An environmentally friendly flame-retardant EPDM foam sealing strip material and its preparation process and application

Abstract

The present invention relates to the technical field of fireproof sealing strips, and in particular to an environmentally friendly flame-retardant EPDM foam sealing strip material, the formula of which is as follows: per 100 parts by weight of rubber (phr): EPDM: 100phr; active agent 1-9phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; compound flame retardant: 30-50phr; carbon black: 60phr; paraffin oil: 50phr; accelerator 1.5-6.8phr; foaming agent: 4-12phr. The environmentally friendly flame-retardant EPDM foam sealing strip material provided by the present invention adopts a halogen-free compound flame retardant with a ratio of 6:1:3. The sealing strip material prepared by the above formula has a foaming specific gravity of 0.55g / cm 3 The flame retardant effect can be achieved by extinguishing the flame immediately after leaving the flame, with low smoke density and smoke toxicity meeting environmental protection requirements and meeting the smoke toxicity requirements of EN45545-2. In addition, the low density of the sealing strip material of the present invention meets the trend of lightweight products and meets the requirements of use in the fields of construction, automobiles, ships, and heavy industry. It has good elasticity and surface quality, and has the advantages of environmental protection and flame retardancy, which can meet the requirements of EU RoHS regulations.

Description

Technical Field

[0001] The present invention relates to the technical field of fireproof sealing strips, and in particular to an environmentally friendly flame-retardant EPDM foam sealing strip material and a preparation method thereof. Background Art

[0002] EPDM flame-retardant foam materials, which are used in environmentally friendly flame-retardant materials, mostly use halogens. The combustion process of these flame retardants produces toxic gases such as HCL and HBr. While these flame retardants meet flame retardancy requirements, they can also cause secondary poisoning to personnel escaping from a fire. Furthermore, in specialized environments such as marine and automotive applications, the acidic gases produced during combustion can damage equipment and cause property loss. Furthermore, existing sealing strip materials often suffer from surface roughness that is unsightly, produce acidic gases that corrode equipment, have high density that fails to meet lightweight requirements, have slow vulcanization rates, and exhibit poor gloss. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an environmentally friendly flame-retardant EPDM foam sealing strip material and its preparation process and application. The environmentally friendly flame-retardant EPDM foam sealing strip material adopts a specific proportion of halogen-free flame retardant, so that the flame retardant effect of the prepared sealing strip material can reach the point where it will be extinguished immediately after leaving the fire. In addition, the smoke density is low, and the smoke toxicity meets environmental protection requirements and can meet the EN45545-2 smoke toxicity requirements.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides an environmentally friendly flame-retardant EPDM foam sealing strip material. The formula of the environmentally friendly flame-retardant EPDM foam sealing material is as follows:

[0006] Per 100 parts by weight of rubber (phr):

[0007] EPDM: 100phr; activator 1-9phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; compound flame retardant: 30-50phr; carbon black: 60phr; paraffin oil: 50phr; accelerator 1.5-6.8phr; foaming agent: 4-12phr.

[0008] The Al(OH)3 and Mg(OH)2 are flame retardants; the carbon black is a reinforcing agent, and N550 is selected; the paraffin oil is a plasticizer, and 2280 is selected.

[0009] Based on the above technical solution, the active agent is one or more of ZnO, stearic acid SA or polyethylene glycol-400PEG-4000; wherein ZnO adopts indirect zinc oxide, which has a small particle size, high purity, large specific surface area, and high chemical activity. Indirect zinc oxide is very easy to disperse into the system and can produce a relatively highly dispersed, uniform and stable dispersion system.

[0010] Appropriate amounts of ZnO and SA participate in the vulcanization reaction to ensure the vulcanization of the product. If they are not added, vulcanization will not occur. If the amount added is inappropriate, the stability of the foaming will be affected. PEG4000 will neutralize the acidity in the filler, increase the vulcanization speed and cross-linking density, and also play a lubricating role. The appropriate amount can not only improve the surface roughness of the extruded product, but also balance the foaming speed and vulcanization speed, and increase EPDM's absorption of microwaves.

