Solvent for a carbon dioxide-based latent foaming agent

Abstract

The present invention discloses a solvent for a CO2-type latent foaming agent of a polyamine polymer, which is composed of an alcohol, an amine and / or an amino alcohol having no more than 8 carbon atoms and a total of 2 to 5 hydroxyl groups and amino groups. The foaming mixture formed after adding this solvent is a liquid, which greatly improves the compatibility of the latent foaming agent in the system, has a high dispersion degree in the foaming system and good foaming effect. This solvent is a reactive solvent and can undergo a chemical reaction with other substances in the foaming system to become a part of the foam.

Description

Technical Field

[0001] The present invention relates to the technical field of blowing agents, and particularly to a solvent for a carbon dioxide (CO2)-type latent blowing agent. Background Art

[0002] Polyurethane foams are widely used in fields such as sofas, mattresses, car seats, refrigerators, pipelines, and building insulation. Generally speaking, the production of polyurethane foams often requires a large amount of blowing agents. Traditional blowing agents are low-boiling chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) compounds, which contain chlorine atoms in their structures and can damage the ozone layer. Currently used blowing agents include hydrofluorocarbons (HFCs) compounds and hydrofluoroolefins (HFOs) compounds that do not contain chlorine and do not damage the ozone layer. However, the former has a strong greenhouse effect and is one of the main causes of global warming, and the decomposition products of the latter in the atmosphere contain trifluoroacetic acid (CF3COOH) and hydrofluoric acid (HF), which may cause acid pollution and damage the ecological environment. Common blowing agents also include alkane blowing agents (such as cyclopentane). The performance of such blowing agents is similar to that of HFOs. Although they have less impact on the environment, there is a risk of explosion and combustion.

[0003] An adduct is formed by the reaction of a polyamine polymer and CO2. The adduct can release CO2 for polyurethane foaming when heated. The advantage of this blowing agent is that CO2 can be fixed in the polyamine polymer at room temperature and can be mixed with polyurethane raw materials, overcoming the disadvantage that gaseous CO2 is difficult to store in foaming raw materials. During the polyurethane foaming process, this blowing agent absorbs the reaction heat and releases CO2 for foaming. Therefore, at room temperature, such blowing agents are potential blowing agents, called CO2-type latent blowing agents. Such blowing agents are solids and are difficult to disperse in polyurethane raw materials. Chinese Patent CN 103965470 A discloses a CO2 adduct blowing agent of hydrophobic modified polyethyleneimine, and the hydrophobic chain used is a polypropylene glycol chain or an alkyl chain. Hydrophobic modification improves the dispersibility of the blowing agent in polyurethane raw materials to a certain extent. Chinese Patent CN 112457520 A adopts mixing hydrophobic modified polyethyleneimine and polyether polyol, and then absorbing CO2 to in-situ generate a CO2 adduct blowing agent of hydrophobic modified polyethyleneimine. This blowing agent exists in the form of nanoparticles in polyether polyol. This method greatly improves the dispersibility of this blowing agent, but also increases the viscosity of the foaming mixture, resulting in inconvenient use; if the viscosity is too high, it may hinder the growth of bubbles and even cause bubble rupture, leading to foaming failure.

[0004] In fact, traditional polyurethane blowing agents are all liquid and are very easy to mix with other liquid raw materials for foaming. Existing CO2-type latent blowing agents are all solid and are very inconvenient to use. Developing a liquid CO2-type latent blowing agent can not only retain the environmentally friendly characteristics of CO2 latent blowing agents but also increase the convenience of construction. Summary of the Invention

