halogen-free, flame-retardant, shock-absorbing EPDM rubber material, comprising the following steps:

[0074] Step (1): adding EPDM rubber to an open mill, followed by adding a modified halogen-free flame retardant and a composite shock-absorbing filler, mixing at 60° C. for 8 minutes, and then thinning the mixture for 5 times;

[0075] Step (2): After thinning, add antioxidant RD and accelerator CZ, mix for 6 minutes, and obtain halogen-free flame retardant and shock-absorbing EPDM rubber.

[0076] Example 3

[0077] This embodiment discloses a method for preparing a modified halogen-free flame retardant, comprising the following steps:

[0078] Q1: 13.75 g of o-hydroxybenzaldehyde, 10.26 g of triethylamine and 100 mL of ethyl acetate were added to a container connected to a reflux tube, and stirred at room temperature until the o-hydroxybenzaldehyde was completely dissolved. 9.9 g of phenylphosphoryl dichloride and 40 mL of ethyl acetate were mixed, and then dripped into the container at 0°C under nitrogen protection. After the addition was completed, the temperature was raised to 60°C for reaction for 24 hours. After the reaction was completed, the precipitate was removed by filtration, and the filtrate was washed 5 times with a saturated sodium chloride solution, dried with anhydrous sodium sulfate, concentrated, and recrystallized to obtain product 1;

[0079] Q2: 8.28g of product 1 and 3.72g of 3-amino-1,2,4-triazole were dissolved in 50mL of anhydrous ethanol, transferred to a container connected to a reflux tube, and heated at 60°C for 10h. 9.28g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was dissolved in 50mL of anhydrous ethanol. After the heating reaction was completed, it was added to the container, and then heated at 90°C for 12h. After the reaction was completed, it was rotary evaporated, washed with anhydrous ethanol 3 times, and dried to obtain a modified halogen-free flame retardant.

[0080] This embodiment discloses a method for preparing a composite shock-absorbing filler, comprising the following steps:

[0081] S1: 202g of palm oil was subjected to rotary evaporation at 110°C for 12h to remove water, and then placed in a container, stirred, and preheated at 70°C, and then 86g of diethanolamine and 4mL of sodium methoxide were added, and mixed evenly. The sampling interval was once every two hours, and the absorption peak change was observed by infrared to control the reaction process, and palm oil alcohol amide was obtained;

[0082] S2: Transfer the palm oil alcohol amide to a container containing a magnetic rotor, add 600 mL of dichloromethane, stir for 8 min, then add 300 mL of a 10vt% sodium bicarbonate solution, continue stirring for 10 min, wash 3 times after the stirring is completed, let stand, separate the liquids, collect the lower organic phase, repeat the washing, mix the collected organic phases, perform vacuum rotary evaporation at 60°C for 4 h, and then heat and rotary evaporate at 110°C for 12 h to obtain palm oil polyol;

[0083] S3: Add 78g palm oil polyol, 18g phthalic anhydride polyester polyol, 1mL N,N-dimethylcyclohexylamine, 2.5g dodecyl dimethyl benzyl ammonium chloride and 3mL deionized water into a container, stir at 700rpm for 2min, add 130mL diphenylmethane diisocyanate after thorough mixing, continue stirring for 40s, stop stirring after thorough mixing to allow free foaming, and cure for 8 days after foaming to obtain a composite shock-absorbing filler.

[0084] The present embodiment discloses a halogen-free flame-retardant shock-absorbing EPDM rubber material, which is composed of the following components in parts by weight: 33 parts of ethylene propylene diene monomer rubber, 6 parts of modified halogen-free flame retardant, 4 parts of composite shock-absorbing filler, 2.1 parts of antioxidant RD, and 0.8 parts of accelerator CZ.

[0085] This embodiment discloses a method for preparing a halogen-free, flame-retardant, shock-absorbing EPDM rubber material, comprising the following steps:

[0086] Step (1): adding EPDM rubber to an open mill, followed by adding a modified halogen-free flame retardant and a composite shock-absorbing filler, mixing at 60° C. for 8 minutes, and then thinning the mixture for 5 times;

[0087] Step (2): After thinning, add antioxidant RD and accelerator CZ, mix for 6 minutes, and obtain halogen-free flame retardant and shock-absorbing EPDM rubber.

