Liquid foaming agent containing carbon dioxide adduct

Abstract

The invention discloses a liquid foaming agent containing a CO2 adduct of a polyamine polymer, which is composed of a CO2 adduct and a solvent; the CO2 adduct is composed of a polyamine polymer and CO2, and CO2 and the polyamine polymer exist in the form of an adduct; or the CO2 adduct is composed of a grafted 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 amine groups in the molecular chain, the atoms connected to the amine groups are carbon atoms, and the structure is at least one of straight chain, branched, and hyperbranched, and the molecular weight is greater than 200. The liquid is added to the foaming mixture, has high dispersibility in the foaming system, and has a good foaming effect. The solvent is a reactive solvent, which can react chemically with other substances in the foaming system to become a part of the foam.

Description

Technical Field

[0001] The invention relates to the technical field of foaming agents, and in particular to a liquid foaming agent containing a carbon dioxide (CO2) adduct. Background Art

[0002] Polyurethane foam is widely used in sofas, mattresses, car seat cushions, refrigerators, pipes and building insulation. Generally speaking, the production of polyurethane foam often requires a large amount of foaming agents. Traditional foaming agents are low-boiling chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) compounds, which contain chlorine atoms in their structure and will destroy the ozone layer. The foaming agents currently used include hydrofluorocarbon (HFC) compounds and fluorinated olefin (HFO) compounds that do not contain chlorine and do not destroy the ozone layer. However, the former has a strong greenhouse effect and is one of the culprits of global warming. The latter's decomposition products in the atmosphere contain trifluoroacetic acid (CF3COOH) and hydrofluoric acid (HF), which may cause acid pollution and damage the ecological environment. Common foaming agents also include alkane foaming agents (such as cyclopentane). The performance of this type of foaming agent is similar to that of HFO. Although it has a smaller impact on the environment, it has the risk of being flammable and explosive.

[0003] An adduct is formed by the reaction of a polyamine polymer and CO2, and the adduct can release CO2 when heated for polyurethane foaming. The advantage of this foaming 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 the foaming raw materials. During the polyurethane foaming process, the foaming agent absorbs the heat of reaction and releases CO2 for foaming. This type of foaming agent is solid and difficult to disperse in the polyurethane raw materials. Chinese patent CN 103965470 A discloses a CO2 adduct foaming agent of hydrophobically modified polyethyleneimine, and the hydrophobic chain used is a polypropylene glycol chain or an alkyl chain. The hydrophobic modification improves the dispersibility of the foaming agent in the polyurethane raw materials to a certain extent. Chinese patent CN 112457520A uses a mixture of hydrophobically modified polyethyleneimine and polyether polyol, and then absorbs CO2 to generate a CO2 adduct foaming agent of hydrophobically modified polyethyleneimine in situ, and the foaming agent is present in the polyether polyol in the form of nanoparticles. This method greatly improves the dispersibility of the foaming agent, but also increases the viscosity of the foaming mixture, causing inconvenience in use; excessively high viscosity may hinder the growth of bubbles and even cause bubble rupture, leading to foaming failure.

[0004] In fact, traditional polyurethane foaming agents are all liquid, which can be easily mixed with other liquid raw materials for foaming. Existing CO2 adduct foaming agents are all solid, which is very inconvenient to use. The development of liquid CO2 adduct foaming agents can not only retain the environmentally friendly characteristics of CO2 adduct foaming agents, but also increase the convenience of construction. Summary of the invention

