Formaldehyde-free compounds, processes for their preparation and their use in the preparation of formaldehyde-free aqueous polyurethane dispersions

Abstract

The application provides a formaldehyde-removing compound with a structure shown in the following formula, a preparation method and use thereof, a formaldehyde-removing aqueous polyurethane dispersion composition and a formaldehyde-removing aqueous polyurethane dispersion prepared therefrom. The formaldehyde-removing compound can be introduced into the polymer chain of polyurethane and has an acetyl acetyl group capable of reacting with formaldehyde, thus having excellent formaldehyde-removing effect. The formaldehyde-removing aqueous polyurethane dispersion can efficiently absorb formaldehyde while exerting the original functions of paint, adhesive and the like, and reducing the harm of formaldehyde to human body. The formaldehyde-removing compound and the formaldehyde-removing aqueous polyurethane dispersion are simple in preparation method, easy to operate, have a wide source of raw materials, and are easy to realize industrialized production, thus conforming to the development concept of green environmental protection, and thus have very important economic and social significance.

Description

Technical Field

[0001] This invention relates to the field of waterborne polyurethane materials, specifically to a formaldehyde-removing compound, its preparation method, and its use in the preparation of formaldehyde-removing waterborne polyurethane dispersions, and also to a formaldehyde-removing waterborne polyurethane dispersion and its use. Background Technology

[0002] With the increasing national requirements for environmental protection and the growing demand for environmentally friendly products, waterborne polyurethane, due to its advantages such as being non-toxic, environmentally friendly, and safe, is gradually replacing traditional solvent-based polyurethane and is being used more and more widely in various fields such as leather finishing, fabric finishing, and adhesives.

[0003] Waterborne polyurethane is increasingly used in upholstered furniture, which can reduce formaldehyde release to some extent. However, it's unavoidable that materials such as furniture, wallpaper, leather sofas, and fabrics can still be sources of formaldehyde. Formaldehyde is extremely harmful to the human body, characterized by its strong irritant properties, high toxicity, and high volatility. When in contact with the human body, it not only irritates the skin, mucous membranes, and respiratory tract but can also produce genotoxic effects. Long-term exposure can lead to skin or respiratory diseases such as asthma or allergies, and cause abnormal liver, lung, and immune function; in severe cases, it can induce cancer. Therefore, reducing indoor formaldehyde levels after home renovation has become one of the important research topics for future sustainable development.

[0004] Chinese patent CN 112795298A discloses a composition, its preparation method, and its application. This patent reduces VOCs by adding an adsorbent to an aqueous polyurethane dispersion, meeting the requirements for low-odor use in automotive interior coatings and adhesives. However, this patent does not explicitly mention the absorption of formaldehyde. Moreover, the adsorbents used are physical adsorbents such as hydrophilic molecular sieves, amphiphilic molecular sieves, and hydrophilic fumed silica nanoparticles.

[0005] Chinese patent CN 114525063A discloses a method for preparing an odor-neutralizing and formaldehyde-resistant water-based interior wall coating. This method involves adding an indium-zinc bimetallic vanadate material modified with formaldehyde-removing agents. Under photocatalytic conditions, formaldehyde is degraded into carbon dioxide and water, thus achieving an odor-neutralizing effect. However, the preparation process of the formaldehyde-resistant material in this patent is complex. Furthermore, introducing the formaldehyde-resistant material into the coating requires the addition of a dispersant, increasing application costs. If the formaldehyde-resistant material is not evenly dispersed in the coating, its formaldehyde adsorption effect will be affected.

[0006] It is evident that existing water-based coatings still have significant room for improvement in formaldehyde removal. Reducing formaldehyde release and mitigating its harm to the human body is a major challenge for researchers, and there is an urgent need to develop new water-based polyurethane coatings with formaldehyde removal capabilities to align with the concept of environmentally friendly development. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, one objective of this invention is to provide a formaldehyde-removing compound that can be incorporated into the polymer chain of polyurethane and react with formaldehyde to achieve efficient formaldehyde removal. This compound is particularly suitable for preparing waterborne polyurethane dispersions for formaldehyde removal, giving them excellent formaldehyde removal performance.

[0008] Another object of the present invention is to provide a method for preparing the formaldehyde-removing compound and its uses.

[0009] Another object of the present invention is to provide a formaldehyde-removing waterborne polyurethane dispersion and its uses.

[0010] The first aspect of the present invention provides a formaldehyde-removing compound with the structure shown in formula (I).

[0011]

[0012] In this context, R1 and R2 each independently represent C1 to C6 alkyl groups, X represents hydroxyl (-OH), amino (-NH2), or mercapto (-SH), L represents C1 to C6 straight-chain or branched alkylene groups, Y represents the absence of a 3- to 8-membered saturated carbon ring or heterocycle, wherein the ring atom of the heterocycle contains at least one N, O, or S atom, and the carbon ring or heterocycle is optionally substituted by 1 to 4 C1 to C6 alkyl groups, and m represents an integer from 1 to 3.

[0013] As shown in formula (I), the formaldehyde-removing compound provided by this invention contains an acetylacetyl group, which can react with the aldehyde group at room temperature, thereby achieving the purpose of formaldehyde removal. The formaldehyde-removing compound provided by this invention also contains an NCO reactive functional group X. Through the reaction of the X group with the NCO group, the formaldehyde-removing compound can be incorporated into the polymer chain of polyurethane, thereby avoiding losses caused during the preparation and use of waterborne polyurethane when using small-molecule formaldehyde-removing additives, and ensuring excellent formaldehyde removal effect.

