Polyether polyol for low-temperature slow-rebound sponge, preparation method and application thereof

Abstract

The present invention relates to a polyether polyol for low-temperature slow-rebound sponge, a preparation method and its application, which mainly solves the problem in the prior art that the slow-rebound polyurethane sponge is sensitive to the use temperature and becomes hard at low temperature (<0°C). The present invention adopts a new polyether polyol for low-temperature slow-rebound sponge, including: a mixture of polyether polyol I with a molecular weight of 600-2000, an average functionality of 2-8, and 5-50% of propylene oxide, and polyether polyol II with a molecular weight of 3000-6000, an average functionality of 2-8, and 5-50% of ethylene oxide; polyether polyol I and polyether polyol II are mixed in a weight ratio of 1:0.5-1 and the technical solution of the preparation method thereof, which solves the problem well and can be used in the industrial preparation of slow-rebound sponge.

Description

Technical Field

[0001] The invention relates to a polyether polyol for a low-temperature slow-rebound sponge, a preparation method and application thereof. Background Art

[0002] Polyurethane is short for carbamate, which refers to a polymer compound with multiple -NH-COO- repeating structures on the main chain. Polyurethane soft foam is a polymer foamed by polyether polyol and isocyanate under the action of catalyst, foaming agent and other additives. It has the characteristics of low density, sound absorption, breathability, heat preservation and good elastic recovery. Slow rebound sponge, also known as "memory foam", will not recover its shape immediately when it is compressed by external force, but needs to delay for a few seconds to slowly recover its original shape. Slow rebound sponge is usually used in home products such as sofas, seats, mattresses, etc., so it has high requirements for elastic recovery and comfort, but most slow rebound polyurethane sponges are sensitive to the use temperature, especially at low temperatures (<0℃), they will harden, seriously affecting their comfort and failing to play the function of slow rebound.

[0003] Chinese patent CN111363112A discloses a low-temperature bloating molded slow-rebound sponge, which includes the following components by mass: polyether polyol A: 65-90 parts; polyether polyol B: 10-35 parts; deionized water: 2-3 parts; physical foaming agent: 0-10 parts; foam leveling agent: 0.2-0.45 parts; amine catalyst: A1 0.1-0.3 parts; A33 0.4-0.6 parts; modified MDI: 30-45 parts. The invention discloses a low-temperature bloating molded slow-rebound sponge and its preparation method. By adjusting the formula, a sponge with a density of 35-80Kg / m 3 , the rebound time is 3-7 seconds, and the prepared sponge has a constant hardness at 0°C and maintains the same shape as at room temperature. However, the invention does not clearly disclose the composition of the polyether polyol.

[0004] Chinese patent CN106065063A discloses a low-temperature resistant, high-density slow-rebound sponge and its preparation method, which is made of the following raw materials: polyether polyol A (hydroxyl value is 30-50, functionality is 2.5-4.5), polyether polyol B (hydroxyl value is 45-65, functionality is 2.5-4.5), polyether polyol C (hydroxyl value is 340-400, functionality is 2.5-3.5), delayed amine, silicone oil, tertiary amine catalyst, organic metal catalyst, deionized water and modified black material. The rebound time is between 3-5 seconds, it has low-temperature resistance, and the bearing capacity is twice as high as that of the slow-rebound sponge on the market. However, the invention does not disclose the specific physical property test data of the slow-rebound sponge. Summary of the invention

[0005] One of the technical problems to be solved by the present invention is that there is a problem in the prior art that the slow-rebound polyurethane sponge is sensitive to the use temperature and will harden at low temperatures (<0°C). A new polyether polyol for low-temperature slow-rebound sponge is provided. The slow-rebound sponge prepared by the polyether polyol sponge has the advantages of excellent rebound performance and small hardness change at low temperatures. The second technical problem to be solved by the present invention is to provide a preparation method of polyether polyol for low-temperature slow-rebound sponge corresponding to the first technical problem. The third technical problem to be solved by the present invention is to provide a use of polyether polyol for low-temperature slow-rebound sponge corresponding to the first technical problem.

