Preparation method of super film pressure finish paint

Abstract

The invention provides a preparation method of super film pressure finish paint, and belongs to the technical field of paint. The finish paint is prepared from epoxy acrylic resin, polyurethane acrylic resin, tripropylene glycol diacrylate and a photoinitiator. The finish paint is prepared through UV curing or a water-based system, has excellent adhesive force, wear resistance, weather resistance and chemical resistance, and meanwhile meets the low-VOC environment-friendly requirement. The preparation method comprises the following steps: uniformly mixing the resin and the auxiliary agent, dispersing the nano filler at a high speed, filtering to remove impurities, filling, storing and the like. The finishing paint disclosed by the invention can be widely applied to the decoration fields of furniture films, building wallboard films and the like, and the surface durability and the environmental protection performance are improved.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a method for preparing a super film-pressed topcoat. Background Art

[0002] In recent years, with the rapid development of the home decoration, building materials, and automotive interior industries, decorative films and papers have become increasingly popular in various products. As the surface protective layer of decorative materials, topcoat's primary functions include enhancing the aesthetics of decorative films and papers, improving their abrasion resistance, scratch resistance, weather resistance, and chemical resistance, while also meeting environmental regulations requiring low volatile organic compound (VOC) emissions.

[0003] Currently, topcoats on the market are mainly divided into three categories: solvent-based coatings, water-based coatings and UV-curing coatings. Each technical route has certain limitations:

[0004] Solvent-based coatings use organic solvents as the main film-forming medium and have good leveling and adhesion, but they have the following problems:

[0005] High VOC emissions: Due to the extensive use of organic solvents, the VOC content of this type of coating is usually between 200-600g / L, which does not meet the restrictions of modern environmental regulations (such as the EU REACH Regulation and China GB / T 23985).

[0006] Safety hazards: Solvent-based coatings are flammable and explosive, and fire and explosion prevention safety measures must be strictly controlled during production and use.

[0007] Insufficient durability: Traditional solvent-based coatings are relatively weak in abrasion resistance, scratch resistance and weather resistance, and cannot meet the stringent requirements of the high-end market for coating performance.

[0008] Water-based paint uses water as a dispersion medium and has low VOC emissions. It is considered one of the representatives of environmentally friendly paints, but it still has the following defects:

[0009] Slow curing speed: Water-based coatings require a long drying time during the film-forming process and usually require an additional heat source to assist in drying, affecting production efficiency.

[0010] Poor water resistance and chemical resistance: Since water is used as the main dispersion medium, the water resistance and chemical resistance of the coating are lower than those of solvent-based and UV-curing coatings.

[0011] Sensitive to construction conditions: Water-based paint has high requirements for the construction environment. Large fluctuations in temperature and humidity will affect the film quality and easily cause defects such as sagging and shrinkage.

[0012] UV (ultraviolet light) curing coatings rely on ultraviolet light to cure the coating within seconds, and have high production efficiency and excellent overall performance, thus gradually becoming the mainstream direction of the industry. However, existing UV curing coatings still face the following problems:

[0013] Adhesion problem: Traditional UV coatings have poor adhesion to low surface energy substrates (such as polypropylene PP, PET, etc.) and require additional corona treatment, plasma treatment or primer to help improve adhesion.

[0014] Lack of flexibility: Some UV coatings have a high degree of cross-linking after curing, resulting in reduced toughness and prone to cracking during bending or impact.

[0015] There is still room for improvement in wear resistance: Although UV-curing coatings have a high hardness, some systems still have problems with insufficient scratch resistance and wear resistance, and scratches or coating wear are prone to occur in high-frequency usage scenarios (such as furniture film, car interiors, etc.). Summary of the Invention

[0016] To address these issues, the present invention provides a method for preparing a super-film-pressed topcoat. This method utilizes epoxy acrylic resin and polyurethane acrylic resin as a matrix to enhance adhesion and abrasion resistance; tripropylene glycol diacrylate (TPGDA) as a reactive diluent to increase curing speed; and a photoinitiator to promote UV curing and ensure film-forming performance. By adjusting the formulation ratio and curing conditions, the coating achieves excellent physical and chemical properties while meeting low-VOC environmental requirements.