[0014] For example, ethyl acetoacetate methacrylate (AAEM) is a known substance with formaldehyde removal function. If this substance is added directly as a formaldehyde removal compound, it is easily lost in the organic solvent removal step during the preparation of waterborne polyurethane. Moreover, when using waterborne polyurethane, the high-pressure spraying process will also cause further reduction of AAEM, making it difficult to achieve the expected formaldehyde removal purpose.

[0015] The inventors of this invention discovered that by modifying small-molecule formaldehyde removal additives and incorporating them into polymer chains, they can achieve a good fixation effect, resulting in a high retention rate of the formaldehyde removal additives and thus achieving efficient formaldehyde adsorption function. Moreover, the reaction rate of X groups with NCO is much higher than that of acetyl groups with NCO, and the formaldehyde removal functional groups will not be lost during the preparation of waterborne polyurethane.

[0016] Furthermore, the inventors of this invention have discovered that the formaldehyde removal compound provided by this invention, due to the presence of highly polar acetyl groups, can improve the adhesion and bonding of polyurethane materials to the substrate, and to a certain extent improve heat resistance. As a result, the prepared waterborne polyurethane exhibits unique and excellent performance on the substrate, and has better applicability.

[0017] In some preferred embodiments, the formaldehyde-removing compound has a structure as shown in formula (I-1).

[0018]

[0019] In this context, R1 and R2 each independently represent C1-C3 alkyl groups (e.g., methyl, ethyl, n-propyl, isopropyl, etc.), L represents C1-C4 straight-chain or branched alkylene groups (e.g., methylene, ethylene, etc.), Y represents the absence of a 5-7 saturated carbon ring, wherein the carbon ring is optionally replaced by 1-3 C1-C3 alkyl groups, and m represents an integer from 1 to 3.

[0020] In some more preferred embodiments, the formaldehyde-removing compound has a structure as shown in formula (I-2).

[0021]

[0022] Wherein, L represents a C1-C4 straight-chain or branched alkylene group (more preferably methylene "-CH2-" and ethylene "-CH2-CH2-"), Y represents the absence of a 5- to 7-membered saturated carbon ring (more preferably a 5- or 6-membered saturated carbon ring), wherein the carbon ring is optionally substituted by 1 to 3 C1-C3 alkyl groups (more preferably substituted by 1 to 3 methyl groups).

[0023] In some further preferred embodiments, the formaldehyde-removing compound has one of the following structures:

[0024]

[0025] The second aspect of the present invention provides a method for preparing the formaldehyde-removing compound according to any one of the above technical solutions, the method comprising: reacting a first raw material with the structure shown in formula (II) and a second raw material with the structure shown in formula (III) in an organic solvent in the presence of an alkaline substance by an addition reaction to obtain the formaldehyde-removing compound;

[0026]

[0027] XYL-NH2

[0028] Equation (III)

[0029] Wherein, X, Y, L, R1, R2 and m are each independently defined as in any of the above technical solutions.

[0030] In some preferred embodiments, the molar ratio of the second raw material to the first raw material can be 1.5 to 1.0:1.0. In some more preferred embodiments, the molar ratio of the second raw material to the first raw material can be 1.2 to 1.0:1.0, for example, 1.05 to 1.0:1.0.

[0031] In some preferred embodiments, the alkaline substance may be one or more of triethylamine, sodium ethoxide, sodium hydride, and sodium amino acid.

[0032] In some preferred embodiments, the mass ratio of the alkaline substance to the second raw material can be 1 to 2:1. In some more preferred embodiments, the mass ratio of the alkaline substance to the second raw material can be 1 to 1.5:1.

[0033] In some preferred embodiments, the reaction temperature of the addition reaction can be 50-80°C, for example 65-75°C, and the reaction time can be 2-6 hours, for example 3-5 hours.

[0034] In some preferred embodiments, the organic solvent may be 1,4-dioxane.

[0035] In some preferred embodiments, the reaction solution can be purified by vacuum distillation after the addition reaction is completed.

[0036] A third aspect of the present invention provides the use of the formaldehyde-removing compound described in any of the above-mentioned technical solutions in the preparation of formaldehyde-removing aqueous polyurethane dispersions.

[0037] The formaldehyde-removing compound provided by this invention can be used as an additive component or monomer material to prepare waterborne polyurethane dispersions, thereby giving the resulting waterborne polyurethane dispersions excellent formaldehyde removal effects, as well as improved adhesion, heat resistance and other properties.

[0038] In some preferred embodiments, the formaldehyde-removing aqueous polyurethane dispersion is used in a two-component spray adhesive. In some more preferred embodiments, the two-component spray adhesive further includes a curing agent component, such as an aqueous solution of CaCl2 and / or ZnSO4 at a concentration of 2–5 wt.%.

[0039] A fourth aspect of the present invention provides a composition for a formaldehyde-removing aqueous polyurethane dispersion, wherein, by mass percentage, the composition comprises 8.5–12% component A, 58–82% component B, 6–25% component C, 1–5% component D, 0–1.1% component E, and 1–5% component F; wherein component A is at least one compound containing a polyisocyanate group, component B is at least one crystalline polyester polyol, component C is at least one amorphous polyester polyol, component D is at least one chain extender, component E is a compound containing 1–3 functional groups capable of reacting with NCO, and component F is the formaldehyde-removing compound described in any of the above-described technical solutions.

