MDI type environment-friendly skin-friendly slow-rebound sponge composite material and preparation method thereof

Abstract

The application belongs to the technical field of polyurethane, and particularly relates to an MDI type environment-friendly skin-friendly slow-rebound sponge combined material and a preparation method thereof. The MDI type environment-friendly skin-friendly slow-rebound sponge combined material is composed of component A and component B. The component A at least comprises high-EO polyether polyol 1, polyether polyol 1, polyether polyol 2 and monofunctional polyether polyol. The component B at least comprises polyether polyol 3 and isocyanate. The high-EO polyether polyol 1 is terminated by a primary hydroxyl group with glycerol as a starter, has a functionality of 3 and a number average molecular weight of 4675-5260 g / mol. The monofunctional polyether polyol is terminated by a primary hydroxyl group with n-propanol as a starter, has a functionality of 1 and a number average molecular weight of 1000-1600 g / mol. The MDI type environment-friendly skin-friendly slow-rebound sponge provided by the application realizes the unity of the environmental protection, skin-friendliness and slow-rebound characteristics of the sponge. The application further provides a preparation method thereof.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane technology, specifically relating to an MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material and its preparation method. Background Technology

[0002] Slow rebound polyurethane foam, also known as memory foam or inert foam, is a type of polyurethane foam material with unique viscoelasticity. When it is deformed by external force, the strain lags behind the change in stress. That is, it does not immediately return to its original shape after the external stress is removed, but undergoes a slow recovery process of 3 to 15 seconds. This special property gives it the name "slow rebound foam" or "memory foam".

[0003] Traditional slow-rebound polyurethane bulk foams mostly use toluene diisocyanate (TDI) as the isocyanate component. TDI is a toxic chemical, classified as a hazardous chemical, with a strong pungent odor, and is detrimental to the environment and health. Simultaneously, organotin catalysts (such as stannous octoate and dibutyltin) and physical blowing agents such as dichloromethane are commonly used. Organotin compounds have significant biotoxicity, and dichloromethane, as a halogenated hydrocarbon solvent, has an anesthetic effect on the nervous system. The use of these toxic additives makes traditional slow-rebound foams significantly inadequate in terms of environmental friendliness and biocompatibility, limiting their application in skin-friendly products and fields with stringent environmental requirements.

[0004] CN118063733A discloses a bio-based ultra-soft environmentally friendly sponge and its preparation method. The foam sponge prepared by this method has good mechanical properties, resistance to compression deformation, and biodegradability. However, the raw materials used contain toluene diisocyanate, which directly damages the respiratory mucosa. In addition, the curing process of the sponge foam not only requires a heat-insulating environment, but also has a long curing cycle (3-5 days), making the production process cumbersome and energy-intensive.

[0005] CN110872371A discloses a method for preparing slow-rebound foam earplugs using Z15 sound-absorbing particles. The slow-rebound products prepared by this method have the advantages of being ultra-soft, having a good feel, and being not easily torn. However, this invention uses organotin catalysts and dichloromethane foaming agents, which may cause discomfort with long-term use.

[0006] CN106632975A discloses a breathable, slow-rebound polyurethane based on an MDI system, which is composed of a mixture of three polyether polyols. In addition, amine catalysts, tin catalysts, crosslinking agents, foam leveling agents, and modified MDI are added. However, a physical foaming agent is also added as an auxiliary foaming agent. Summary of the Invention

[0007] The technical problem to be solved by this invention is to overcome the above-mentioned defects in the existing technology and provide an MDI-type environmentally friendly, skin-friendly, slow-rebound sponge that achieves a balance between the sponge's environmental friendliness, skin-friendliness, and slow-rebound properties. This invention also provides its preparation method.

[0008] The MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material of the present invention is composed of component A and component B. Component A includes at least high EO polyether polyol 1, polyether polyol 1, polyether polyol 2, and monofunctional polyether polyol, and component B includes at least polyether polyol 3 and isocyanate.

[0009] The high-EO polyether polyol 1 is prepared by catalytic polymerization using glycerol as an initiator and propylene oxide and ethylene oxide as monomers, with a high proportion of primary hydroxyl groups for end-capping. The resulting polyether polyol has a functionality of 3, an EO content >75%, a hydroxyl value of 32-36 mgKOH / g, and a number-average molecular weight of 4675-5260 g / mol; more preferably, it has a number-average molecular weight of 4950 g / mol. Monofunctional polyether polyols refer to polyether polyols with a single functionality.