[0005] The inventors of the present invention have actively sought for solvents for the existing CO2 adduct foaming agents of polyamine polymers, which are inconvenient to use, in the hope of developing a liquid CO2 adduct foaming agent system. The foaming agent is a CO2 adduct, which contains zwitterions (hydrophilic structures) composed of alkylammonium cations and carbamate anions in its molecular structure, and it is difficult for general organic solvents to dissolve the foaming agent. Water can dissolve the CO2 adduct of polyamine polymers. However, water itself is also a foaming agent for polyurethane. Introducing too much water will cause a large number of urea bonds to be generated in the generated polymer structure, and the foam will become brittle. At the same time, the coexistence of water and the CO2 adduct foaming agent of polyamine polymers in a system will bring constraints to the foam formula design. For example, in order to obtain low-density foam, it is necessary to increase the amount of foaming agent; if there is water in the foaming agent, the amount of water will inevitably be increased, and the increase in water will increase the amount of isocyanate, making the foam brittle. In other words, it is difficult to prepare low-density and soft foam. In addition, in general, CO2 adduct foaming agents of polyamine polymers need to be hydrophobically modified (in order to improve the dispersibility of the foaming agent in the polyurethane raw material; at the same time, grafting modification will increase steric hindrance to avoid excessive reaction between the free amino groups formed after the polyamine polymer releases CO2 and isocyanate, which will lead to excessive cross-linking density of the foam and also cause the foam to become brittle). After hydrophobic modification, the solubility in water will decrease a lot. Therefore, it is not appropriate to use water alone as a solvent for CO2 adduct foaming agents of polyamine polymers.

[0006] The inventors carefully studied the molecular structure of the CO2 adduct of polyamine polymers and found that the alkyl ammonium cations and carbamate anions contained in the structure can form hydrogen bonds, so they actively explored the feasibility of using compounds containing hydroxyl and amino groups as solvents for the CO2 adduct of polyamine polymers. After a lot of exploration, it was found that alcohols, amines and / or alcoholamines with a carbon number of ≤8 and a total of hydroxyl and amino groups of 2 to 5 can dissolve the CO2 adduct of polyamine polymers. At the same time, the alcohols, amines and / or alcoholamines can also react with isocyanates, one of the raw materials of polyurethane, to become part of the polyurethane foam product. Therefore, the alcohols, amines and / or alcoholamines dissolve the CO2 adduct foaming agent of polyamine polymers (i.e., the CO2 adduct foaming agent of polyamine polymers) on the one hand, so that the foaming agent can be fully mixed with the liquid polyurethane raw material and play the role of a foaming agent in the foam preparation process; at the same time, the alcohols, amines and / or alcoholamines can also react with isocyanates to play the role of a chain extender and eventually become part of the foam material.

[0007] One of the purposes of the present invention is to provide a liquid foaming agent containing CO2 adduct, which is at least composed of CO2 adduct and solvent. The CO2 adduct is composed of polyamine polymer and CO2, CO2 and polyamine polymer exist in the form of adduct; or the CO2 adduct is composed of grafted modified polyamine polymer and CO2, CO2 and polyamine polymer main chain exist in the form of adduct; the polyamine polymer is a polymer containing 4 or more amine groups in the molecular chain, the atoms connected to the amine groups are carbon atoms, and its structure is at least one of straight chain, branched, and hyperbranched, and the molecular weight is greater than 200. The solvent is composed of alcohol, amine and / or alcohol amine with a carbon number of ≤8 and a total of hydroxyl and amino groups of 2 to 5; and it is a reactive solvent, that is, the solvent can both dissolve the CO2 adduct and react chemically with other substances in the foaming system to become a part of the foam.

[0008] The polyamine polymer includes but is not limited to at least one of polyethyleneimine, polypropyleneimine, polybutyleneimine, polyethyleneamine, and polyallylamine; the graft-modified polyamine polymer may be grafted with at least one of the following side chains:

[0009] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1;

[0010] (2) The side chain contains a trimethylsilyl group;

[0011] (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms;

[0012] (4) The side chain contains a fluorinated alkyl group having 1 to 22 carbon atoms.