[0040] In some preferred embodiments, the composition may comprise, by mass percentage, 8.5–10% of component A, 65–80% of component B, 8–20% of component C, 2–4% of component D, 0–0.6% of component E, and 1–3% of component F. In other preferred embodiments, the composition may comprise, by mass percentage, 8.5–10% of component A, 65–80% of component B, 8–18% of component C, 2–4% of component D, 0.4–0.6% of component E, and 1–3% of component F.

[0041] In some preferred embodiments, component A may be a diisocyanate. In some more preferred embodiments, the diisocyanate may be one or more of isoflurane diisocyanate, 1,4'-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecyl diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate. In some further preferred embodiments, the diisocyanate may be one or more of 4,4'-dicyclohexylmethane diisocyanate, isoflurane diisocyanate, and hexamethylene diisocyanate. In some most preferred embodiments, the diisocyanate may be a mixture of isoflurane diisocyanate (IPDI) and hexamethylene diisocyanate (HDI), for example, the mass ratio of IPDI to HDI may be 1:5 to 10.

[0042] In some preferred embodiments, the number-average molecular weight of component B can be 500-10000, for example, 1000-5000, and the crystalline polyester polyol can be one or more of polyester diol, polyester triol, and polyester tetraol. In some more preferred embodiments, component B can be one or more of polyadipate polyol, polycarbonate polyol, and polycaprolactone polyol with a number-average molecular weight of 1000-4000 and a functionality of 1-3. In some most preferred embodiments, component B can be polybutylene adipate diol with a number-average molecular weight of 2000-4000.

[0043] In some preferred embodiments, the number-average molecular weight of component C can be 500-10000, for example, 1000-4000, and the amorphous polyester polyol can be a polyester diol and / or a polyester triol. In some more preferred embodiments, component C can be one or more of polyadipate polyol, polybenzoic acid polyol, and polycarbonate polyol with a number-average molecular weight of 1000-3000, for example, one or more of polyhexylene adipate neopentyl glycol diol, polyhexylene adipate neopentyl glycol diol, and polyhexyl phthalate diol. In some most preferred embodiments, component C can be polyhexyl phthalate diol with a number-average molecular weight of 1000-2000.

[0044] In some preferred embodiments, component D can be a compound containing 2 to 3 functional groups capable of reacting with an NCO group, such as di- or trihydroxycarboxylic acid, di- or trihydroxysulfonic acid, di- or triaminosulfonic acid, di- or triaminocarboxylic acid, or their respective salts. In some more preferred embodiments, component D can be dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(2-aminoethyl)-β-alanine, or their respective alkali metal salts or ammonium salts. In some most preferred embodiments, component D can be sodium salt of N-(2-aminoethyl)-2-aminoethanesulfonate and / or sodium salt of N-(2-aminoethyl)-β-alanine.

[0045] In some preferred embodiments, component E may be one or more of the following C2-C10 aliphatic primary monoamines, aliphatic secondary monoamines, alicyclic primary monoamines, alicyclic secondary monoamines, amino alcohols, aliphatic diamines, alicyclic diamines, aliphatic triamines, and alicyclic triamine ethylhydrazine. In some more preferred embodiments, component E may be one or more of isophorone diamine, N-(2-hydroxyethyl)ethylenediamine, and 1,6-hexamethylenediamine. In some most preferred embodiments, component E may be isophorone diamine (IPDA).

[0046] A fifth aspect of the present invention provides a formaldehyde-removing aqueous polyurethane dispersion, which is made from the composition described in any of the above embodiments.

[0047] In some preferred embodiments, the solid content of the formaldehyde-removing aqueous polyurethane dispersion can be 30-55 wt.%, for example, 40-50 wt.%.

[0048] In some preferred embodiments, the average particle size of the formaldehyde-removing aqueous polyurethane dispersion can be 120–300 nm, for example, 140–200 nm.

[0049] In some preferred embodiments, the pH value of the formaldehyde-removing aqueous polyurethane dispersion can be 5 to 10, for example, 6 to 9.

[0050] In some preferred embodiments, the preparation method of the formaldehyde-removing aqueous polyurethane dispersion may include the following steps:

[0051] S1: React components A, B and C in an organic solvent in the presence of a catalyst until the theoretical NCO content is reached to obtain an aqueous polyurethane prepolymer.

[0052] S2: Continue to add organic solvent to the waterborne polyurethane prepolymer for dilution;

[0053] S3: Adding a mixture of components D, E, F, and water to the diluted waterborne polyurethane prepolymer to carry out a chain extension reaction; and

[0054] S4: After the chain extension reaction is completed, water is added for emulsification to remove the organic solvent and adjust to the required solid content to obtain the final product.

[0055] In some preferred embodiments, the catalyst may be an organobismuth catalyst.

[0056] In some preferred embodiments, the organic solvent may be acetone.

[0057] In some preferred embodiments, the reaction temperature of step S1 can be 70-90°C, and the reaction time can be 2-6 hours.

[0058] In some preferred embodiments, in step S2, after adding the organic solvent, the mixture is stirred for 10 to 30 minutes, and the temperature is controlled at 35 to 40°C.

[0059] In some preferred embodiments, a capping agent may also be added to the chain extension reaction in step S3.

[0060] The sixth aspect of the present invention provides the use of the formaldehyde-removing aqueous polyurethane dispersion described in any of the above-described embodiments in furniture (e.g., upholstered furniture), leather, fabric, or decorative materials.

