Composite material for slow-rebound low-temperature noise-reducing earplugs and preparation method thereof

Abstract

The present invention relates to a composite material for slow-rebound low-temperature noise reduction earplugs, a preparation method and an application thereof, which mainly solves the technical problems of high hardness, hardening at low temperatures, and poor tensile tearing after washing of polyurethane noise reduction earplugs. The present invention adopts a composite material for slow-rebound low-temperature noise reduction earplugs and a preparation method thereof, which is composed of components A and B. The invention comprises the following components in parts by weight: component A: 30 to 60 parts of polyether polyol a, 25 to 60 parts of polyether polyol b, 5 to 15 parts of polymer polyol c, 0.8 to 2.3 parts of water, 0.5 to 1.5 parts of reaction catalyst, 0.5 to 1.5 parts of foam stabilizer, 0.5 to 1.5 parts of cross-linking agent, 1 to 3 parts of chain extender, 1 to 5 parts of pore opening agent and 1 to 3 parts of antibacterial agent; component B: 20 ​​to 60 parts of modified isocyanate and 5 to 30 parts of polyether polyol d; the weight ratio of component A to component B is 100:(60 to 80), which can better solve the technical problem and is applied in the earplug preparation industry.

Description

Technical Field

[0001] The invention relates to a composite material for a slow-rebound low-temperature noise reduction earplug and a preparation method thereof, belonging to the technical field of polyurethane foaming. Background Art

[0002] Noise pollution, along with air pollution and water pollution, has been recognized as one of the three major pollutions of our time, and has attracted great attention from people. The prevention and control of noise pollution has become a major issue that needs to be solved globally today. People seek to reduce noise by improving process technology, mechanical structure (controlling sound sources) and preventing its propagation during the propagation process, but due to restrictions in the economy, technology, production environment, etc., it is difficult to implement. Therefore, wearing noise-reducing earplugs to reduce the impact of noise on the body at the human ear becomes effective and practical.

[0003] The mainstream earplugs on the market are roughly divided into three categories: PVC foam plastics, silicone, and slow-rebound polyurethane sponges. The slow-rebound polyurethane sponge is lightweight and soft, and its high viscoelastic properties make it widely used in sound absorption and insulation. However, the rebound time of the slow-rebound polyurethane sponge on the market is about 10 seconds, and at low temperatures, the slow-rebound sponge tends to harden, which makes it uncomfortable to wear.

[0004] Chinese patent CN 110872371A discloses a method for preparing a slow-rebound sponge earplug using Z15 sound-absorbing particles. The invention develops a polyurethane soft sponge soundproof earplug with high rebound and slow rebound. On the basis of maintaining the stable sound insulation effect, it increases its ultra-softness, good hand feel, not easy to tear, and comfortable to wear, and eliminates the phenomenon that traditional earplugs are prone to cracking, hardening and powdering after wearing for a period of time. There are problems such as unclear description in this invention. Its main purpose is to improve the problems of stretching, tearing, hardening and powdering, but the specific physical performance data of the prepared earplug is not disclosed in the full text. In addition, the additives used in this invention contain organic tin catalysts and dichloromethane foaming agents. Long-term wearing will cause ear discomfort and even inflammation.

[0005] Chinese patent CN 112794970A discloses a noise-reducing earplug with a slightly bloated feeling and an ultra-soft noise-reducing earplug and a preparation method thereof. The noise-reducing earplug prepared in the invention has a density of up to 550kg / m3, and a large amount of low molecular weight, high hydroxyl value polyether is still used in the formula, so that the surface hardness of the earplug at 25°C reaches 55, and the slow rebound time is relatively short, which will affect the user's wearing experience and physiological health. First, too high a density will improve the sound insulation performance to a certain extent, but this will inevitably cause too high a hardness, which will aggravate its high temperature effect. At the same time, superimposed with a faster recovery time, this will easily cause swelling and pressure when people wear earplugs. Second, there are a lot of bacteria in the human ear, and the ear accommodates bacteria to a much higher degree than other parts. Research has found that if you wear earplugs for one hour, the number of bacteria will reach 700 times the original amount, which is extremely detrimental to the health of the ears. This is because after wearing earplugs, the air in the ears is difficult to circulate, and the temperature in the ears rises sharply, making it easier for bacteria to breed. Therefore, it is particularly important to develop a relatively breathable earplug that can also remove mites and kill bacteria, which is not yet mentioned in this invention. Summary of the invention

[0006] One of the technical problems to be solved by the present invention is that the existing polyurethane noise reduction earplugs have the technical problems of high hardness, hardening at low temperature, and poor stretching and tearing after washing. A new combination material for slow-rebound low-temperature noise reduction earplugs is provided. The slow-rebound low-temperature noise reduction earplugs prepared by the combination material have the advantages of softness, weak temperature sensitivity, long recovery time and high tearing and stretching. The second technical problem to be solved by the present invention is to provide a preparation method of the slow-rebound low-temperature noise reduction earplug corresponding to the solution to the first problem.