[0013] Specifically, the grafted side chain can be a polyether oligomer such as polyethylene glycol, polypropylene oxide, polyoxetane and polytetrahydrofuran, or polysiloxane, containing at least one repeating unit, and the structure is exemplified as follows:

[0014]

[0015] Wherein m is at least 1, n is a positive integer from 1 to 4, and Q and T are connecting groups between the grafted side chain and the main chain of the polyamine polymer. The connecting groups Q and T are replaceable groups, and the groups that can be selected are:

[0016]

[0017] The grafted side chain of the grafted polyamine polymer may also contain silane, and its structure may be:

[0018]

[0019] T is a linking group between the side chain and the main chain of the polyamine polymer, and T can be:

[0020]

[0021] The grafted side chain of the grafted polyamine polymer may also contain a hydrocarbon group with 1 to 22 carbon atoms and at least one unsaturated bond, and its structure is exemplified as follows:

[0022] C n H 2n-1 -M-,

[0023] Wherein n is an integer from 1 to 22, and M is a linking group between the hydrophobic side chain and the main chain of the polyamine polymer. The linking group M is a replaceable group, and M can be directly a covalent bond or an amide bond.

[0024] The grafted side chain of the grafted polyamine polymer may also contain an alkyl group or a fluorinated alkyl group having 1 to 22 carbon atoms, and its structure is exemplified as follows:

[0025] C n H 2n+1-m F m -M-,

[0026] Wherein n is an integer from 1 to 22, m is an integer from 0 or 1 to 43, and M is a linking group between the grafted side chain and the main chain of the polyamine polymer. The linking group M is a replaceable group, and M can be directly a covalent bond or an amide bond, and can also be selected from the following groups:

[0027]

[0028] It should be pointed out that the linking groups Q, T and M between the above-mentioned grafted side chains and the main chain of the polyamine polymer are all replaceable groups, and those skilled in the art can also select other groups for replacement, which are not listed here one by one.

[0029] As for the specific preparation method of the above-mentioned grafted polyamine polymer, the glycidyl ether with grafted side chains and the polyamine polymer can be reacted in an ethanol solution to obtain a grafted modified polyamine polymer. The structure of the glycidyl ether with a hydrophobic chain is:

[0030]

[0031] Wherein m is at least 1, n is a positive integer from 1 to 4, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is Q1; the structure of the glycidyl ether with a hydrophobic chain can also be:

[0032]

[0033] Wherein m is 0 or a positive integer, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is T; the structure of the glycidyl ether with a hydrophobic chain can also be:

[0034]

[0035] Wherein n is an integer from 1 to 22, m is an integer from 0 or 1 to 43, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is M2.

[0036] Alternatively, an alkyl group with an epoxy group or a fluorinated alkyl group with an epoxy group and a polyamine polymer may be reacted in an ethanol solution to obtain a grafted polyamine polymer. The structure of the alkyl group with an epoxy group or the fluorinated alkyl group may be:

[0037]

[0038] Wherein n is an integer from 1 to 22, m is an integer from 0 or 1 to 43, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is M1.

[0039] The grafted polyamine polymer can also be prepared by the following method: first, the alkoxy polyether oligomer is reacted with iodoacetic acid and 2-bromoisocyanate to obtain a halogenated hydrocarbon-terminated product, and the reaction is as follows (wherein m is at least 1, and n is a positive integer from 1 to 4):

[0040]

[0041] The above reaction is based on an alkoxy polypropylene glycol oligomer as an example, wherein the repeating units may also be repeating units of polyethylene glycol, polyoxetane and polytetrahydrofuran.

[0042] Secondly, the above-mentioned halogenated hydrocarbon end-capping product is reacted with a polyamine polymer to remove the hydrogen halide to obtain N-substituted hydrophobic modified polyethyleneimine (the connecting group between the side chain and the main chain is Q2 or Q3).

[0043] The grafted polyamine polymer can also be prepared by reacting a bromide or iodide of an alkane or a fluorine-containing alkane with a polyamine polymer. The structure of the bromide or iodide can be:

[0044] C n H 2n+1-m F m -Br, or C n H 2n+1-m F m -I,

[0045] wherein n is an integer from 1 to 22, and m is an integer from 0 or 1 to 43. The linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is a covalent bond.

