Preparation method and application of colored particles based on electron beam curing

Abstract

The invention discloses a preparation method and application of colored particles based on electron beam curing, and belongs to the technical field of fine chemical engineering. Coloring particles are prepared by taking a small molecule dye as a core and taking a polymer capable of being cured by electron beam radiation as a shell, and a coloring agent paint vehicle prepared from the coloring particles is used for spraying and coloring a plate. The method has the characteristics of high curing speed and low energy consumption, avoids the key problems of thermocuring and photocuring in plate coloring and curing, and solves the problems of cracking and difficulty in curing of electron beam curing micromolecule dye in textile coloring. The paint can be widely applied to plate coloring and building material coating, and can also be applied to the fields of vehicle paint, wood, textiles and the like. Compared with the traditional coloring and curing technology, the method has the characteristics of short time consumption and low energy consumption.

Description

Technical Field

[0001] The invention relates to a preparation method and application of colored particles based on electron beam curing, belonging to the technical field of fine chemical industry. Background Art

[0002] Electron beam curing (EB curing for short) is a technology that uses high-energy electron beams to irradiate materials. It has the characteristics of fast curing speed, low energy consumption, no VOC gas emissions, and can be applied to temperature-sensitive substrates. At present, electron beam curing colorants usually include resins, curing agents, adhesives, additives and colorants such as pigments or small molecule dyes. Although electron beam curing colorants have been widely used in the field of flat sheet coating, current colorants usually exist in the form of blends, and a large amount of additives need to be added, which increases the risk of formaldehyde release. Pigments or small molecule dyes usually exist in the system in a dispersed state, and it is difficult to ensure uniformity, and small molecule dyes will have problems of migration and decomposition during the electron beam curing process.

[0003] Polymer dyes are small molecule colorants connected to polymer segments by covalent "anchoring", which can protect small molecule dyes from migration and effectively improve the color fastness of small molecule dye printing. For polymer dyes, the currently widely used curing methods are light curing and thermal curing. These curing methods require the presence of additional additives in the dyes. For example, thermal curing requires the addition of adhesives and curing agents, and light curing requires the addition of initiators. These additives will continuously release formaldehyde and VOCs, causing environmental pollution and posing a threat to human health. With the increasing requirements for green and environmentally friendly production, the development of a low-energy, fast colorant with integrated color fixation and coloring functions has great application value. Summary of the invention

[0004] [Technical issues]

[0005] During the electron beam curing process, small molecule dyes are prone to cleavage, making it difficult to achieve curing and coloring. Traditional colorant curing methods (thermal curing and light curing) require additional adhesives or initiators, which will release formaldehyde and VOC gases, causing environmental pollution.

[0006] [Technical solution]

[0007] In order to solve the above problems, the present invention designs and develops a preparation method and application of colored particles based on electron beam curing. Specifically, the present invention relates to a colored particle that can be used for electron beam curing, which has a core-shell structure, wherein the core material is a pigment or dye, and the shell material is a polymer with a wrapping and protection function and can be cured by electron beam irradiation. Since the small molecule dye is covalently anchored by the polymer, degradation and migration under electron beam radiation conditions can be avoided. At the same time, the shell material can be cured by electron beam radiation without the need for additional adhesives or initiators, which greatly reduces the release of formaldehyde and VOC gases. The invention can be widely used in plate coloring, building material coating, and can also be used in car paint, wood, textiles and other fields. Compared with traditional coloring and curing technology, it has the characteristics of short time consumption and low energy consumption.

[0008] To achieve the above objectives, the present invention provides a colored particle based on electron beam curing; the colored particle consists of a core material and a wall material; the core material includes a dye; the wall material includes a polymer that can be grafted by electron beam radiation polymerization, and the mass of the core material accounts for 0.1-8% of the mass of the wall material.

[0009] In one embodiment of the present invention, the dye includes at least one of olefin double bond anthraquinone type dyes, Disperse Violet 93, Disperse Blue 73, Disperse Blue 60, Disperse Yellow 64, Disperse Red 79, carbon black, phthalocyanine pigments, titanium white, and chrome green.

[0010] In one embodiment of the present invention, the electron beam radiation polymerizable grafted polymer comprises at least one of acrylonitrile, polyurethane, ethylene-vinyl acetate copolymer (EVA), isobornyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, methacrylic acid, and glycidyl methacrylate.