[0007] In order to solve one of the above technical problems, the technical solution adopted by the present invention is as follows: a composite material for slow-rebound low-temperature noise reduction earplugs, comprising the following components in parts by weight: component A: polyether polyol a: 30-60 parts, polyether polyol b: 25-60 parts, polymer polyol c: 5-15 parts, water: 0.8-2.3 parts, reaction catalyst: 0.5-1.5 parts, foam stabilizer: 0.5-1.5 parts, cross-linking agent: 0.5-2 parts, chain extender: 1-3 parts, pore opener: 1-5 parts, antibacterial agent: 1 ~3 parts; component B: modified isocyanate: 20~60 parts, polyether polyol d: 5~30 parts; the weight ratio of component A to component B is 100:60~80; wherein, polyether polyol a is a polyether polyol copolymerized with ethylene oxide and propylene oxide with a molecular weight of 4000~8000 and at least one of glycerol, trimethylolpropane, ethanolamine or sorbitol as an initiator, and the EO content is ≥70%, the unsaturation is 0.01~0.2mmol / g, and the functionality is 2~4; polyether polyol b is glycerol, At least one of pentaerythritol, xylitol, sorbitol or sucrose is used as an initiator, a polyether polyol with a molecular weight of 1000-2500, an unsaturation of 0.01-0.2 mmol / g, and a functionality of 2-4; the functionality of the polymer polyol c is 2-4, the viscosity is 2500-3500 mPa·s, and the solid content is 26%-30%; the foam stabilizer is a polysiloxane-oxidized olefin block or graft copolymer; the crosslinking agent is a small molecule polyol containing two or more functional groups and a polyamine compound; The chain extender is a non-amine small molecule alcohol compound containing two functional groups; the pore opening agent is a polyoxyolefin-polysiloxane copolymer; the antibacterial agent is a quaternary ammonium salt reactive antibacterial agent; the isocyanate is selected from at least one of toluene diisocyanate, crude MDI or carbodiimide modified isocyanate; the polyether polyol d is selected from at least one of polyester polyol, polyoxypropylene polyol, polytetramethylene glycol or other olefin polyols, with a functionality of not less than 2 and a molecular weight of 1000 to 3000.

[0008] In the above technical solution, preferably, the B component also includes a storage stabilizer, and the weight percentage of the storage stabilizer is 20-40×10 -6 ; The storage stabilizer is selected from one of phosphoric acid or benzoyl chloride.

[0009] In the above technical scheme, preferably, the reaction catalyst is selected from at least one of a foaming tertiary amine catalyst, a gel tertiary amine catalyst or a balanced tertiary amine catalyst; the foam stabilizer is selected from at least one of B-8002 or L-580; the cross-linking agent is at least one of diethanolamine or triethanolamine; the chain extender is selected from at least one of 1,4-butanediol, ethylene glycol, diethylene glycol or neopentyl glycol; the pore opening agent is selected from at least one of CHE-350D or SKC-1900; the antibacterial agent is at least one of a silver ion antibacterial agent or a quaternary ammonium salt reactive antibacterial agent; the isocyanate is selected from one of MDI-LL, BASF-103C or MDI-100L; and the polyether polyol d is polytetramethylene glycol ether.

[0010] In the above technical scheme, preferably, the foaming tertiary amine catalyst is selected from at least one of dimethylaminoethoxyethanol, trimethylhydroxyethylethylenediamine or N,N,N'-trimethyl-N'-hydroxyethylbisaminoethyl ether; the gel tertiary amine catalyst is selected from N,N-bis(dimethylaminopropyl)isopropanolamine or N-(dimethylaminopropyl)diisopropanolamine; and the balanced tertiary amine catalyst is dimethylethanolamine.