[0011] Based on the above technical solution, the compound flame retardant includes one or more of red phosphorus P, melamine Melamine and ammonium octamolybdate AOM.

[0012] Preferably, the mass ratio of red phosphorus P, melamine Melamine and ammonium octamolybdate AOM in the compound flame retardant is 6:1:3.

[0013] Preferably, the preparation method of the compound flame retardant is as follows:

[0014] Red phosphorus P, melamine Melamine and ammonium octamolybdate AOM were mechanically mixed in a mass ratio of 6:1:3, and pentaerythritol was added for surface modification.

[0015] Based on the above technical solution, the accelerator is one or more of S-80, M-80, PZ-75 or BZ, wherein S-80 is a vulcanizing agent, M-80 is a fast accelerator, BZ is a fast accelerator, and PZ-75 is an ultra-fast accelerator, which is beneficial to the matching of vulcanization speed and foaming speed. The combined use can take into account both product density and reduce product surface roughness. If the foaming speed and vulcanization speed at other ratios do not match, the product surface roughness will be higher.

[0016] Based on the above technical solution, the foaming agent is one or both of azodicarbonamide AC and 4,4'-oxybisbenzenesulfonylhydrazine OBSH. The use of the foaming agents in this ratio can achieve a balance between product density and low surface roughness. Other ratios do not match the foaming speed and vulcanization speed, resulting in high surface roughness.

[0017] The optimal formula is as follows:

[0018] Per 100 parts by weight of rubber (phr):

[0019] EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; Red phosphorus: 30phr; Melamine: 5phr; Ammonium octamolybdate: 15phr; Carbon black: 60phr; Paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ: 2phr; AC: 8phr; OBSH: 4phr.

[0020] In a second aspect, the present invention provides a preparation process for an environmentally friendly flame-retardant EPDM foam sealing strip material as described in the first aspect, wherein the preparation process includes the preparation of a first-stage glue and a second-stage glue, and the preparation steps are as follows:

[0021] S1: Preparation of one-stage rubber: add EPDM raw rubber at a temperature of <90°C and mix for 1 minute. After removing the plug, add ZnO, SA, and PEG-4000 and mix for 1 minute. After removing the plug, add Al(OH)3, Mg(OH)2, compound flame retardant, carbon black, and paraffin oil and mix for 3 minutes. After removing the plug and cleaning, mix for another 2 minutes and then discharge the rubber. After thinning twice on the mill, remove the sheet and cool.

[0022] S2: Place the glue obtained in S1 in a constant temperature room (25±5°C, humidity below 70%) for 24 hours for later use;

[0023] S3: Preparation of second-stage rubber: When the temperature is less than 60℃, add the first-stage rubber and mix for 30 seconds. Then add S-80, M-80, PZ-75, BZ-80, AC, and OBSH and mix for 1 minute. Discharge the material. After the open mill is thinned twice, the sheet is removed and cooled.

[0024] In a third aspect, the present invention provides the use of the environmentally friendly, flame-retardant EPDM foam sealing strip material described in the first aspect in the manufacture of sealing strips. The material can be used in automotive and marine doors and windows. Its flame retardancy, low smoke density, low smoke toxicity, and low density meet customer requirements for a smooth, lightweight, and safe sealing strip.

[0025] The present invention has the following advantages:

[0026] 1. The environmentally friendly flame-retardant EPDM foam sealing strip material provided by the present invention adopts a halogen-free compound flame retardant with a ratio of 6:1:3. The sealing strip material prepared by the above formula has a foaming density of 0.55g / cm 3 The flame retardant effect can achieve the effect of extinguishing the flame as soon as it is away from the fire. In addition, the smoke density is low and the smoke toxicity meets the environmental protection requirements and meets the EN45545-2 smoke toxicity requirements.

[0027] 2. The low density of the environmentally friendly flame-retardant EPDM foam sealing strip material provided by the present invention meets the trend of lightweight products and provides core competitiveness for the product at a relatively low cost.

