Anti-fingerprint impregnated bond paper and preparation method thereof

Abstract

The invention discloses fingerprint-resistant impregnated bond paper and a preparation method thereof, and belongs to the technical field of decorative materials. The method comprises the following steps: firstly, carrying out primary impregnation on decorative raw paper by using melamine modified urea resin, and then impregnating the decorative raw paper by using melamine formaldehyde resin modified by a fluorinated inorganic SiO2 core-Gemini organic shell core-shell structure, so as to prepare the fingerprint-resistant impregnated bond paper. The Gemini organic shell can improve the compatibility of fluorinated nano SiO2 and resin, particle aggregation is avoided, and meanwhile, a functional micro-area is driven to be enriched towards the surface layer by utilizing water-isopropanol volatilization gradient, so that a compact low-surface-energy anti-fingerprint layer is formed. The static water contact angle of the obtained adhesive film paper can reach 142 degrees, an excellent anti-fingerprint effect is still kept after 1000 times of dry wiping, and the durability is remarkably improved. The problems that traditional fluorine series modification is prone to agglomeration and fluorine components are prone to loss are solved, the process is stable and controllable, and the method is suitable for industrial production of anti-fingerprint ecological boards for high-end furniture and smart home panels.

Description

Technical Field

[0001] This invention belongs to the field of decorative material preparation technology, specifically relating to an anti-fingerprint impregnated adhesive film paper and its preparation method. Background Technology

[0002] Melamine-formaldehyde (MF) resin, with its advantages of high hardness, excellent wear resistance, chemical corrosion resistance, and good molding smoothness, has become the core adhesive for impregnated paper and is widely used in furniture boards, interior decoration, and home appliance panels. It is currently the most widely used thermosetting resin in the decorative materials field. However, MF resin has a high surface energy after curing and strong oleophilicity. In daily use, it easily absorbs fingerprints, grease, human sweat, and oil stains from the air, leaving clear residues that are difficult to wipe completely. Long-term use will seriously affect the appearance of the boards and greatly limit its application in high-end custom furniture, smart home panels, and other scenarios with strict requirements for surface texture.

[0003] Existing fluorine-based anti-fingerprint modification technologies suffer from two major, insurmountable defects that limit their long-term application: First, hydrophobic fluorides have extremely poor compatibility with water-based MF resins. Fluorinated nanoparticles, with their highly hydrophobic surface, tend to agglomerate and settle after direct incorporation into the resin system, failing to disperse evenly. This not only damages the integrity of the adhesive film structure but also results in uneven distribution of the anti-fingerprint effect. Second, fluorine components are prone to loss and failure. Externally coated fluorocarbon coatings rely solely on physical adsorption and quickly detach after friction and wiping. Internally incorporated fluorinated particles lack a protective structure and are prone to migration and precipitation during hot pressing and use, leading to a significant decline in anti-fingerprint performance within a short period. Their durability cannot meet the long-term use requirements of the boards. Furthermore, to achieve the basic effect, a large amount of fluoride needs to be added, increasing costs and posing environmental risks. Summary of the Invention

[0004] In view of the poor compatibility between hydrophobic fluorides and resins and the easy migration and detachment of fluorine components in the prior art, the present invention modifies the fluorinated particles by constructing a core-shell structure and coating them with an outer organic material. The organic shell layer improves the interfacial compatibility between the fluorinated particles and the waterborne MF resin, solves the particle agglomeration problem, and at the same time, the organic coating layer forms an anchoring protection for the fluorine components, blocks fluorine failure, and improves the stability of the fluorine components.