[0011] To solve the second of the above technical problems, the technical solution adopted by the present invention is as follows:

[0012] A method for preparing the aforementioned slow-rebound low-temperature noise reduction earplug is characterized by comprising the following steps:

[0013] (1) Preparation of component A:

[0014] Weigh 30-60 parts of polyether polyol a, 25-60 parts of polyether polyol b, 5-15 parts of polymer polyol c, 0.8-2.3 parts of water, 0.5-1.5 parts of reaction catalyst, 0.5-1.5 parts of foam stabilizer, 0.5-2 parts of cross-linking agent, 1-3 parts of chain extender, 1-5 parts of cell opener and 1-3 parts of antibacterial agent respectively, add them into a container in sequence, stir and mix thoroughly to obtain component A;

[0015] (2) Preparation of component B:

[0016] Weigh 5-30 parts of polyether polyol d by weight, add to the reactor, stir and heat to 100-110°C, dehydrate and degas under vacuum for 2-3 hours, cool to 40-45°C, add 20-60 parts of modified isocyanate, 20-40×10 -6 The mixture is heated to 80-85°C for 2-3 hours, and component B is obtained when the NCO content is 18%-24%.

[0017] (3) Preparation method of slow-rebound low-temperature noise reduction earplugs:

[0018] a) Raise the mold temperature to 40-60°C and evenly spray the release agent on the inner surface of the mold;

[0019] b) Wait for 2 to 3 minutes until the release agent solidifies into a film on the mold surface;

[0020] c) Mix the prepared component A and component B in a ratio of 100:60-80, stir them thoroughly for 3-5 seconds at a speed of 2000-5000 rpm, quickly inject them into the mold and lock the mold;

[0021] d) Maintaining the mold for 6 to 10 minutes, then opening the mold, taking out the product, and aging it at room temperature for 2 to 4 days to obtain the slow-rebound low-temperature noise-reducing earplugs.

[0022] In the above technical solution, preferably, the release agent is a water-soluble release agent.

[0023] In the above technical solution, preferably, the release agent is 3011B.

[0024] The invention provides a combination material for slow-rebound low-temperature noise reduction earplugs. The component A mainly composed of polyol and the self-made prepolymerized modified isocyanate component B are combined and foamed to form a slow-rebound low-temperature noise reduction earplug. The invention adopts low-temperature polyether to completely replace the traditional slow-rebound polyether. While obtaining a more excellent slow-rebound effect (the recovery time can reach 20 seconds), it also greatly improves the problem of low-temperature hardening; secondly, the isocyanate is prepolymerized and modified, which effectively improves the tensile and tearing properties of the polyurethane noise reduction earplug, so that it can be repeatedly washed; then, by introducing a reactive cationic quaternary ammonium chloride antibacterial agent, bacteria can be effectively killed, and allergic inflammation caused by wearing earplugs for a long time can be improved. At the same time, it can also avoid the situation that the traditional silver ion antibacterial agent migrates to the surface due to long-term washing and is finally washed away. The tensile strength of the slow-rebound low-temperature noise reduction earplug prepared by the combination material of the invention is ≧200kpa, the elongation at break is ≧120%, and the tear strength is ≧4.0, which has achieved good technical effects. DETAILED DESCRIPTION

[0025] Table 1 List of raw materials – additives

[0026]

[0027] Table 2 Raw materials list – main raw materials

[0028]

[0029] [Example 1]

[0030] (1) Preparation of component A

[0031] In parts by weight, respectively weigh 30 parts of polyether polyol a CHK-3602, 60 parts of polyether polyol b CHE-5110VE, 10 parts of polymer polyol c CHP-H30, 0.8 parts of water, 0.5 parts of reaction catalyst 33LV, 0.2 parts of DMEA, 1 part of foam stabilizer B-8002, 0.5 parts of crosslinking agent DEOA, 1 part of chain extender EG, 2 parts of BDO, 3 parts of cell opener SKC-1900 and 1 part of antibacterial agent Fresche 4850, and add them into a container in sequence, stir and mix thoroughly to obtain component A.

[0032] (2) Preparation of component B

[0033] In parts by weight, weigh 10 parts of polyether polyol d PTMG-2000, add it into the reactor, stir and heat it to 105°C, dehydrate and degas under vacuum for 2 hours, cool it to 40°C, add 30 parts of modified isocyanate LL, storage stabilizer benzoyl chloride: 20×10 -6 The mixture was heated to 5°C for 2h and the NCO content was detected to be 21%, thereby obtaining component B.