[0028] 3. The environmentally friendly flame-retardant EPDM foam sealing strip produced by the present invention can meet the use requirements of construction, automobile, shipbuilding, and heavy industry fields, has good elasticity and surface, and has the advantages of environmental protection and flame retardancy, and can meet the requirements of EU RoSH regulations. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described below in conjunction with specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0030] Example 1

[0031] This example provides three formulations of environmentally friendly flame-retardant EPDM foam sealing materials, and sets up three comparative experiments, which are as follows:

[0032] 1.1 The formulas of environmentally friendly flame retardant EPDM foam sealing materials are as follows:

[0033] Experiment 1: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; red phosphorus: 30phr; melamine: 15phr; ammonium octamolybdate: 5phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr.

[0034] Experiment 2: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; red phosphorus: 30phr; melamine: 10phr; ammonium octamolybdate: 10phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr.

[0035] Experiment 3: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; red phosphorus: 30phr; melamine 5phr; ammonium octamolybdate 15phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr.

[0036] The experimental test indicators are as follows: Mooney, ML: minimum torque, MH: maximum torque, TS1: time when the rubber torque reaches (minimum torque + 1), T10: time when the rubber torque reaches (ML + 10% (MH-ML), T90: time when the rubber torque reaches (ML + 90% (MH-ML), T5: time corresponding to the minimum Mooney value rising by 5 Mooney values in the Mooney scorch test, hardness, tensile strength, elongation at break, density, flame retardant grade, smoke toxicity, and smoke density grade.

[0037] Test method:

[0038] 1. Mooney scorch is measured in accordance with the national standard GB / T1233-1992.

[0039] 2. Hardness refers to the method specified in the national standard "GB / T531.1-2008";

[0040] 3. The tensile strength and elongation at break shall refer to the method specified in the national standard "GB / T528-2009";

[0041] 4. Density refers to the method specified in the national standard "GB / T14853.1-2013";

[0042] 5. The vulcanization characteristics test refers to the method specified in the national standard "GB / T 16584-1996";

[0043] 6. Flame retardant grade test method refers to UL94 standard;

[0044] 7. Smoke toxicity test refers to standard BSS7239;

[0045] 8. The smoke density level test shall refer to the method specified in the national standard "GB / T 8627-2007".

[0046] 1.2 Preparation process:

[0047] S1: Preparation of one-stage rubber: add EPDM raw rubber at a temperature of <90°C and mix for 1 minute. After removing the plug, add ZnO, SA, and PEG-4000 and mix for 1 minute. After removing the plug, add Al(OH)3, Mg(OH)2, compound flame retardant, carbon black, and paraffin oil and mix for 3 minutes. After removing the plug and cleaning, mix for another 2 minutes and then discharge the rubber. After thinning twice on the mill, remove the sheet and cool.

[0048] S2: Place the glue obtained in S1 in a constant temperature room (25±5℃ and humidity below 70%) for 24 hours for later use;

[0049] S3: Preparation of second-stage rubber: When the temperature is less than 60℃, add first-stage rubber and mix for 30 seconds, then add S-80, M-80, PZ-75 and BZ-80 and mix for 1 minute to discharge; pass the open mill through the mill twice and then remove the sheet to cool.

[0050] 1.3 Experimental test results of the formula of environmentally friendly flame retardant EPDM foam sealing material

[0051] The experimental data are shown in Table 1:

[0052] Table 1 Experimental data of Example 1

[0053]

[0054]

[0055] The experimental data analysis is as follows:

[0056] Example 1 experimentally verified the flame retardant compounding ratio. As shown in the experimental data in Table 1, the formula in Experiment 3 achieved the best effect, meeting the requirements of smoke density, smoke toxicity, and flame retardancy rating UL94 V-0. The second best results were achieved by the formulas in Experiment 2 and Experiment 1, which met the requirements of smoke toxicity and flame retardancy rating UL94 V-1, but had poor smoke density. Thus, the flame retardant effects of the formulas in the three experimental examples in Example 1 were all qualified, and the optimal flame retardant compounding ratio in Experiment 3 was red phosphorus: melamine: ammonium octamolybdate = 6:1:3.

