An eb-cured matte skin-feel coating, and a preparation method and application thereof

Abstract

The application discloses an EB-cured matt skin-feeling paint as well as a preparation method and application thereof, and belongs to the technical field of functional paint, and comprises the following raw materials in parts by weight: 20-30 parts of polyester modified polyurethane acrylate, 10-30 parts of organic silicon modified polyurethane acrylate, 10-30 parts of amine modified polyurethane acrylate, 20 parts of 1,6-hexanediol diacrylate, 0.2 parts of a leveling agent, 0.5 parts of a wetting agent, 0.2 parts of a defoaming agent and 1 part of silica matting powder; after being uniformly mixed in a dispersing machine, the EB-cured matt skin-feeling paint is obtained; then the paint is coated on the surface of a wood board, EB preliminary curing is carried out in an aerobic environment, then curing is carried out in an anaerobic environment by using a 172nm excimer lamp, and finally EB final curing is carried out, so that a matt skin-feeling coating with excellent comprehensive performances such as high hardness, scratch resistance, yellowing resistance and easy cleaning is formed; the curing process is more simple and efficient, and is suitable for industrialized continuous production.

Description

Technical Field

[0001] This invention belongs to the field of functional coatings technology, specifically relating to an EB-cured matte skin-feel coating, its preparation method, and its application. Background Technology

[0002] As consumers demand higher quality of life, furniture surfaces not only require excellent physical and chemical properties and aesthetically pleasing colors, but also a delicate and warm feel upon contact. The key to achieving this feel lies in the ability of the coating surface to create unique microscopic wrinkles or ripples. Currently, UV-cured coatings are commonly used to achieve this effect, typically requiring multiple processes including LED pre-curing, curing under an oxygen-free environment with a 172nm excimer lamp, and mercury lamp curing. However, existing UV curing technologies have significant drawbacks: First, photoinitiators must be added to the formula, and their residues or decomposition byproducts after curing can easily cause yellowing of the coating, affecting its appearance; second, residual photoinitiators or small molecule fragments may migrate, potentially contaminating contact items and posing potential health risks; third, the multi-step curing process is complex, requires sophisticated equipment, and increases production costs.

[0003] The invention patent with authorization announcement number CN116809356B discloses a preparation process for an initiator-free, EB-cured, yellowing-resistant, odor-free, skin-feeling wood coating. It involves three coatings: an adhesion primer, a sanding primer, and a skin-feeling topcoat. The process includes: first, applying the adhesion primer and performing EB semi-curing; then applying the sanding primer and performing EB full curing; then applying the skin-feeling topcoat and performing EB pre-curing; followed by 172nm excimer lamp curing; and finally, EB full curing. This invention achieves the effect of pre-curing the bottom layer while leaving the surface uncured through EB pre-curing. The subsequent 172nm excimer lamp curing causes uneven shrinkage in the pre-cured bottom layer, resulting in wrinkles and achieving a matte, skin-feeling effect even without an initiator. However, it requires three different functional coatings, making the curing process extremely complex and demanding on high-performance production equipment.

[0004] Therefore, developing a coating that requires no photoinitiator, has a simplified curing process, and can impart excellent matte finish and comprehensive performance has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide an EB-cured matte skin-feel coating, its preparation method, and its application, in order to solve the problems in the background art.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An EB-cured matte finish coating comprises the following raw materials in parts by weight:

[0008] 20-30 parts of polyester-modified polyurethane acrylate, 10-30 parts of silicone-modified polyurethane acrylate, 10-30 parts of amine-modified polyurethane acrylate, 20 parts of 1,6-hexanediol diacrylate, 0.2 parts of leveling agent, 0.5 parts of wetting agent, 0.2 parts of defoamer, and 1 part of silica matting powder.

[0009] Further, the polyester-modified polyurethane acrylate is prepared by the following steps:

[0010] Hydroxyethyl acrylate and hydroquinone were added to isoflurane diisocyanate and stirred until homogeneous. Then, an organotin catalyst was added dropwise, and stirring was continued for 30 minutes until homogeneous. The mixture was then slowly heated to 40-50℃ and reacted for 3-4 hours. Subsequently, adipic acid polyester diol, which had been pre-dehydrated under vacuum at 100-110℃ for 2 hours, was slowly added, and the mixture was reacted at 60-70℃ for 2.5-3.5 hours. After cooling to room temperature, polyester-modified polyurethane acrylate was obtained. The reaction process is shown below:

[0011] .

[0012] Furthermore, the ratio of isophorone diisocyanate, hydroxyethyl acrylate, hydroquinone, organotin catalyst, and adipic acid polyester diol is 100g: 58-60g: 0.18-0.3g: 0.2-0.3g: 500g; the adipic acid polyester diol is HP-1310, a polyester polyol for TPU, produced by Zhejiang Hexin Technology Co., Ltd.

[0013] Furthermore, the silicone-modified polyurethane acrylate is prepared through the following steps:

[0014] The isocyanate-functionalized silicone prepolymer was vacuum dehydrated at 60-70℃ until no bubbles were generated. After cooling to 40℃, pentaerythritol triacrylate and hydroquinone were added and stirred until homogeneous. Then, an organotin catalyst was added dropwise, and stirring was continued for 30 minutes until homogeneous. Finally, the temperature was slowly increased to 60℃ and reacted for 3-4 hours to obtain a hexafunctional silicone-modified polyurethane acrylate. The reaction process is shown below:

[0015] .

[0016] Furthermore, the ratio of the isocyanate-functionalized organosilicon prepolymer, pentaerythritol triacrylate, hydroquinone, and organotin catalyst is 500g:69-71g:0.6-1g:0.5-0.7g; the isocyanate-functionalized organosilicon prepolymer is produced by Jianyi Chemical and is designated as Silmer NCO Di-50.

[0017] Furthermore, the amine-modified polyurethane acrylate is model 7683, produced by Dongguan Huihe New Materials Co., Ltd.; the leveling agent is an acrylate copolymer solution, model 5100, produced by Anshan Huihong New Materials Chemical Co., Ltd.; the wetting agent is polyether-modified polydimethylsiloxane, model 2405, produced by Guangdong Shierli New Materials Co., Ltd.; and the defoamer is a polysiloxane mixture containing defoaming particles, model 4016, produced by Guangdong Sloco New Materials Co., Ltd.

[0018] A method for preparing an EB-cured matte skin-feel coating includes the following steps:

[0019] Weigh out the polyester-modified polyurethane acrylate, silicone-modified polyurethane acrylate, amine-modified polyurethane acrylate, 1,6-hexanediol diacrylate, leveling agent, wetting agent, defoamer, and silica matting powder according to the specified ratio, and then add them to a disperser to disperse and mix evenly to obtain EB-cured matte skin-feel coating.

[0020] The application of an EB-cured matte finish coating includes the following steps:

[0021] The EB-cured matte skin-feel coating was applied to the surface of the wood board using a 30μm wire rod. It was first initially cured with an electron beam in an oxygen-rich environment, then cured with a 172nm excimer lamp in an oxygen-free environment, and finally cured again with an electron beam.

[0022] Furthermore, the parameters for the initial curing and final curing are the same: voltage of 200kV and energy of 40kGy.

[0023] Furthermore, the energy density of the 172nm excimer lamp is 50mW / cm². 2 .

[0024] Beneficial effects:

[0025] The EB-cured matte skin-feel coating composition prepared by this invention is completely free of photoinitiators, eliminating yellowing and migration of the coating caused by photoinitiator residues or decomposition from the source, making it more environmentally friendly and safer. This invention achieves precise control over the formation of the coating surface microstructure through the synergistic effect of polyester-modified polyurethane acrylate, silicone-modified polyurethane acrylate, and amine-modified polyurethane acrylate, thereby obtaining a delicate and uniform skin-feel and a stable matte effect. Ordinary polyurethane acrylate cannot achieve the same skin-feel effect, and all three are indispensable. The introduction of silicone-modified polyurethane acrylate significantly improves the coating's stain resistance; amine-modified polyurethane acrylate helps to increase crosslinking density and hardness.

[0026] This invention employs a three-step curing process: aerobic initial curing, oxygen-free 172nm excimer lamp curing, and final curing. This ensures that the coating is fully cured internally and has a smooth, matte surface. As a result, the final coating possesses comprehensive properties such as high hardness (up to 4H-5H), excellent adhesion (grade 0), scratch resistance, yellowing resistance (low ΔE value), and easy cleaning. Compared with the multi-step process of traditional UV curing, the curing process of this invention is simpler and more efficient, making it suitable for continuous industrial production. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] This embodiment provides a polyester-modified polyurethane acrylate, which is prepared through the following steps:

[0030] Add 58g of hydroxyethyl acrylate and 0.18g of hydroquinone as a polymerization inhibitor to 100g of isoflurane diisocyanate and stir until homogeneous. Then add 0.2g of organotin catalyst dropwise and continue stirring for 30min until homogeneous. Slowly raise the temperature to 40℃ and react for 4h. Then slowly add 500g of adipic acid polyester diol (HP-1310) that has been vacuum dehydrated at 100℃ for 2h. React at 60℃ for 2.5h and cool to room temperature to obtain polyester-modified polyurethane acrylate.

[0031] Example 2

[0032] This embodiment provides a polyester-modified polyurethane acrylate, which is prepared through the following steps:

[0033] Add 59g of hydroxyethyl acrylate and 0.25g of hydroquinone as a polymerization inhibitor to 100g of isoflurane diisocyanate and stir until homogeneous. Then add 0.25g of organotin catalyst dropwise and continue stirring for 30min until homogeneous. Slowly heat to 45℃ and react for 3.5h. Then slowly add 500g of adipic acid polyester diol (HP-1310) that has been vacuum dehydrated at 110℃ for 2h. React at 65℃ for 3h. After cooling to room temperature, polyester-modified polyurethane acrylate is obtained.

[0034] Example 3

[0035] This embodiment provides a polyester-modified polyurethane acrylate, which is prepared through the following steps:

[0036] Add 60g of hydroxyethyl acrylate and 0.3g of hydroquinone as a polymerization inhibitor to 100g of isoflurane diisocyanate and stir until homogeneous. Then add 0.3g of organotin catalyst dropwise and continue stirring for 30min until homogeneous. Slowly heat to 50℃ and react for 3h. Then slowly add 500g of adipic acid polyester diol (HP-1310) that has been vacuum dehydrated at 110℃ for 2h. React at 70℃ for 2.5h. After cooling to room temperature, polyester-modified polyurethane acrylate is obtained.

[0037] Example 4

[0038] This embodiment provides a silicone-modified polyurethane acrylate, which is prepared through the following steps:

[0039] 500g of isocyanate-functionalized organosilicon prepolymer (Silmer NCO Di-50) was vacuum dehydrated at 60℃ until no bubbles were generated. After cooling to 40℃, 69g of pentaerythritol triacrylate and 0.6g of hydroquinone were added and stirred until homogeneous. Then, 0.5g of organotin catalyst was added dropwise and stirred for another 30 minutes until homogeneous. The mixture was then slowly heated to 60℃ and reacted for 3 hours to obtain organosilicon-modified polyurethane acrylate.

[0040] