Formaldehyde removal sponge based on water-based polymer and preparation method and application of formaldehyde removal sponge

Abstract

The invention discloses a formaldehyde removal sponge based on a water-based polymer and a preparation method and application thereof, belongs to the technical field of high polymer material treatment and air purification functions, and provides the preparation method of the formaldehyde removal sponge based on the water-based polymer in order to solve the problem that an existing formaldehyde removal sponge is not ideal in formaldehyde removal effect. Comprising the following steps: uniformly mixing a water-based polymer emulsion and an aldehyde removal catalyst to prepare a water-based polymer suspension, and in the water-based polymer suspension, uniformly attaching the water-based polymer suspension to polyurethane sponge, so that the aldehyde removal catalyst is attached to the surface of the polyurethane sponge to form a pretreated sponge base material; and heating and drying the pretreated sponge base material. The water-based emulsion is cured to form a polymeric membrane, it can be guaranteed that the formaldehyde removal particles are stably attached to the surface of the sponge, it can also be guaranteed that the formaldehyde removal particles make contact with air, and the formaldehyde removal effect is guaranteed. And the method is easy to control and realize large-scale continuous production, and the whole product is safe and environment-friendly in the production and use processes.

Description

Technical Field

[0001] This invention relates to the field of polymer material processing and air purification technology, specifically to a formaldehyde-removing sponge based on an aqueous polymer, its preparation method, and its application. Background Technology

[0002] Mattresses are a core piece of bedroom furniture that comes into close contact with people for extended periods, and the adhesives commonly used inside them pose a structural risk of continuous formaldehyde release. Frequently exposed incidents of excessive formaldehyde levels and their health hazards have sparked widespread public concern, even leading to widespread anxiety about formaldehyde. As a result, products with formaldehyde removal functions or zero formaldehyde are rapidly gaining popularity among consumers.

[0003] Existing formaldehyde removal materials used for air purification (such as porous materials and photocatalytic materials) have significant limitations and are difficult to apply directly to mattresses. Adsorbent materials: They are used to adsorb pollutants such as formaldehyde due to their strong adsorption properties, but they are easily saturated and there is a risk of secondary release in complex environments such as mattresses being squeezed by the human body and experiencing temperature changes.

[0004] Photocatalyst materials require ultraviolet light to be activated, but the interior of the mattress and the bedroom environment at night are basically dark, so they cannot work effectively.

[0005] Ordinary load-bearing foam: In existing foam mattresses, a non-woven fabric carrier is used, with granules containing formaldehyde removal function sandwiched between two layers of non-woven fabric. However, it is difficult to distribute the granules evenly during the manufacturing process. The bond between the loaded active ingredients and the foam substrate is weak. Under the long-term use conditions of pressure, deformation and friction, the active ingredients are prone to falling off and becoming ineffective, resulting in poor durability.

[0006] Currently, there is a lack of built-in purification materials on the market that perfectly match the structure and usage characteristics of mattresses, efficiently decomposing formaldehyde while maintaining stable performance and safety under long-term dynamic loads. Therefore, developing a core sponge material specifically for mattresses with long-lasting formaldehyde removal capabilities has become a key technological bottleneck in improving the health quality of mattress products.

[0007] Existing formaldehyde removal catalysts, such as those described in patent application CN101380574A, utilize supported formaldehyde catalysts. These catalysts are formaldehyde oxidants that operate at room temperature without the need for light (UV light) triggering, decomposing formaldehyde into carbon dioxide and water at room temperature. However, these catalysts are granular or powdered. If these catalysts are applied to a sponge system for foaming, the sponge polymer will encapsulate the particles, affecting the contact between the catalyst and formaldehyde and thus reducing the formaldehyde removal effect. Therefore, current technologies for fixing catalytic particles onto sponges are not very convenient to implement. Summary of the Invention

