CN118638472A - An EB-cured ecological home cabinet door panel - Google Patents

Abstract

The invention relates to an EB curing ecological home cabinet door plate, which comprises a substrate layer, a bottom coating and a top coating, wherein the top coating is formed by curing a flame-retardant and reinforcing modifier compound coating through EB electron beams, and the reinforcing modifier coating comprises nano silicon powder, alumina powder and boric acid or borax powder; the bottom coating is prepared from aqueous fluorinated polyurethane or acrylic emulsion; and 2-3 layers of base coat are coated on the substrate layer, then the outer surface coating is coated, and the coated base coat is cured by EB electron beams in a nitrogen environment to obtain the EB cured ecological household cabinet door plate, and the produced cabinet door plate has the excellent performances of low cost, pollution resistance, wear resistance, corrosion resistance, high hardness, impact resistance, yellowing resistance and fingerprint resistance.

Description

An EB-cured ecological home cabinet door panel

Technical Field

The invention relates to the field of furniture, and in particular to the field of EB-cured ecological home cabinet door panels.

Background Art

Wood-based panels include natural wood-based panels and a large number of wood-based panels (plywood, particleboard, fiberboard, etc.), which are widely used in furniture, building materials and other fields. In the production process of wood-based panels, wood-based panels that have not undergone the final finishing process are called plain panels. After the surface of the plain panels is painted and cured, they can form colorful, diverse tones, and varied patterns of decorative coatings, as well as protective coatings with high surface performance and high adhesion.

However, the heat curing method consumes a lot of heat or electricity during the curing process of liquid coatings, and energy cannot be used efficiently. At the same time, the thermal curing process uses coatings containing a large amount of solvents. The solvents evaporate when heated, and the volatile organic compounds (VOCs) in them are released into the air, causing serious air pollution.

The UV curing process is an alternative to thermal curing. It triggers a radiation chemical reaction in the coating through UV irradiation, generates reactive free radicals or ions, and then triggers chain growth (polymerization/cross-linking, etc.), so that the liquid coating forms a film quickly and solidifies. Since UV curing coatings use little or no solvent, UV curing can reduce VOCs emissions during the curing production process and reduce energy consumption. However, due to the limitations of the UV curing principle, when curing thick or colored coatings containing metal powder or inorganic fillers, it is difficult for UV light to penetrate the entire coating, and multiple UV curing processes are required, which increases the complexity of the production line and the space occupied by the production line, and reduces the controllability of product quality. During UV curing, the high temperature of the UV lamp itself and the infrared section of its emission spectrum will cause the irradiated object to heat up and deform, especially when processing large-area thin plates, there will be product deformation problems, quality problems and production safety hazards. In addition, the photoinitiator used in UV curing is expensive and will also bring health risks.

Not only that, the microstructure of thermosetting paint is a two-dimensional linear interlaced structure, and the structure of UV-curing materials is mostly a 2.5-dimensional dendritic cross-linked structure. Their curing degrees are around 60% and 40%-70% respectively. Insufficient curing degree may affect the performance of subsequent related products.

Summary of the invention

The technical purpose of the present invention is to solve the problems in the background technology and provide an EB-cured ecological home cabinet door panel.

The above technical objectives of the present invention are achieved through the following technical solutions:

An EB-cured ecological home cabinet door panel is prepared by coating a multi-layer coating structure on a substrate layer and then curing it with an EB electron beam;

The multi-layer coating is coated on a substrate layer, and comprises a plurality of primer layers, a flame retardant layer and an outer layer coating from the substrate layer outward; the primer layer is composed of an aqueous fluorinated polyurethane emulsion or an acrylic emulsion, and the top coating comprises a flame retardant coating and an EB cured layer, the EB cured layer is composed of a reinforced modifier compound coating and EB electron beam cured, and the compound flame retardant in the flame retardant modified coating is prepared by melamine, a rosin-based phosphazene cross-linked flame retardant, formaldehyde and urea.

EB stands for electron beam, which is the abbreviation of the first letter of the English word Electron Beam. Just like UV is taken from the English word Ultra-Violet. Therefore, UV stands for ultraviolet light, and EB stands for electron beam. The so-called EB curing is also electron beam curing. In this scheme, under the electron beam environment, nitrogen molecules are in a plasma state. Under high energy, plasma nitrogen instantly reacts with nano-silicon, aluminum oxide and boric acid or Si, Al and B in borax coated in the surface modifier coating of the plate to generate silicon nitride Si ₃ N ₄ , aluminum nitride AlN and boron nitride BN. Silicon nitride, aluminum nitride and boron nitride are all high-hardness ceramic materials with anti-fouling, wear-resistant and anti-fingerprint properties. These nitrogen compounds evenly distributed on the outer layer of the coating have the effect of high surface performance and high adhesion strength.