[0005] In addition, by utilizing the volatilization behavior of the original water-isopropanol mixed solvent in the system during the drying stage, a self-volatilization-driven effect is formed, which promotes the directional enrichment of core-shell functional microdomains to the resin surface. High efficiency and long-lasting anti-fingerprint effect can be achieved with low fluorine addition, thereby preparing impregnated film paper with excellent durability and stable anti-fingerprint performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing an anti-fingerprint impregnated adhesive film paper includes the following steps:

[0008] S11. First impregnation: Impregnate the decorative base paper in melamine-modified urea-formaldehyde resin, controlling the impregnation amount to be 50-80 g / m². 2 After drying, a single-impregnated paper is obtained;

[0009] S12. Second Impregnation: Impregnate the first-impregnated paper in anti-fingerprint modified melamine-formaldehyde resin, and add chlorine curing agent, penetrant, release agent, and dispersant. Stir evenly, and control the impregnation amount to 50-80 g / m². 2 After drying, an anti-fingerprint impregnated paper is obtained;

[0010] The preparation method of the fingerprint-resistant modified melamine-formaldehyde resin includes the following steps:

[0011] S21: Preparation of Fluorinated Nano-SiO2

[0012] Nano-sized SiO2 particles (15–30 nm) were ultrasonically dispersed in a water-isopropanol mixed solvent (volume ratio 1:1–1:1.2), with a solid content of 5–8%; the pH of the system was adjusted to 4.0–5.0 using acetic acid; and a perfluoroalkylsilane (general formula Rf-(CH2)) was added. n -Si(OR)3, Rf=C5~C 12 Perfluoroalkyl (n=1~3, R=methoxy or ethoxy); react at room temperature with stirring for 0.5~3.0h to obtain a fluorinated nano-SiO2 dispersion of perfluoroalkylsilane.

[0013] S22: Construction of Functional Microregions of Core-Shell Structure

[0014] The pH of the dispersion obtained in step S21 was adjusted to 6.0–7.5 using ammonia; Gemini bis-quaternary ammonium salt (general formula: [R]) was slowly added. 1 R 2 N + -(CH2) x -N + R3R4]·2X - R1 to R4 are C 12 ~C 14 Alkyl group, x=2~6, X=Cl or Br); stir the reaction for 1.0~2.0 h to allow Gemini to adsorb onto the surface of fluorinated SiO2, forming a core-shell structured functional dispersion of "fluorinated inorganic SiO2 core-Gemini organic shell".

[0015] S23: Formulation of anti-fingerprint modified melamine-formaldehyde resin:

[0016] Based on 100 parts by weight of MF resin (solid content 50%~60%), the functional dispersion obtained in step S22 is added to the MF resin aqueous solution, 4~6 parts by weight of isopropanol are added, and the mixture is stirred evenly to obtain anti-fingerprint modified melamine resin.

[0017] Isopropanol is significantly more volatile than water. During the drying stage of the impregnated film paper, the surface isopropanol rapidly escapes, creating a solvent concentration difference, viscosity difference, and surface energy gradient between the resin surface and interior. The core-shell functional microdomains exhibit overall hydrophobicity and low surface energy characteristics, spontaneously migrating and accumulating towards the surface under the influence of the aforementioned gradient. Finally, they are anchored and locked during hot pressing and curing, forming a continuous and dense anti-fingerprint surface layer. Relying on the natural volatilization of the original isopropanol in the system ensures both efficient enrichment of fluorine components and avoids the migration and shedding of fluorides, significantly improving anti-fingerprint properties.

[0018] According to the above preparation method, an anti-fingerprint impregnated adhesive film paper is obtained.

[0019] The present invention also provides an anti-fingerprint eco-board, comprising a substrate and a fingerprint-impregnated adhesive film paper covered on the surface of the substrate.

[0020] The substrate is plywood or blockboard with poplar veneer or reconstituted decorative veneer on the surface.

[0021] The manufacturing process of the anti-fingerprint eco-board includes the following steps:

[0022] S1. Substrate pretreatment: Sand the plywood or blockboard substrate and cover its surface with poplar veneer or reconstituted decorative veneer with a thickness of 0.4-0.6mm and a moisture content of ≤12%.

[0023] S2. Assembly and hot pressing: Assemble the obtained anti-fingerprint impregnated paper with the substrate obtained in step S1, and hot press for 7 to 15 minutes at a hot pressing temperature of 100 to 135°C and a hot pressing pressure of 0.6 to 1.0 MPa;

[0024] S3. Subsequent processing: The hot-pressed board is cured and graded to obtain the anti-fingerprint eco-board.