[0008] To address the challenge of achieving efficient, long-lasting, and safe formaldehyde removal in the specific application of mattresses using existing technologies, this invention provides a formaldehyde-removing sponge based on water-based polymers, its preparation method, and its application. The resulting sponge not only boasts a high initial formaldehyde removal rate but also withstands the pressure and deformation of mattresses during long-term use, maintaining stable performance over time. Its preparation method is simple and suitable for industrial production.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: The preparation method of formaldehyde-removing sponge based on aqueous polymer includes the following steps: Step 1: Mix the aqueous polymer emulsion and the formaldehyde removal catalyst evenly to prepare an aqueous polymer suspension. In the aqueous polymer suspension, the aqueous polymer solid and the formaldehyde removal catalyst are mixed at a mass ratio of (10-50):4. Step 2: The aqueous polymer suspension is uniformly attached to the polyurethane sponge, so that the formaldehyde removal catalyst is attached to the surface of the polyurethane sponge to form a pretreated sponge substrate. Step 3: Heat and dry the pretreated sponge substrate at 60-160°C to crosslink and solidify the aqueous polymer emulsion, forming a polymer functional film loaded with a formaldehyde removal catalyst on the sponge skeleton.

[0010] In step 1, regardless of how the solid content of the aqueous polymer emulsion stock solution changes, that is, no matter how many times water is used for dilution, the mass ratio of solid polymer to aldehyde removal catalyst in the final prepared suspension is maintained at (10-50):4. Too much water will prolong the drying time and affect the efficiency.

[0011] Heating curing can shorten curing time and produce stable products, with less influence from ambient temperature and humidity, which is beneficial for improving production efficiency, but requires greater equipment investment and energy consumption; room temperature curing has the opposite effect.

[0012] When water-based polymers are mixed with formaldehyde removal catalysts, if there is too little polymer solids, the formaldehyde removal catalyst will easily fall off; if there is too much polymer solids, the sponge will feel too hard.

[0013] The formaldehyde removal catalyst is existing technology. In this application, the formaldehyde removal catalyst is a supported formaldehyde removal catalyst or simply activated carbon. The supported formaldehyde removal catalyst has a support and an active component, with the active component supported on the support. The support is a porous material such as activated carbon or titanium dioxide, preferably activated carbon. The active component is a precious metal such as platinum or palladium, preferably platinum.

[0014] Furthermore, the waterborne polymer includes waterborne polyurethane resin, waterborne acrylic resin, waterborne epoxy resin, and mixtures thereof. The waterborne polyurethane emulsion serves as an environmentally friendly adhesive. Waterborne polyurethane resin, waterborne acrylic resin, waterborne epoxy resin, and other waterborne polymers whose mixed emulsions have low VOCs, are odorless after drying and curing, and possess strong adhesive properties and adhesion are all acceptable. These waterborne polymers include waterborne polyurethane resin, waterborne acrylic resin, waterborne epoxy resin, and their mixed emulsions.

[0015] Furthermore, the particle size of the aldehyde removal catalyst is 100-300 mesh. The aldehyde removal catalyst is a supported catalyst.

[0016] Furthermore, the aqueous polymer content in the aqueous polymer emulsion is 10%-50%.

[0017] Furthermore, in step 3, the loading of formaldehyde removal catalyst per unit area of ​​sponge is controlled to be (1.0~8.0) g / m².

[0018] The second inventive point of this invention is the sponge obtained by the above-mentioned method for preparing formaldehyde-removing sponge based on aqueous polymers.

[0019] The third inventive aspect of this invention is the application of the aforementioned sponge in household products, particularly mattresses and sofa cushions.

[0020] The fourth inventive point of this invention is a formaldehyde-removing sponge, comprising a sponge body and formaldehyde-removing catalytic particles attached to the sponge body, wherein the formaldehyde-removing catalytic particles are connected to the sponge body through an aqueous polymer membrane.

[0021] The present invention has at least the following beneficial effects: Synergistic Effect and Robust Loading: This invention creatively uses an aqueous emulsion as both a binder and a carrier. The formaldehyde removal catalyst is dispersed within the aqueous emulsion, which serves as the carrier. When the aqueous emulsion adheres to the polyurethane sponge, the formaldehyde removal catalyst is uniformly distributed onto the sponge as well. During heat treatment, the aqueous polymer emulsion solidifies to form a polymer film, tightly fixing the formaldehyde removal catalyst within the three-dimensional network structure of the sponge. This prevents the active ingredient from detaching during use, ensuring the product's long-lasting performance. Simultaneously, the aqueous polymer emulsion adheres very thinly to the polyurethane sponge, allowing the catalyst particles to adhere to the sponge while remaining exposed to air. This ensures both stable adhesion of the formaldehyde removal particles to the sponge surface and contact with air, guaranteeing the formaldehyde removal effect.