[0011] The present invention also discloses a method for preparing colored particles based on electron beam curing, comprising the following steps:

[0012] 1) Preparation of oil phase: using dye as core material and electron beam radiation polymerizable grafted polymer as wall material, adding the core material and wall material into a beaker, fully mixing and stirring, and then adding an emulsifier and an initiator to prepare an oil phase;

[0013] 2) Preparation of aqueous phase: Add emulsifier and deionized water into a beaker and stir to prepare aqueous phase;

[0014] 3) Preparation of emulsion: slowly add the oil phase prepared in step 1) to the water phase prepared in step 2), emulsify with a high-speed emulsifier, transfer the emulsified emulsion to a three-necked flask, and obtain an emulsion after mechanical stirring;

[0015] 4) Preparation of electron beam cured colored particles: Heat the emulsion obtained in step 3), reduce the rotation speed, slowly add the initiator to the emulsion several times, and obtain the electron beam cured colored particle dispersion after a period of reaction; filter, centrifuge, wash and dry to obtain the electron beam cured colored particles.

[0016] In one embodiment of the present invention, the mass of the core material accounts for 0.1-8% of the mass of the wall material.

[0017] In one embodiment of the present invention, the auxiliary emulsifier includes one or more emulsifiers selected from hexadecane, hexadecanol, glycerol, and fatty acid sorbitan.

[0018] In one embodiment of the present invention, the initiator includes at least one of dibenzoyl peroxide, azobisisobutyronitrile, azobisisoheptylnitrile, persulfate, and azobisisobutylamidine dihydrochloride.

[0019] In one embodiment of the present invention, the mass of the co-emulsifier accounts for 1-5% of the mass of the wall material.

[0020] In one embodiment of the present invention, the mass of the initiator accounts for 0.1-5% of the mass of the wall material.

[0021] In one embodiment of the present invention, the emulsifier in step (2) includes one or more of DM1501, Span 20, Span 40, Span 60, DNS-86, SR-10, TMN-10, TMN-6, sodium p-styrene sulfonate, and DNS-628.

[0022] In one embodiment of the present invention, the mass ratio of the emulsifier to the core material in step (2) is 0.5-2:1.

[0023] In one embodiment of the present invention, the mass ratio of the oil phase to the water phase in step (3) is 1:1.2-3.

[0024] In one embodiment of the present invention, the amount of the initiator added in step (4) is 0.5-5% of the total mass of the oil phase.

[0025] In one embodiment of the present invention, in step (4), the reaction temperature is 60-80° C., the rotation speed is 500-100 rpm, and the reaction time is 5-7 h.

[0026] In one embodiment of the present invention, the particle size of the electron beam cured colored particles is 100-500 nm.

[0027] The present invention also provides an application of the above-mentioned electron beam solidified colored particles in plate coloring.

[0028] In one embodiment of the present invention, the application is to color the plate by spraying the paint containing the electron beam-cured colored particles, and the colored plate can be obtained by electron beam curing.

[0029] In one embodiment of the present invention, the spraying method is to prepare the above-mentioned electron beam-curable colored particles into a paint, evenly apply it to the plate by spraying, and obtain a colored plate after electron beam curing.

[0030] In one embodiment of the present invention, the components of the paint containing electron beam cured coloring particles include 5-20% electron beam cured coloring particles, 1%-10% dispersant, 1%-10% cross-linking agent, 0.5-10% thickener, and the balance deionized water, and the viscosity of the paint is 100-2000cps.

[0031] In one embodiment of the present invention, the spraying method is to use a spray gun to spray on the plate dried at room temperature at intervals of 20-30 cm, a spraying speed of 30-60 cm / s, spraying in small amounts multiple times, and controlling the spraying thickness to be 0.5-3 mm.

[0032] In one embodiment of the present invention, the dispersant includes one or more of sodium lignin sulfonate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, styrene maleic anhydride copolymer, AX-20, and NNO.

[0033] In one embodiment of the present invention, the crosslinking agent includes one or more of hydroxyethyl acrylate, trimethylolpropane triacrylate, hydroxyethyl methacrylate, N-hydroxymethyl acrylamide, N,N-dimethyl acrylamide, acrylic acid, and dodecyl methacrylate.