[0057] Example 2

[0058] 2.1 The formulas of environmentally friendly flame retardant EPDM foam sealing materials are as follows:

[0059] The experimental study was conducted based on the optimal compound flame retardant ratio of red phosphorus: melamine: ammonium octamolybdate = 6:1:3 obtained in Example 1.

[0060] Comparative experiment of halogen flame retardants: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; chlorinated paraffin: 160phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr; AC: 8phr; OBSH: 4phr.

[0061] Experiment 4: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; compound flame retardant: 30phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr; AC: 8phr; OBSH: 4phr.

[0062] Experiment 5: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; compound flame retardant: 40phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr; AC: 8phr; OBSH: 4phr.

[0063] Experiment 6: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; compound flame retardant: 50phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ-80: 2phr; AC: 8phr; OBSH: 4phr.

[0064] The experimental test indicators are as follows: Mooney, ML: minimum torque, MH: maximum torque, TS1: time when the rubber torque reaches (minimum torque + 1), T10: time when the rubber torque reaches (ML + 10% (MH-ML), T90: time when the rubber torque reaches (ML + 90% (MH-ML), T5: time corresponding to the minimum Mooney value rising by 5 Mooney values in the Mooney scorch test, density, flame retardant grade, smoke toxicity, and smoke density grade.

[0065] The testing method is the same as that in Example 1.

[0066] 2.2 Preparation process:

[0067] S1: Preparation of one-stage rubber: add EPDM raw rubber at a temperature of <90°C and mix for 1 minute. After removing the plug, add ZnO, SA, and PEG-4000 and mix for 1 minute. After removing the plug, add Al(OH)3, Mg(OH)2, compound flame retardant, carbon black, and paraffin oil and mix for 3 minutes. After removing the plug and cleaning, mix for another 2 minutes and then discharge the rubber. After thinning twice on the mill, remove the sheet and cool.

[0068] S2: Place the glue obtained in S1 in a constant temperature room (25±5℃ and humidity below 70%) for 24 hours for later use;

[0069] S3: Preparation of second-stage rubber: When the temperature is less than 60℃, add the first-stage rubber and mix for 30 seconds. Then add S-80, M-80, PZ-75, BZ-80, AC, and OBSH and mix for 1 minute. Discharge the material. After the open mill is thinned twice, the sheet is removed and cooled.

[0070] 2.3 Experimental test results of the formula of environmentally friendly flame retardant EPDM foam sealing material

[0071] The experimental data are shown in Table 2:

[0072] Table 2 Experimental data of Example 2

[0073]

[0074]

[0075] The experimental data analysis is as follows:

[0076] Example 2 was further tested for foaming based on the optimal flame retardant ratio of red phosphorus: melamine: ammonium octamolybdate = 6:1:3 obtained in Example 1. A halogen flame retardant was used as a comparative experiment, and the formulas with different flame retardant dosages in Experiments 4, 5, and 6 were compared and verified. The experimental results are shown in Table 2. The formula in Experiment 6 was the best, meeting the requirements of smoke density, smoke toxicity, and flame retardancy rating UL94 V-0 simultaneously. The results of Experiments 5 and 4 were second, meeting the requirements of smoke density, smoke toxicity, and flame retardancy rating UL94 V-1 simultaneously. In the comparative experiment with the halogen flame retardant, only the flame retardancy rating met the UL94 V-0 requirement, while both the smoke toxicity and smoke density were unqualified.

[0077] The flame retardant used in the present invention does not contain halogen, has good synergistic flame retardant effect, is low in price, has a smooth extruded surface and high product surface gloss. These flame retardant materials have a high specific gravity and a fast extrusion speed, and their refractive index of 1.5-1.8 is lower than that of carbon black (1.8-2).