[0022] The process is simple and suitable for industrial production: the entire preparation process involves only three steps: solution preparation, loading and drying. It is easy to operate, the conditions are mild, and it is easy to control and achieve large-scale continuous production.

[0023] Safe and environmentally friendly: The water-based polymer emulsion used has water as the dispersion medium and low VOC content. The formaldehyde removal catalyst is a safe catalytic material. The entire product is safe and environmentally friendly in both production and use. Attached Figure Description

[0024] Figure 1 The surface morphology of the formaldehyde-removing sponge prepared in Example 1 (350x magnification); Figure 2 The surface morphology of the formaldehyde-removing sponge prepared in Example 1 is shown at 1000x magnification. Figure 3 The surface morphology of the formaldehyde-removing sponge prepared in Example 1 is shown at 12000x magnification. Figure 4 The surface morphology of the formaldehyde-removing sponge prepared in Example 1 is shown at 2000x magnification. Figure 5 for Figure 4 The energy spectrum of the location; Figure 6 for Figure 5 Resulting graph; Figure 7 The surface morphology of the formaldehyde-removing sponge prepared in Comparative Example 1 is shown at 350x magnification. Figure 8 The surface morphology of the formaldehyde-removing sponge prepared in Comparative Example 1 is shown at 2000x magnification. Figure 9 for Figure 8 The energy spectrum of the location; Figure 10 for Figure 9 The result image. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments.

[0026] First, an aldehyde removal catalyst is prepared, which is an existing technology. A suspension mixture of porous material and pure water is prepared, wherein the mass concentration of the porous material in the suspension mixture is 15%–20%, and titanium dioxide is used as the porous material. Under stirring conditions, a first solution is added to the suspension mixture, using an alkali metal salt (sodium carbonate) as the solute and pure water as the solvent, to form a mixed solution. The mass concentration of the solute in the first solution is 10%–15%. A second solution is prepared, using chloroplatinic acid as the solute and pure water as the solvent, with a solute mass concentration of 1.5%–3.5%. Under stirring conditions, the prepared second solution is poured into the mixed solution to form a homogeneous slurry. During the mixing process, the acid-base system is modified using acid-base reagents to achieve a pH of 6 in the slurry. The prepared slurry is placed in a rotary evaporator and evaporated to dryness under vacuum to remove pure water. Then, it is sintered in a muffle furnace at 300–500°C for 2 seconds. The sintered block was heated and calcined for 3 hours to obtain a sintered block; the sintered block was then transferred to a sintering furnace and reduced by a mixture of hydrogen and nitrogen at 200–300°C. For 2 hours, the volume ratio of hydrogen to nitrogen is 1:(4.5~5.5), and the reduced sintered block is crushed and ground.

[0027] Example 1 Raw material preparation: Prepare a water-based polyurethane emulsion with a solid content of 50%, water, and a formaldehyde removal catalyst. The sponge substrate is a common polyurethane sponge with dimensions of 50cm × 50cm × 2cm.

[0028] Solution preparation: Prepare 500g of water-based polyurethane emulsion with a solid content of 10%, then add 20g of formaldehyde removal catalyst and stir for 5-10 minutes until evenly mixed.

[0029] Loading: Using an air source and spray gun, the working fluid is evenly sprayed onto the upper surface of the sponge. By controlling the spraying time and moving speed, the amount of formaldehyde removal catalyst sprayed per unit area is ensured to be controlled at 4g / m², that is, the amount of working fluid sprayed is 104g / m².

[0030] Drying: Place the sprayed sponge into an oven preheated to 120°C and heat until dry. Then remove it and allow it to cool naturally to room temperature to obtain the high-efficiency formaldehyde-removing sponge described in this invention.