[0010] The monofunctional polyether polyol is a polyether polyol prepared by polymerization reaction using n-propanol as the initiator and propylene oxide as the polymerizing monomer. It has a hydroxyl value of 35-56 mgKOH / g, a functionality of 1, and a number-average molecular weight of 1000-1600 g / mol; more preferably, it is a polyether polyol with a number-average molecular weight of 1168 g / mol.

[0011] The polyether polyol 1 has a number average molecular weight of 500~1000g / mol, an acid value ≤0.08mgKOH / g, and a functionality of 3, and is further preferably CHE-307, a commercially available product of Changhua Chemical Technology Co., Ltd.

[0012] The polyether polyol 2 has a number average molecular weight of 1500~3000g / mol, an acid value ≤0.05mgKOH / g, and a functionality of 2. It is preferably polyether polyol DL2000D, a commercially available product of Shandong Lanxing Dongda Co., Ltd.

[0013] The polyether polyol 3 has a number-average molecular weight of 4700~5300g / mol, an acid value ≤0.08mgKOH / g, and a functionality of 3. The preferred polyether polyol is INOVOLS350T, a commercially available product from Shandong Yinuowei New Materials Co., Ltd.

[0014] Component A also includes silicone oil, catalyst, crosslinking agent, and foaming agent; Component B's isocyanate is a mixture of diphenylmethane diisocyanate and polymethylene polyphenyl diisocyanate. The diphenylmethane diisocyanate is a mixture of pure MDI and MDI-50 (pure MDI:MDI-50 = 1:2 mass ratio), wherein the pure MDI is either 44C (a commercially available product from Bayer) or MDI-100 (a commercially available product from Wanhua); and MDI-50 is a commercially available product from Wanhua. The polymethylene polyphenyl diisocyanate is either M20S (a commercially available product from BASF) or PM-200 (a commercially available product from Wanhua).

[0015] The silicone oil is a polysiloxane-oxidized olefin block copolymer, preferably Evonik Specialty Chemicals (Shanghai) Co., Ltd.'s commercially available product TEGOSTABB8002.

[0016] The catalyst is a mixture of FOCAT-8003M and DMEA at a mass ratio of 1:0.3~0.5. DMEA is a commercially available product from Huntsman, and FOCAT-8003M is a commercially available product from Guangzhou Yourun Synthetic Materials Co., Ltd.

[0017] The crosslinking agent is one or both of diethanolamine and triethanolamine. The foaming agent is water.

[0018] The weight ratio of component A to component B is 100:44~47; wherein, by weight parts,

[0019] Component A: 60-70 parts of high EO polyether polyol 1, 10-15 parts of polyether polyol 1, 20-25 parts of polyether polyol 2, 2.0-3.0 parts of monofunctional polyether polyol, 1.0-1.5 parts of silicone oil, 0.5-1.0 parts of catalyst, 0.5-1.0 parts of crosslinking agent, and 3.8-4.0 parts of foaming agent;

[0020] Component B: 3.0-6.0 parts of polyether polyol 3, 60-70 parts of diphenylmethane diisocyanate, and 20-30 parts of polymethylene polyphenyl diisocyanate.

[0021] The high-EO polyether polyol 1 is synthesized in-house, and the specific steps are as follows: glycerol is used as the initiator, potassium hydroxide is used as the catalyst, propylene oxide is added, unreacted monomers and small molecule byproducts are removed under pressure, phosphazene is added, dehydration is carried out under vacuum, ethylene oxide is continuously added, and after the addition is completed, the reaction continues under internal pressure, unreacted monomers and small molecule byproducts are removed under vacuum, the mixture is cooled and neutralized with water and phosphoric acid, then magnesium silicate is added for adsorption, and then the mixture is dried and filtered to obtain the long-chain polyether, namely high-EO polyether polyol 1.