[0005] In view of the inconvenient use of the CO2 latent blowing agent of existing polyamine polymers, the present inventors actively searched for its solvent, hoping to develop a liquid CO2 latent blowing agent system. This blowing agent is a CO2 adduct, and its molecular structure contains an amphoteric ion composed of an alkylammonium cation and a carbamate anion (which is a hydrophilic structure), and it is difficult to dissolve this blowing agent in general organic solvents. Water can dissolve the CO2 adduct of polyamine polymers. However, water itself is also a blowing agent for polyurethanes. Introducing too much water will cause a large number of urea bonds to be formed in the structure of the resulting polymer, making the foam brittle. At the same time, when water and the CO2 adduct blowing agent of polyamine polymers coexist in a system, it will pose constraints on the foam formulation design. For example, to obtain low-density foam, it is necessary to increase the amount of blowing agent; if there is water in the blowing agent, the amount of water will inevitably be increased, and the increase in water will increase the amount of isocyanate, making the foam brittle. That is to say, it is very difficult to prepare low-density and soft foam. In addition, generally, the CO2 adduct blowing agent of polyamine polymers needs to be hydrophobically modified (to improve the dispersion ability of this blowing agent in polyurethane raw materials; at the same time, graft modification will increase steric hindrance and avoid excessive reaction between the free amino group and isocyanate formed after the polyamine polymer releases CO2 and foams, which will lead to too high a crosslinking density of the foam and also make the foam brittle), and its solubility in water will decrease significantly after hydrophobic modification. Therefore, pure water is not suitable as the solvent for the CO2 latent blowing agent of polyamine polymers.

[0006] The present inventors carefully studied the molecular structure of the CO2 adduct of polyamine polymers and found that both the alkylammonium cation and the carbamate anion contained in this structure can form hydrogen bonds. Thus, they actively explored the feasibility of using compounds containing hydroxyl and amino groups as solvents for the CO2 adduct of polyamine polymers. After extensive exploration, it was found that alcohols, amines, and / or amino alcohols with a carbon atom number ≤ 8 and a total number of hydroxyl and amino groups of 2 - 5 can dissolve the CO2 adduct of polyamine polymers. At the same time, the alcohols, amines, and / or amino alcohols described above can also react with isocyanate, one of the raw materials of polyurethanes, and become a part of polyurethane foam products. Therefore, on the one hand, the alcohols, amines, and / or amino alcohols dissolve the CO2 adduct blowing agent of polyamine polymers (i.e., the CO2 latent blowing agent of polyamine polymers), enabling this blowing agent to be fully mixed with liquid polyurethane raw materials and playing the role of a blowing agent during the foam preparation process; at the same time, the alcohols, amines, and / or amino alcohols can also react with isocyanate and play the role of a chain extender, and ultimately become a part of the foam material.

[0007] One object of the present invention is to provide a solvent for a CO2-based latent foaming agent, which is composed of an alcohol, an amine, and / or an alkanolamine having ≤8 carbon atoms and a total of 2 to 5 hydroxyl and amino groups. It is a reactive solvent, that is, the solvent can not only dissolve the CO2-based latent foaming agent, but also chemically react with other substances in the foaming system to become part of the foam. The CO2-based latent foaming agent is composed of a polyamine polymer and CO2, and CO2 and the polyamine polymer exist in the form of an adduct; or the CO2-based latent foaming agent is composed of a graft-modified polyamine polymer and CO2, and CO2 and the main chain of the polyamine polymer exist in the form of an adduct. The polyamine polymer is a polymer containing 4 or more amino groups in the molecular chain, the atoms connected to the amino groups are carbon atoms, and its structure is at least one of linear, branched, and hyperbranched, and the molecular weight is greater than 200. The polyamine polymer includes but is not limited to at least one of polyethyleneimine, polypropyleneimine, polybutyleneimine, polyvinylamine, and polyallylamine; the graft-modified polyamine polymer may be grafted with at least one of the following side chains:

[0008] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran, or polysiloxane, and the degree of polymerization is at least 1;

[0009] (2) The side chain contains a trimethylsilyl group;

[0010] (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms;

[0011] (4) The side chain contains a fluoroalkyl group having 1 to 22 carbon atoms.