[0034] In one embodiment of the present invention, the thickener includes one or more of sodium alginate, xanthan gum, starch derivatives, carboxymethyl cellulose (CMC), methyl cellulose, and polyacrylic acid polymers.

[0035] In one embodiment of the present invention, the radiation dose of the electron beam curing is 10 kGy-100 kGy, and the curing time is 0.1-3 s.

[0036] The beneficial effects of the present invention are:

[0037] (1) The present invention provides a preparation method and application of coloring particles based on electron beam curing, wherein the coloring particles are formed with a small molecule dye as a core and a polymer that can be cured by electron beam radiation as a shell, and the coloring paint prepared by the coloring particles is sprayed on the board. Compared with the paint prepared by the conventional method, the present invention prepares the coloring particles with a core-shell structure by preparing the dye and the polymerizable monomer, and then disperses the coloring particles with a crosslinking agent and a dispersant to prepare the paint. After the paint prepared by the present invention is used to color the board, the color fastness is good and the color difference is small. Most importantly, the method of the present invention helps to reduce the release of formaldehyde in the board.

[0038] (2) The method of the present invention has the characteristics of fast curing speed and low energy consumption, avoiding the key difficulties of thermal curing and light curing in the coloring and curing of the plate, and at the same time solving the problem of cracking and difficult curing of small molecule dyes by electron beam curing when the plate is colored.

[0039] (3) The colored particles of the present invention can be widely used in the fields of plate coloring, building material coating, car paint, wood, textiles, etc. Compared with the traditional coloring and curing technology, it has the characteristics of short time consumption and low energy consumption. DETAILED DESCRIPTION

[0040] The present invention is further described below through specific examples, but the embodiments of the present invention are not limited thereto.

[0041] Embodiment 1:

[0042] (1) A method for preparing colored particles based on electron beam curing

[0043] Weigh 18g of acrylonitrile and 2g of hydroxyethyl acrylate mixed solution, and weigh 0.86g of Disperse Yellow 64, slowly stir into the system to obtain an oil phase, then add 0.2g of hexadecane and 0.6g of azobisisobutyronitrile; mix 1.34g of emulsifier SR-10 and 30g of water evenly into the water phase.

[0044] Use a high-speed emulsifier to emulsify, slowly add the oil phase into the water phase during the emulsification process, set the emulsifier speed to 4000r / min, the high-speed emulsification time to 20min, then transfer the emulsified emulsion to a three-necked flask, set the oil bath temperature to 50°C, the speed to 1000r / min, and mechanically stir for 30min to obtain a pre-emulsion;

[0045] The system was heated to 70°C, the rotation speed was reduced to 700 r / min, and prepolymerization was carried out for 2 hours; the temperature was then raised to 80°C, the rotation speed was reduced to 300 r / min, and 5 mL of a 3% by mass aqueous solution of ammonium persulfate was added dropwise, and the reaction was carried out for 3 hours. 5 mL of a 3% by mass aqueous solution of ammonium persulfate was continued to be added dropwise, and the mixture was filtered and centrifuged to obtain electron beam cured colored particles.

[0046] (2) Application of electron beam cured coloring particles in plate coloring

[0047] Weigh 10 g of the electron beam cured colored particles prepared in step (1) of Example 1, add 5 g of SR-10, 1 g of trimethylolpropane triacrylate and 30 g of water to obtain a spray slurry. Spray the surface of the plate with an interval of 30 cm, a spray speed of 10 cm / s, spray in small amounts multiple times, and a coating thickness of 1 mm. After spraying evenly, perform electron beam curing with an energy of 50 kGy and a curing time of 1 s to obtain an electron beam cured colored plate.

[0048] The formaldehyde emission, light fastness and energy consumption of the colored plate prepared by the above method were evaluated. The formaldehyde emission was measured by the climate chamber method in GB18580-2001. The light fastness was determined by the national standard GB / T 17657-2013. The fixed color plate was irradiated with ultraviolet light for 300 hours, and the sample was taken out and compared with the unirradiated sample to obtain the color difference. The ΔE value test was to take different points on the same colored plate for color testing and calculate the color difference.

[0049] Example 2

[0050] The acrylonitrile in step (1) of Example 1 is adjusted to ethylene-vinyl acetate copolymer.

[0051] Example 3

[0052] The trimethylolpropane triacrylate in step (2) of Example 1 was adjusted to dodecyl methacrylate.