[0046] The grafted polyamine polymer can also be prepared by reacting an alkyl or fluorinated alkyl carboxylic acid with a polyamine polymer. The structure of the carboxylic acid can be:

[0047] C n H 2n+1-m F m -COOH,

[0048] wherein n is an integer from 1 to 22, and m is an integer from 0 or 1 to 43. The linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is an amide bond.

[0049] The grafted polyamine polymer can also be prepared by reacting unsaturated fatty acids with polyamine polymers. The structure of the fatty acid can be:

[0050] C n H 2n-1 -M-,

[0051] wherein n is an integer from 1 to 22. The linking group M between the side chain and the main chain of the grafted polyamine polymer prepared by this method is an amide bond.

[0052] All these reactions are known chemical reactions, and their specific preparation methods can refer to existing disclosed technologies, such as patent document CN 108355472 A.

[0053] In addition, in the preparation method of the grafted polyamine polymer provided by the present invention, the grafting degree of the grafted polyamine polymer is 1 to 45 mol% based on the N atoms of the polyamine polymer. Preferably, the grafting degree of the grafted polyamine polymer is 3 to 20 mol% based on the N atoms of the polyamine polymer. Generally, the greater the grafting degree of the grafted polyamine polymer, the more conducive it is to dissolve in the solvent. However, if the grafting rate is too large, the number of amino groups of the grafted polyamine polymer that react with CO2 will decrease, and the CO2 content in the grafted polyamine polymer CO2 adduct will decrease, thereby reducing the foaming ability.

[0054] Specifically, the solvent in the CO2 adduct liquid foaming agent of the present invention is at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butanediol, pentanediol, glycerol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, diethylene glycol, and diglycolamine; the butanediol is 1,4-butylene glycol or any isomer of 1,4-butylene glycol 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. Ethylene glycol is relatively cheap and is often used as the preferred solvent.

[0055] When ethylene glycol is mixed with other small molecules containing hydroxyl groups and / or amino groups, it can also have a good dissolving effect. The other small molecules containing hydroxyl groups and / or amino groups are at least one of 1,2-propylene glycol, 1,3-propylene glycol, glycerol, butanediol, pentanediol, hexanediol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, butanediamine, diethylene glycol, diglycolamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; the butanediol, pentanediol, and hexanediol are any isomers containing two hydroxyl groups of the corresponding diols; the butanediamine is any isomer containing two amino groups of 1,4-butanediamine or 1,4-butanediamine. When ethylene glycol is mixed with other small molecules containing hydroxyl groups and / or amino groups, the mass percentage of ethylene glycol is preferably not less than 50%.

[0056] It should be noted that the liquid foaming agent containing CO2 adducts of the present invention may also contain water, and the amount of water used does not exceed 40% of the mass of the solvent in the liquid foaming agent containing CO2 adducts. Water itself is also a chemical foaming agent for polyurethane materials, and water also has a certain dissolving effect. However, if the amount of water used is too large, it will be unfavorable for the dissolution of the CO2 adducts of the polyamine polymer grafted with hydrophobic links; at the same time, too much water will also cause the prepared foam to become brittle.

[0057] Another object of the present invention is to provide a use of the liquid blowing agent containing CO2 adduct for preparing polyurethane foam. In the process of using the liquid blowing agent containing CO2 adduct, other liquid components of polyurethane foam, such as foam leveling agent, catalyst, etc., can be added thereto in advance, which still belongs to the protection scope of the present invention, because these additives themselves cannot dissolve the CO2 adduct, but only form a uniform mixture with the liquid blowing agent.

[0058] Compared with the prior art, the present invention has the following positive effects:

[0059] 1. The present invention provides a liquid CO2 adduct foaming agent containing a polyamine polymer, which can be fully mixed with a liquid polyurethane raw material, thereby solving the problem that the solid CO2 adduct of the polyamine polymer is difficult to disperse in the polyurethane raw material, and facilitating the application of the CO2 adduct of the polyamine polymer as an environmentally friendly foaming agent in polyurethane foam.