[0006] In order to solve one of the above technical problems, the technical solution adopted by the present invention is as follows: a polyether polyol for low-temperature slow-rebound sponge, characterized in that it is composed of a mixture of polyether polyol I with a molecular weight of 600-2000, an average functionality of 2-8, and 5-50% of propylene oxide, and polyether polyol II with a molecular weight of 3000-6000, an average functionality of 2-8, and 5-50% of ethylene oxide; polyether polyol I and polyether polyol II are mixed in a weight ratio of 1:0.5-1.

[0007] In the above technical solution, preferably, the polyether polyol I and polyether polyol II are prepared by copolymerizing small molecule polyols as initiators with alkylene oxides under the action of potassium hydroxide or DMC catalyst.

[0008] In the above technical solution, preferably, the small molecule polyol is prepared by using at least one of propylene glycol, diethylene glycol, glycerol, trimethylolpropane, pentaerythritol, xylitol, sorbitol or sucrose as a starting agent.

[0009] In the above technical solution, preferably, the polyether polyol has a hydroxyl value of 145-165 mgKOH / g and a functionality of 3-6.

[0010] To solve the second of the above technical problems, the technical solution adopted by the present invention is as follows:

[0011] A method for preparing the aforementioned low-temperature slow-rebound polyether polyol comprises the following steps:

[0012] 1) preparing polyether polyol I, which has a molecular weight of 600 to 2000, an average functionality of 2 to 8, and a propylene oxide content of 5 to 50%;

[0013] 2) preparing polyether polyol II with a molecular weight of 3000-6000, an average functionality of 2-8, and an ethylene oxide content of 5-50%;

[0014] 3) At room temperature, polyether polyol I and polyether polyol II are mixed and stirred at a weight ratio of 1:0.5-1 to obtain a polyether polyol for a low-temperature slow-rebound sponge.

[0015] To solve the third of the above technical problems, the technical solution adopted by the present invention is as follows:

[0016] The aforementioned low-temperature slow-rebound polyether polyol is used in the preparation of a slow-rebound sponge.

[0017] The invention provides a polyether polyol for a low-temperature slow-rebound sponge. The polyether fully phase-separates a soft segment region and a hard segment region. The polyether as a soft segment has a relatively high molecular weight and provides a high glass transition temperature. The low-molecular-weight polyether forms a hard segment region with isocyanate and provides a low glass transition temperature. The high-molecular-weight long-chain polyether gives the sponge excellent low-temperature performance and softness. The invention selects specific long-chain polyethers and short-chain polyethers and adopts a certain combination ratio at the same time, so that the prepared slow-rebound sponge has low-temperature resistance, that is, when the temperature is reduced to below zero, the change rate of hardness compared with that at room temperature is less than 15%, thereby achieving a good technical effect. DETAILED DESCRIPTION

[0018] [Example 1]

[0019] Preparation of polyether polyol I: Add 1000g of sorbitol and 16.5g of potassium hydroxide as a catalyst to a 10L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the reactor in a vacuum state, stir slowly and heat to 115°C, dehydrate for 0.5h, and replace the propylene oxide storage tank with nitrogen. First, introduce 200g of propylene oxide into the reactor at -0.01Mpa, and continue to add propylene oxide to 5066g after the reaction starts, and mature for 3h. Mature at 115°C for 3h. Under a slight positive pressure, introduce 527g of ethylene oxide into the reactor for end-capping, mature at 120°C for 2h, cool down, and obtain crude ether.