[0061] In some preferred embodiments, the formaldehyde-removing aqueous polyurethane dispersion is used in the form of a two-component spray adhesive in furniture (e.g., upholstered furniture), leather, fabric, or decorative materials.

[0062] In some preferred embodiments, the two-component spray adhesive further includes a curing agent component, such as an aqueous solution of CaCl2 and / or an aqueous solution of ZnSO4 with a concentration of 2 to 5 wt.%.

[0063] A seventh aspect of the present invention provides a two-component spray adhesive, comprising: 1) an aqueous polyurethane dispersion component; and 2) a curing agent component; wherein, component 1) is the formaldehyde-removing aqueous polyurethane dispersion described in any of the above embodiments.

[0064] In some preferred embodiments, component 2) is an aqueous solution of CaCl2 and / or an aqueous solution of ZnSO4 with a concentration of 2 to 5 wt.%.

[0065] The technical solution provided by this invention has the following advantages:

[0066] (1) The formaldehyde removal compound provided by the present invention can be incorporated into the polymer chain of polyurethane and has an acetyl acetyl active group that can react with formaldehyde, thus having an excellent formaldehyde removal effect. Moreover, the acetyl acetyl group can be fixed on the polymer and will not be lost due to processing and use.

[0067] (2) In addition to the formaldehyde removal function, the formaldehyde removal compound provided by the present invention can also give polyurethane materials better adhesion, better adaptability to substrates, and further improve heat resistance.

[0068] (3) The formaldehyde-removing waterborne polyurethane dispersion provided by the present invention is very suitable for furniture, leather, fabric, decorative materials and other fields due to its excellent formaldehyde removal effect. It can not only play the original functions of coatings and adhesives, but also efficiently absorb formaldehyde, reduce the harm of formaldehyde to the human body, and create a more comfortable and safe environment. Therefore, it has a broad market and development prospects.

[0069] (4) The method for preparing formaldehyde removal compounds and waterborne polyurethane dispersions provided by the present invention is simple, easy to operate, and has a wide range of raw material sources. It is easy to achieve industrial-scale production, which is in line with the current green and environmentally friendly development concept. Therefore, it has very important economic and social significance. Attached Figure Description

[0070] Figure 1 AAEM raw materials1 H-NMR spectrum (solvent: deuterated chloroform);

[0071] Figure 2 For product F1 of Example 1 1 H-NMR spectrum (solvent: deuterated chloroform);

[0072] Figure 3 For product F2 of Example 2 1 H-NMR spectrum (solvent: deuterated chloroform). Detailed Implementation

[0073] the term

[0074] The term “non-existent” as used alone or in combination in this article means that the indicated group is not present in the chemical structure to which other groups are directly connected by chemical bonds.

[0075] As used herein, "C1-Cn" includes C1-C2, C1-C3, ..., C1-Cn. For example, the term "C1-C6" refers to a group having 1 to 6 carbon atoms, meaning the group contains 1, 2, 3, 4, 5, or 6 carbon atoms. Therefore, for example, "C1-C4 alkyl" refers to an alkyl group containing 1 to 4 carbon atoms, where the alkyl group is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. Numerical ranges, such as "1-6," refer to integers within a given range.

[0076] The term "alkyl" as used alone or in combination herein refers to a saturated aliphatic hydrocarbon that is optionally substituted with a straight chain or optionally substituted with a branched chain. "alkyl" as used herein preferably has 1 to 6 carbon atoms, for example, 1 to 6 carbon atoms, or 1 to 5 carbon atoms, or 1 to 4 carbon atoms, or 1 to 3 carbon atoms. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, and hexyl. When the group defined in this article, such as "alkyl", has a numerical range, for example, "C1 to C6 alkyl" means an alkyl group that can be composed of 1, 2, 3, 4, 5 or 6 carbon atoms. The term alkyl in this article also includes cases where no numerical range is specified.

[0077] The term "saturated" as used alone or in combination herein refers to a carbide ring or heterocycle that does not contain unsaturated double or triple bonds. Non-limiting examples of saturated carbocycles include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl rings. A saturated heterocycle is a saturated carbide ring in which at least one heteroatom selected from N, O, or S atoms is present in the ring atoms.

[0078] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0079] The test methods involved in the embodiments and comparative examples of the present invention are as follows:

[0080] Solid content test method: Take an appropriate amount of emulsion in a container made of tin foil, place it in an oven at 150℃ for 20 minutes, weigh the change in mass, and calculate the solid content.

[0081] Particle size testing method: Malvern particle size analyzer was used.

[0082] pH testing method: A pH meter is used.

[0083] Adhesion test: Spray the two-component spray adhesive evenly onto the sponge surface (100g / m²). 2 Fold the sponge in half and examine its wet tackiness. Wet tackiness is divided into 5 levels from low to high: A, A+, A++, A+++, and A++++. "A" indicates the worst tackiness, and "A++++" indicates the best tackiness.

[0084] Adhesion test: The two-component spray adhesive was evenly sprayed onto the sponge surface (100g / m²). 2 Fold the sponge in half and stick it on. Then tear the sponge by hand and observe the film formation on the sponge surface. Give a score of 1-3 based on the film formation, with 1 point being the worst and 3 points being the best.