[0022] The monofunctional polyether polyol was synthesized in-house, and the specific steps are as follows: using n-propanol as the initiator and potassium hydroxide as the catalyst, propylene oxide was catalyzed to undergo a ring-opening polymerization reaction. After neutralization, adsorption, drying and filtration to remove the catalyst, the monofunctional polyether polyol was obtained.

[0023] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material includes the following steps:

[0024] (1) Preparation of component A:

[0025] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are put into reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 25~35℃ to obtain component A.

[0026] (2) Preparation of component B:

[0027] Polyether polyol 3 was added to reaction vessel B, and the temperature was controlled at 44~50℃. Phosphoric acid was added, followed by diphenylmethane diisocyanate. The temperature was raised to 77~83℃ and reacted for 40 min. Finally, polymethylene polyphenyl diisocyanate was added, and the temperature was lowered to 40~45℃. The reaction was stirred to obtain component B with an isocyanate content of 30.5~31.5%.

[0028] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0029] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 20~30℃. Then, components A and B are mixed in the machine head according to the mass ratio and injected into the mold. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly skin-friendly slow rebound sponge.

[0030] In step (3), the mold temperature is controlled at 40~45℃ and the curing and mold opening time is 4min.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] (1) This invention is an MDI-type all-water foaming system that does not add any physical foaming agent or TDI, and has low residual isocyanate monomer. At the same time, it uses tin-free elements, which meets environmental protection requirements and skin-friendly requirements, and is suitable for home and medical fields.

[0033] (2) The present invention introduces polyether polyol with high EO content to improve reaction activity and reduce the amount of catalyst used; at the same time, it lowers the glass transition temperature (Tg) of the molecular chain, resulting in a more comfortable feel and improved skin affinity of the product.

[0034] (3) In this invention, a monofunctional polyether polyol is introduced to avoid severe closed-cell phenomenon during the foaming process. The main reason is that it contains only one active hydroxyl group. When it reacts with other polyfunctional polyether polyols or isocyanates, it terminates chain growth and forms a linear or less branched structure, which restricts crosslinking and achieves the effect of opening cells.

[0035] (4) The polyether polyol combination optimization of the present invention achieves excellent slow rebound performance through synergistic effect, with controllable rebound time, high comfort, good mechanical properties and strong durability.

[0036] (5) The preparation process of the present invention is simple, the conditions are mild, the curing time is short, the production efficiency is high, the product has uniform pore size, delicate feel, and low overall cost. Detailed Implementation

[0037] The present invention will be further described below with reference to specific embodiments.

[0038] Specifically, the preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0039] (1) Preparation of component A:

[0040] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 25~35℃ to obtain component A.

[0041] (2) Preparation of component B:

[0042] Polyether polyol 3 was added to reaction vessel B, stirring was started, and the material temperature was controlled at 44~50℃. Phosphoric acid (accounting for 0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 77~83℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, and the temperature was lowered to 40~45℃. The reaction was stirred to obtain component B with an isocyanate content of 30.5~31.5%.

[0043] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0044] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 20~30℃. Components A and B are mixed at the machine head at a mass ratio of 100:44~47 and then injected into the mold. The mold temperature is controlled at 40~45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0045] Unless otherwise specified, all raw materials used in the examples and comparative examples were commercially available.

[0046] The high-EO polyether polyol 1 was synthesized in-house, with the following specific steps: 138g of glycerol was used as the initiator, 23g of potassium hydroxide as the catalyst, and the temperature inside the reactor was controlled at 145℃. 1028g of propylene oxide was added, and the internal pressure was maintained for 1.5h after the addition was completed. Unreacted monomers and small molecule byproducts were removed under a vacuum of -0.091MPa for 1h. 7.9g of phosphazene was added, and dehydration was carried out at 110℃ under a vacuum of -0.091MPa for 1.5h. 6615g of ethylene oxide was added continuously, and the reaction was continued under internal pressure for 1h after the addition was completed. Unreacted monomers and small molecule byproducts were removed under a vacuum of -0.091MPa for 1h. The temperature was lowered to 80.3℃, and 184g of water and 26g of phosphoric acid were added for neutralization. Then, 5.2g of magnesium silicate was added for adsorption, followed by drying and filtration to obtain the long-chain polyether. The high-EO polyether polyol 1 has 85% ethylene oxide (EO) by mass fraction, a functionality of 3, and a number-average molecular weight of 4950 g / mol.