[0060] 2. The solvent in the CO2 adduct liquid foaming agent containing polyamine polymer provided by the present invention contains hydroxyl and / or amino groups in its molecular structure, which can react with isocyanate to become a part of the foam structure, thereby preventing the solvent from becoming a volatile substance to pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Attached Figure 1The chemical structural formula of the side chain raw material used in preparing the grafted polyamine polymer in Examples (1) to (21) of the preparation of the grafted polyamine polymer. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be noted that all these embodiments are for further illustrating the present invention and shall not be construed as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention according to the above-mentioned content of the present invention still belong to the protection scope of the present invention.

[0063] Preparation Example of Grafted Polyamine Polymer

[0064] Before describing the specific embodiments, the preparation of the grafted polyamine polymer of the present invention is first described. The polyamine polymer of the present invention is a polymer containing amino groups in the molecular structure, including but not limited to polyethyleneimine (PEI), polypropyleneimine (PPI), polybutyleneimine (PBI), and its molecular structure is respectively 2, 3, 4 methylene groups between amino groups, and of course polyamine polymers with 5 or 6 methylene groups are also possible (these polyalkyleneamines can have linear, branched and hyperbranched structural changes), but the more methylene groups there are, the less amino group content that absorbs CO2, and the foaming ability of the foaming agent per unit mass is reduced. In addition, polyamine polymers containing primary amine groups such as polyethyleneamine (PEA) and polyallylamine (PAA) can also be used. Its structure is shown below:

[0065]

[0066] The polyamine polymer of the present invention may be grafted with side chains to increase the dispersibility of its CO2 adduct in the polyurethane raw material, and the side chains include but are not limited to at least one of the following:

[0067] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1;

[0068] (2) The side chain contains a trimethylsilyl group;

[0069] (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms;

[0070] (4) The side chain contains a fluorinated alkyl group having 1 to 22 carbon atoms.

[0071] The grafting degree of the grafted side chain can be changed as required, and can be changed between 1% and 45%.

[0072] Specifically, the structure of the synthesized grafted modified polyamine polymer is shown in Table 1. The theoretical grafting degree is calculated by 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 by the area ratio of the proton signals related to the side chains and the main chain in the nuclear magnetic resonance spectrum. It should be noted that the sample code in the table is composed of the codes of the side chain and the polyamine polymer, such as 5% C8-PEI, wherein 5% C8 means that the side chain is an alkyl chain containing 8 carbon atoms, 5% means the designed grafting degree of the side chain (i.e., the theoretical grafting degree), PEI means that the polyamine polymer is polyethyleneimine, and the source of the side chain is C8-EPO, and its structure is shown in Figure 1 The codes of other samples have similar meanings. Some samples have two grafted side chains, and the theoretical grafting degree and side chain code of each side chain are listed separately. The sources of all side chains are listed in Figure 1 The code names of polyamine polymers are: PEI polyethylene imine, PPI polypropylene imine, PBI polybutylene imine, PEA polyethylene amine, PAA polyallyl amine. Except for PEA and PAA, the other polyamine polymers have linear, branched or hyperbranched structural variations.

[0073] Table 1

[0074]

[0075] The process conditions and steps of the preparation examples (1) to (16), (20) and (21) of the grafted polyamine polymer are as follows: the corresponding polyamine polymer is added to a reaction kettle, and ethanol is added to the reaction kettle to make the mass concentration of the polyamine polymer about 10%, the polyamine polymer is completely dissolved under stirring, and then the corresponding glycidyl ether compound (Table 1, side chain raw material) is added to make the theoretical grafting degree of the side chain conform to the value listed in Table 1, the reaction is stirred at 50°C for 15 hours, and then the ethanol is removed by rotary evaporation; first, 10 parts by volume of petroleum ether is added to the product after rotary evaporation to dissolve the product and unreacted glycidyl ether compounds, and then 1 / 3 of the volume of petroleum ether is added to distilled water to precipitate the grafted modified polyamine polymer; the precipitated polyamine polymer is then washed with petroleum ether for at least three times, and then the petroleum ether is removed by rotary evaporation and dried to constant weight to obtain the product.