Preferably, the composite reinforcing modifier is composed of three modified raw materials, and the reinforcing modifier coating raw materials are nano silicon powder, aluminum oxide powder and boric acid or borax powder respectively; the preparation process of the reinforcing modified coating is: adding the nano silicon powder, aluminum oxide powder and boric acid powder into a mixed solution of 50-65°C acrylate and waterborne polyurethane in a certain proportion and stirring to obtain the reinforcing modifier coating after the particulate matter in the solution is evenly dispersed.

Preferably, the mass fraction of reinforcing modifier nano silicon powder in the compound coating is 1-5 parts, the mass fraction of aluminum oxide powder is 1-3 parts, the mass fraction of boric acid or borax powder is 1-5 parts, and the rest is acrylic emulsion or waterborne polyurethane emulsion of conventional coating.

The advantage of the present invention is that a small amount of nano silicon powder, aluminum oxide and boric acid or borax powder is mixed into the emulsion coating, which can greatly enhance the anti-fouling, wear resistance, impact resistance, yellowing resistance and other properties of the board surface under electron beam irradiation. In addition, since the added amount is not large and only stirring is required after heating, the process is low-cost and easy to operate.

Preferably, the preparation process of the flame retardant modified coating is: 30-70 parts, 15-25 parts, 15-25 parts of melamine, formaldehyde and urea are added into a reaction kettle for dimer reaction, and after 60-90 minutes, 5-15 parts of rosin-based phosphazene cross-linked flame retardant are added as a primer to continue the reaction for 60-90 minutes to obtain a composite flame retardant modifier coating.

Preferably, the rosin-based phosphazene cross-linked flame retardant adopts chlorinated rosin acid, acrylpimaric acid, and phosphorus-containing diol, and after esterification with triethanolamine as a catalyst, an ethanol aqueous solution is added and mixed and stirred evenly, and then acetaminophen hexaaminocyclotriphosphazene is added. After stirring for a period of time, a rosin-based phosphazene cross-linked flame retardant is generated; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, and the phosphorus-containing diol and the acetaminophen hexaaminocyclotriphosphazene are 20 parts each.

The present invention has the advantage that the present invention further uses melamine, formaldehyde and urea, and adds a rosin-based phosphazene cross-linked flame retardant as a primer during the dimer reaction to effectively generate an organophosphorus grafted low-formaldehyde type environmentally friendly flame retardant, and its flame retardant, environmentally friendly and safe properties are continuously improved during the organophosphorus grafting reaction due to the introduction of functional groups such as aldehyde groups.

Preferably, the aqueous fluorinated polyurethane emulsion in the primer layer is prepared by using polyethylene adipate glycol, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG; first, the polyethylene adipate glycol is vacuum dehydrated at 120°C and placed for 2-3 hours, then diphenylmethane diisocyanate is placed in the above container, and the container is placed in a nitrogen environment at a temperature of 65-70°C, stirred for 1-2 hours, and then cooled to a temperature of 45-55°C, then DMG is added to the mixture and stirred for 30-45 minutes, and finally deionized water is added and stirred for 10-20 minutes to obtain the aqueous fluorinated polyurethane emulsion.

Preferably, the molar mass fraction of the polyethylene adipate glycol is 10-20 parts, the mass fraction of the diphenylmethane diisocyanate is 45-60 parts, the mass fraction of the fluorinated polyether polyol is 10-20 parts, the mass fraction of the guanidine-containing chain extender DMG is 5-15 parts, and the rest is deionized water.

The advantage of adopting the present invention is that the water-based fluorinated polyurethane containing DMG has good thermal properties and crystallization properties. In addition, adding it to the coating formula is very helpful in improving the antibacterial and heat-resistant properties of the board surface.

Preferably, the primer layer is sanded after being coated and cured, and then the topcoat is coated, and the coating amount of the primer layer is 30-50g/ ^m2 ; the topcoat is applied by roller coating or flow coating, and the coating amounts of the flame retardant modified layer and the enhanced modified EB cured layer in the topcoat are 10-20g/ ^m2 respectively, and the flame retardant modified layer is coated first and pre-cured, and then the enhanced modified EB cured layer is coated; after the topcoat is coated, the whole system is placed in an environment of nitrogen ( _N2 ) above 99.9% for electron beam curing.