[0017] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0018] A method for preparing a super film-pressed topcoat, characterized in that it comprises the following components in parts by mass:

[0019] Epoxy acrylic resin: 40-60 parts;

[0020] Polyurethane acrylic resin: 5-10 parts;

[0021] Tripropylene glycol diacrylate (TPGDA): 20-40 parts;

[0022] Photoinitiator: 3-6 parts;

[0023] Nano silicon dioxide: 0.5-2.0 parts;

[0024] Film-forming aid: 0.2-1.5 parts;

[0025] Leveling agent: 0.1-0.5 parts;

[0026] Defoaming agent: 0.1-0.5 parts;

[0027] The epoxy acrylic resin is a graft-modified epoxy acrylic resin, which is prepared by reacting E-51 epoxy resin with acrylate monomer in the presence of benzoyl peroxide (BPO) as an initiator and then distilling under reduced pressure.

[0028] In the present invention, the epoxy acrylic resin is a graft-modified epoxy acrylic resin, and its preparation method is as follows:

[0029] 100 parts by weight of E-51 epoxy resin are dissolved in 150-300 parts of acetone to form an epoxy resin solution; 20-50 parts of acrylate monomer are added to the epoxy resin solution and mixed uniformly; 0.5-2 parts of benzoyl peroxide (BPO) are added as an initiator, the temperature is raised to 80-90° C., and the mixture is stirred and reacted for 4-6 hours at a stirring speed of 200-500 r / min; after the reaction is completed, the acetone solvent is removed by vacuum distillation at a pressure of 10-50 mmHg and a temperature of 40-60° C. to obtain a graft-modified epoxy acrylic resin.

[0030] In the present invention, the acrylic acid ester monomer is selected from at least one of butyl acrylate and methyl methacrylate.

[0031] In the present invention, the photoinitiator is at least one selected from Irgacure 1173, Irgacure 184, Omnirad 819, and Esacure KIP 150.

[0032] In the present invention, the film-forming aid is selected from ethylene glycol butyl ether, glycol ester-12, dipropylene glycol butyl ether, dipropylene glycol methyl ether or a combination thereof.

[0033] In the present invention, the average particle size of the nano-silicon dioxide is 5-50 nm.

[0034] In the present invention, the leveling agent is selected from BYK-333, TEGO Gl ide 410, EFKA-3777 or a combination thereof.

[0035] In the present invention, the defoamer is selected from TEGO 450, BYK-024, Foamaster VL or a combination thereof.

[0036] In the present invention, the preparation method of the super film pressing topcoat comprises the following steps:

[0037] a) Raw material mixing: Add epoxy acrylic resin, polyurethane acrylic resin, tripropylene glycol diacrylate, and photoinitiator in proportion at 25-35°C, stir evenly at a stirring speed of 50-200 rpm for 20-40 minutes, and cure under UV irradiation;

[0038] b) Nanofiller dispersion: Add nanosilica and disperse at high speed at 3000-6000 rpm for 15-30 min until the fineness is ≤10 μm;

[0039] c) Adding additives: Add film-forming additive, leveling agent, and defoamer in sequence, and continue stirring for 10-20 minutes to evenly disperse them;

[0040] d) Filtration and curing: Filter through a 200-400 mesh filter to remove large particles and impurities; cure under UV irradiation to obtain a topcoat;

[0041] e) Filling and storage: Fill the topcoat into a sealed container and store it away from light at a temperature of 5-30°C.

[0042] In the present invention, the UV irradiation energy is 300-1000mJ / cm 2 , curing time ≤ 3 seconds; mercury lamp, LED-UV lamp or excimer lamp is used as UV light source, and the wavelength range is 250-420nm.

[0043] Compared with traditional coatings, the topcoat of the present invention has the following advantages:

[0044] Improved physical properties: The super-film-pressed topcoat of this invention exhibits excellent adhesion and abrasion resistance. The epoxy acrylate resin and polyurethane acrylate resin act synergistically as a matrix, significantly enhancing adhesion between the coating and the substrate. 9,9-di(methyl acrylate)fluorene and 4,4'-biphenyldi(oxy-6,1-hexanediyl) diacrylate participate in the cross-linking reaction to form a dense cross-linked network, enhancing the coating's abrasion resistance.