[0025] Beneficial effects:

[0026] (1) By constructing a fluorinated inorganic core-Gemini organic shell core-shell structure functional microregion, this invention effectively improves the interfacial compatibility between fluorinated nano-SiO2 and waterborne melamine formaldehyde (MF) resin, solves the problem of easy agglomeration and sedimentation of fluorinated particles when directly incorporated, and ensures the integrity and uniformity of the film structure.

[0027] (2) The organic shell forms an anchoring protection for the fluorine component, which effectively improves the defects of easy detachment of fluorine component and rapid decay of anti-fingerprint performance in fluorine-based modification technology, and improves anti-fingerprint durability.

[0028] (3) By utilizing the gradient effect generated by the evaporation of water-isopropanol mixed solvent, the core-shell functional micro-regions are driven to be directionally enriched on the resin surface. A low amount of fluorine can achieve a high-efficiency anti-fingerprint effect, and the static water contact angle of the product reaches 142°. Attached Figure Description

[0029] Figure 1 (a)-(d) represent the water contact angles of the anti-fingerprint eco-boards prepared in Example 3 and Comparative Examples 1-3, respectively;

[0030] Figure 2 (a)-(d) are fingerprint photographs of the fingerprint-resistant eco-boards prepared in Example 3 and Comparative Examples 1-3, respectively. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to examples. The following content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the concept of the invention, they should all fall within the protection scope of the present invention.

[0032] The preparation method of the present invention will be described below through specific embodiments.

[0033] Example 1: Preparation of anti-fingerprint modified melamine-formaldehyde resin

[0034] Step A: Preparation of fluorinated nano-SiO2:

[0035] 10 g of nano-SiO2 (average particle size 20 nm) was added to 200 mL of a water-isopropanol mixed solvent (volume ratio 1:1) and ultrasonically dispersed for 30 min to prepare a dispersion with a solid content of 5%. The pH of the system was adjusted to 4.5 using acetic acid, and 2 g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane was added. The mixture was stirred at room temperature for 2 h to obtain a fluorinated nano-SiO2 dispersion.

[0036] Step B: Construction of functional microregions in the core-shell structure:

[0037] Adjust the pH of the dispersion obtained in step A to 7.0 using dilute ammonia water, slowly add 0.5 g of N,N'-bis(dodecyl)-N,N,N',N'-tetramethyl-1,6-hexammonium dibromide (Gemini type bis-quaternary ammonium salt), and stir the reaction for 1 h.

[0038] Step C: Resin Modification

[0039] Take 100 parts by weight of melamine-formaldehyde resin (solid content 55%), add the functional micro-area dispersion obtained in step B (containing 2.0 parts by weight of fluorinated nano-SiO2 and 0.5 parts by weight of Gemini bisquaternary ammonium salt), add isopropanol to 5.0 parts by weight, stir and mix evenly to obtain anti-fingerprint modified melamine-formaldehyde resin.

[0040] Example 2: Preparation of anti-fingerprint impregnated adhesive film paper

[0041] S1. First impregnation: The amount is 80g / m 2 The decorative base paper is impregnated in melamine-modified urea-formaldehyde resin, with the impregnation amount controlled at 65 g / m². 2 The paper is dried at 120°C until the volatile content is 8%, thus obtaining primary impregnated paper.

[0042] S2. Second Impregnation: The first-impregnated paper is impregnated in the anti-fingerprint modified melamine-formaldehyde resin prepared in Example 1, and curing agent A1008, penetrant A883-T, release agent A183, and dispersant SN-5027 are added, controlling the impregnation amount to 60 g / m². 2 The paper is dried at 135°C until the volatile content is 6% to obtain an anti-fingerprint impregnated paper.

[0043] Example 3: Preparation of anti-fingerprint eco-board:

[0044] S1. Substrate pretreatment: The 18mm thick plywood substrate is sanded on both sides, and a 0.6mm thick poplar veneer with a moisture content of 10% is pasted on its front side.