[0078] Therefore, the best environmentally friendly flame-retardant EPDM foam sealing strip material formula in the present invention is as follows: EPDM: 100phr; ZnO: 5phr; SA: 1phr; PEG-4000: 3phr; Al(OH)3: 70phr; Mg(OH)2: 40phr; red phosphorus: 30phr; melamine: 5phr; ammonium octamolybdate: 15phr; carbon black: 60phr; paraffin oil: 50phr; S-80: 1.5phr; M-80: 1.5phr; PZ-75: 1.8phr; BZ: 2phr; AC: 8phr; OBSH: 4phr.

[0079] The present invention has been described above by way of embodiments, but the invention is not limited to the above specific embodiments. Any changes or modifications based on the present invention fall within the scope of protection claimed by the present invention.

Claims

1. An environmentally friendly flame-retardant EPDM foam sealing strip material, characterized in that: The formula of the environmentally friendly flame-retardant EPDM foam sealing material is as follows: Per 100 parts by weight of rubber (phr): EPDM: 100 phr; Activator 1-9 phr; Al(OH)3: 70 phr; Mg(OH)2: 40 phr; Compound flame retardant: 30-50 phr; Carbon black: 60 phr; Paraffin oil: 50 phr; accelerator 1.5-6.8 phr; Foaming agent: 4-12 phr; The active agent is multiple types of ZnO, SA or PEG-4000, and the ZnO is produced by indirect zinc oxidation; The mass ratio of red phosphorus, melamine and ammonium octamolybdate in the compound flame retardant is 6:1:

3.

2. The environmentally friendly flame-retardant EPDM foam sealing strip material according to claim 1, characterized in that: The preparation method of the compound flame retardant is as follows: Red phosphorus, melamine and ammonium octamolybdate were mechanically mixed in a mass ratio of 6:1:3, and pentaerythritol was added for surface modification.

3. The environmentally friendly flame-retardant EPDM foam sealing strip material according to claim 1, characterized in that: The accelerator is one or more of S-80, M-80, PZ-75 or BZ.

4. The environmentally friendly flame-retardant EPDM foam sealing strip material according to claim 1, characterized in that: The foaming agent is one or both of AC and OBSH.

5. The environmentally friendly flame-retardant EPDM foam sealing strip material according to any one of claims 1 to 4, characterized in that: The formula of the environmentally friendly flame-retardant EPDM foam sealing material is as follows: Per 100 parts by weight of rubber (phr): EPDM: 100 phr; ZnO: 5 phr; SA: 1 phr; PEG-4000: 3 phr; Al(OH)3: 70 phr; Mg(OH)2: 40phr; Red phosphorus: 30 phr; Melamine: 5 phr; Ammonium octamolybdate: 15 phr; Carbon black: 60 phr; Paraffin oil: 50 phr; S-80: 1.5 phr; M-80: 1.5 phr; PZ-75: 1.8 phr; BZ: 2 phr; AC: 8 phr; OBSH: 4 phr.

6. A process for preparing the environmentally friendly flame-retardant EPDM foam sealing strip material according to claim 1, characterized in that: The preparation process includes the preparation of the first stage glue and the preparation of the second stage glue, and the preparation steps are as follows: S1: Preparation of one-stage rubber: add EPDM raw rubber at a temperature of <90°C and mix for 1 minute. After removing the plug, add ZnO, SA, and PEG-4000 and mix for 1 minute. After removing the plug, add Al(OH)3, Mg(OH)2, compound flame retardant, carbon black, and paraffin oil and mix for 3 minutes. After removing the plug and cleaning, mix for another 2 minutes and then discharge the rubber. After thinning twice on the mill, remove the sheet and cool. S2: Place the glue obtained in S1 in a constant temperature room for 24 hours for later use; S3: Preparation of second-stage rubber: When the temperature is less than 60℃, add the first-stage rubber and mix for 30 seconds. Then add S-80, M-80, PZ-75, BZ-80, AC, and OBSH and mix for 1 minute. Discharge the material. Pass the mill through twice and then remove the sheet to cool.

7. Use of the environmentally friendly flame-retardant EPDM foam sealing strip material according to any one of claims 1 to 5 in the preparation of sealing strips.

Images