[0088] Example 4

[0089] This embodiment discloses a method for preparing a modified halogen-free flame retardant, comprising the following steps:

[0090] Q1: 11.97 g of o-hydroxybenzaldehyde, 10.17 g of triethylamine and 100 mL of ethyl acetate were added to a container connected to a reflux tube, and stirred at room temperature until the o-hydroxybenzaldehyde was completely dissolved. 9.6 g of phenylphosphoryl dichloride and 40 mL of ethyl acetate were mixed, and then dripped into the container at 0°C under nitrogen protection. After the addition was completed, the temperature was raised to 60°C for reaction for 24 hours. After the reaction was completed, the precipitate was removed by filtration, and the filtrate was washed 5 times with a saturated sodium chloride solution, dried with anhydrous sodium sulfate, concentrated, and recrystallized to obtain product 1;

[0091] Q2: 7.49 g of product 1 and 3.12 g of 3-amino-1,2,4-triazole were dissolved in 50 mL of anhydrous ethanol, transferred to a container connected to a reflux tube, and heated at 60°C for 10 h. 8.17 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was dissolved in 50 mL of anhydrous ethanol. After the heating reaction was completed, the mixture was added to the container, and then heated at 90°C for 12 h. After the reaction was completed, the mixture was rotary evaporated, washed with anhydrous ethanol for 3 times, and dried to obtain a modified halogen-free flame retardant.

[0092] This embodiment discloses a method for preparing a composite shock-absorbing filler, comprising the following steps:

[0093] S1: 201g of palm oil was subjected to rotary evaporation at 110°C for 12h to remove water, then placed in a container, stirred, preheated at 70°C, added with 84.5g of diethanolamine and 4mL of sodium methoxide, mixed evenly, and sampled once every two hours. The absorption peak change was observed by infrared to control the reaction process, and palm oil alcohol amide was obtained;

[0094] S2: Transfer the palm oil alcohol amide to a container containing a magnetic rotor, add 600 mL of dichloromethane, stir for 8 min, then add 300 mL of a 10vt% sodium bicarbonate solution, continue stirring for 10 min, wash 3 times after the stirring is completed, let stand, separate the liquids, collect the lower organic phase, repeat the washing, mix the collected organic phases, perform vacuum rotary evaporation at 60°C for 4 h, and then heat and rotary evaporate at 110°C for 12 h to obtain palm oil polyol;

[0095] S3: Add 79g palm oil polyol, 19g phthalic anhydride polyester polyol, 1.07mL N,N-dimethylcyclohexylamine, 2.5g dodecyl dimethyl benzyl ammonium chloride and 3mL deionized water into a container, stir at 700rpm for 2min, add 130.07mL diphenylmethane diisocyanate after thorough mixing, continue stirring for 40s, stop stirring after thorough mixing to allow free foaming, and cure for 8 days after foaming to obtain a composite shock-absorbing filler.

[0096] The present embodiment discloses a halogen-free flame-retardant shock-absorbing EPDM rubber material, which is composed of the following components in parts by weight: 28 parts of ethylene propylene diene monomer rubber, 3 parts of modified halogen-free flame retardant, 2 parts of composite shock-absorbing filler, 1.2 parts of antioxidant RD, and 0.5 parts of accelerator CZ.

[0097] This embodiment discloses a method for preparing a halogen-free, flame-retardant, shock-absorbing EPDM rubber material, comprising the following steps:

[0098] Step (1): adding EPDM rubber to an open mill, followed by adding a modified halogen-free flame retardant and a composite shock-absorbing filler, mixing at 60° C. for 8 minutes, and then thinning the mixture for 5 times;

[0099] Step (2): After thinning, add antioxidant RD and accelerator CZ, mix for 6 minutes, and obtain halogen-free flame retardant and shock-absorbing EPDM rubber.

[0100] Comparative Example 1

[0101] Comparative Example 1 Compared with Example 1, in the process of preparing the modified halogen-free flame retardant in Comparative Example 1, o-hydroxybenzaldehyde is not added, and other conditions remain unchanged.

[0102] Comparative Example 2

[0103] Comparative Example 2 Compared with Example 1, in the process of preparing the modified halogen-free flame retardant in Comparative Example 2, no phenylphosphoryl dichloride was added, and other conditions remained unchanged.

[0104] Comparative Example 3

[0105] Comparative Example 3 Compared with Example 1, in the process of preparing the modified halogen-free flame retardant in Comparative Example 3, 3-amino-1,2,4-triazole is not added, and other conditions remain unchanged.

[0106] Comparative Example 4

[0107] Comparative Example 4 Compared with Example 1, in the process of preparing the composite shock-absorbing filler in Comparative Example 4, no diethanolamine was added, and other conditions remained unchanged.

[0108] Comparative Example 5

[0109] Comparative Example 5 Compared with Example 1, in the process of preparing the composite shock-absorbing filler in Comparative Example 5, no phthalic anhydride polyester polyol is added, and other conditions remain unchanged.