[0012] Specifically, the solvent for the CO2-based latent foaming agent of the present invention is at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, pentanediol, glycerol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, diethylene glycol, and diglycolamine; the butanediol is 1,4-butanediol or any isomer of 1,4-butanediol containing two hydroxyl groups, and the pentanediol is 1,5-pentanediol or any isomer of 1,5-pentanediol containing two hydroxyl groups. Among them, ethylene glycol, ethanolamine, diethanolamine, and triethanolamine have good solubility. And ethylene glycol is relatively inexpensive and is often used as the preferred solvent.

[0013] When ethylene glycol is mixed with other small molecules containing hydroxyl groups and / or amino groups, good dissolution effects can also be achieved. The other small molecules containing hydroxyl groups and / or amino groups are at least one of 1,2-propanediol, 1,3-propanediol, glycerol, butanediol, pentanediol, hexanediol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, butanediamine, diethylene glycol, diglycolamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine; the butanediol, pentanediol and hexanediol are any isomers with two hydroxyl groups of the corresponding diols; the butanediamine is 1,4-butanediamine or any isomer with two amino groups of 1,4-butanediamine. When ethylene glycol is mixed with other small molecules containing hydroxyl groups and / or amino groups, the mass percentage content of ethylene glycol is preferably not less than 50%.

[0014] Another object of the present invention is to provide the use of a solvent composed of the above-mentioned alcohols, amines and / or amino alcohols with carbon atom number ≤8 and the total number of hydroxyl groups and amino groups being 2-5 for dissolving a CO2-type latent foaming agent; the CO2-type latent foaming agent is composed of a polyamine polymer and CO2, and CO2 and the polyamine polymer exist in the form of an adduct, or the CO2-type latent foaming agent is composed of a graft-modified polyamine polymer and CO2, and CO2 and the main chain of the polyamine polymer exist in the form of an adduct; the polyamine polymer is a polymer containing 4 or more amino groups in the molecular chain and has a molecular weight greater than 200; the graft-modified polyamine polymer contains a side chain and is at least one of the following situations:

[0015] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1;

[0016] (2) The side chain contains a trimethylsilyl group;

[0017] (3) The side chain contains a hydrocarbon group with 1 to 22 carbon atoms;

[0018] (4) The side chain contains a fluoroalkyl group with 1 to 22 carbon atoms.

[0019] In the process of using the solvent to dissolve the CO2-type latent foaming agent, the use of water is not excluded. Water itself is also a foaming agent. When using the CO2-type latent foaming agent and water as co-foaming agents, water can be added to the solvent composed of the alcohols, amines and / or amino alcohols, and this still belongs to the use of the solvent to dissolve the CO2-type latent foaming agent. Of course, other components of the polyurethane foam, such as foam stabilizers, catalysts, etc., can also be added to the solvent composed of the alcohols, amines and / or amino alcohols in advance, and this still belongs to the protection scope of the present invention because these auxiliaries themselves cannot dissolve the CO2-type latent foaming agent, and the solvent that plays the dissolving role is still the solvent composed of the alcohols, amines and / or amino alcohols.

[0020] Compared with the prior art, the present invention has the following positive effects:

[0021] 1. The present invention provides a solvent for the CO2 latent blowing agent of the polyamine polymer, obtaining a liquid foaming mixture containing the CO2 latent blowing agent of the polyamine polymer, which can be fully mixed with the liquid polyurethane raw material, solving the problem that the solid CO2 latent blowing agent of the polyamine polymer is difficult to disperse in the polyurethane raw material, and facilitating the application of the CO2 latent blowing agent of the polyamine polymer in the polyurethane foam.

[0022] 2. The solvent for the CO2 latent blowing agent of the polyamine polymer provided by the present invention contains hydroxyl groups and / or amino groups in its molecular structure, and can react with isocyanates to become a part of the foam structure, avoiding the solvent becoming a volatile substance to pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Appendix Figure 1 It is the chemical structural formula of the side chain raw materials used to prepare the grafted polyamine polymer in the preparation examples (1)-(21) of the grafted polyamine polymer. DETAILED DESCRIPTION OF THE INVENTION

[0024] In order to make the objectives, technical solutions and technical effects of the present invention clearer, the following further describes the present invention in detail with reference to specific embodiments. It should be noted that all these embodiments are for further illustrating the present invention and should not be construed as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention still fall within the protection scope of the present invention.

[0025] Preparation Examples of Grafted Polyamine Polymer

[0026] Before describing the specific embodiments, the preparation of the grafted polyamine polymer in the "CO2 adduct of the grafted polyamine polymer" dissolved by the solvent of the present invention will be described first. The polyamine polymer described in the present invention is a polymer containing amino groups in its molecular structure, including but not limited to polyethyleneimine (PEI), polypropyleneimine (PPI), polybutyleneimine (PBI), and the methylene groups between the amino groups in their molecular structures are spaced 2, 3, and 4 respectively. Of course, polyamine polymers with 5 or 6 methylene groups spaced are also possible (these polyalkyleneamines can have structural variations such as linear, branched, and hyperbranched), but the more methylene groups there are, the relatively lower the amino content for absorbing CO2, and the foaming ability of the blowing agent per unit mass decreases. In addition, polyamine polymers containing primary amino groups such as polyvinylamine (PEA) and polyallylamine (PAA) can also be used. Their structures are shown as follows:

[0027]

[0028] The polyamine polymer described in the present invention can be grafted with side chains to increase the dispersibility of its CO2 adduct in polyurethane raw materials. The side chains include but are not limited to at least one of the following:

[0029] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1;

[0030] (2) The side chain contains trimethylsilyl;

[0031] (3) The side chain contains a hydrocarbon group with 1 to 22 carbon atoms;

[0032] (4) The side chain contains a fluoroalkyl group with 1 to 22 carbon atoms.

[0033] The grafting degree of the grafted side chain can vary as needed and can vary between 1% and 45%.

[0034] The structure of the synthesized graft-modified polyamine polymer is shown in Table 1. The theoretical grafting degree is calculated from the molar ratio of the amino groups grafted with side chains to all the amino groups on the main chain, and the actual grafting degree is calculated from the area ratio of the proton signals related to the side chain and the main chain in the NMR spectrum. It should be noted that the sample codes in the table are composed of the codes of the side chain and the polyamine polymer. For example, 5%C8-PEI, where 5%C8 represents an alkyl chain with 8 carbon atoms as the side chain, 5% represents the designed grafting degree of the side chain (i.e., the theoretical grafting degree), and PEI represents the polyamine polymer as polyethyleneimine. The source of the side chain is C8-EPO, and its structure is shown in Figure 1 . The code meanings of other samples are similar. Some samples have two grafted side chains, and the theoretical grafting degrees and side chain codes of their respective side chains are listed separately. The sources of all side chains are listed in Figure 1 . The codes of polyamine polymers are: PEI for polyethyleneimine, PPI for polypropyleneimine, PBI for polybutyleneimine, PEA for polyvinylamine, and PAA for polyallylamine. Except for PEA and PAA, the remaining polyamine polymers have structural variations of linear, branched or hyperbranched.

[0035] The process conditions and steps for the preparation of grafted polyamine polymers in Examples (1) to (16), (20) and (21) are as follows: Add the corresponding polyamine polymer to the reaction kettle, and add ethanol to the reaction kettle to make the mass concentration of the polyamine polymer about 10%. Under stirring conditions, completely dissolve the polyamine polymer, and then add the corresponding glycidyl ether compound (Table 1, side chain raw material) to make the theoretical grafting degree of the side chain meet the values listed in Table 1. Stir and react at 50 °C for 15 hours, and then rotary evaporate to remove ethanol; First, add 10 parts by volume of petroleum ether to the product after rotary evaporation to dissolve the product and the unreacted glycidyl ether compounds, and then add 1 / 3 of the distilled water based on the volume of petroleum ether to precipitate the grafted modified polyamine polymer; Then wash the precipitated polyamine polymer with petroleum ether at least three times, and then rotary evaporate to remove petroleum ether and dry to constant weight to obtain the product.