[0031] Example 2 The difference between this embodiment and Embodiment 1 is that 500 grams of an aqueous polyurethane emulsion with a solid content of 50% is prepared.

[0032] Example 3 The difference between this embodiment and Embodiment 1 is that the amount of formaldehyde removal catalyst sprayed per unit area is changed from 4g / m² to 8g / m², that is, the amount of working liquid sprayed is 208g / m².

[0033] Example 4 The difference between this embodiment and Embodiment 1 is that the amount of formaldehyde removal catalyst sprayed per unit area is changed from 4g / m² to 2g / m², that is, the amount of working liquid sprayed is 52g / m².

[0034] Example 5 The difference between this embodiment and Embodiment 1 is that the oven temperature is changed from 120℃ to 160℃.

[0035] Example 6 The difference between this embodiment and Embodiment 1 is that the oven temperature is changed from 120℃ to 60℃.

[0036] Example 7 The difference between this embodiment and Embodiment 1 is that the waterborne polyurethane emulsion is replaced with an environmentally friendly waterborne acrylic emulsion.

[0037] Example 8 The difference between this embodiment and Embodiment 1 is that the load is changed from spraying to roller coating.

[0038] Example 9 The difference between this embodiment and Embodiment 1 is that the load is changed from spraying to immersion.

[0039] Example 10 The difference between this embodiment and Embodiment 1 is that the waterborne polyurethane emulsion is replaced with waterborne epoxy resin.

[0040] Comparative Example 1 The difference between this comparative example and Example 1 is that the sponge is not sprayed or heated, that is, the sponge remains blank.

[0041] Comparative Example 2 The difference between this comparative example and Example 1 is that no aldehyde removal catalyst is added during solution preparation.

[0042] Comparative Example 3 The difference between this comparative example and Example 1 is that water was used instead of waterborne polyurethane emulsion when preparing the solution.

[0043] Comparative Example 4 The difference between this comparative example and Example 1 is that the solid content of the aqueous polyurethane emulsion is 5% when preparing the solution.

[0044] Comparative Example 5 The difference between this comparative example and Example 1 is that the amount of formaldehyde removal catalyst sprayed per unit area is changed from 4 g / m² to 0.5 g / m², that is, the amount of working liquid sprayed is 13 g / m².

[0045] Surface morphology: Surface morphology diagram of Example 1 is shown below. Figures 1 to 5 As shown in the figure, granular formaldehyde removal catalyst is attached to the sponge body. Figure 5 (a) in the diagram is an EDS stratification diagram. Figure 5 (b) in the figure is the C distribution plot. Figure 5 (c) in the figure is the O distribution plot; Figure 5 (d) in the figure represents the distribution of Pt. Figure 5 (e) in the diagram represents the Si distribution. Figure 5 (f) in the figure is the Ti distribution map. Figure 6 for Figure 5 The energy spectrum results, combined with Figure 5 , Figure 6 The product surface morphology contains elements such as C, O, Si, Ti, and Pt, which is compatible with the components of the sponge body and the formaldehyde removal catalyst used.

[0046] The surface morphology diagram of Comparative Example 1 is shown below. Figures 7 to 9 As shown in the figure, the surface of the untreated sponge is relatively smooth. Figure 9 (a) in the diagram is an EDS stratification diagram. Figure 9 (b) in the figure is the C distribution plot. Figure 9 (c) in the figure is the O distribution plot; Figure 9 (d) in the figure represents the Si distribution; combined with Figure 9 , Figure 10 The sponge itself does not contain Ti or Pt elements, further proving that the particulate matter attached to the surface of the sponge in the embodiment is a formaldehyde removal catalyst.

[0047] Performance testing: The formaldehyde removal rate was tested according to QB / T 2761-2006 "Test Method for Purification Effect of Indoor Air Purification Products".