[0076] The process conditions and steps of the preparation of the graft modified polyamine polymer raw material (17) are as follows: 1 mol of polyethyleneimine measured by the repeating unit of polyethyleneimine is dissolved in chloroform to a mass concentration of about 10%, and then 0.03 mol of C 17 H 33 -COOH( Figure 1) and N,N'-carbonyldiimidazole (CDI), the theoretical grafting rate is 3%. Then the reaction is stirred under reflux for 12 hours, extracted with saturated brine three times, the chloroform layer is taken, the solvent is removed by rotary evaporation at 50°C, and finally dried in an oven at 75°C to obtain a purified hydrophobic link grafted polyethyleneimine product 3% C 17 H 33 -PEI.

[0077] The process conditions and steps for preparing the grafted modified polyamine polymer raw material example (18) are as follows: take 1 mol portion of polyethyleneimine measured by the repeating unit of polyethyleneimine and dissolve it in chloroform to make its mass concentration about 10%, then add 0.2 mol portion of C2F3-I (Table 1), reflux for 3 hours, cool to room temperature, extract the reaction mixture three times with a 5% aqueous solution of sodium hydroxide equal in volume to chloroform, remove the water layer, wash with water until the pH value of the water 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 hydrophobic chain modified polyethyleneimine 20% C2F3-PEI.

[0078] The process conditions and steps for preparing the grafted polyamine polymer raw material example (19) are as follows: take 1 mol portion of polyethyleneimine measured on the basis of the repeating unit of polyethyleneimine and dissolve it in chloroform to make its mass concentration about 10%, then add 0.45 mol portion of C4-Br (Table 1), reflux for 6 hours, cool to room temperature, extract the reaction mixture three times with an equal volume of 5% sodium hydroxide aqueous solution as chloroform, remove the water layer, wash with water until the pH value of the water 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 hydrophobic chain modified polyethyleneimine 45% C4-PEI.

[0079] It can be seen from Table 1 that the actual grafting degree of each product is very close to the theoretical grafting degree, indicating that the grafting reaction is very complete. The theoretical grafting degree is calculated by the ratio of the molar number of the side chain to the molar number of the main chain nitrogen atoms, and the actual grafting degree is calculated by the area ratio of the proton signals related to the side chain and the main chain in the nuclear magnetic resonance spectrum. It can be seen from Table 1 that the grafting degree of the hydrophobic chain of each product is between 1 and 45%.

[0080] Examples 1 to 37

[0081] In this group of examples, grafted polyamine polymers (see Table 1) are prepared into corresponding CO2 adducts, which are then dissolved in corresponding solvents (see Table 2) to form liquid foaming agents containing CO2 adducts of polyamine polymers. The preparation method of CO2 adducts of polyamine polymers is as follows: 1 mass part of polyamine polymer (the source is listed in Table 2, and the numbers in brackets refer to the serial numbers in Table 1) is dissolved in ethanol to obtain a polyamine polymer solution with a mass concentration of 10%, which is placed in a sealed reactor, and 0.5 MPa of CO2 is introduced to react for 5 hours to obtain a white precipitate, which is filtered to remove the solvent, and then vacuum dried at 40°C for 3 days, and then placed in a sealed reactor and 0.5 MPa of CO2 is introduced to maintain the pressure for 2 days to obtain CO2 adducts of polyamine polymers, which are dissolved in the corresponding solvents shown in Table 2 as solutes. It should be pointed out that the polyamine polymers of Examples 33 to 37 in Table 2 do not have grafted side chains.