[0085] Heat resistance test: The two-component spray adhesive was evenly sprayed onto the surface of the sponge (100g / m²). 2 After the prepared sponge samples were placed at room temperature for 30 minutes, they were then placed in an 80℃ oven for 8 hours. The sponge was judged based on the distance it bounced back (unit: cm). The greater the bounced distance, the worse the heat resistance; conversely, the smaller the bounced distance, the better the heat resistance.

[0086] Formaldehyde test: Apply a 200μm thick layer of water-based polyurethane dispersion (15cm x 10cm) to a glass plate. After surface drying, place the plate in a 1L glass bottle (the bottle is pre-filled with formaldehyde gas at a concentration of 2 × 10⁻⁶). -4 mg / L), after 7 days of maintenance, formaldehyde release was tested by odor test; odor rating standard: 0-5 points, 0 points is the best (no odor, or pleasant odor), 5 points is the worst (throat discomfort, pain), sample size: 10.

[0087] The main sources of raw materials involved in the embodiments and comparative examples of the present invention are shown below. Unless otherwise specified, other raw materials or reagents are commercially available products.

[0088] Isoflurone diisocyanate (IPDI): Wanhua Chemical Group Co., Ltd., industrial product.

[0089] Hexamethylene diisocyanate (HDI): Wanhua Chemical Group Co., Ltd., industrial product.

[0090] Poly(1,4-butanediol adipate) diol (PBA, number average molecular weight 3000, functionality 2): Wanhua Chemical Group Co., Ltd., industrial product.

[0091] Poly(1,6-hexanediol) phthalate diol (pH 56, number average molecular weight 2000): Wanhua Chemical Group Co., Ltd., industrial product.

[0092] N-(2-Aminoethyl)-2-aminoethane sulfonate (A95): EVONIK, USA, industrial product.

[0093] Catalyst: Organic bismuth 8108, from a leading US company, industrial product.

[0094] Diethanolamine (capping agent): BASF, industrial product.

[0095] Ethylenediamine: BASF, industrial product.

[0096] Isoflurane diamine (IPDA): Wanhua Chemical Group Co., Ltd., industrial product.

[0097] Ethyl acetoacetate methacrylate (AAEM): Lonza, Switzerland, industrial product.

[0098] Unless otherwise specified, all percentages used in the embodiments and comparative examples of this invention are mass percentages.

[0099] Example 1: Preparation of formaldehyde-removing compounds

[0100] In a 1000 ml three-necked flask equipped with a stirrer, reflux condenser, and thermocouple, 15 g of ethylenediamine, 53.5 g of AAEM, and 500 g of 1,4-dioxane solvent were added sequentially. 23 g of triethylamine was added as a base. The mixture was reacted at 70 °C for 4 h. After the reaction was complete, the mixture was cooled to room temperature. The resulting solution was then subjected to vacuum distillation, and the fraction collected at 80–100 °C yielded the functional compound F1. The reaction formula is as follows:

[0101]

[0102] AAEM raw materials and F1 1 The H-NMR nuclear magnetic spectrum is as follows: Figure 1 and Figure 2 As shown, comparison revealed that the signals at 2.62 ppm and 2.81 ppm were mainly from the -CH2 group on the ethylenediamine chain, while the signal at 5.11 ppm was mainly from the -NH2 group. The -CH2 group on the AAEM double bond disappeared at 6.15 ppm and 5.58 ppm, but new signals appeared at 3.02 ppm and 2.77 ppm. Therefore, the NMR spectra confirmed the formation of the F1 product.

[0103] Example 2: Preparation of formaldehyde-removing compounds

[0104] In a 1000 ml three-necked flask equipped with a stirrer, reflux condenser, and thermocouple, 42.5 g of isoflurane diamine, 53.5 g of AAEM, and 500 g of 1,4-dioxane solvent were added sequentially. 60 g of triethylamine was added as a base. The reaction was carried out at 70 °C for 4 h. After the reaction was completed, the mixture was cooled to room temperature. The resulting solution was then subjected to vacuum distillation, and the fraction collected at 80–100 °C yielded the functional compound F2. The reaction formula is as follows:

[0105]

[0106] AAEM raw materials and F2 1 The H-NMR nuclear magnetic spectrum is as follows: Figure 1 and Figure 3 As shown, through comparison, we found that: Figure 3The NMR spectrum showed numerous -CH2- and -CH3 signals in the range of 1 ppm to 3 pmm, and a -NH2 signal appeared at 5.11 ppm. Furthermore, the peak signals of -CH2 on the original AAEM segment shifted from 6.15 ppm and 5.58 ppm to 3.02 ppm and 2.77 ppm. Therefore, the NMR spectrum confirmed the formation of the F2 product.

[0107] Example 3: Preparation of waterborne polyurethane dispersion

[0108] In a 2000ml four-necked flask equipped with a stirrer, reflux condenser, and thermocouple, 414.2g of PBA3000, 55.2g of PH56, 5.6g of IPDI, and 42.7g of HDI were added sequentially, along with 150ppm of organic bismuth catalyst and 100g of acetone solvent. The mixture was reacted at 75℃ for 3 hours to reach a theoretical NCO content of 1.55%. 800g of diluted acetone solution was then added, and the mixture was stirred for 20 minutes to ensure homogeneity. The temperature was then controlled at 35–40℃ to prepare an aqueous polyurethane prepolymer.

[0109] 14.9 g of A95, 10 g of functional compound F1, 3.18 g of diethanolamine, and 50 g of deionized water were mixed evenly and slowly added to the prepolymer above for chain extension. After 20 min, 784.7 g of water was added for emulsification. The resulting emulsion was distilled under reduced pressure to remove acetone and some water, yielding a water-permeable polyurethane dispersion with a solid content of 42 wt%, a particle size of 170 nm, and a pH of 7.3.