[0110] Comparative Example 6

[0111] Comparative Example 6 Compared with Example 1, in the process of preparing the EPDM rubber compound in Comparative Example 6, no modified halogen-free flame retardant is added, and other conditions remain unchanged.

[0112] Comparative Example 7

[0113] Compared with Example 1, in Comparative Example 7, during the preparation of the EPDM rubber compound, no composite shock-absorbing filler was added, and other conditions remained unchanged.

[0114] The samples prepared in Examples 1-4 and Comparative Examples 1-7 were subjected to performance tests. The combustion performance of the samples was tested according to GB / T 10707-2008, the air heat aging test was performed on the samples according to GB / T 3512-2014, and the sound insulation and shock absorption performance test was performed on the samples according to HG / T5328-2018. The test results are shown in Table 1:

[0115] Table 1

[0116] project Vertical Burning Performance Grade Performance reduction rate / % Impact sound pressure level improvement / dB Example 1 FV-0 7.31 22.1 Example 2 FV-0 7.57 21.8 Example 3 FV-0 7.64 21.4 Example 4 FV-0 7.73 20.2 Comparative Example 1 FV-1 8.45 20.1 Comparative Example 2 FV-1 8.75 19.8 Comparative Example 3 FV-1 8.14 19.4 Comparative Example 4 FV-0 9.74 15.3 Comparative Example 5 FV-0 9.87 14.9 Comparative Example 6 FV-2 9.01 17.5 Comparative Example 7 FV-1 10.06 12.3

[0117] It can be seen from the test results in Table 1 that the EPDM rubber materials prepared in Examples 1-4 of the present invention have excellent flame retardant effect, aging resistance and shock absorption effect. From the comparison between comparative example 1 and examples 1-4, it can be seen that the addition of o-hydroxybenzaldehyde can effectively improve the flame retardant properties of EPDM rubber; from the comparison between comparative example 2 and examples 1-4, it can be seen that the addition of phenylphosphinoyl dichloride can effectively improve the flame retardant properties of EPDM rubber; from the comparison between comparative example 3 and examples 1-4, it can be seen that the addition of 3-amino-1,2,4-triazole can effectively improve the flame retardant properties of EPDM rubber; from the comparison between comparative example 4 and examples 1-4, it can be seen that the addition of diethanolamine can effectively improve the aging resistance and shock absorption properties of EPDM rubber; from the comparison between comparative example 5 and examples 1-4, it can be seen that the addition of phthalic anhydride polyester polyol can effectively improve the aging resistance and shock absorption properties of EPDM rubber; from the comparison between comparative example 6 and examples 1-4, it can be seen that the addition of modified halogen-free flame retardant can effectively improve the flame retardant properties of EPDM rubber; from the comparison between comparative example 7 and examples 1-4, it can be seen that the addition of composite shock-absorbing filler can effectively improve the aging resistance and shock absorption properties of EPDM rubber.

[0118] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0119] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A halogen-free flame-retardant shock-absorbing EPDM rubber compound, characterized in that: The invention is composed of the following components in parts by weight: 22-33 parts of ethylene propylene diene monomer rubber, 2-6 parts of modified halogen-free flame retardant, 1-4 parts of composite shock-absorbing filler, 0.8-2.1 parts of antioxidant and 0.4-0.8 parts of accelerator; wherein the modified halogen-free flame retardant is synthesized from o-hydroxybenzaldehyde, phenyl phosphoryl dichloride and 3-amino-1,2,4-triazole, and the composite shock-absorbing filler is synthesized from palm oil polyol, phthalic anhydride polyester polyol and diphenylmethane diisocyanate.

2. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 1, characterized in that: The preparation method of the modified halogen-free flame retardant, The following steps are involved: Q1: o-hydroxybenzaldehyde, triethylamine and ethyl acetate are added to a container connected to a reflux tube, stirred at room temperature until o-hydroxybenzaldehyde is completely dissolved, phenylphosphoryl dichloride and ethyl acetate are mixed, and then dripped into the container. After the dripping is completed, the temperature is raised to react. After the reaction is completed, the precipitate is removed by filtration, and the filtrate is washed, dried, concentrated, and recrystallized to obtain product 1; Q2: Dissolve the product 1 and 3-amino-1,2,4-triazole in anhydrous ethanol, transfer to a container connected to a reflux tube, heat to react, dissolve 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in anhydrous ethanol, add to the container after the heating reaction is completed, then heat to react, and after the reaction is completed, rotary evaporate, wash, and dry to obtain a modified halogen-free flame retardant.

3. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 2, characterized in that: In the Q1, the mass ratio of o-hydroxybenzaldehyde, triethylamine and phenylphosphoryl dichloride is (11.41-13.75) g: (10-10.26) g: (9.5-9.9) g, the dosage ratio of o-hydroxybenzaldehyde to ethyl acetate is (11.41-13.75) g: 100 mL, and the dosage ratio of phenylphosphoryl dichloride to ethyl acetate is (9.5-9.9) g: 40 mL. Nitrogen protection is provided during the dropwise addition process, and the temperature during the dropwise addition process is 0-1°C, the temperature of the heating reaction is 60-70°C, and the time is 24-30 h. Saturated sodium chloride solution is used during the washing process, the number of washings is 3-5 times, and the product is dried using anhydrous sodium sulfate.

4. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 2, characterized in that: In Q2, the mass ratio of product 1, 3-amino-1,2,4-triazole, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is (7.1-8.28) g: (3-3.72) g: (8-9.28) g, the dosage ratio of product 1 and anhydrous ethanol is (7.1-8.28) g: 50 mL, the dosage ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and anhydrous ethanol is (8-9.28) g: 50 mL, the heating reaction temperature is 50-70°C, the heating reaction time is 8-10 h, the temperature rise reaction temperature is 80-90°C, the temperature rise reaction time is 12-14 h, anhydrous ethanol is used in the washing process, and the number of washing times is 3-5 times.

5. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 1, characterized in that: The preparation method of the composite shock-absorbing filler comprises the following steps: S1: After removing water from palm oil by rotary evaporation, place the palm oil in a container, stir, preheat, add diethanolamine and sodium methoxide, mix well, take a sample, and obtain palm oil alcohol amide; S2: transferring the palm oil alcohol amide to a container containing a magnetic rotor, adding dichloromethane, stirring, then adding sodium bicarbonate solution, continuing stirring, washing after the stirring is completed, standing, separating, collecting the lower organic phase, repeating the washing, mixing the collected organic phases, vacuum rotary evaporation, heating rotary evaporation, and obtaining palm oil polyol; S3: Add palm oil polyol, phthalic anhydride polyester polyol, N,N-dimethylcyclohexylamine, dodecyl dimethyl benzyl ammonium chloride and deionized water into a container, mix and stir, add diphenylmethane diisocyanate after sufficient mixing, continue stirring, stop stirring after sufficient mixing to allow free foaming, and solidify after foaming to obtain a composite shock-absorbing filler.

6. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 5, characterized in that: In S1, the temperature of rotary evaporation to remove water is 100-110°C, the time is 10-12h, the dosage ratio of palm oil, diethanolamine and sodium methoxide is (198-202)g:(84-86)g:4mL, the preheating temperature is 60-70°C, the sampling interval is once every two hours, and the change of absorption peak is observed by infrared to control the reaction progress.

7. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 5, characterized in that: In S2, the stirring time is 5-8 min, the volume ratio of dichloromethane to sodium bicarbonate solution is 2:1, the volume concentration of sodium bicarbonate solution is 10vt%, the stirring time is continued for 4-10 min, the washing is repeated 3-5 times, the vacuum rotary evaporation temperature is 40-60°C, the time is 4-6h, and the heating rotary evaporation temperature is 100-110°C, and the time is 12-14h.

8. The halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 5, characterized in that: In S3, the dosage ratio of palm oil polyol, phthalic anhydride polyester polyol, N,N-dimethylcyclohexylamine, dodecyl dimethyl benzyl ammonium chloride, deionized water and diphenylmethane diisocyanate is (78-82) g: (18-22) g: (1-1.1) mL: 2.5 g: 3 mL: (130-130.28) mL, the mixing time is 1-2 min, the stirring speed is 500-700 rpm, the continued stirring time is 20-40 s, and the curing time is 7-10 days.

9. A method for preparing a halogen-free flame-retardant shock-absorbing EPDM rubber compound according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step (1): adding EPDM rubber into an open mill, and then adding a modified halogen-free flame retardant and a composite shock-absorbing filler, mixing and kneading uniformly and then thinning; Step (2): After thinning, adding antioxidant and accelerator, mixing, and obtaining halogen-free flame retardant shock-absorbing EPDM rubber.

10. The method for preparing a halogen-free flame-retardant shock-absorbing EPDM rubber compound according to claim 9, characterized in that: In the step (1), the mixing time is 5-8 minutes, the mixing temperature is 50-70° C., and the number of thin passes is 3-5 times; in the step (2), the mixing time is 4-7 minutes.

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