[0082] The percentage of solute in Table 2 refers to the maximum percentage of mass content that the solute can dissolve. The specific test method is: take a 50mL centrifuge tube, add 0.5g of the CO2 adduct (i.e., solute) powder of the polyamine polymer listed in Table 2, then add 3g of the corresponding solvent (see Table 2, wherein butanediol, pentanediol and hexanediol are straight-chain diols, and dibutylene glycol is 1,4-dibutylene glycol; when two or more substances are used as mixed solvents, the value after the substance is the mass percentage of the substance), treat with ultrasound (KQ-300DE CNC ultrasonic cleaner, Kunshan Ultrasonic Instrument Co., Ltd.) for 10 minutes to disperse the solid into the liquid, put it in a 30℃ constant temperature water bath and let it stand until the solid is completely dissolved to form a transparent liquid, then add 0.5g of solute powder, repeat the operation until there is insoluble solid matter in the system, record the mass ratio of the solute to the solvent at this time, select the average value of the mass of this insoluble point and the mass of the previous dissolved point to perform the dissolution test again. If it is dissolved, the solubility of the mass between this dissolving point and the insoluble point is tested; if it is insoluble, the solubility of the mass between this insoluble point and the previous dissolving point is tested. Repeat this operation until the difference in the solute mass between the insoluble point and the previous dissolving point accounts for less than 2% of the solute mass of the previous dissolving point. The mass of the previous dissolving point is regarded as the maximum dissolved mass, and the percentage of this mass to the total mass of the solution is the solute percentage listed in Table 2 (obviously the error is less than 2%). It should be pointed out 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 diols or diamines with branches instead. The resulting solute percentage fluctuates slightly, and compared with the values ​​of the corresponding straight-chain diols or diamines, the fluctuation is less than 10%.

[0083] In Table 2, Examples 3 to 10 use the same CO2 adduct of polyamine polymer (10% C8-PEI) as solute and dissolve in different solvents; it can be seen that ethylene glycol has a relatively high solubility. In addition, ethylene glycol is cheap, so ethylene glycol should be a good solvent for CO2 adduct of polyamine polymer. CO2 adduct of ungrafted polyamine polymer has better solubility, with a mass concentration of 66% (Example 33).

[0084] Table 2

[0085]

[0086]

[0087] 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.

[0088] Examples 20, 27, 32 and 34 also use water as a component of the solvent. A mixed solvent consisting of an organic solvent and water also has a relatively good effect. The amount of water used can reach 40% of the mass of the mixed solvent.

[0089] It should be noted that the content of the solute (i.e., the CO2 adduct of the polyamine polymer) in the liquid foaming agent containing the CO2 adduct of the polyamine polymer listed in Table 2 reaches the maximum percentage of the solute. In actual use, the amount of the solute used can be less than the maximum percentage.

[0090] Application Examples 1-5

[0091] 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).

[0092] Table 3

[0093]

[0094]

[0095] 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.

[0096] Polyurethane foams containing different foaming agents were prepared, and the formulas were shown in Table 3. Comparative Example 1 (referred to as Comparative Example 1) did not add any foaming agent, and foaming was performed by a trace amount of water in the raw materials. The foaming agent solution and other white material components were mixed according to the formula ratio, mechanically stirred at 800 r / min for 30 seconds, and then the black material was added, and then mechanically stirred at 1800 r / min for 15 seconds, and the foam was allowed to grow naturally. When the top of the foam was no longer sticky, the foaming was completed to obtain polyurethane foam.

[0097] Since the foaming agent in Table 3 is an ethylene glycol solution of the CO2 adduct of the grafted polyamine polymer, it can be easily mixed with other components. The density of the foam prepared by Application Examples 1 to 4 is much lower than that of the control sample, indicating that the foaming agent does play a foaming role. Application Example 5 adds 0.1 parts by mass of water as an additional foaming agent on the basis of Application Example 4 (water accounts for 10% of the ethylene glycol solvent in the foaming agent and 9.1% of the total amount of water and ethylene glycol). Since water consumes isocyanate, the amount of PM-200 is also increased accordingly. The density of Application Example 5 is further reduced, and the density is also lower than that of Control Sample 2 (vs. 2) using only water as the foaming agent, indicating that water and the foaming mixture of Example 12 play a foaming role together.