[0045] Improved chemical properties: Tripropylene glycol diacrylate (TPGDA) acts as a reactive diluent, accelerating curing. 1-allyl-3-methylimidazolium tetrafluoroborate promotes the generation and reaction of free radicals, further increasing both the curing speed and degree of cure. Furthermore, through rational adjustment of the formulation and curing conditions, excellent film-forming properties are ensured.

[0046] Excellent environmental performance: Using active diluent TPGDA, almost no VOC emissions are generated during the curing process, meeting environmental protection requirements. DETAILED DESCRIPTION

[0047] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0048] The testing method involved in the present invention is as follows:

[0049] 1. Adhesion test

[0050] Test Method: Conduct the test in accordance with GB / T9286-1998 "Cross-cut Test for Paints and Varnishes." Use a dedicated cross-cut tool to make six vertical and horizontal cuts across the coating surface, forming a grid of 25 small squares. The cuts must penetrate the coating to the substrate. Use a soft-bristled brush to gently brush back and forth five times along the diagonal lines of the grid. Then, apply tape to the cross-cut areas. Quickly remove the tape and observe any coating shedding.

[0051] Rating standard: The rating is divided into 0-5 levels, level 0 means that the cutting edge is completely smooth and no grid has fallen off; level 1 means that there is a little coating falling off at the intersection of the cut, but the affected cross-cut area does not exceed 5%; level 2 means that the coating has fallen off at the intersection of the cut and / or along the edge of the cut, and the affected cross-cut area is greater than 5% but not more than 15%; level 3 means that the coating has fallen off in large pieces along the cutting edge, and / or has fallen off partially or completely at different parts of the grid, and the affected cross-cut area is greater than 15% but not more than 35%; level 4 means that the coating has fallen off in large pieces along the cutting edge, and / or some squares have fallen off partially or completely, and the affected cross-cut area is greater than 35% but not more than 65%; level 5 means that more than 65% of the squares have fallen off.

[0052] 2. Wear resistance test

[0053] Test Method: Test in accordance with GB / T1768-2006, "Paints and varnishes - Determination of abrasion resistance - Rotating rubber wheel method." A test panel coated with the sample is mounted on the workbench of an abrasion testing machine and subjected to abrasion testing using the specified grinding wheel, load, and speed. After the test, the panel is weighed before and after abrasion using a balance to calculate the abrasion weight loss.

[0054] The results show that the wear resistance of the coating is expressed by the abrasion weight loss (g). The smaller the abrasion weight loss, the better the wear resistance of the coating.

[0055] 3. VOC content detection

[0056] Testing method: Testing was conducted in accordance with the method specified in GB18581-2020, "Limits of Hazardous Substances in Wood Coatings." Gas chromatography-mass spectrometry (GC-MS) was used for qualitative and quantitative analysis of volatile organic compounds in the samples.

[0057] Result calculation: Calculate the VOC content (g / L) in the sample and round the result to the nearest integer.

[0058] Example 1

[0059] a) Raw material mixing

[0060] At 30°C, add the following raw materials in the mixing tank:

[0061] Epoxy acrylic resin: 40g

[0062] The epoxy acrylic resin is a graft-modified epoxy acrylic resin, and its preparation method is as follows:

[0063] 100 g of E-51 epoxy resin was dissolved in 150 g of acetone to form an epoxy resin solution; 20 g of butyl acrylate was added to the epoxy resin solution and mixed uniformly; 0.5 g of benzoyl peroxide (BPO) was added as an initiator, the temperature was raised to 80° C., and the mixture was stirred for 4 hours at a stirring speed of 200 r / min; after the reaction, the acetone solvent was removed by vacuum distillation at a pressure of 10 mmHg and a temperature of 40° C. to obtain a graft-modified epoxy acrylic resin.