[0047] The monofunctional polyether polyol was synthesized in-house. The specific steps are as follows: 120.2g of n-propanol was used as the initiator and 19.6g of potassium hydroxide was used as the catalyst to catalyze the ring-opening polymerization of 2439g of propylene oxide. After neutralization, adsorption, drying and filtration to remove the catalyst, a monofunctional polyether polyol with a functionality of 1 and a number average molecular weight of 1168g / mol was obtained.

[0048] The high-EO polyether polyol 2 was synthesized in-house, with the following specific steps: Using 138g glycerol as the initiator and 23g potassium hydroxide as the catalyst, the temperature inside the reactor was controlled at 145±3℃. The remaining 1804g propylene oxide was continuously added, and after the addition was completed, the internal pressure was maintained for 1.5 hours. Unreacted monomers and small molecule byproducts were removed under a vacuum of -0.091MPa for 1 hour. Then, 6.7g phosphazene was added, and dehydration was carried out at 110℃ under a vacuum of -0.091MPa for 1.5 hours. 5840g of ethylene oxide was added, and the reaction continued under internal pressure for 1 hour after the addition was completed. Unreacted monomers and small molecule byproducts were removed under a vacuum of -0.091MPa for 1 hour. The temperature was lowered to 80℃, and 184g of water and 26g of phosphoric acid were added for neutralization. Then, 5.2g of magnesium silicate was added for adsorption. After drying and filtration, long-chain polyether was obtained, with ethylene oxide accounting for 75% of the polyether mass fraction, a functionality of 3, and a number-average molecular weight of 4950g / mol.

[0049] Polyether polyol 1: CHE-307, hydroxyl value 230-250mgKOH / g, acid value ≤0.08mgKOH / g, purchased from Changhua Chemical Technology Co., Ltd.

[0050] Polyether polyol 2: DL2000D, hydroxyl value 54.5-57.5mgKOH / g, acid value ≤0.05mgKOH / g, purchased from Shandong Lanxing Dongda Co., Ltd.

[0051] Polyether polyol 3: INOVOLS350T, with a hydroxyl value of 32.5-35.5 mgKOH / g and an acid value of ≤0.08 mgKOH / g, purchased from Shandong Yinuowei New Materials Co., Ltd.

[0052] Silicone oil: TEGOSTABB8002, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0053] Catalyst: It is a combination of DMEA and FOCAT-8003M. DMEA is a commercially available product from Huntsman, and FOCAT-8003M is a commercially available product from Guangzhou Yourun Synthetic Materials Co., Ltd.

[0054] A33: is made by mixing 33% triethylenediamine with 67% propylene glycol.

[0055] Diphenylmethane diisocyanate: is a compound of pure MDI and MDI-50. The pure MDI is either 44C (a commercially available product from Bayer) or MDI-100 (a commercially available product from Wanhua). MDI-50 is a commercially available product from Wanhua.

[0056] Polymethylene polyphenyl diisocyanate: one of M20S (BASF's commercially available product) or PM-200 (Wanhua's commercially available product).

[0057] Example 1

[0058] The aforementioned MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material is composed of component A and component B.

[0059] Component A comprises the following raw materials in parts by weight: 70 parts of high EO polyether polyol 1, 10 parts of polyether polyol 1, 20 parts of polyether polyol 2, 3.0 parts of monofunctional polyether polyol, 1.2 parts of silicone oil, 0.6 parts of catalyst (FOCAT-8003M:DMEA=1:0.3), 1.0 part of crosslinking agent (triethanolamine), and 3.8 parts of foaming agent (water).

[0060] Component B comprises the following raw materials in parts by weight: 3.0 parts of polyether polyol 3, 60 parts of diphenylmethane diisocyanate (44C:DI-50=1:2 mass ratio), and 25 parts of polymethylene polyphenyl diisocyanate (M20S).

[0061] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0062] (1) Preparation of component A:

[0063] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 30°C to obtain component A.

[0064] (2) Preparation of component B:

[0065] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 47°C, phosphoric acid (0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 80°C and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 42°C, and the reaction was stirred to obtain component B with an isocyanate content of 31.5%.