Preferably, the number of layers of the primer layer is preferably 2-3, and each layer of the primer layer must be sanded once; the substrate board is one of an impregnated film paper veneer artificial board, a polyester film veneer panel, a polyolefin film veneer panel, an HPL veneer panel, an artificial board plain board or an inorganic fine sand board.

The advantage of adopting the present invention is that the EB-cured ecological home cabinet door panel manufactured by this scheme has excellent properties such as anti-fouling and wear resistance, high hardness, impact resistance, anti-yellowing, anti-fingerprint, and green ecology.

In summary, the present invention has the following beneficial effects:

1. By adding nano-silicon powder, alumina and boric acid or borax powder to the enhanced modified coating formula, in a nitrogen environment and under the radiation of EB high-energy electron beam, nitrogen is in a plasma state and reacts electrochemically with silicon, aluminum and boron to generate high-hardness ceramic materials on the coating surface, thereby greatly improving the wear resistance, corrosion resistance, high hardness, anti-fouling, impact resistance, anti-yellowing, anti-fingerprint and other properties of home cabinet door panels, and maintaining a green ecology and environmental friendliness in the process; by adding a specially formulated compound flame retardant, the material is difficult to burn, which is of great significance to the field of home cabinet door panels;

2. By adding water-based fluorinated polyurethane emulsion containing chain extender DMG to the primer, the antibacterial and heat resistance of the board surface can be improved;

3. The EB-cured ecological home cabinet door panel prepared by the scheme of the present invention is ecologically pollution-free, has low production cost, simple and convenient process, and can be mass-produced.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a manufacturing process flow chart of an EB-cured ecological home cabinet door panel.

DETAILED DESCRIPTION

The following specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, such modifications are protected by the patent law as long as they are within the scope of the claims of the present invention.

Example 1

(1) Preparation of modifier coating: The modifier coating is composed of three modified raw materials, namely nano-silicon powder, aluminum oxide powder and boric acid powder. The mass fraction of nano-silicon powder, aluminum oxide powder and boric acid powder in the modifier coating is 1 part, the mass fraction of aluminum oxide powder and the mass fraction of boric acid powder are 1 part, and the rest are acrylic emulsion and waterborne polyurethane emulsion of conventional coatings. The preparation process of the modifier coating is as follows: after the above-mentioned nano-silicon powder, aluminum oxide powder and boric acid powder are ground into fine powder, the fine powder is added into a mixed solution of 50°C acrylic emulsion and waterborne polyurethane emulsion, and stirred to evenly disperse the material particles in the solution to obtain the modifier coating.

(2) Preparation of composite flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by using chlorinated rosin acid, acrylpimaric acid and phosphorus-containing diol, and then adding ethanol aqueous solution to mix and stir evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added and stirred for a period of time until the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 20 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is as follows: 45 parts, 22.5 parts and 22.5 parts of melamine, formaldehyde and urea are added to the reactor respectively to carry out dimer reaction. After the reaction for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as a primer and the reaction is continued for 80 minutes to obtain the composite flame retardant.

(3) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared by using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, the polyethylene adipate is vacuum dehydrated at 120°C for 2 hours, and then the diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is 65°C. After stirring for 1 hour, it is cooled to 45°C, and then DMG is added to the mixture and stirred for 30 minutes. Finally, deionized water is added and stirred for 10 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 10 parts, the mass fraction of diphenylmethane diisocyanate is 45 parts, the mass fraction of fluorinated polyether polyol is 10 parts, the mass fraction of guanidine-containing chain extender DMG is 5 parts, and the rest is deionized water.

(4) Door panel coating: Two layers of primer are applied on the substrate layer. Each layer of primer must be cured and sanded. The coating amount of each primer layer is 30g/ ^m2 . Then the topcoat is applied. The coating amount of the flame retardant layer and the EB curing enhancement modifier layer in the topcoat is 10g/ ^m2 respectively.

(5) EB electron beam curing: The plate coated with the top coating is cured by electron beam irradiation in an atmosphere of nitrogen above 99.9% to obtain an electron beam cured cabinet door panel.