[0034] (3) Preparation of slow-rebound low-temperature noise-reducing earplugs

[0035] ①Raise the mold temperature to 50°C and evenly spray the release agent on the inner surface of the mold;

[0036] ②Wait for 3 minutes until the release agent solidifies into a film on the mold surface;

[0037] ③ Mix the prepared component A and component B in a ratio of 100:60, stir thoroughly for 5 seconds at a speed of 2500rpm, quickly inject into the mold and lock the mold;

[0038] ④ The mold was maintained for 7 minutes, then the mold was opened, and after the product was taken out, it was aged at room temperature for 2 days to obtain the slow-rebound low-temperature noise-reducing earplug. The conventional physical property test data of the prepared slow-rebound low-temperature noise-reducing earplug are shown in Table 5.

[0039] ⑤

[0040] [Examples 2 to 7 and Comparative Examples 1 to 2]

[0041] Examples 2 to 4 are carried out according to the steps of Example 1, with the only difference being the types of reaction raw materials, catalysts, raw material ratios, and process parameters, as shown in Table 3. The conventional physical property test data of the prepared slow-rebound low-temperature noise reduction earplugs are shown in Table 5.

[0042] Examples 5 to 7 and Comparative Examples 1 to 2 are carried out according to the steps of Example 1, with the only difference being the types of reaction raw materials, catalysts, raw material ratios, and process parameters, as shown in Table 4. The conventional physical property test data of the prepared slow-rebound, low-temperature noise-reducing earplugs are shown in Table 5.

[0043] Table 3 Weight parts of raw materials of each component in Examples 1 to 4

[0044]

[0045]

[0046] Table 4 Weight percentage of raw materials of each component in Examples 5 to 7 and Comparative Examples 1 to 2

[0047]

[0048]

[0049] Table 5 Performance test data of polyurethane noise reduction earplugs prepared in Examples 1 to 7 and Comparative Examples 1 to 2

[0050]

[0051]

[0052]

[0053] Note: The noise value test method refers to T / CAIACN 006-2021 "Technical Requirements and Measurement Methods for Wireless Noise Cancelling Headphones".

[0054] It can be seen from Examples 1 to 7 that the rebound time of the polyurethane slow-rebound earplugs provided by the present invention is maintained above 20s, which is much longer than the conventional slow rebound on the market, giving users enough time to shape and wear, and the operation is simple. At the same time, the lower temperature sensation and density also make the hardness of the earplug moderate, greatly reducing the swelling feeling of the user when wearing it. Comparative Example 1 is prepared by reacting component A in the present invention with unmodified isocyanate. It can be found that after pre-polymerization modification, component B can effectively improve the tensile tearing properties of the earplug (tensile strength ≧200kpa, elongation at break ≧120%, tear strength ≧4.0), so that it can still maintain a high tearing performance after multiple washings. Comparative Example 2 is a conventional preparation route of polyurethane noise reduction earplugs on the market, and its performance in all aspects is relatively poor compared with the polyurethane slow-rebound earplugs provided in the present invention.

[0055] The above content introduces in detail a slow rebound low temperature noise reduction earplug provided by the present invention. The embodiments in this article illustrate the principles and implementation methods of the present invention. The introduction of the above embodiments is only for understanding the core idea of ​​the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field of technology shall make modifications to the present invention without departing from the principles of the present invention, and the modifications shall fall within the protection scope of the claims.

Claims

1. A composite material for slow-rebound low-temperature noise reduction earplugs, composed of the following components in parts by weight: Component A: polyether polyol a: 30-60 parts, polyether polyol b: 25-60 parts, polymer polyol c: 5-15 parts, water: 0.8-2.3 parts, reaction catalyst: 0.5-1.5 parts, foam stabilizer: 0.5-1.5 parts, cross-linking agent: 0.5-2 parts, chain extender: 1-3 parts, pore opener: 1-5 parts, antibacterial agent: 1-3 parts; Component B: modified isocyanate: 20-60 parts, polyether polyol d: 5-30 parts; the weight ratio of component A to component B is 100:60-80; wherein, polyether polyol a is a polyether polyol copolymerized with ethylene oxide and propylene oxide with a molecular weight of 4000-8000 and at least one of glycerol, trimethylolpropane, ethanolamine or sorbitol as an initiator, and its EO content is ≥70% and the unsaturation is 0.01-0.2 mmol / g, functionality 2-4; polyether polyol b is a polyether polyol with at least one of glycerol, pentaerythritol, xylitol, sorbitol or sucrose as an initiator, a molecular weight of 1000-2500, and an unsaturation of 0.01-0.2 mmol / g, functionality is 2 to 4; the functionality of polymer polyol c is 2 to 4, the viscosity is 2500 to 3500 mpa·s, and the solid content is 26% to 30%; the foam stabilizer is a polysiloxane-oxidized olefin block or graft copolymer; the cross-linking agent is a small molecule polyol and a polyamine compound containing more than two functional groups; the chain extender is a non-amine small molecule alcohol compound containing two functional groups; the pore opening agent is a polyoxyalkylene-polysiloxane copolymer; the antibacterial agent is a quaternary ammonium salt reactive antibacterial agent; the isocyanate is selected from at least one of toluene diisocyanate, crude MDI or carbodiimide modified isocyanate; the polyether polyol d is polytetramethylene glycol, the functionality is not less than 2, and the molecular weight is 1000 to 3000.