[0020] 3000g of crude ether was added to a reaction kettle equipped with a 3L stirring device, 180g of distilled water was added to the kettle for dilution, 48.1g of phosphoric acid was added after stirring at 85℃ for 20 minutes and continued stirring for 1h, then 10g of magnesium silicate and 10g of aluminum silicate were added and stirred for 0.5h, the temperature was raised to 95℃ and stirred for 0.5h, the temperature was slowly raised to 115℃, and then vacuum dehydration was performed until the water content was less than 0.1%, and silicate was filtered to remove the short-chain polyether. Polyether polyol I with ethylene oxide accounting for 8% of the total mass and hydroxyl value of 280.5mgKOH / g.

[0021] Preparation of polyether polyol II: Add 228g of propylene glycol as an initiator and 3.1g of potassium hydroxide as a catalyst to a 2L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the reactor in a vacuum state, stir slowly and heat to 115°C, and replace the storage tank of propylene oxide with nitrogen at the same time. At -0.01Mpa, introduce propylene oxide into the reactor at a uniform speed, keep the pressure in the reactor not more than 0.4Mpa, add to 972g, and mature for 3h to obtain 204 crude ether.

[0022] Add 135g of the above 204 crude ether and 0.07g of DMC as a catalyst to a 2L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the vacuum state in the reactor, stir slowly and heat to 135°C, and replace the storage tanks of ethylene oxide and propylene oxide with nitrogen at the same time. First, introduce 130g of ethylene oxide and propylene oxide into the reactor at -0.01Mpa to induce the reaction. The temperature in the reactor rises rapidly and the pressure drops in about half an hour, indicating that the DMC induced reaction is successful. When the temperature in the reactor drops to 135°C, continue to add ethylene oxide and propylene oxide to 1365g. After adding, continue to react for 1h without refining to obtain a long-chain polyether. Ethylene oxide accounts for 45% of the mass fraction of the polyether, and the hydroxyl value is 28.1mgKOH / g of polyether polyol II.

[0023] At room temperature, the above-mentioned polyether polyol I and polyether polyol II were mixed in a weight ratio of 1:1 to obtain polyether polyol-1 for low-temperature slow-rebound sponge. The performance test data thereof are shown in Table 1.

[0024] [Example 2]

[0025] Preparation of polyether polyol I: Add 912g of xylitol as an initiator and 15.3g of potassium hydroxide as a catalyst to a 10L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the reactor in a vacuum state, stir slowly and heat to 115°C, dehydrate for 0.5h, and replace the storage tank of propylene oxide with nitrogen. Add propylene oxide to 4608g at -0.01Mpa, keep the pressure in the reactor not more than 0.5Mpa, add propylene oxide, and mature at 115°C for 3h. Pass 480g of ethylene oxide into the reactor under a slight positive pressure for end-capping, and mature at 120°C for 2h to obtain crude ether.

[0026] 3000g of crude ether was added to a reactor equipped with a 3L stirring device, 180g of distilled water was added to the reactor for dilution, 45.2g of phosphoric acid was added after stirring at 85°C for 20 minutes and continued stirring for 1h, then 20g of magnesium silicate and aluminum silicate were added and stirred for 0.5h, the temperature was raised to 95°C and stirred for 0.5h, the temperature was slowly raised to 115°C, and then vacuum dehydrated to 0.1% of the water content, and silicate was filtered to obtain short-chain polyether. Ethylene oxide accounted for 8% of the total mass, and the hydroxyl value was 280.5mgKOH / g of polyether polyol I.

[0027] Preparation of polyether polyol II: Add 250g of trimethylolpropane as initiator and 3.8g of potassium hydroxide as catalyst to a 2L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the reactor in a vacuum state, stir slowly and heat to 115°C, and replace the storage tanks of propylene oxide and ethylene oxide with nitrogen at the same time, where ethylene oxide accounts for 45% of the mass fraction of the mixed alkane. At -0.01Mpa, introduce propylene oxide and ethylene oxide into the reactor at a uniform speed, keep the pressure in the reactor not more than 0.4Mpa, add to 1243g, mature for 3h, and obtain trimethylolpropane head crude ether. Place 1200g of head crude ether in a 2L reactor equipped with a stirring device, add 100g of water, stir for 15 minutes, raise the temperature to 85°C, add 17.8g of phosphoric acid, and stir for 0.5h. Add 10g of magnesium silicate and aluminum silicate adsorbents to the kettle, stir for 1h, start vacuum dehydration, and gradually raise the temperature to 115°C. Dehydrate until the water content is less than 0.1%, filter to remove silicate, and obtain the refined ether of trimethylolpropane head with a hydroxyl value of 210.4mgKOH / g.