[0036] Table 1

[0037]

[0038] The process conditions and steps for the preparation of the grafted modified polyamine polymerization raw material in Example (17) are as follows: Dissolve 1 mole part of this polyethyleneimine measured by the repeating unit of polyethyleneimine in chloroform to make its mass concentration about 10%, and then add 0.03 mole part of C 17 H 33 -COOH( Figure 1 ) and N,N'-carbonyldiimidazole (CDI), and the theoretical grafting rate is 3%. Then stir and react under reflux conditions for 12 hours, extract with saturated brine 3 times, take the chloroform layer, rotary evaporate to remove the solvent at 50 °C, and finally dry in an oven at 75 °C to obtain 3% C 17 H 33 -PEI, the purified product of hydrophobic chain grafted polyethyleneimine.

[0039] The process conditions and steps for the preparation of the grafted modified polyamine polymer raw material in Example (18) are as follows: Dissolve 1 mole part of this polyethyleneimine measured by the repeating unit of polyethyleneimine in chloroform to make its mass concentration about 10%, and then add 0.2 mole part of C2F3-I (Table 1), and reflux for 3 hours,

[0040] Cool to room temperature, extract the reaction mixture three times with 5% sodium hydroxide aqueous solution with the same volume as chloroform, remove the water layer, wash until the pH value of the water layer is neutral, dry the organic layer with anhydrous sodium sulfate, and rotary evaporate under vacuum at 40 °C to remove the solvent to obtain 20% C2F3-PEI, the corresponding hydrophobic chain modified polyethyleneimine.

[0041] The process conditions and steps for preparing the grafted polyamine polymer raw material in Example (19) are as follows: Take 1 mole of this polyethyleneimine measured by the repeating unit of polyethyleneimine and dissolve it in chloroform to make its mass concentration about 10%. Then add 0.45 mole of C4-Br (Table 1), reflux for 6 hours, cool to room temperature, and extract the reaction mixture three times with 5% sodium hydroxide aqueous solution with the same volume as chloroform.

[0042] Remove the aqueous layer, wash with water until the pH value of the aqueous layer is neutral, dry the organic layer with anhydrous sodium sulfate, and remove the solvent by vacuum rotary evaporation at 40°C to obtain the corresponding polyethyleneimine modified with hydrophobic chains, 45% C4-PEI.

[0043] As can be seen from Table 1, the actual grafting degree and the theoretical grafting degree of each product are very close, indicating that the grafting reaction proceeds completely. The theoretical grafting degree is calculated by the ratio of the number of moles of the side chain to the number of moles of the nitrogen atoms in the main chain, and the actual grafting degree is calculated by the area ratio of the relevant proton signals of the side chain and the main chain in the NMR spectrum. As can be seen from Table 1, the grafting degree of the hydrophobic chains of each product is between 1% and 45%.

[0044] Examples 1 - 37

[0045] In this group of examples, the grafted polyamine polymer (see Table 1) was prepared into the corresponding CO2 adduct, and then dissolved in the corresponding solvent (see Table 2). The preparation method of the CO2 adduct of the polyamine polymer is as follows: Take 1 part by mass of the polyamine polymer (the source is listed in Table 2, and the numbers in parentheses refer to the serial numbers in Table 1) and dissolve it in ethanol to obtain a 10% mass concentration polyamine polymer solution. Put it into a closed reaction kettle, introduce 0.5 MPa of CO2 and react for 5 hours to obtain a white precipitate. Filter to remove the solvent, then dry it in vacuum at 40°C for 3 days, and then put it into a closed reaction kettle and introduce 0.5 MPa of CO2 to keep the pressure for 2 days to obtain the CO2 adduct of the polyamine polymer. Use this adduct as the solute and dissolve it in the corresponding solvent shown in Table 2. It should be noted that the polyamine polymers in Examples 33 - 37 in Table 2 do not have grafted side chains.