2. The combination material for slow-rebound low-temperature noise reduction earplugs according to claim 1, characterized in that: The B component also includes a storage stabilizer, and the weight percentage of the storage stabilizer is 20-40×10 -6 ; The storage stabilizer is selected from one of phosphoric acid or benzoyl chloride.

3. The combination material for slow-rebound low-temperature noise reduction earplugs according to claim 1, characterized in that: The reaction catalyst is selected from at least one of a foaming tertiary amine catalyst, a gel tertiary amine catalyst or a balanced tertiary amine catalyst; the foam stabilizer is selected from at least one of B-8002 or L-580; the cross-linking agent is at least one of diethanolamine or triethanolamine; the chain extender is selected from at least one of 1,4-butanediol, ethylene glycol, diethylene glycol or neopentyl glycol; the cell opener is selected from at least one of CHE-350D or SKC-1900; the isocyanate is selected from one of MDI-LL, BASF-103C or MDI-100L.

4. The combination material for slow-rebound low-temperature noise reduction earplugs according to claim 3, characterized in that: The foaming tertiary amine catalyst is selected from at least one of dimethylaminoethoxyethanol, trimethylhydroxyethylethylenediamine or N,N,N'-trimethyl-N'-hydroxyethylbisaminoethyl ether; the gel tertiary amine catalyst is selected from N,N-bis(dimethylaminopropyl)isopropanolamine or N-(dimethylaminopropyl)diisopropanolamine; and the balanced tertiary amine catalyst is dimethylethanolamine.

5. A method for preparing the slow-rebound low-temperature noise reduction earplug according to claim 2, characterized in that: The following steps are involved: (1) Preparation of component A: Weigh 30-60 parts of polyether polyol a, 25-60 parts of polyether polyol b, 5-15 parts of polymer polyol c, 0.8-2.3 parts of water, 0.5-1.5 parts of reaction catalyst, 0.5-1.5 parts of foam stabilizer, 0.5-2 parts of cross-linking agent, 1-3 parts of chain extender, 1-5 parts of cell opener and 1-3 parts of antibacterial agent respectively, add them into a container in sequence, stir and mix thoroughly to obtain component A; (2) Preparation of component B: Weigh 5-30 parts of polyether polyol d by weight, add to the reactor, stir and heat to 100-110°C, dehydrate and degas under vacuum for 2-3 hours, cool to 40-45°C, add 20-60 parts of modified isocyanate, 20-40×10 -6 The mixture is heated to 80-85°C for 2-3 hours, and component B is obtained when the NCO content is 18%-24%. (3) Preparation method of slow-rebound low-temperature noise reduction earplugs: a) Raise the mold temperature to 40-60°C and evenly spray the release agent on the inner surface of the mold; b) Wait for 2 to 3 minutes until the release agent solidifies into a film on the mold surface; c) Mix the prepared component A and component B in a ratio of 100:60-80, stir thoroughly for 3-5 seconds at a speed of 2000-5000 rpm, quickly inject into the mold and lock the mold; d) Maintain the mold for 6 to 10 minutes, then open the mold, take out the product, and mature it at room temperature for 2 to 4 days to obtain the slow-rebound low-temperature noise-reducing earplugs.

6. The method for preparing the slow-rebound low-temperature noise reduction earplug according to claim 5, characterized in that: The release agent is a water-soluble release agent.

7. The method for preparing the slow-rebound low-temperature noise reduction earplug according to claim 6, characterized in that: The release agent is 3011B.

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