[0028] Add 180g of the above trimethylolpropane head and 0.07g of DMC as a catalyst to a 2L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the vacuum state in the reactor, stir slowly and heat to 135°C, and replace the storage tanks of ethylene oxide and propylene oxide with nitrogen at the same time. First, introduce 130g of ethylene oxide and propylene oxide into the reactor at -0.01Mpa to induce the reaction. After about 40 minutes, the temperature in the reactor rises rapidly and the pressure drops, indicating that DMC induces the induction successfully. When the pressure in the reactor drops to 135°C, continue to add ethylene oxide and propylene oxide to 1320g. After adding, continue to react for 1h without refining to obtain a long-chain polyether. Ethylene oxide accounts for 45% of the mass fraction of the polyether, and the hydroxyl value is 28.1mgKOH / g of polyether polyol II.

[0029] At room temperature, the above-mentioned polyether polyol I and polyether polyol II were mixed in a weight ratio of 1:1 to obtain polyether polyol-2 for low-temperature slow-rebound sponge. The performance test data thereof are shown in Table 1.

[0030] [Example 3]

[0031] Preparation of polyether polyol I: Add 1140g of sucrose as an initiator and 15.5g of potassium hydroxide as a catalyst to a 10L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the reactor in a vacuum state, stir slowly and heat to 115°C, dehydrate for 0.5h, and replace the storage tank of propylene oxide with nitrogen. First, introduce 200g of propylene oxide into the reactor at -0.01Mpa, and continue to add propylene oxide to 3960g at the beginning of the reaction, keeping the pressure in the reactor not more than 0.5Mpa, and mature at 115°C for 3h after adding. Under a slight positive pressure, introduce 900g of ethylene oxide into the reactor for end-capping, and mature at 120°C for 2h to obtain crude ether.

[0032] 3000g of crude ether was added to a reactor equipped with a 3L stirring device, 180g of distilled water was added to the reactor for dilution, 43.8g of phosphoric acid was added after stirring at 85°C for 20 minutes, stirring was continued for 1h, and then 20g of magnesium silicate and aluminum silicate were added and stirred for 0.5h, the temperature was raised to 95°C and stirred for 0.5h, the temperature was slowly raised to 115°C, and then vacuum dehydration was performed to 0.1% of the water content, and silicate was filtered to remove it to obtain a short-chain polyether. Ethylene oxide accounted for 15% of the total mass, and the hydroxyl value was 249.3mgKOH / g.

[0033] Preparation of polyether polyol II: Add 265g of diethylene glycol as an initiator and 3.8g of potassium hydroxide as a catalyst to a 2L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the reactor in a vacuum state, stir slowly and heat to 115°C, and replace the storage tanks of propylene oxide and ethylene oxide with nitrogen at the same time, where ethylene oxide accounts for 45% of the mass fraction of the mixed alkane. At -0.01Mpa, introduce propylene oxide and ethylene oxide into the reactor at a uniform speed, keep the pressure in the reactor not more than 0.4Mpa, add to 1235g, mature for 3h, and obtain trimethylolpropane head crude ether. Place 1200g of the head crude ether in a 2L reactor equipped with a stirring device, add 100g of water, stir for 15 minutes, raise the temperature to 85°C, add 17.5g of phosphoric acid, and stir for 0.5h. Add 10g of magnesium silicate and aluminum silicate adsorbents to the kettle, stir for 1h, start vacuum dehydration, and gradually raise the temperature to 115°C. Dehydrate until the water content is less than 0.1%, filter to remove silicate, and obtain the refined ether of diethylene glycol head with a hydroxyl value of 187mgKOH / g.