[0110] Example 4: Preparation of Waterborne Polyurethane Dispersion

[0111] In a 2000ml four-necked flask equipped with a stirrer, reflux condenser, and thermocouple, 414.2g of PBA3000, 55.2g of PH56, 5.6g of IPDI, and 42.7g of HDI were added sequentially, along with 150ppm of organic bismuth catalyst and 100g of acetone solvent. The mixture was reacted at 75℃ for 3 hours to reach a theoretical NCO content of 1.55%. 800g of diluted acetone solution was then added, and the mixture was stirred for 20 minutes to ensure homogeneity. The temperature was then controlled at 35–40℃ to prepare an aqueous polyurethane prepolymer.

[0112] 22g of A95, 14.3g of functional compound F2, 3.18g of diethanolamine, and 50g of deionized water were mixed evenly and slowly added to the prepolymer above for chain extension. After 20 minutes, 784.7g of water was added for emulsification. The resulting emulsion was distilled under reduced pressure to remove acetone and some water, yielding a water-permeable polyurethane dispersion with a solid content of 42wt%, a particle size of 145nm, and a pH of 8.0.

[0113] Example 5: Preparation of Waterborne Polyurethane Dispersion

[0114] In a 2000ml four-necked flask equipped with a stirrer, reflux condenser, and thermocouple, 414.2g of PBA3000, 55.2g of PH56, 5.6g of IPDI, and 42.7g of HDI were added sequentially, along with 150ppm of organic bismuth catalyst and 100g of acetone solvent. The mixture was reacted at 75℃ for 3 hours to reach a theoretical NCO content of 1.55%. 800g of diluted acetone solution was then added, and the mixture was stirred for 20 minutes to ensure homogeneity. The temperature was then controlled at 35–40℃ to prepare an aqueous polyurethane prepolymer.

[0115] 14.9 g of A95, 6 g of functional compound F1, 3.18 g of diethanolamine, 2.65 g of IPDA, and 50 g of deionized water were mixed evenly and slowly added to the prepolymer above for chain extension. After 20 min, 784.7 g of water was added for emulsification. The resulting emulsion was distilled under reduced pressure to remove acetone and some water, yielding a water-permeable polyurethane dispersion with a solid content of 42 wt%, a particle size of 180 nm, and a pH of 7.5.

[0116] Example 6: Preparation of Waterborne Polyurethane Dispersion

[0117] In a 2000ml four-necked flask equipped with a stirrer, reflux condenser, and thermocouple, 414.2g of PBA3000, 100g of PH56, 5.6g of IPDI, and 55g of HDI were added sequentially, along with 150ppm of organic bismuth catalyst and 100g of acetone solvent. The mixture was reacted at 75℃ for 3 hours to reach a theoretical NCO content of 2.24%. Then, 1000g of diluted acetone solution was added, and the mixture was stirred for 20 minutes to ensure homogeneity. The temperature was then controlled at 35–40℃ to prepare an aqueous polyurethane prepolymer.

[0118] 14.9 g A95, 18 g functional compound F1, 3.18 g diethanolamine, 2.65 g IPDA, and 80 g deionized water were mixed evenly and slowly added to the prepolymer for chain extension. After 20 min, 784.7 g of water was added for emulsification. The resulting emulsion was distilled under reduced pressure to remove acetone and some water, yielding a water-permeable polyurethane dispersion with a solid content of 42 wt%, a particle size of 189 nm, and a pH of 7.8.

[0119] Comparative Example 1: Preparation of Waterborne Polyurethane Dispersion

[0120] Except for the absence of the functional compound F1, the other steps were the same as in Example 3, resulting in a water-permeable polyurethane dispersion with a solid content of 42 wt%, a particle size of 178 nm, and a pH of 7.5.

[0121] Comparative Example 2: Preparation of Waterborne Polyurethane Dispersion

[0122] Except for the absence of the functional compound F2, the remaining steps were the same as in Example 4, resulting in a water-permeable polyurethane dispersion with a solid content of 42 wt%, a particle size of 153 nm, and a pH of 7.7.

[0123] Comparative Example 3: Preparation of Waterborne Polyurethane Dispersion

[0124] Except for replacing 10g of functional compound F1 with 8.36g of AAEM, the remaining steps were the same as in Example 3, resulting in a water-permeable polyurethane dispersion with a solid content of 42wt%, a particle size of 185nm, and a pH of 7.4.

[0125] Performance testing

[0126] Adhesive application: Prepare an air compressor with the pressure adjusted to 3 Bar, a 1.5 mm nozzle spray gun, and a sponge with dimensions of 10×5×5 cm. Place 200 g of the prepared waterborne polyurethane dispersion in the emulsion tank of the two-component spray gun as component A, and place 200 g of a 2.5 wt% CaCl2 aqueous solution in the curing agent tank of the two-component spray gun as component B. Adjust the flow rate of the two nozzles using a flow meter to control the mass ratio of the emulsion nozzle to the curing agent nozzle to be 100:7. Test the tack, adhesion, and heat resistance of the two-component spray adhesive.

[0127] Formaldehyde testing uses water-based polyurethane dispersions directly.

[0128] The performance test results of the aqueous polyurethane dispersions prepared in the above embodiments and comparative examples, as well as the two-component spray adhesives prepared therefrom, are shown in Table 1.