[0066] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0067] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 25℃. Components A and B are mixed at the machine head at a mass ratio of 100:44 and then injected into the mold. The mold temperature is controlled at 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0068] Example 2

[0069] The aforementioned MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material is composed of component A and component B.

[0070] Component A comprises the following raw materials in parts by weight: 60 parts of high EO polyether polyol 1, 15 parts of polyether polyol 1, 25 parts of polyether polyol 2, 2.4 parts of monofunctional polyether polyol, 1.5 parts of silicone oil, 1.0 part of catalyst (FOCAT-8003M:DMEA=1:0.3), 0.8 parts of crosslinking agent (diethanolamine), and 4.0 parts of foaming agent (water).

[0071] Component B comprises the following raw materials in parts by weight: 5.0 parts of polyether polyol 3, 68 parts of diphenylmethane diisocyanate (MDI-100:MDI-50=1:2), and 20 parts of polymethylene polyphenyl diisocyanate (PM-200).

[0072] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0073] (1) Preparation of component A:

[0074] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 25°C to obtain component A.

[0075] (2) Preparation of component B:

[0076] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 50℃, phosphoric acid (0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 83℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 40℃, and the reaction was stirred to obtain component B with an isocyanate content of 31.02%.

[0077] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0078] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 30℃. Components A and B are mixed at the machine head at a mass ratio of 100:47 and then injected into the mold. The mold temperature is controlled at 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0079] Example 3

[0080] The aforementioned MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material is composed of component A and component B.

[0081] Component A comprises the following raw materials in parts by weight: 63 parts of high-EO polyether polyol 1, 15 parts of polyether polyol 1, 22 parts of polyether polyol 2, 2.7 parts of monofunctional polyether polyol, 1.0 part of silicone oil, 0.5 parts of catalyst (FOCAT-8003M:DMEA=1:0.3), 1.0 part of crosslinking agent (diethanolamine), and 3.9 parts of foaming agent (water).

[0082] Component B comprises the following raw materials in parts by weight: 6.0 parts of polyether polyol 3, 63 parts of diphenylmethane diisocyanate (44C:MDI-50=1:2), and 25 parts of polymethylene polyphenyl diisocyanate (PM-200).

[0083] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0084] (1) Preparation of component A:

[0085] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 25°C to obtain component A.

[0086] (2) Preparation of component B:

[0087] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 44℃, phosphoric acid (0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 77℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 45℃, and the reaction was stirred to obtain component B with an isocyanate content of 30.5%.

[0088] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0089] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 20~30℃. Components A and B are mixed at the machine head at a mass ratio of 100:47 and then injected into the mold. The mold temperature is controlled at 40℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0090] Example 4

[0091] The aforementioned MDI-type environmentally friendly, skin-friendly, slow-rebound sponge composite material is composed of component A and component B.

[0092] Component A comprises the following raw materials in parts by weight: 67 parts of high EO polyether polyol 1, 13 parts of polyether polyol 1, 20 parts of polyether polyol 2, 2.0 parts of monofunctional polyether polyol, 1.0 part of silicone oil, 0.6 parts of catalyst (FOCAT-8003M:DMEA=1:0.5), 0.5 parts of crosslinking agent (triethanolamine), and 3.8 parts of foaming agent (water).

[0093] Component B comprises the following raw materials in parts by weight: 5.0 parts of polyether polyol 3, 70 parts of diphenylmethane diisocyanate (44C:MDI-50=1:2), and 30 parts of polymethylene polyphenyl diisocyanate (M20S).

[0094] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0095] (1) Preparation of component A:

[0096] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 35°C to obtain component A.

[0097] (2) Preparation of component B:

[0098] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 50℃, phosphoric acid (accounting for 0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 83℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 45℃, and the reaction was stirred to obtain component B with an isocyanate content of 31.04%.

[0099] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0100] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 20℃. Components A and B are mixed at the machine head at a mass ratio of 100:45 and then injected into the mold. The mold temperature is 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0101] Comparative Example 1

[0102] The aforementioned sponge composite material is composed of component A and component B.