[0053] Example 4

[0054] The electron beam curing energy of Example 1 was adjusted to 70 kGy, and other conditions remained unchanged.

[0055] Comparative Example 1

[0056] The electron beam curing energy in Example 1 was adjusted to 5 kGy, and other conditions remained unchanged.

[0057] Comparative Example 2

[0058] The electron beam curing energy in Example 1 was adjusted to 200 kGy, and other conditions remained unchanged.

[0059] Comparative Example 3

[0060] The application in step (2) in Example 1 is adjusted to weigh the electron beam cured colored particles prepared in Example 1, the amount is 10%, 10% of trimethylolpropane triacrylate and 5% of adhesive DM5128 are added, 5% of SR-10 and the balance of deionized water are added, the electron beam curing method is adjusted to the thermal curing method, and after the spraying is completed, hot pressing is performed, the hot pressing temperature is 120°C, and the pressure is 8 MPa.

[0061] Comparative Example 4

[0062] The application in step (2) of Example 1 is adjusted to be 10% of the electron beam curing colored particles prepared in Example 1, 10% of trimethylolpropane triacrylate and 3% of photoinitiator 1173, 5% of SR-10 and the balance of deionized water. The electron beam curing method is adjusted to the light curing method, using ultraviolet light of 465nm band for curing, the distance is 15cm, and the curing time is 5min.

[0063] Comparative Example 5

[0064] The spraying slurry in step (2) of Example 1 was adjusted to commercially available plate paint. The curing method was adjusted to thermal curing, and hot pressing was performed after spraying, with a hot pressing temperature of 120° C. and a pressure of 8 MPa.

[0065] Comparative Example 6

[0066] The spraying slurry in step (2) of Example 1 is adjusted to be a commercially available plate paint. The curing method is electron beam curing.

[0067] Comparative Example 7

[0068] The spray slurry components in step (2) of Example 1 are adjusted to: 10g epoxy acrylate, 5g amino acrylate, 5g glycidyl methacrylate, dispersant 0.6g SR-10, 5g chrome green, 3g talcum powder (3000 mesh), 2g wetting agent X-405, 3g leveling agent BYK316, and the slurry is mixed with these substances.

[0069] Comparative Example 8

[0070] The spraying slurry in step (2) in Example 1 was adjusted to a mixed slurry of 10 g epoxy acrylate, 5 g amino acrylate, 5 g glycidyl methacrylate, 0.6 g SR-10 dispersant, 3 g Disperse Yellow 64, 3 g talc (3000 mesh), 2 g wetting agent X-405, and 3 g leveling agent BYK316.

[0071] Table 1 Properties of electron beam cured colored sheets

[0072]

[0073] It can be seen from Examples 1 and 4 and Comparative Examples 1 and 2 that the formaldehyde released during electron beam curing comes from the release of the sheet itself. When the electron beam radiation intensity is too low to achieve the curing effect, the crosslinking agent and the colored particles are not completely crosslinked. When the electron beam energy is large, on the one hand, it will cause excessive crosslinking and reduce the mechanical properties of the sheet, and on the other hand, it will cause the polymer to decompose and the mechanical properties to decrease, thereby causing the light fastness of the sheet to decrease.

[0074] It can be seen from Example 1 and Comparative Example 3 that the coloring effect of electron beam radiation curing is almost the same as that of thermal curing, but the energy consumption is significantly reduced, and the use of adhesives is avoided, which greatly reduces the formaldehyde emission.

[0075] It can be seen from Example 1 and Comparative Example 4 that electron beam curing can solve the problem that it is difficult to cure colored systems in UV curing systems. It is superior to UV curing in all aspects, and can avoid the use of initiators and reduce formaldehyde emissions.

[0076] It can be seen from Example 1 and Comparative Examples 5 and 6 that commercially available board paint is not suitable for electron beam curing. However, the formaldehyde emission of the electron beam cured colored particles is significantly lower than that of commercially available board paint.

[0077] It can be seen from Example 1 and Comparative Examples 7 and 8 that, compared with traditional electron beam curing coatings, the electron beam curing colored particles have extremely small color difference and are applicable to small molecule dyes, indicating that there are no problems of migration and decomposition of dye molecules during the electron beam curing process, which broadens the application scope of electron beam curing.