[0129] Table 1 Performance Test Results

[0130]

[0131] A comparison of the performance data of Comparative Examples 1-2 and Examples 3-4 shows that: compared with Examples 3-4, Comparative Examples 1-2 have a stronger formaldehyde odor. This is mainly because the waterborne polyurethane in Comparative Examples 1-2 does not contain functional groups that absorb formaldehyde, resulting in a large amount of formaldehyde gas still being present. In contrast, Examples 3-4 contain component F, which has formaldehyde absorption function, so the formaldehyde odor is significantly reduced.

[0132] Furthermore, it can be learned that the introduction of component F can further improve the adhesion of the waterborne polyurethane dispersion and also improve the heat resistance of the product. This is because component F contains strong polar groups, which have good adhesion to the substrate.

[0133] A comparison of the performance data from Examples 3, 5, and 6 shows that by increasing the amount of formaldehyde-absorbing groups (i.e., component F), the odor in Example 6 can be reduced from 5 to 0, with virtually no formaldehyde odor and no irritation to personnel.

[0134] By comparing the performance data of Example 3 and Comparative Example 3, it can also be found that: when an equimolar amount of AAEM is directly added to the waterborne polyurethane of Comparative Example 3 during the preparation process, the ability of the resulting dispersion to adsorb formaldehyde is significantly reduced. This is because AAEM is lost during the preparation of the waterborne polyurethane dispersion and during use, which significantly reduces the ability to adsorb formaldehyde, and the adhesion is not improved.

[0135] Unless otherwise specified, the terms used in this invention have the meanings commonly understood by those skilled in the art.

[0136] The embodiments described in this invention are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Those skilled in the art can make various other substitutions, changes and improvements within the scope of this invention. Therefore, this invention is not limited to the above embodiments, but is only defined by the claims.

Claims

1. A formaldehyde-removing compound having a structure as shown in formula (I), wherein R1 and R2 each independently represent a C1-C6 alkyl group, X represents an amino group, L represents a C1-C6 straight chain or branched chain alkylene group, Y represents nothing or represents a 3-8 membered saturated carbocyclic ring, wherein the carbocyclic ring is optionally substituted with 1-4 C1-C6 alkyl groups, and m represents an integer of 1-3. wherein The formaldehyde-removing compound has a structure as shown in formula (I-1), wherein R1 and R2 each independently represent a C1-C3 alkyl group, L represents a C1-C4 straight chain or branched chain alkylene group, Y represents nothing or represents a 5-7 membered saturated carbocyclic ring, wherein the carbocyclic ring is optionally substituted with 1-3 C1-C3 alkyl groups, and m represents an integer of 1-3. 2.The formaldehyde removal compound according to claim 1, characterized in that, The formaldehyde-removing compound has a structure as shown in formula (I-2), wherein L represents a C1-C4 straight chain or branched chain alkylene group, and Y represents nothing or represents a 5-7 membered saturated carbocyclic ring, wherein the carbocyclic ring is optionally substituted with 1-3 C1-C3 alkyl groups. The formaldehyde-removing compound has one of the following structures:

3. The formaldehyde removal compound according to claim 2, characterized in that, A first raw material having a structure as shown in formula (II) and a second raw material having a structure as shown in formula (III) are reacted by an addition reaction in the presence of a basic substance in an organic solvent to obtain the formaldehyde-removing compound. wherein X, Y, L, R1, R2 and m are each independently defined as in any one of claims 1-4.

4. The formaldehyde removal compound according to any one of claims 1-3, characterized in that, The molar ratio of the second raw material to the first raw material is 1.5-1.0: 1.

0.

5. The method of preparing a formaldehyde scavenging compound according to any one of claims 1 to 4, characterized in that, The molar ratio of the second raw material to the first raw material is 1.2-1.0: 1.

0. The basic substance is one or more of triethylamine, sodium ethoxide, sodium hydride and sodium amide.

6. The production method according to claim 5, wherein The mass ratio of the basic substance to the second raw material is 1-2:

1.

7. The production method according to claim 6, wherein The reaction temperature of the addition reaction is 50-80°C, and the reaction time is 2-6 h.

8. The preparation method according to claim 5, characterized in that, The reaction temperature of the addition reaction is 65-75°C, and the reaction time is 3-5 h.

9. The production method according to claim 8, characterized by, The organic solvent is 1,4-dioxane.

10. The method of claim 5, wherein, 13. Use of the formaldehyde-removing compound of any one of claims 1-4 in the preparation of a formaldehyde-removing aqueous polyurethane dispersion.

11. The method of claim 10, wherein, The formaldehyde-removing aqueous polyurethane dispersion is used in two-component spray adhesive.

12. The method of claim 5, wherein, The composition comprises 8.5-12% of component A, 58-82% of component B, 6-25% of component C, 1-5% of component D, 0-1.1% of component E and 1-5% of component F in terms of mass percentage; wherein the component A is at least one compound containing a polyisocyanate group, the component B is at least one crystalline polyester polyol, the component C is at least one non-crystalline polyester polyol, the component D is at least one chain extender, the component E is at least one compound containing 1-3 functional groups reactive with NCO, and the component F is the formaldehyde-removing compound of any one of claims 1-4.

14. Use according to claim 13, characterized in that, The composition comprises 8.5-10% of component A, 65-80% of component B, 8-20% of component C, 2-4% of component D, 0-0.6% of component E and 1-3% of component F in terms of mass percentage.