[0098] In Application Example 5, the foaming agent water is directly mixed with the foaming mixture of Example 12 to obtain a uniform foaming mixture. This shows that when the solvent of the present invention is actually used to dissolve the CO2 adduct foaming agent of the polyamine polymer, water can be added to the solvent of the present invention, and the added water also acts as a foaming agent. Such a use method also belongs to the protection scope of the present invention.

[0099] It should be pointed out that the polyurethane foam formula listed in the present invention is only to verify that the uniform mixture formed by the modified polyamine polymer foaming agent capable of releasing carbon dioxide and the solvent prepared in the present invention can be used for the preparation of polyurethane foam, and it should not be understood as limiting the scope of use of the foaming agent material and the solvent prepared in the present invention. The formation process of polyurethane foam is an exothermic reaction, and the heat released is just used to release the carbon dioxide in the foaming agent prepared in the present invention. Therefore, the foaming agent material and solvent system prepared in the present invention can be used in various polyurethane foams.

[0100] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A foaming agent, characterized in that The foaming agent consists of at least a CO2 adduct and a solvent; The CO2 adduct is composed of a grafted 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 amine groups in the molecular chain, the atoms connected to the amine groups are carbon atoms, and its structure is at least one of linear, branched, and hyperbranched, and the molecular weight is greater than 500; the grafted modified polyamine polymer is grafted with a side chain, and the side chain is at least one of the following: (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1; (2) The side chain contains a trimethylsilyl group; (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms; (4) The side chain contains a fluorinated alkyl group having 1 to 22 carbon atoms; The grafting degree of the graft-modified polyamine polymer is 1 to 45 mol% based on the N atoms of the polyamine polymer; The solvent is composed of alcohol, amine and / or alcoholamine with a carbon number of ≤8 and a total of hydroxyl and amino groups of 2 to 5; and is a reactive solvent, that is, the solvent can both dissolve the CO2 adduct and react chemically with other substances in the foaming system to become a part of the foam.

2. The foaming agent according to claim 1, characterized in that The foaming agent also contains water, and the amount of water does not exceed 40% of the total mass of the solvent and the water.

3. The foaming agent according to claim 1, characterized in that The solvent is at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butylene glycol, pentanediol, glycerol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, diethylene glycol, and diglycolamine; the butylene glycol is 1,4-butylene glycol or any isomer of 1,4-butylene glycol containing two hydroxyl groups; the pentanediol is 1,5-pentanediol or any isomer of 1,5-pentanediol containing two hydroxyl groups.

4. The foaming agent according to claim 1, characterized in that The solvent composition contains at least two components, component one is ethylene glycol, and component two is at least one of 1,2-propylene glycol, 1,3-propylene glycol, glycerol, butanediol, pentanediol, hexanediol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, butanediamine, diethylene glycol, diglycolamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; the butanediol, pentanediol, and hexanediol are any isomers of the corresponding diols containing two hydroxyl groups; the butanediamine is any isomer of 1,4-butanediamine or 1,4-butanediamine containing two amino groups.

5. The foaming agent according to claim 4, characterized in that The mass fraction of ethylene glycol is ≥50%.

6. The foaming agent according to claim 1, characterized in that The polyamine polymer is selected from polyethyleneimine, polypropyleneimine, polybutyleneimine, polyethyleneamine, and polyallylamine.

7. The foaming agent according to claim 1, characterized in that The polyamine polymer is polyethyleneimine.

8. The foaming agent according to claim 1, wherein the polypropylene oxide contains in, m is an integer of 1 to 15, and n is an integer of 1 to 6; the polysiloxane contains Wherein, m is an integer of 0 to 10, T is a linking group of the main chain of the polysiloxane and the graft-modified polyamine polymer, and the structure of T is 9. Use of the blowing agent according to any one of claims 1 to 8 for preparing polyurethane foam.

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