Example 2

(1) Preparation of modifier coating: The modifier coating is composed of three modified raw materials, namely nano-silicon powder, aluminum oxide powder and borax powder. The mass fraction of nano-silicon powder in the modifier coating is 5 parts, the mass fraction of aluminum oxide powder is 3 parts, the mass fraction of boric acid powder is 5 parts, and the rest is acrylic emulsion and waterborne polyurethane emulsion of conventional coatings. The preparation process of the modifier coating is as follows: after the above-mentioned nano-silicon powder, aluminum oxide powder and boric acid powder are ground into fine powder, the fine powder is added into a mixed solution of 65°C acrylic emulsion and waterborne polyurethane emulsion, and stirred to make the material particles in the solution evenly dispersed to obtain the modifier coating.

(2) Preparation of composite flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by using chlorinated rosin acid, acrylpimaric acid and phosphorus-containing diol, and then adding ethanol aqueous solution to mix and stir evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added and stirred for a period of time until the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 26 parts, the acrylpimaric acid is 38 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 18 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is to add 46 parts, 22 parts and 22 parts of melamine, formaldehyde and urea respectively into the reactor for dimer reaction. After the reaction for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as primer and the reaction is continued for 80 minutes to obtain composite flame retardant.

(3) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared by using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, the polyethylene adipate is vacuum dehydrated at 120°C for 3 hours, and then the diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is kept at 70°C. After stirring for 2 hours, it is cooled to 55°C, and then DMG is added to the mixture and stirred for 45 minutes. Finally, deionized water is added and stirred for 20 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 20 parts, the mass fraction of diphenylmethane diisocyanate is 60 parts, the mass fraction of fluorinated polyether polyol is 10 parts, the mass fraction of guanidine-containing chain extender DMG is 5 parts, and the rest is deionized water.

(4) Door panel coating: 3 layers of primer are applied on the substrate layer. Each layer of primer must be cured and sanded. The coating amount of each primer layer is 50g/ ^m2 . Then the topcoat is applied. The coating amount of the flame retardant layer and the EB curing enhancement modifier layer in the topcoat is 20g/ ^m2 respectively.

(5) EB electron beam curing: The plate coated with the top coating is cured by electron beam irradiation in an atmosphere of nitrogen above 99.9% to obtain an electron beam cured cabinet door panel.

Example 3

(1) Preparation of modifier coating: The modifier coating is composed of three modified raw materials, namely nano-silicon powder, aluminum oxide powder and boric acid powder. The mass fraction of nano-silicon powder in the modifier coating is 4 parts, the mass fraction of aluminum oxide powder is 2 parts, the mass fraction of boric acid powder is 3.5 parts, and the rest is acrylic emulsion and waterborne polyurethane emulsion of conventional coatings. The preparation process of the modifier coating is as follows: after the above-mentioned nano-silicon powder, aluminum oxide powder and boric acid powder are ground into fine powder, the fine powder is added into a mixed solution of 60°C acrylic emulsion and waterborne polyurethane emulsion, and stirred to make the material particles in the solution evenly dispersed to obtain the modifier coating.

(2) Preparation of composite flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by using chlorinated rosin acid, acrylpimaric acid and phosphorus-containing diol, and then adding ethanol aqueous solution to mix and stir evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added and stirred for a period of time until the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 20 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is to add 45 parts, 22.5 parts and 22.5 parts of melamine, formaldehyde and urea respectively into the reactor to carry out dimer reaction. After reacting for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as primer and the reaction is continued for 80 minutes to obtain composite flame retardant.

(3) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared by using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, the polyethylene adipate is vacuum dehydrated at 120°C for 2 hours, and then the diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is kept at 67°C. After stirring for 2 hours, the container is cooled to 50°C, and then DMG is added to the mixture and stirred for 40 minutes. Finally, deionized water is added and stirred for 15 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 10 parts, the mass fraction of diphenylmethane diisocyanate is 50 parts, the mass fraction of fluorinated polyether polyol is 20 parts, the mass fraction of guanidine-containing chain extender DMG is 15 parts, and the rest is deionized water.

(4) Door panel coating: Two layers of primer are applied on the substrate layer. Each layer of primer must be cured and sanded. The coating amount of each primer layer is 35g/ ^m2 . Then the topcoat is applied. The coating amount of the flame retardant layer and the EB curing enhancement modifier layer in the topcoat is 15g/ ^m2 respectively.

(5) EB electron beam curing: The plate coated with the top coating is cured by electron beam irradiation in an atmosphere of nitrogen above 99.9% to obtain an electron beam cured cabinet door panel.