[0064] Polyurethane acrylic resin: 8g

[0065] Tripropylene glycol diacrylate (TPGDA): 30g

[0066] Photoinitiator (Irgacure 1173): 4g

[0067] The stirring speed was 150 rpm and the stirring time was 30 min to form a uniform mixture.

[0068] b) Nanofiller dispersion

[0069] Add 1.5 g of nano-silicon dioxide (particle size 10 nm) and disperse at high speed at 4000 rpm for 25 min until the coating fineness is ≤ 8 μm.

[0070] c) Adding additives

[0071] Add the following additives in sequence:

[0072] Film-forming aid (ethylene glycol butyl ether): 1.0g

[0073] Leveling agent (BYK-333): 0.3g

[0074] Defoaming agent (TEGO 450): 0.2g

[0075] Continue stirring for 15 minutes to evenly disperse the additive.

[0076] d) Filtration and solidification

[0077] Filter through a 300-mesh filter to remove large particles and impurities; then cure under UV irradiation to obtain a topcoat with a UV irradiation energy of 300mJ / cm 2, curing time ≤ 3 seconds; LED-UV lamp is used as UV light source with a wavelength range of 250 to 420nm.

[0078] e) Filling and storage

[0079] Fill the topcoat into a sealed container and store it away from light at a storage temperature of 10°C.

[0080] Example 2

[0081] a) Raw material mixing

[0082] At 28°C, add the following raw materials in the mixing tank:

[0083] Epoxy acrylic resin: 50g

[0084] The epoxy acrylic resin is a graft-modified epoxy acrylic resin, and its preparation method is as follows:

[0085] 100 g of E-51 epoxy resin was dissolved in 200 g of acetone to form an epoxy resin solution; 30 g of methyl methacrylate was added to the epoxy resin solution and mixed uniformly; 1 g of benzoyl peroxide (BPO) was added as an initiator, the temperature was raised to 85° C., and the mixture was stirred for 5 hours at a stirring speed of 300 r / min; after the reaction, the acetone solvent was removed by vacuum distillation at a pressure of 25 mmHg and a temperature of 50° C. to obtain a graft-modified epoxy acrylic resin.

[0086] Polyurethane acrylic resin: 7g

[0087] Tripropylene glycol diacrylate (TPGDA): 35g

[0088] Photoinitiator (Irgacure 184): 5g

[0089] The stirring speed was 100 rpm and the stirring time was 35 min to form a uniform mixture.

[0090] b) Nanofiller dispersion

[0091] Add 1.0 g of nano-silicon dioxide (particle size 30 nm) and disperse at high speed at 5000 rpm for 20 min until the coating fineness is ≤ 9 μm.

[0092] c) Adding additives

[0093] Add the following additives in sequence:

[0094] Film-forming aid (alcohol ester-12): 0.8g

[0095] Leveling agent (TEGO Glide 410): 0.4g

[0096] Defoamer (BYK-024): 0.3g

[0097] Continue stirring for 12 minutes to evenly disperse the additive.

[0098] d) Filtration and solidification

[0099] Filter with a 250-mesh filter to remove large particles and impurities; then cure under UV irradiation to obtain the topcoat with a UV irradiation energy of 500mJ / cm 2 , curing time ≤ 3 seconds; LED-UV lamp is used as UV light source with a wavelength range of 250 to 420nm.

[0100] e) Filling and storage

[0101] Fill the topcoat into a sealed container and store it away from light at a storage temperature of 15°C.

[0102] Example 3

[0103] a) Raw material mixing

[0104] At 32°C, add the following raw materials in the mixing tank:

[0105] Epoxy acrylic resin: 55g

[0106] The epoxy acrylic resin is a graft-modified epoxy acrylic resin, and its preparation method is as follows:

[0107] 100 g of E-51 epoxy resin was dissolved in 250 g of acetone to form an epoxy resin solution; 40 g of butyl acrylate was added to the epoxy resin solution and mixed uniformly; 1.5 g of benzoyl peroxide (BPO) was added as an initiator, the temperature was raised to 85° C., and the mixture was stirred for 5 hours at a stirring speed of 400 r / min; after the reaction, the acetone solvent was removed by vacuum distillation at a pressure of 40 mmHg and a temperature of 50° C. to obtain a graft-modified epoxy acrylic resin.