[0045] S2. Assembly: The anti-fingerprint impregnated paper (surface layer) prepared in Example 2 is assembled with the substrate treated in step S1.

[0046] S3. Hot pressing: Hot pressing for 10 minutes at a hot pressing temperature of 125℃ and a hot pressing pressure of 0.8MPa.

[0047] S4. Subsequent processing: After hot pressing, the boards are cured at room temperature for 48 hours, and then trimmed, graded, and packaged to obtain the finished anti-fingerprint eco-board.

[0048] Comparative Example 1: Unmodified MF resin impregnated paper

[0049] Except for using ordinary melamine-formaldehyde resin without the added anti-fingerprint micro-areas, the rest of the process was the same as in Example 2. The resulting eco-board had a static water contact angle of 68°, and fingerprint residue was obvious, leaving traces even after wiping.

[0050] Comparative Example 2: Melamine-formaldehyde resin with direct addition of fluorinated nano-SiO2

[0051] Fluorinated nano-SiO2 (uncoated with Gemini) was directly dispersed in MF resin at a dosage of 5 parts by weight. Due to severe particle agglomeration and poor stability of the impregnation solution, significant precipitation occurred after 2 hours. The resulting eco-board had a water contact angle of 122° and poor dry-rub resistance.

[0052] Comparative Example 3:

[0053] Isopropanol is not used; water is used as the dispersion solvent only.

[0054] Step A: Add 10g of nano-SiO2 (average particle size 20nm) to 200mL of pure water and ultrasonically disperse for 30min to prepare a dispersion with a solid content of 5%. Adjust the pH to 4.5 using acetic acid, add 2g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, and stir the reaction at room temperature for 2h.

[0055] Step B: Adjust the pH to 7.0 with dilute ammonia water, add 0.5g of Gemini bisquaternary ammonium salt, and stir for 1 hour.

[0056] Step C: Take 100 parts by weight of MF resin, add it to the above dispersion without introducing any isopropanol, stir evenly, and the rest of the process is the same as in Example 1.

[0057] Impregnated paper and eco-board were prepared using the same process as in Examples 2 and 3.

[0058] The resulting impregnation solution exhibits moderate stability and slight agglomeration; the static water contact angle on the surface is only 110°; after 1000 dry rubbing cycles, the contact angle decreases to 94°; the fluorine component cannot be effectively enriched on the surface, fingerprint residue is obvious, and the anti-fingerprint durability is significantly reduced.

[0059] Figure 1 (a)-(d) represent the water contact angles of the ecological boards prepared in Example 3 and Comparative Examples 1-3, respectively; Figure 2 (a)-(d) are fingerprint images of the eco-boards prepared in Example 3 and Comparative Examples 1-3, respectively. The specific values ​​obtained are shown in Table 1.

[0060] Table 1. Performance comparison of the ecological boards prepared in Example 3 and Comparative Examples 1-3

[0061] Test Project Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Static water contact angle 142° 68° 122° 110° Dry rub resistance (1000 cycles) Static water contact angle 136° 65° 102° 94° Anti-fingerprint performance No obvious residue Obvious residue No obvious residue Residue

[0062] Comparative Example 1 uses ordinary melamine-formaldehyde resin without added anti-fingerprint functional micro-areas to prepare impregnated film paper and ecological board. According to the test data, its surface static water contact angle is only 68°, with high surface energy and strong oleophilicity. It does not have anti-fingerprint performance at all. During use, fingerprint grease and oil stains are easily adsorbed and left behind, and the marks cannot be removed after wiping.