Example 4

(1) Preparation of modifier coating: The modifier coating is composed of three modified raw materials, namely nano-silicon powder, aluminum oxide powder and boric acid powder. The mass fraction of nano-silicon powder in the modifier coating is 3.6 parts, the mass fraction of aluminum oxide powder is 1.8 parts, the mass fraction of boric acid powder is 3 parts, and the rest is acrylic emulsion and waterborne polyurethane emulsion of conventional coatings. The preparation process of the modifier coating is as follows: after the above-mentioned nano-silicon powder, aluminum oxide powder and boric acid powder are ground into fine powder, the fine powder is added into a mixed solution of 60°C acrylic emulsion and waterborne polyurethane emulsion, and stirred to make the material particles in the solution evenly dispersed to obtain the modifier coating.

(2) Preparation of composite flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by using chlorinated rosin acid, acrylpimaric acid and phosphorus-containing diol, and then adding ethanol aqueous solution to mix and stir evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added and stirred for a period of time until the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 20 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is as follows: 45 parts, 22.5 parts and 22.5 parts of melamine, formaldehyde and urea are added to the reactor respectively to carry out dimer reaction. After the reaction for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as a primer and the reaction is continued for 80 minutes to obtain the composite flame retardant.

(3) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, polyethylene adipate is vacuum dehydrated at 120°C for 2 hours, and then diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is 70°C. After stirring for 1.5 hours, it is cooled to 50°C, and then DMG is added to the mixture and stirred for 40 minutes. Finally, deionized water is added and stirred for 15 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 18 parts, the mass fraction of diphenylmethane diisocyanate is 54 parts, the mass fraction of fluorinated polyether polyol is 13 parts, the mass fraction of guanidine-containing chain extender DMG is 8 parts, and the rest is deionized water.

(3) Door panel coating: Two layers of primer are applied on the substrate layer. Each layer of primer is cured and sanded. The coating amount of each primer layer is 42g/ ^m2 . Then the topcoat is applied. The coating amount of the flame retardant layer and the EB curing enhancement modifier layer in the topcoat is 15g/ ^m2 respectively.

(5) EB electron beam curing: The plate coated with the top coating is cured by electron beam irradiation in an atmosphere of nitrogen above 99.9% to obtain an electron beam cured cabinet door panel.

Example 5

(1) Preparation of modifier coating: The modifier coating is composed of three modified raw materials, namely nano-silicon powder, aluminum oxide powder and boric acid powder. The mass fraction of nano-silicon powder in the modifier coating is 3.5 parts, the mass fraction of aluminum oxide powder is 1.3 parts, the mass fraction of boric acid powder is 2 parts, and the rest is acrylic emulsion and waterborne polyurethane emulsion of conventional coatings. The preparation process of the modifier coating is as follows: after the above-mentioned nano-silicon powder, aluminum oxide powder and boric acid powder are ground into fine powder, the fine powder is added into a mixed solution of 60°C acrylic emulsion and waterborne polyurethane emulsion, and stirred to make the material particles in the solution evenly dispersed to obtain the modifier coating.

(2) Preparation of composite flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by using chlorinated rosin acid, acrylpimaric acid and phosphorus-containing diol, and then adding ethanol aqueous solution to mix and stir evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added and stirred for a period of time until the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 20 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is as follows: 45 parts, 22.5 parts and 22.5 parts of melamine, formaldehyde and urea are added to the reactor respectively to carry out dimer reaction. After the reaction for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as a primer and the reaction is continued for 80 minutes to obtain the composite flame retardant.

(3) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared by using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, the polyethylene adipate is vacuum dehydrated at 120°C and placed for 2.5 hours. Then, diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is kept at 65°C. After stirring for 1 hour, it is cooled to 45°C. Then, DMG is added to the mixture and stirred for 45 minutes. Finally, deionized water is added and stirred for 20 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 15 parts, the mass fraction of diphenylmethane diisocyanate is 50 parts, the mass fraction of fluorinated polyether polyol is 16 parts, the mass fraction of guanidine-containing chain extender DMG is 9 parts, and the rest is deionized water.

(4) Door panel coating: Two layers of primer are applied on the substrate layer. Each layer of primer is cured and sanded. The coating amount of each primer layer is 40g/ ^m2 . Then the topcoat is applied. The coating amount of the flame retardant layer and the EB curing enhancement modifier layer in the topcoat is 13g/ ^m2 respectively.

(5) EB electron beam curing: The plate coated with the top coating is cured by electron beam irradiation in an atmosphere of nitrogen above 99.9% to obtain an electron beam cured cabinet door panel.