[0108] Polyurethane acrylic resin: 9g

[0109] Tripropylene glycol diacrylate (TPGDA): 25g

[0110] Photoinitiator (Esacure KIP 150): 3g

[0111] The stirring speed was 200 rpm and the stirring time was 20 min to form a uniform mixture.

[0112] b) Nanofiller dispersion

[0113] Add 2.0 g of nano-silicon dioxide (particle size 50 nm) and disperse at high speed at 4500 rpm for 30 min until the coating fineness is ≤7 μm.

[0114] c) Adding additives

[0115] Add the following additives in sequence:

[0116] Film-forming aid (dipropylene glycol butyl ether): 1.2g

[0117] Leveling agent (EFKA-3777): 0.2g

[0118] Defoaming agent (Foamaster VL): 0.1g

[0119] Continue stirring for 10 minutes to evenly disperse the additive.

[0120] d) Filtration and solidification

[0121] Filter through a 400-mesh filter to remove large particles and impurities; then cure under UV irradiation to obtain a topcoat with a UV irradiation energy of 800mJ / cm 2 , curing time ≤ 3 seconds; LED-UV lamp is used as UV light source with a wavelength range of 250 to 420nm.

[0122] e) Filling and storage

[0123] Fill the topcoat into a sealed container and store it away from light at a storage temperature of 8°C.

[0124] Example 4

[0125] a) Raw material mixing

[0126] At 27°C, add the following raw materials in the mixing tank:

[0127] Epoxy acrylic resin: 60g

[0128] The epoxy acrylic resin is a graft-modified epoxy acrylic resin, and its preparation method is as follows:

[0129] 100 g of E-51 epoxy resin was dissolved in 300 g of acetone to form an epoxy resin solution; 50 g of methyl methacrylate was added to the epoxy resin solution and mixed uniformly; 2 g of benzoyl peroxide (BPO) was added as an initiator, the temperature was raised to 90° C., and the mixture was stirred for 6 hours at a stirring speed of 500 r / min; after the reaction, the acetone solvent was removed by vacuum distillation at a pressure of 50 mmHg and a temperature of 60° C. to obtain a graft-modified epoxy acrylic resin.

[0130] Polyurethane acrylic resin: 5g

[0131] Tripropylene glycol diacrylate (TPGDA): 40g

[0132] Photoinitiator (Irgacure 184): 6g

[0133] The stirring speed was 50 rpm and the stirring time was 40 min to form a uniform mixture.

[0134] b) Nanofiller dispersion

[0135] Add 0.5 g of nano-silicon dioxide (particle size 5 nm) and disperse at high speed at 6000 rpm for 15 min until the coating fineness is ≤10 μm.

[0136] c) Adding additives

[0137] Add the following additives in sequence:

[0138] Film-forming aid (dipropylene glycol methyl ether): 0.5g

[0139] Leveling agent (TEGO Glide 410): 0.5g

[0140] Defoamer (BYK-024): 0.5g

[0141] Continue stirring for 20 minutes to evenly disperse the additive.

[0142] d) Filtration and solidification

[0143] Filter through a 350-mesh filter to remove large particles and impurities; then cure under UV irradiation to obtain the topcoat with a UV irradiation energy of 1000mJ / cm 2 , curing time ≤ 3 seconds; LED-UV lamp is used as UV light source with a wavelength range of 250 to 420nm.

[0144] e) Filling and storage

[0145] Fill the topcoat into a sealed container and store it away from light at a storage temperature of 12°C.

[0146] Comparative Example

[0147] This example is the same as Example 1 except that an equal amount of E-51 epoxy resin is used to replace the graft-modified epoxy acrylic resin.

[0148] Table 1 Test results

[0149]

[0150] It can be seen from the above test data that the super film-pressed topcoat of the present invention is superior to the comparative example in adhesion, wear resistance and environmental protection performance, and has significant technical advantages.