[0046] The solute percentage content in Table 2 refers to the maximum percentage mass content that the solute can dissolve. The specific test method is as follows: Take a 50 mL centrifuge tube, add 0.5 g of the CO2 adduct of the polyamine polymer listed in Table 2 (i.e., the solute) powder, and then add 3 g of the corresponding solvent (see Table 2, where butanediol, pentanediol, and hexanediol are straight-chain diols, and butanediamine is 1,4-butanediamine; when using two or more substances as a mixed solvent, the value after the substance is the mass percentage of the substance). Treat it with ultrasonic waves (KQ-300DE numerical control ultrasonic cleaner, Kunshan Ultrasonic Instrument Co., Ltd.) for 10 minutes to disperse the solid into the liquid. Place it in a 30 °C constant temperature water bath and let it stand still. Wait until the solid completely dissolves to form a transparent liquid, then add 0.5 g of the solute powder and repeat the operation until there is undissolved solid matter in the system. Record the mass ratio of the solute to the solvent at this time, and select the average value of the mass at this undissolved point and the mass at the previous dissolved point to conduct another solubility test. If it dissolves, test the solubility of the intermediate mass between this dissolved point and the undissolved point; if it does not dissolve, test the solubility of the intermediate mass between this undissolved point and the previous dissolved point. Repeat this operation until the percentage of the solute mass difference between the undissolved point and the previous dissolved point to the solute mass at the previous dissolved point is less than 2%. Then, the mass at the previous dissolved point is regarded as the maximum dissolved mass, and the percentage of this mass in the total mass of the solution is the solute percentage content listed in Table 2 (obviously with an error less than 2%). It should be noted that although butanediol, pentanediol, and hexanediol in Table 2 are straight-chain diols and butanediamine is a straight-chain diamine, it is also possible to use the corresponding branched-chain diols or diamines for substitution. The obtained solute percentage content fluctuates slightly, and compared with the values of the corresponding straight-chain diols or diamines, the fluctuation is less than 10%.

[0047] In Examples 3 to 10 in Table 2, the CO2 adduct of the same polyamine polymer (10% C8-PEI) was used as the solute and dissolved in different solvents; it can be seen that the solubility of ethylene glycol is relatively high. Coupled with the low price of ethylene glycol, ethylene glycol should be a good solvent for the CO2 adduct of the polyamine polymer, and the solubility of the un-grafted CO2 adduct of the polyamine polymer is better, with a mass concentration of 66% (Example 33).

[0048] From the data in Table 2, it can be seen that the solubility of ethylene glycol, propylene glycol, ethanolamine, diethanolamine, and triethanolamine is relatively large (Examples 1 to 18), and the solubility of glycerol, butanediol, pentanediol, ethylenediamine, 1,2-propylene diamine, and 1,3-propylene diamine is relatively small. Obviously, ethylene glycol, 1,2-propylene glycol, 1,3-propylene diamine, butanediol, pentanediol, glycerol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propylene diamine, 1,3-propylene diamine, diethylene glycol, diglycolamine, etc. have relatively considerable solubility (mass percentage is greater than 20%), and their mixed solvents are also very good solvents (see Examples 19 to 37). In addition, when hexanediol, butanediamine, diethylenetriamine, triethylenetetramine and tetraethylenetetramine are used alone as solvents, their solubility is relatively low, and their solute percentage is less than 10%. However, when they are mixed with other solvents, the resulting mixed solvent exhibits a higher solubility, indicating that there is a certain synergistic effect between different solvents, as shown in Examples 21, 24, 25, 29 and 30.

[0049] Table 2

[0050]

[0051]

[0052] Application Examples 1-5

[0053] In this application example, the CO2 adduct solution of the grafted polyamine polymer (Examples 2, 4, 11 and 12) is selected to prepare the corresponding polyurethane foam, and the formula is shown in Table 3 (this formula is only used to illustrate the foaming effect of different foaming agents, and the foaming formula can be adjusted according to different purposes of use).