[0103] Component A comprises the following raw materials in parts by weight: 70 parts of high EO polyether polyol 2, 10 parts of polyether polyol 1, 20 parts of polyether polyol 2, 3.0 parts of monofunctional polyether polyol, 1.2 parts of silicone oil, 0.6 parts of catalyst (FOCAT-8003M:DMEA=1:0.3), 1.0 part of crosslinking agent (triethanolamine), and 3.8 parts of foaming agent (water).

[0104] Component B comprises the following raw materials in parts by weight: 3.0 parts of polyether polyol 3; 60 parts of diphenylmethane diisocyanate (44C:MDI-50=1:2); and 25 parts of polymethylene polyphenyl diisocyanate (M20S).

[0105] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0106] (1) Preparation of component A:

[0107] First, high EO polyether polyol 2, polyether polyol 1 and polyether polyol 2 are put into reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 30°C to obtain component A.

[0108] (2) Preparation of component B:

[0109] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 47°C, phosphoric acid (0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 80°C and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 42°C, and the reaction was stirred to obtain component B with an isocyanate content of 31.5%.

[0110] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0111] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 25℃. Components A and B are mixed at the machine head at a mass ratio of 100:44 and then injected into the mold. The mold temperature is controlled at 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0112] Comparative Example 2

[0113] The aforementioned sponge composite material is composed of component A and component B.

[0114] The A component comprises the following raw materials in parts by weight: 60 parts of high EO polyether polyol 1, 15 parts of polyether polyol 1, 25 parts of polyether polyol 2, 2.4 parts of monofunctional polyether polyol, 1.5 parts of silicone oil, 1.0 part of catalyst (A33:DMEA=1:0.3), 0.8 parts of crosslinking agent (diethanolamine), and 4.0 parts of foaming agent (water).

[0115] Component B comprises the following raw materials in parts by weight: 5.0 parts of polyether polyol 3; 68 parts of diphenylmethane diisocyanate (MDI-100:MDI-50=1:2); and 20 parts of polymethylene polyphenyl diisocyanate (PM-200).

[0116] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0117] (1) Preparation of component A:

[0118] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, monofunctional polyether polyol, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 30°C to obtain component A.

[0119] (2) Preparation of component B:

[0120] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 50℃, phosphoric acid (0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 83℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 40℃, and the reaction was stirred to obtain component B with an isocyanate content of 31.02%.

[0121] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0122] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 25℃. Components A and B are mixed at the machine head at a mass ratio of 100:47 and then injected into the mold. The mold temperature is controlled at 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0123] Comparative Example 3

[0124] The aforementioned sponge composite material is composed of component A and component B.

[0125] The A component comprises the following raw materials in parts by weight: 63 parts of high EO polyether polyol 2, 15 parts of polyether polyol 1, 22 parts of polyether polyol 2, 1.0 part of silicone oil, 0.8 parts of catalyst (A33:DMEA=1:0.3), 1.0 part of crosslinking agent (diethanolamine), and 3.9 parts of foaming agent (water).

[0126] Component B comprises the following raw materials in parts by weight: 6.0 parts of polyether polyol 3, 63 parts of diphenylmethane diisocyanate (44C:MDI-50=1:2), and 25 parts of polymethylene polyphenyl diisocyanate (PM-200).

[0127] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0128] (1) Preparation of component A:

[0129] First, high EO polyether polyol 2, polyether polyol 1 and polyether polyol 2 are put into reaction vessel A and stirred. Then, silicone oil, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 25°C to obtain component A.

[0130] (2) Preparation of component B:

[0131] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 44℃, phosphoric acid (0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 77℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 45℃, and the reaction was stirred to obtain component B with an isocyanate content of 30.5%.

[0132] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0133] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 25℃. Components A and B are mixed at the machine head at a mass ratio of 100:47 and then injected into the mold. The mold temperature is controlled at 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0134] Comparative Example 4

[0135] The aforementioned sponge composite material is composed of component A and component B.

[0136] Component A comprises the following raw materials in parts by weight: 67 parts of high EO polyether polyol 1, 13 parts of polyether polyol 1, 20 parts of polyether polyol 2, 1.0 part of silicone oil, 0.6 parts of catalyst (FOCAT-8003M:DMEA=1:0.5), 0.5 parts of crosslinking agent (triethanolamine), and 3.8 parts of foaming agent (water).