Example 6

(1) Preparation of modifier coating: The modifier coating is composed of three modified raw materials, namely nano-silicon powder, aluminum oxide powder and boric acid powder. The mass fraction of nano-silicon powder in the modifier coating is 4 parts, the mass fraction of aluminum oxide powder is 2 parts, the mass fraction of boric acid powder is 3.5 parts, and the rest is acrylic emulsion and waterborne polyurethane emulsion of conventional coatings. The preparation process of the modifier coating is as follows: after the above-mentioned nano-silicon powder, aluminum oxide powder and boric acid powder are ground into fine powder, the fine powder is added into a mixed solution of 60°C acrylic emulsion and waterborne polyurethane emulsion, and stirred to make the material particles in the solution evenly dispersed to obtain the modifier coating.

(2) Preparation of composite flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by using chlorinated rosin acid, acrylpimaric acid and phosphorus-containing diol, and then adding ethanol aqueous solution to mix and stir evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added and stirred for a period of time until the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 20 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is to add 45 parts, 22.5 parts and 22.5 parts of melamine, formaldehyde and urea respectively into the reactor to carry out dimer reaction. After reacting for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as primer and the reaction is continued for 80 minutes to obtain composite flame retardant.

(3) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared by using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, the polyethylene adipate is vacuum dehydrated at 120°C for 2 hours, and then the diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is kept at 67°C. After stirring for 2 hours, the container is cooled to 50°C, and then DMG is added to the mixture and stirred for 40 minutes. Finally, deionized water is added and stirred for 15 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 10 parts, the mass fraction of diphenylmethane diisocyanate is 50 parts, the mass fraction of fluorinated polyether polyol is 20 parts, the mass fraction of guanidine-containing chain extender DMG is 15 parts, and the rest is deionized water.

(4) Door panel coating: Two layers of primer are applied on the substrate layer. Each layer of primer must be cured and sanded. The coating amount of each primer layer is 40g/ ^m2 . Then the topcoat is applied. The coating amount of the flame retardant layer and the EB curing enhancement modifier coating in the topcoat is 16g/ ^m2 respectively.

(5) EB electron beam curing: The plate coated with the top coating is cured by electron beam irradiation in an atmosphere of nitrogen above 99.9% to obtain an electron beam cured cabinet door panel.

Comparative Example 1

(1) Preparation of compound flame retardant coating: Rosin-based phosphazene cross-linked flame retardant is prepared by acylating rosin acid, acrylpimaric acid and phosphorus-containing diol with triethanolamine as catalyst for esterification. After the esterification is completed, ethanol aqueous solution is added and mixed and stirred evenly. Then, acetaminophen hexaaminocyclotriphosphazene is added. After stirring for a period of time, the reaction is completed to generate rosin-based phosphazene cross-linked flame retardant; wherein the rosin acid is 25 parts, the acrylpimaric acid is 35 parts, the phosphorus-containing diol and acetaminophen hexaaminocyclotriphosphazene are 20 parts each; then, melamine, rosin-based phosphazene cross-linked flame retardant, urea and formaldehyde are used to prepare phosphorus-containing flame retardant adhesive. The preparation process is to add 45 parts, 22.5 parts and 22.5 parts of melamine, formaldehyde and urea respectively into a reactor for dimer reaction. After the reaction for 60 minutes, 10 parts of rosin-based phosphazene cross-linked flame retardant are added as a primer and the reaction is continued for 80 minutes to obtain a compound flame retardant, which is the top coating.

(2) Preparation of primer coating: The aqueous fluorinated polyurethane emulsion in the primer coating is prepared by using polyethylene adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and guanidine-containing chain extender DMG. First, the polyethylene adipate is vacuum dehydrated at 120°C and placed for 2 hours. Then, diphenylmethane diisocyanate is placed in the above container, and the container is filled with nitrogen atmosphere and the temperature is kept at 67°C. After stirring for 2 hours, it is cooled to 50°C. Then, DMG is added to the mixture and stirred for 40 minutes. Finally, deionized water is added and stirred for 15 minutes to obtain an aqueous fluorinated polyurethane emulsion, wherein the molar mass fraction of polyethylene adipate is 10 parts, the mass fraction of diphenylmethane diisocyanate is 50 parts, the mass fraction of fluorinated polyether polyol is 20 parts, the mass fraction of guanidine-containing chain extender DMG is 15 parts, and the rest is deionized water.

(3) Door panel coating: Two layers of primer are applied on the substrate layer. Each layer of primer is cured and sanded. The coating amount of each primer layer is 35g/ ^m2 . Then the flame retardant coating is applied at a coating amount of 15g/ ^m2 .