[0063] Comparative Example 2 directly incorporated uncoated fluorinated nano-SiO2 into the MF resin system. Although fluorinated components were added, the lack of a core-shell coating structure resulted in extremely poor interfacial compatibility between the hydrophobic fluorinated particles and the aqueous MF resin. During the preparation process, significant particle agglomeration and sedimentation occurred after only 2 hours in the impregnation solution, disrupting the structural uniformity of the film. Test data showed an initial static water contact angle of 122°, indicating some anti-fingerprint effect, but extremely poor dry-wiping performance. After 1000 dry wipes, the contact angle plummeted to 102°, a decrease of 20°. This is because the exposed fluorinated particles lack an organic shell for anchoring and protection, making them prone to migration and detachment during friction and daily use. The rapid loss of fluorine components leads to a significant decrease in anti-fingerprint performance, failing to achieve a long-lasting anti-fingerprint effect. Furthermore, achieving a basic anti-fingerprint effect requires increasing the amount of fluoride added, increasing production costs and posing environmental risks.

[0064] Comparative Example 3 was a control sample completely free of isopropanol, using only water as the dispersion solvent. All other components and processes were consistent with the present invention. Results showed that the water contact angle on the surface of Comparative Example 3 was only 110°, significantly lower than the 142° of Example 3; the contact angle decayed significantly after dry wiping, resulting in a substantial decrease in durability; the surface fluorine enrichment was low, and the anti-fingerprint effect was not significant. These results directly demonstrate that the presence of isopropanol in the system and its preferential volatilization during the drying process are the key driving forces for the migration and enrichment of core-shell functional microdomains to the resin surface; without isopropanol, an effective concentration gradient and surface energy gradient cannot be formed, functional microdomains cannot be directionally enriched, and the anti-fingerprint performance is significantly deteriorated.

Claims

1. A method for preparing an anti-fingerprint impregnated adhesive film paper, characterized in that, Includes the following steps: S11. First impregnation: Impregnate the decorative base paper in melamine-modified urea-formaldehyde resin, controlling the impregnation amount to be 50-80 g / m². 2 After drying, a single-impregnated paper is obtained; S12. Second Impregnation: Impregnate the first-impregnated paper in anti-fingerprint modified melamine-formaldehyde resin, adding curing agent, penetrant, release agent and dispersant, controlling the impregnation amount to 50-80 g / m². 2 After drying, an anti-fingerprint impregnated paper is obtained; The preparation of the anti-fingerprint modified melamine-formaldehyde resin includes: modifying nano-SiO2 particles in a water-isopropanol mixed solvent with perfluoroalkylsilane, then adding Gemini bisquaternary ammonium salt to form fluorinated inorganic core-Gemini organic shell core-shell structure functional microregions, mixing the functional microregion dispersion with melamine-formaldehyde resin and adding isopropanol, and stirring evenly to obtain the final product.

2. The preparation method according to claim 1, characterized in that, The curing agent, penetrant, release agent, and dispersant are respectively curing agent A1008, penetrant A883-T, release agent A183, and dispersant SN-5027.

3. The preparation method according to claim 1, characterized in that, The size of the nano-SiO2 particles is 15~30nm.

4. The preparation method according to claim 1, characterized in that, The water-isopropanol volume ratio is 1:1 to 1:1.2, and the pH of the system is 4.0 to 5.

0.

5. The preparation method according to claim 1, characterized in that, Gemini bisquaternary ammonium salt has an alkyl chain of C12 to C14 and adsorbs and coats the target substance for 1.0 to 2.0 hours at pH 6.0 to 7.

5.

6. The preparation method according to claim 1, characterized in that, For every 100 parts by weight of melamine-formaldehyde resin with a solid content of 50% to 60%, add 4 to 6 parts by weight of isopropanol.

7. The anti-fingerprint impregnated adhesive film paper prepared by the preparation method according to any one of claims 1 to 6.

8. A fingerprint-resistant eco-board, characterized in that, The invention includes a substrate and the anti-fingerprint impregnated paper of claim 7, which is applied to the surface of the substrate. The substrate is plywood or blockboard with poplar veneer or reconstituted decorative veneer applied to its surface.

9. The anti-fingerprint eco-board according to claim 8, characterized in that, Hot pressing temperature: 100-135℃, pressure: 0.6-1.0MPa, hot pressing time: 7-15min.

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