[0137] Component B comprises the following raw materials in parts by weight: 5.0 parts of polyether polyol 3, 70 parts of diphenylmethane diisocyanate (44C:MDI-50=1:2), and 30 parts of polymethylene polyphenyl diisocyanate (M20S).

[0138] The preparation method of the MDI-type environmentally friendly, skin-friendly, slow-rebound sponge includes the following steps:

[0139] (1) Preparation of component A:

[0140] First, high EO polyether polyol 1, polyether polyol 1 and polyether polyol 2 are added to reaction vessel A and stirred. Then, silicone oil, catalyst, crosslinking agent and foaming agent are added in sequence and mixed at 25°C to obtain component A.

[0141] (2) Preparation of component B:

[0142] Polyether polyol 3 was added to reaction vessel B, stirring was started, the material temperature was controlled at 50℃, phosphoric acid (accounting for 0.002% of the total weight of component B) was added, and diphenylmethane diisocyanate was added. The temperature was raised to 83℃ and reacted for 40 minutes. Finally, polymethylene polyphenyl diisocyanate was added, the temperature was lowered to 45℃, and the reaction was stirred to obtain component B with an isocyanate content of 31.04%.

[0143] (3) Preparation of MDI-type environmentally friendly skin-friendly slow-rebound sponge:

[0144] Components A and B are injected into the material tank of a low-pressure casting machine, and the material temperature is controlled at 25℃. Components A and B are mixed at the machine head at a mass ratio of 100:45 and then injected into the mold. The mold temperature is controlled at 45℃. After curing, the mold is opened and demolded to obtain MDI-type environmentally friendly, skin-friendly, slow-rebound sponge.

[0145] The polyurethane flexible foams prepared in Examples 1-4 and Comparative Examples 1-4 were subjected to performance tests. The product density was tested according to standard GB / T6343-2009; the hardness was tested according to standard GB / T531-1999; the indentation hardness (IFD, 65% refers to the 65% indentation force ratio) was tested according to GB / T10807-2006; the elongation at break and tensile strength were tested according to GB / T3903.22-2008; the slow rebound recovery time was tested by compressing the foam to 95% of its height and then removing the external force to allow the foam to return to its original shape; the air flow rate was tested according to ASTM D3574 to characterize the open-cell and air permeability of the foam.

[0146] The test results are shown in Table 1.

[0147] Table 1. Performance test results of products from Examples 1-4 and Comparative Examples 1-4

[0148]

[0149] As shown in Table 1 above, compared with Comparative Example 1, the product of Example 1 showed no deformation or fingerprint issues upon mold opening at 4 minutes, and exhibited better skin-friendliness. This is mainly due to the introduction of high-EO polyether polyol 1 into the formulation. The EO content is positively correlated with the activity and skin-friendliness of the formulation, not only shortening the product's production cycle but also improving its tactile feel. Meanwhile, compared with Comparative Example 2, the product of Example 2 showed better curing performance. The main difference lies in the catalyst used in Example 2, FOCAT-8003M, which can form a denser skin cell structure under the same silicone oil, additives, and mold temperature conditions, resulting in a smoother and more attractive product appearance. Compared with Comparative Example 4, Example 4, due to the absence of monofunctional polyether polyol, showed a significant change in the final product's feel. Excessive closed-cell structure negatively impacted the overall comfort, breathability, and mechanical properties of the product. Compared with Comparative Example 3, Example 1 introduced high EO polyether polyol 1, and also added monofunctional polyether polyol and catalyst FOCAT-8003M. First, the open cell property of the product was adjusted to ensure that no serious closed cell problem would occur during the entire foaming process; second, the mechanical properties of the product were improved, with a significant increase in 65% indentation hardness, giving the product excellent support; at the same time, the uniform cell structure also optimized the air permeability of the product.