[0054] Table 3

[0055]

[0056] In Table 3, the polyester polyol is polybutylene glycol adipate (butanediol and ethylene glycol molar ratio 1:1), molecular weight about 1500g / mol, hydroxyl value 76.2mgKOH / g, from Sigma; propylene glycol is from Chengdu Changlian Chemical Reagent Co., Ltd.; stannous octoate and triethylenediamine are from Chengdu High-end Polymer Technology Co., Ltd.; foam leveler BL-8530 is from Shanghai Maihao New Materials Technology Co., Ltd.; PM-200 is polymethylene polyphenyl isocyanate, from Wanhua Chemical Group Co., Ltd., -NCO content is 30.5-32.0%. Example 2 in the table refers to Example 2 (see Table 2), and so on.

[0057] Polyurethane foams containing different blowing agents were prepared, and the formulations are shown in Table 3. In Comparative Example 1 (abbreviated as Du1), no additional blowing agent was added, and the foaming was carried out by the trace water in the raw materials. The blowing agent solution and other white component materials were mixed according to the formulation ratio, mechanically stirred at 800 r / min for 30 s, then the black material was added, and then mechanically stirred at 1800 r / min for 15 s. The foam was allowed to grow naturally, and the foaming was completed when the top of the foam was no longer sticky, obtaining polyurethane foam.

[0058] Since the blowing agent in Table 3 is an ethylene glycol solution of a CO2 adduct of a grafted polyamine polymer, it can be easily mixed with other components. The densities of the foams prepared in Application Examples 1 to 4 are much smaller than those of the control samples, indicating that the blowing agent indeed plays a role in foaming. In Application Example 5, 0.1 part by mass of water was added as an additional blowing agent on the basis of Application Example 4. Since water consumes isocyanate, the dosage of PM-200 was also increased accordingly. The density of Application Example 5 further decreased, and the density was also smaller than that of Control Sample 2 (Du2) using only water as the blowing agent, indicating that water and the blowing mixture of Example 12 jointly play a role in foaming.

[0059] In Application Example 5, the blowing agent water was directly mixed with the blowing mixture of Example 12 to obtain a uniform blowing mixture. This shows that when actually using the solvent of the present invention to dissolve the CO2 adduct blowing agent of the polyamine polymer, water can be added to the solvent of the present invention, and the added water also plays the role of a blowing agent. Such a usage mode also belongs to the protection scope of the present invention.

[0060] It should be noted that the polyurethane foam formulations listed in the present invention are only for verifying that the uniform mixture formed by the modified polyamine polymer blowing agent capable of releasing carbon dioxide prepared by the present invention and the solvent can be used for the preparation of polyurethane foams, and should not be construed as a limitation on the usage scope of the blowing agent material and solvent prepared by the present invention. The formation process of polyurethane foam is an exothermic reaction, and the released heat is just used to release the carbon dioxide in the blowing agent prepared by the present invention. Therefore, the blowing agent material and solvent system prepared by the present invention can be used in various polyurethane foams.

[0061] The above are only the embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A liquid foaming mixture, characterized in that, The foaming mixture consists of a CO2 adduct of graft-modified polyethyleneimine and ethylene glycol. The main chain of the graft-modified polyethyleneimine is a branched polyethyleneimine with a molecular weight of 2500, and the side chain of the graft-modified polyethyleneimine is any one of the following cases: (1) The side chain is derived from C4-EPO and has a structure of The theoretical grafting degree of the side chain is 10%; (2) The side chain is derived from C8-EPO and has a structure of The theoretical grafting degree of the side chain is 10%; (3) The side chain is derived from C 12 -EPO, and the structure is The theoretical grafting degree of the side chain is 10%; (4) The side chain is derived from C8-EPO and has a structure of The theoretical grafting degree of the side chain is 15%; The "theoretical grafting degree" in any of the above cases is calculated by the molar ratio of the amino groups grafted with the side chain and all the amino groups on the main chain; The mass percentage contents of the CO2 adducts of the graft-modified polyethyleneimines corresponding to the above four cases (1), (2), (3), and (4) in the foaming mixture are 60%, 55%, 50%, and 50% respectively.

2. Use of the foaming mixture according to claim 1 for preparing polyurethane foam.

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