[0078] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A colored particle based on electron beam curing, characterized in that: The colored particles are composed of a core material and a wall material; the core material includes a dye; the wall material includes a polymer that can be grafted by electron beam radiation polymerization, and the mass of the core material accounts for 0.1-8% of the mass of the wall material.

2. The colored particle according to claim 1, characterized in that The dye includes at least one of olefin double-bond anthraquinone dyes, Disperse Violet 93, Disperse Blue 73, Disperse Blue 60, Disperse Yellow 64, Disperse Red 79, carbon black, phthalocyanine pigments, titanium white, and chrome green; the polymer that can be grafted by electron beam radiation polymerization includes at least one of acrylonitrile, polyurethane, ethylene-vinyl acetate copolymer, isobornyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, methacrylic acid, and glycidyl methacrylate.

3. The method for preparing colored particles according to claim 1 or 2, characterized in that: The following steps are involved: 1) Preparation of oil phase: using dye as core material and electron beam radiation polymerizable grafted polymer as wall material, adding the core material and wall material into a beaker, fully mixing and stirring, and then adding an emulsifier and an initiator to prepare an oil phase; 2) Preparation of aqueous phase: Add emulsifier and deionized water into a beaker and stir to prepare aqueous phase; 3) Preparation of emulsion: slowly adding the oil phase prepared in step 1) into the water phase prepared in step 2), wherein the mass ratio of the oil phase to the water phase is 1:1.2-3, emulsifying with a high-speed emulsifier, transferring the emulsified emulsion into a three-necked flask, and mechanically stirring to obtain an emulsion; 4) Preparation of electron beam cured colored particles: Heat the emulsion obtained in step 3), reduce the rotation speed, slowly add the initiator to the emulsion multiple times, and obtain an electron beam cured colored particle dispersion after a period of reaction; filter, centrifuge, wash and dry to obtain electron beam cured colored particles, the particle size of the colored particles is 100-500nm.

4. The preparation method according to claim 3, characterized in that: The auxiliary emulsifier includes one or more emulsifiers selected from hexadecane, hexadecanol, glycerol, and fatty acid sorbitan. The weight of the auxiliary emulsifier accounts for 1-5% of the weight of the wall material.

5. The preparation method according to claim 3, characterized in that: The initiator comprises at least one of dibenzoyl peroxide, azobisisobutyronitrile, azobisisoheptylonitrile, persulfate, and azobisisobutylamidine dihydrochloride, and the mass of the initiator accounts for 0.1-5% of the mass of the wall material.

6. The preparation method according to claim 3, characterized in that: The emulsifier in step (2) includes one or more of DM1501, Span 20, Span 40, Span 60, DNS-86, SR-10, TMN-10, TMN-6, sodium p-styrene sulfonate, and DNS-628, and the mass ratio of the emulsifier to the core material is 0.5-2:

1.

7. The preparation method according to claim 3, characterized in that: In step (4), the amount of the initiator added is 0.5-5% of the total mass of the oil phase, the reaction temperature is 60-80° C., the rotation speed is 500-100 rpm, and the reaction time is 5-7 h.

8. Application of the colored particles according to claim 1 or 2 in coloring a sheet, the application being to color a sheet by spraying the slurry containing the electron beam-cured colored particles, and to obtain a colored sheet by electron beam curing, wherein the radiation dose of the electron beam curing is 10 kGy-100 kGy, and the curing time is 0.1-3 s.

9. The use according to claim 8, characterized in that: Calculated by mass percentage, the components of the slurry containing electron beam cured colored particles include 5-20% electron beam cured colored particles, 1%-10% dispersant, 1%-10% crosslinking agent, 0.5-10% thickener, and the balance is deionized water. The viscosity of the paint is 100-2000cps.

10. The use according to claim 9, characterized in that: The dispersant includes one or more of sodium lignin sulfonate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, styrene maleic anhydride copolymer, AX-20, and NNO; the crosslinking agent includes one or more of hydroxyethyl acrylate, trimethylolpropane triacrylate, hydroxyethyl methacrylate, N-hydroxymethyl acrylamide, N,N-dimethyl acrylamide, acrylic acid, and dodecyl methacrylate; and the thickener includes one or more of sodium alginate, xanthan gum, starch derivatives, carboxymethyl cellulose, methyl cellulose, and polyacrylic acid polymers.

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