Claims

1. A type of MDI-based environmentally friendly, skin-friendly, slow-rebound sponge composite material, characterized in that: The combination material is composed of A component and B component, the A component includes high EO polyether polyol 1, polyether polyol 1, polyether polyol 2, monofunctional polyether polyol, catalyst, foaming agent, and the B component includes polyether polyol 3 and isocyanate; The catalyst is a compound of FOCAT-8003M and DMEA with a mass ratio of 1:0.3-0.5; the foaming agent is water; The high EO polyether polyol 1 is a polyether polyol prepared by using glycerol as a starter, using propylene oxide and ethylene oxide as polymerization monomers, and using primary hydroxyl groups for end capping, and has a functionality of 3, a hydroxyl value of 32-36 mgKOH / g, a number average molecular weight of 4675-5260 g / mol, and an EO content of >75%; The monofunctional polyether polyol is a polyether polyol prepared by using n-propanol as a starter and using propylene oxide as a polymerization monomer, and has a hydroxyl value of 35-56 mgKOH / g, a functionality of 1, and a number average molecular weight of 1000-1600 g / mol; The polyether polyol 1 has a number average molecular weight of 500-1000 g / mol, an acid value of ≤0.08 mgKOH / g, and a functionality of 3; the polyether polyol 2 has a number average molecular weight of 1500-3000 g / mol, an acid value of ≤0.05 mgKOH / g, and a functionality of 2; and the polyether polyol 3 has a number average molecular weight of 4700-5300 g / mol, an acid value of ≤0.08 mgKOH / g, and a functionality of 3; The isocyanate is a mixture of diphenylmethane diisocyanate and polymethylene polyphenyl diisocyanate.

2. The environmentally friendly skin-friendly slow-rebound MDI-based sponge composite material according to claim 1, characterized in that: The A component further includes silicone oil and crosslinking agent. 3.The environmentally friendly and skin-friendly MDI-based slow-rebound sponge composite material of claim 1, wherein: The diphenylmethane diisocyanate is a mixture of pure MDI and MDI-50.

4. The environmentally friendly skin-friendly slow-rebound MDI-based sponge composite material according to claim 2, characterized in that: The silicone oil is polysiloxane-alkylene oxide block copolymer.

5. The environmentally friendly and skin-friendly MDI-based slow-rebound sponge composite material according to claim 2, characterized in that: The crosslinking agent is one or both of diethanolamine and triethanolamine.

6. The environmentally friendly, skin-friendly, and slow-rebound MDI-based sponge composite material according to claim 2, wherein: The weight ratio of the A component to the B component is 100:44-47; wherein, in terms of weight parts, The A component: the high EO polyether polyol 1 is 60-70 parts, the polyether polyol 1 is 10-15 parts, the polyether polyol 2 is 20-25 parts, the monofunctional polyether polyol is 2.0-3.0 parts, the silicone oil is 1.0-1.5 parts, the catalyst is 0.5-1.0 part, the crosslinking agent is 0.5-1.0 part, and the foaming agent is 3.8-4.0 parts; The B component: the polyether polyol 3 is 3.0-6.0 parts, the diphenylmethane diisocyanate is 60-70 parts, and the polymethylene polyphenyl diisocyanate is 20-30 parts.

7. A process for preparing the environmentally friendly skin-friendly slow-rebound MDI-based sponge composite material according to any one of claims 1-6, characterized in that: The method includes the following steps: (1) Preparation of the A component: First, the high EO polyether polyol 1, the polyether polyol 1, and the polyether polyol 2 are stirred in a reaction container A, and then the silicone oil, the monofunctional polyether polyol, the catalyst, the crosslinking agent, and the foaming agent are sequentially added and mixed at 25-35°C to obtain the A component; (2) Preparation of the B component: Polyether polyol 3 is put into reaction container B, temperature is controlled at 44~50℃, phosphoric acid is added, and diphenyl methane diisocyanate is put in, temperature is raised to 77~83℃ for reaction, finally, polymethylene polyphenyl diisocyanate is added, temperature is lowered to 40~45℃, and stirring reaction is carried out to obtain component B with isocyanate content of 30.5~31.5%; (3) Preparation of MDI type environment-friendly skin-friendly slow-rebound sponge: Components A and B are respectively injected into the material tank of a low-pressure casting machine, the material temperature is controlled at 20~30℃, then components A and B are mixed in the machine head according to the mass ratio and injected into a mold, the mold is cured, opened and demolded to obtain the MDI type environment-friendly skin-friendly slow-rebound sponge.

8. The preparation method of the MDI-type environmentally friendly skin-friendly slow-rebound sponge composite material according to claim 7, characterized in that: In step (3), the mold temperature is controlled at 40~45℃.

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