[0151] The above description is only a preferred specific embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Any simple change or equivalent replacement of the technical solution that can be obviously obtained by any technician familiar with this technical field within the technical scope disclosed in the present invention falls within the protection scope of the present invention.

Claims

1. A method for preparing a super film pressed topcoat, characterized in that: Calculated by mass, it includes the following components in parts by mass: Epoxy acrylic resin: 40-60 parts; Polyurethane acrylic resin: 5-10 parts; Tripropylene glycol diacrylate (TPGDA): 20-40 parts; Photoinitiator: 3-6 parts; Nano silicon dioxide: 0.5-2.0 parts; Film-forming aid: 0.2-1.5 parts; Leveling agent: 0.1-0.5 parts; Defoaming agent: 0.1-0.5 parts; The epoxy acrylic resin is a graft-modified epoxy acrylic resin, which is prepared by reacting E-51 epoxy resin with acrylate monomer in the presence of benzoyl peroxide (BPO) as an initiator and then distilling under reduced pressure.

2. The method for preparing a super film-pressed topcoat according to claim 1, wherein: The epoxy acrylic resin is a graft-modified epoxy acrylic resin, and its preparation method is as follows: 100 parts by weight of E-51 epoxy resin are dissolved in 150-300 parts of acetone to form an epoxy resin solution; 20-50 parts of acrylate monomer are added to the epoxy resin solution and mixed uniformly; 0.5-2 parts of benzoyl peroxide (BPO) are added as an initiator, the temperature is raised to 80-90° C., and the mixture is stirred and reacted for 4-6 hours at a stirring speed of 200-500 r / min; after the reaction is completed, the acetone solvent is removed by vacuum distillation at a pressure of 10-50 mmHg and a temperature of 40-60° C. to obtain a graft-modified epoxy acrylic resin.

3. The method for preparing a super film-pressed topcoat according to claim 2, wherein: The acrylic acid ester monomer is selected from at least one of butyl acrylate and methyl methacrylate.

4. The method for preparing a super film-pressed topcoat according to claim 1, wherein: The photoinitiator is selected from at least one of Irgacure 1173, Irgacure 184, Omnirad 819, and Esacure KIP 150.

5. The method for preparing a super film-pressed topcoat according to claim 1, wherein: The film-forming aid is selected from ethylene glycol butyl ether, alcohol ester-12, dipropylene glycol butyl ether, dipropylene glycol methyl ether or a combination thereof.

6. The method for preparing a super film-pressed topcoat according to claim 1, wherein: The average particle size of the nano-silicon dioxide is 5-50 nm.

7. The method for preparing a super film-pressed topcoat according to claim 1, wherein: The leveling agent is selected from BYK-333, TEGO Gl ide 410, EFKA-3777 or a combination thereof.

8. The method for preparing a super film-pressed topcoat according to claim 1, wherein: The defoaming agent is selected from TEGO 450, BYK-024, Foamaster VL or a combination thereof.

9. The method for preparing a super film-pressed topcoat according to claims 1-8, characterized in that: The preparation method of the super film pressing topcoat comprises the following steps: a) Raw material mixing: Add epoxy acrylic resin, polyurethane acrylic resin, tripropylene glycol diacrylate, and photoinitiator in proportion at 25-35°C, stir evenly at a speed of 50-200 rpm for 20-40 minutes; b) Nanofiller dispersion: Add nanosilica and disperse at high speed at 3000-6000 rpm for 15-30 min until the fineness is ≤10 μm; c) Adding additives: Add film-forming additive, leveling agent, and defoamer in sequence, and continue stirring for 10-20 minutes to evenly disperse them; d) Filtration and curing: Filter through a 200-400 mesh filter to remove large particles and impurities; cure under UV irradiation to obtain a topcoat; e) Filling and storage: Fill the topcoat into a sealed container and store it away from light at a temperature of 5-30°C.

10. The method for preparing a super film-pressed topcoat according to claim 9, characterized in that: The UV irradiation energy is 300-1000 mJ / cm 2 , curing time ≤ 3 seconds; mercury lamp, LED-UV lamp or excimer lamp is used as UV light source, and the wavelength range is 250-420nm.

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