Comparative Example 2

Conventional home cabinet door panels on the market.

The blockboards obtained in the above-mentioned embodiments and comparative examples were subjected to hardness test, wear resistance test, yellowing resistance test and formaldehyde emission level evaluation.

The method of coating hardness test is to use a Mitsubishi test pencil of specified 1H, sharpen the pencil until the cylindrical lead core is exposed about 3mm in length (be careful not to damage the lead core), hold the pencil at a 90-degree angle with No. 400 sandpaper, and continuously circle the end face of the lead core on the sandpaper until the end face is flat and the edge of the lead core is sharp. Install it on a special pencil hardness tester, apply a load of 500gf to the tip of the pencil, and the front end of the pencil core contacts the surface to be tested. The angle between the pencil core and the surface to be tested is 45°. Push the pencil forward at a speed of 0.5mm/s~lmm/s for about 5m (try to test on the sample surface when the sample length is less than 5m), draw 5 lines in total, and rotate the pencil about 60° for each line. After the test is completed, use an eraser to erase the black pencil scratches on the paint coating surface and compare them with the test sample. The judgment standard is that no indentation or scratches are allowed on the outer surface, and indentations that can be restored within 24 hours are not judged. Problem: small scratches at the starting position (1/5 of the total length) are allowed.

The method of coating wear test is to use a special wear tester and a special paper tape produced by the manufacturer, apply a load of 175g, and drive the paper tape to rub the surface of the sample for a specified number of consecutive circles. This test must be carried out in a room with a humidity of 40%~60%. The paper tape is stored in an environment of 40%±5% humidity and 24℃±2℃. Put the paper tape into the paper supply wheel of the wear tester, and be careful not to put the paper tape upside down; the paper tape is only rubbed once with the inner surface, and it needs to be stored in a drying oven if it is not used for more than 4 hours: install and fix the sample, keep it parallel to the horizontal plane, and the sample tested area cannot be suspended, and ensure that there is a physical object inside: adjust the balance bar so that the gravity pressing on the surface of the oil coating is exactly 175g: rub 200 times. The judgment standard is to observe with a magnifying glass, and it is passed if the substrate is not exposed.

The yellowing resistance test method is to use an ultraviolet light source to irradiate the sample for 200 hours of continuous illumination. The judgment level is divided into 1-5 levels. Level 1 means that under the specified test conditions, the color of the material is almost unchanged, maintaining the original color, and has extremely high yellowing resistance; Level 2 means that the color of the material changes slightly during the test, but the change is minor and has little impact on the overall aesthetics; Level 3 means that under the test conditions, the color of the material changes significantly, but it can still maintain a certain aesthetics; Level 4 means that the color of the material changes significantly after the test, which has a great impact on the aesthetics, but it can still be used; Level 5 means that the color of the material changes very seriously after the test, which seriously affects the aesthetics and use value, and it is almost impossible to continue to use.

The formaldehyde emission level assessment method is _E1 , _E0 , and _ENF , among which _ENF is the best, and the formaldehyde emission limit is ≤0.025.

In addition, the anti-fingerprint performance of the door panels was visually observed by pressing the sample surface with fingers to ensure that the fingerprints were clearly visible. The fingerprints were carefully observed, and the number, shape and depth of fingerprints were recorded. The sample surface was scored based on the number of fingerprints on the surface. The score ranged from 1 to 10, with higher scores indicating worse anti-fingerprint performance.

The test results are as follows:

From the above data, it can be concluded that with the experimental conditions close to those of Example 4, the best ecological home cabinet door panels in the embodiments and the comparative examples can be obtained, and the results of other embodiments are also good; compared with the comparative examples, it can be clearly seen that the modifier and the compound flame retardant coating have a significant effect on improving the scratch resistance, anti-fingerprint, anti-yellowing and other properties of the board; the addition of water-based fluorinated polyurethane coating in the primer layer and the antibacterial design of the coating structure also make the combination of various materials in this scheme more complete.

Claims (9)

1. The EB curing ecological household cabinet door plate is characterized in that the EB curing ecological household cabinet door plate is prepared by a method of EB electron beam curing after a multi-layer coating framework is coated on a substrate layer;

The multi-layer coating is coated on the substrate layer, and the substrate layer is outwards provided with a plurality of bottom coatings, flame retardant layers and outer layer coatings respectively; the base coat comprises aqueous fluorinated polyurethane emulsion or acrylic emulsion, the top coat comprises a flame retardant coating and an EB curing layer, the EB curing layer is formed by adopting an enhanced modifier compound coating after EB electron beam curing, and the compound flame retardant in the flame retardant modified coating is prepared by adopting melamine, rosin-based phosphazene crosslinking flame retardant, formaldehyde and urea.