15. A composition for formaldehyde-free aqueous polyurethane dispersions, characterized in that, ​ ​ 16. The composition of claim 15, wherein, ​ 17. The composition of claim 15, wherein, The component A is one or more of isophorone diisocyanate, 1,4'-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate; and / or The number average molecular weight of the component B is 500 to 10,000, and the crystalline polyester polyol is one or more of a polyester diol, a polyester triol, and a polyester tetrol; and / or The number average molecular weight of the component C is 500 to 10,000, and the non-crystalline polyester polyol is a polyester diol and / or a polyester triol; and / or The component D is a compound containing 2 to 3 functional groups reactive with NCO, which is a di- or tri-hydroxy carboxylic acid, a di- or tri-hydroxy sulfonic acid, a di- or tri-amino sulfonic acid, a di- or tri-amino carboxylic acid, or a salt of each thereof; and / or The component E is one or more of a C2 to C10 aliphatic primary monoamine, an aliphatic secondary monoamine, an alicyclic primary monoamine, an alicyclic secondary monoamine, an amino alcohol, an aliphatic diamine, an alicyclic diamine, an aliphatic triamine, an alicyclic triamine, and ethyl hydrazine.

18. The composition of claim 17, wherein, The component A is one or more of 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.

19. The composition of claim 17, wherein, The number average molecular weight of the component B is 1,000 to 5,000.

20. The composition of claim 19, wherein, The component B is one or more of a polyadipic acid polyol, a polycarbonate polyol, and a polycaprolactone polyol having a number average molecular weight of 1,000 to 4,000 and a functionality of 1 to 3.

21. The composition of claim 20, wherein, The component B is a polybutylene adipate diol having a number average molecular weight of 2,000 to 4,000.

22. The composition of claim 17, wherein, The number average molecular weight of the component C is 1,000 to 4,000.

23. The composition of claim 22, wherein, The component C is one or more of a polyadipic acid polyol, a polyphthalic acid polyol, and a polycarbonate polyol having a number average molecular weight of 1,000 to 3,000.

24. The composition of claim 23, wherein, The component C is one or more of a polyhexylene adipate neopentyl glycol diol, a polyadipic acid neopentyl glycol diol, and a polyhexylene phthalate diol.

25. The composition of claim 17, wherein, The component D is dimethylol propanoic acid, dimethylol butanoic acid, dimethylol acetic acid, dihydroxy succinic acid, N-(2-aminoethyl)-2-aminoethane sulfonic acid, N-(2-aminoethyl)-beta-alanine, or an alkali metal salt or an ammonium salt of each thereof.

26. The composition of claim 25, wherein, The component D is N-(2-aminoethyl)-2-aminoethane sulfonic acid sodium salt and / or N-(2-aminoethyl)-beta-alanine sodium salt.

27. The composition of claim 17, wherein The component E is one or more of isophorone diamine, N-(2-hydroxyethyl) ethylene diamine, and 1,6-hexamethylene diamine.

28. An aqueous polyurethane dispersion for formaldehyde removal, characterized in that, The composition of any one of claims 15 to 27.

29. The formaldehyde-free aqueous polyurethane dispersion according to claim 28, wherein, The formaldehyde-removing aqueous polyurethane dispersion has a solid content of 30 to 55 wt.%; and / or The formaldehyde-removing aqueous polyurethane dispersion has an average particle size of 120 to 300 nm; and / or The formaldehyde-removing aqueous polyurethane dispersion has a pH of 5 to 10.

30. The formaldehyde-free aqueous polyurethane dispersion according to claim 29, wherein, The solid content of the formaldehyde-free waterborne polyurethane dispersion is 40-50 wt.%; and / or The average particle size of the formaldehyde-free waterborne polyurethane dispersion is 140-200 nm; and / or The pH value of the formaldehyde-free waterborne polyurethane dispersion is 6-9.

31. The formaldehyde-free aqueous polyurethane dispersion according to any one of claims 28-30, characterized in that, The preparation method of the formaldehyde-free waterborne polyurethane dispersion comprises the following steps: S1: reacting the component A, component B and component C in the presence of a catalyst in an organic solvent until the theoretical NCO amount is reached to obtain a waterborne polyurethane prepolymer; S2: continuously adding an organic solvent to the waterborne polyurethane prepolymer for dilution; S3: adding a mixture of component D, component E, component F and water to the diluted waterborne polyurethane prepolymer for chain extension reaction; and S4: after the chain extension reaction, adding water for emulsification, removing the organic solvent and adjusting to the required solid content.

32. The formaldehyde-free aqueous polyurethane dispersion according to claim 31, characterized in that The catalyst is an organic bismuth catalyst.

33. The formaldehyde removal waterborne polyurethane dispersion according to claim 31, wherein, The organic solvent is acetone.

34. The formaldehyde removal waterborne polyurethane dispersion according to claim 31, wherein, The reaction temperature of step S1 is 70-90℃, and the reaction time is 2-6 h.

35. The formaldehyde removal waterborne polyurethane dispersion according to claim 31, wherein, In step S2, after adding the organic solvent, stirring for 10-30 min and controlling the temperature to 35-40℃.

36. The use of the formaldehyde-free waterborne polyurethane dispersion according to any one of claims 28-35 in furniture, leather, cloth or decorative materials.

37. The use according to claim 36, characterized in that The furniture is soft furniture.

Images