[0048] The test results are as follows:

[0049] Based on the table above, most of the examples achieved formaldehyde removal rates of over 85%, while Example 4, with a relatively lower removal rate, still achieved over 65%. In Example 2, compared to Example 1, the surface of the sprayed sponge hardened, which is related to the high solid content of the working fluid. Example 3 had the highest formaldehyde removal rate, but the surface of the sprayed sponge also hardened, both related to the large amount of working fluid used. Example 4 had the lowest formaldehyde removal rate among all examples, which is related to the smallest amount of formaldehyde removal catalyst sprayed. The formaldehyde removal rates of Examples 5 and 6 were similar to those of Example 1, and appropriately increasing the temperature during drying helped shorten the drying time and improve drying efficiency. The formaldehyde removal rate of Example 7 was similar to that of Example 1, indicating that waterborne polyurethane, used as a binder between the formaldehyde removal catalyst and the polyurethane sponge, can be replaced by other environmentally friendly waterborne polymer emulsions such as waterborne acrylic acid. The formaldehyde removal rates of Examples 8 and 9 were similar to those of Example 1, indicating that different loading methods can be selected while ensuring uniform distribution of the formaldehyde removal catalyst. In addition, in Examples 1 to 10, the formaldehyde removal catalyst is not easy to fall off, which can ensure that the formaldehyde removal particles are stably attached to the sponge surface and that the formaldehyde removal particles are in contact with the air, thus ensuring the formaldehyde removal effect.

[0050] Compared to Example 1, Comparative Example 1 showed a lower formaldehyde removal rate, indicating that the treatment in Example 1 significantly improved the formaldehyde removal rate. Comparative Example 2 also had a low formaldehyde removal rate, suggesting that the water-based polymer had virtually no impact on the formaldehyde removal rate. The catalyst detachment in Comparative Examples 3 and 4 indicated that the absence of a water-based polymer or a very low solids content resulted in insufficient adhesion of the formaldehyde removal catalyst. The low formaldehyde removal rate in Comparative Example 5 indicated that insufficient catalyst application affected the formaldehyde removal effect.

[0051] High formaldehyde removal efficiency: The formaldehyde removal rate of the sponge treated by the method of this invention can reach more than 85% (according to QB / T 2761-2006 standard), which is more than 136% higher than the untreated blank sponge (formaldehyde removal rate of 36%), and the effect is very significant.

Claims

1. A method for preparing a formaldehyde-removing sponge based on an aqueous polymer, characterized in that, The preparation method of formaldehyde-removing sponge based on aqueous polymer includes the following steps: Step 1: Mix the aqueous polymer emulsion and the formaldehyde removal catalyst evenly to prepare an aqueous polymer suspension. In the aqueous polymer suspension, the aqueous polymer solid and the formaldehyde removal catalyst are mixed at a mass ratio of (10-50):

4. Step 2: The aqueous polymer suspension is uniformly attached to the polyurethane sponge, so that the formaldehyde removal catalyst is attached to the polyurethane sponge to form a pretreated sponge substrate. Step 3: Heat and dry the pretreated sponge substrate at 60-160°C to crosslink and solidify the aqueous polymer emulsion, forming a polymer functional film loaded with a formaldehyde removal catalyst on the sponge skeleton.

2. The method for preparing formaldehyde-removing sponge based on aqueous polymer according to claim 1, characterized in that, The waterborne polymers include waterborne polyurethane resins, waterborne acrylic resins, waterborne epoxy resins, and mixtures thereof.

3. The method for preparing formaldehyde-removing sponge based on water-based polymer according to claim 1, characterized in that, The particle size of the aldehyde removal catalyst is 100-300 mesh.

4. The method for preparing formaldehyde-removing sponge based on aqueous polymer according to claim 1, characterized in that, The aqueous polymer emulsion contains 10%-50% aqueous polymer.

5. The method for preparing formaldehyde-removing sponge based on aqueous polymer according to claim 1, characterized in that, In step 3, the loading of formaldehyde removal catalyst per unit area of ​​sponge is controlled to be (1.0~8.0) g / m².

6. The sponge obtained by the method for preparing formaldehyde-removing sponge based on water-based polymers according to any one of claims 1-5.

7. The application of the sponge as described in claim 6 in household products.

8. A formaldehyde-removing sponge, comprising a sponge body and formaldehyde-removing catalytic particles attached to the sponge body, wherein the formaldehyde-removing catalytic particles are connected to the sponge body via an aqueous polymer membrane.

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