2. The EB cured ecological home cabinet door panel as defined in claim 1, wherein:

The compound enhanced modifier consists of three modified raw materials, wherein the enhanced modifier coating raw materials are nano silicon powder, aluminum oxide powder and boric acid or borax powder respectively; the preparation process of the reinforced modified paint comprises the following steps: and adding the nano silicon powder, the aluminum oxide powder and the boric acid powder into a mixed solution of acrylic ester and aqueous polyurethane at 50-65 ℃ according to a certain proportion, and stirring to uniformly disperse the particulate matters in the solution, thereby obtaining the reinforced modifier coating.

3. The EB cured ecological home cabinet door panel as defined in claim 2, wherein:

The reinforcing modifier nano silicon powder in the compound coating is 1-5 parts by weight, the alumina powder is 1-3 parts by weight, the boric acid or borax powder is 1-5 parts by weight, and the balance is the acrylic emulsion or the aqueous polyurethane emulsion of the conventional coating.

4. The EB cured ecological home cabinet door panel as defined in claim 1, wherein:

The preparation process of the flame-retardant modified paint comprises the following steps: adding 30-70 parts of melamine, 15-25 parts of formaldehyde and 15-25 parts of urea into a reaction kettle for dimer reaction, adding 5-15 parts of rosin-based phosphazene crosslinking flame retardant as a primer after 60-90min, and continuously reacting for 60-90min to obtain the compound flame retardant modifier coating.

5. The EB cured ecological home cabinet door panel as defined in claim 4, wherein:

The rosin-based phosphazene crosslinking flame retardant adopts acyl-chloridized abietic acid, acrylic pimaric acid and phosphorus-containing dihydric alcohol, ethanol aqueous solution is added after esterification by taking triethanolamine as a catalyst, the mixture is uniformly mixed and stirred, acetaminophen hexaamino cyclotriphosphazene is added, and after a period of time of stirring, the rosin-based phosphazene crosslinking flame retardant is generated; wherein, 25 parts of abietic acid, 35 parts of acrylic pimaric acid, 20 parts of phosphorus-containing dihydric alcohol and acetaminophen hexaamino cyclotriphosphazene.

6. The EB cured ecological home cabinet door panel as defined in claim 1, wherein:

The aqueous fluorinated polyurethane emulsion in the primer layer is prepared from polyethylene glycol adipate, diphenylmethane diisocyanate, fluorinated polyether polyol and a chain extender DMG containing guanidine groups; firstly, carrying out vacuum dehydration on polyethylene glycol adipate at 120 ℃ for 2-3h, then placing diphenylmethane diisocyanate into the container, placing the container in a nitrogen environment at 65-70 ℃, stirring for 1-2h, cooling to 45-55 ℃, adding DMG into the mixture, stirring for 30-45min, and finally adding deionized water, stirring for 10-20min to obtain the aqueous fluorinated polyurethane emulsion.

7. The EB cured ecological home cabinet door panel as defined in claim 6, wherein:

The polyurethane foam comprises, by mass, 10-20 parts of polyethylene glycol adipate, 45-60 parts of diphenylmethane diisocyanate, 10-20 parts of fluorinated polyether polyol, 5-15 parts of chain extender DMG containing guanidine groups and the balance of deionized water.

8. The EB cured ecological home cabinet door panel as defined in claim 1, wherein:

Sanding after the base coat is coated and cured, and then coating with the surface coating, wherein the coating amount of the base coat layer is 30-50g/m ²; the mode of the surface coating is roller coating or curtain coating, the coating amount of the flame retardant modified layer and the reinforced modified EB cured layer in the surface coating is 10-20g/m ² respectively, and the reinforced modified EB cured layer is coated after the flame retardant modified layer is pre-cured; after the top coat paint is applied, the whole system is placed in a nitrogen (N ₂) environment with the concentration of more than 99.9 percent for electron beam curing.

9. The EB cured ecological home cabinet door panel as defined in claim 1, wherein:

The number of layers of the bottom coating is preferably 2-3, and each layer of bottom coating needs sanding once; the substrate board is one of an impregnated film paper facing artificial board, a polyester film facing board, a polyolefin film facing board, an HPL facing board, an artificial board blank board or an inorganic fine sand board.