[0034] Add 200g of the above-mentioned diethylene glycol refined ether head and 0.07g of DMC as a catalyst to a 2L high temperature and high pressure reactor equipped with a stirring device. Replace the air in the reactor with nitrogen, keep the vacuum state in the reactor, stir slowly and heat to 135°C, and replace the storage tanks of ethylene oxide and propylene oxide with nitrogen at the same time. First, introduce 130g of ethylene oxide and propylene oxide into the reactor at -0.01Mpa to induce the reaction. The temperature in the reactor rises rapidly and the pressure drops in about 40 minutes, indicating that DMC has successfully induced the induction. When the pressure in the reactor drops to 135°C, continue to add ethylene oxide and propylene oxide to 1281g. After adding, continue to react for 1h without refining to obtain a long-chain polyether. Ethylene oxide accounts for 45% of the mass fraction of the polyether, and the hydroxyl value is 28.1mgKOH / g.

[0035] At room temperature, the above-mentioned polyether polyol I and polyether polyol II were mixed in a weight ratio of 1:0.8 to obtain polyether polyol-3 for low-temperature slow-rebound sponge. The performance test data thereof are shown in Table 1.

[0036] Table 1 Performance indicators of polyether polyols for low temperature slow rebound sponge

[0037] product <![CDATA[H + ]]> H2O PH <![CDATA[K + ]]> Vis OHV Example 1 Polyether polyol-1 0.021 0.033 6.51 <1 696 158.1 Example 2 Polyether polyol-2 0.032 0.026 6.04 <1 717 157.7 Example 3 Polyether polyol-3 0.018 0.076 6.45 <1 832 155.2

[0038] [Example 4]

[0039] Weigh 20 parts of polyether polyol-1, 35 parts of polyether polyol CHE-307, 45 parts of polymer polyol CHE-5602, 0.3 parts of amine catalyst A33, 1.1 parts of silicone oil L-580, 0.12 parts of tin catalyst T9, 1.85 parts of deionized water, and 3 parts of pore opener KTM-3, stir quickly in a high-speed stirrer at 3000r / min, mix evenly, add 48 parts of black material BASF-8122, mix evenly again with a high-speed stirrer, pour quickly into a mold at 50°C, close the mold, cure, demold after 5 minutes, and leave the foam at room temperature for 48 hours to obtain a low-temperature slow-rebound foam sponge. The results of its physical properties test are shown in Table 2.

[0040] [Example 5]

[0041] Weigh 20 parts of polyether polyol-2, 35 parts of polyether polyol CHE-307, 45 parts of polymer polyol CHE-5602, 0.3 parts of amine catalyst A33, 1.1 parts of silicone oil L-580, 0.12 parts of tin catalyst T9, 1.85 parts of deionized water, and 3 parts of pore opener KTM-3, stir quickly in a high-speed stirrer at 3000r / min, mix evenly, add 48 parts of black material BASF-8122, mix evenly again with a high-speed stirrer, quickly pour into a mold at 50°C, close the mold, cure, demold after 5 minutes, and leave the foam at room temperature for 48 hours to obtain a low-temperature slow-rebound foam sponge. The results of its physical properties test are shown in Table 2.

[0042] [Example 6]

[0043] Weigh 20 parts of polyether polyol-3, 35 parts of polyether polyol CHE-307, 45 parts of polymer polyol CHE-5602, 0.3 parts of amine catalyst A33, 1.1 parts of silicone oil L-580, 0.12 parts of tin catalyst T9, 1.85 parts of deionized water, and 3 parts of pore opener KTM-3, stir quickly in a high-speed stirrer at 3000r / min, mix evenly, then add 47 parts of black material BASF-8122, mix evenly again with a high-speed stirrer, quickly pour into a mold at 50°C, close the mold, cure, demold after 5 minutes, and leave the foam at room temperature for 48 hours to obtain a low-temperature slow-rebound foam sponge. The results of its physical properties test are shown in Table 2.

[0044] [Comparative Example 1]

[0045] Weigh 55 parts of polyether polyol CHE-307, 45 parts of polymer polyol CHE-5602, 0.3 parts of amine catalyst A33, 1.1 parts of silicone oil L-580, 0.12 parts of tin catalyst T9, 1.85 parts of deionized water, and 3 parts of pore opener KTM-3, stir quickly in a high-speed stirrer at 3000r / min to mix evenly, then add 50 parts of black material BASF-8122, mix evenly again with a high-speed stirrer, quickly pour into a mold at 50°C, close the mold, cure, demold after 5 minutes, and leave the foam at room temperature for 48 hours to obtain a slow rebound foam sponge. The results of its physical properties test are shown in Table 2.

[0046] Table 2 Slow rebound foam sponge physical properties test results

[0047]

[0048]

[0049] Comparative Example 1 is a foaming formula of an ordinary slow rebound sponge. The polyether polyols in Examples 1, 2, and 3 are used to replace 20 parts of polyether polyol CHE-307 to obtain Examples 4, 5, and 6. It can be seen from the experimental results that at room temperature, the polyether polyols in Examples 1, 2, and 3 replace 20 parts of CHE-307 and have little effect on the sponge recovery time. In the hardness change with temperature test experiment, the hardness of Comparative Example 1 at room temperature and -5°C changes greatly, and the hardness increases as the temperature decreases; the hardness of the sponge in Examples 4, 5, and 6 at -5°C is slightly greater than that at room temperature, and is much smaller than that in Comparative Example 1, which indicates that the appropriate addition of the polyether polyols in the examples has the effect of preventing the sponge from hardening in a low temperature environment, and can be used to prepare a slow rebound sponge, so that the prepared slow rebound sponge has a low temperature resistance, and the hardness change rate at -5°C and at room temperature is less than 15%, achieving a good technical effect.

Claims

1. A polyether polyol for low-temperature slow-rebound sponge, characterized in that: The composition is a mixture of polyether polyol I with a molecular weight of 600-2000, an average functionality of 2-8, and propylene oxide accounting for 5-50%, and polyether polyol II with a molecular weight of 3000-6000, an average functionality of 2-8, and ethylene oxide accounting for 45%. The polyether polyol I and the polyether polyol II are mixed in a weight ratio of 1:0.5-1. The polyether polyol I is prepared by using one of diethylene glycol, trimethylolpropane, xylitol or sucrose as an initiator; the polyether polyol II is prepared by using at least one of propylene glycol, diethylene glycol, trimethylolpropane, pentaerythritol, xylitol, sorbitol or sucrose as an initiator and copolymerizing with alkylene oxide under the action of potassium hydroxide and DMC catalyst; the hydroxyl value of the polyether polyol for low-temperature slow rebound sponge is 155.2-165 mgKOH / g, and the functionality is 3-6.

2. A method for preparing the low-temperature slow-rebound polyether polyol according to claim 1, comprising the following steps: (1) preparing polyether polyol I, which has a molecular weight of 600 to 2000, an average functionality of 2 to 8, and a propylene oxide content of 5 to 50%; (2) preparing polyether polyol II with a molecular weight of 3000 to 6000, an average functionality of 2 to 8, and an ethylene oxide content of 45%; (3) At room temperature, polyether polyol I and polyether polyol II are mixed and stirred in a weight ratio of 1:0.5-1 to obtain a polyether polyol for a low-temperature slow-rebound sponge.

3. Use of the low-temperature slow-rebound polyether polyol according to claim 1 in the preparation of a slow-rebound sponge, wherein the hardness change rate of the prepared slow-rebound sponge at -5°C and 25°C is less than 15%.

Images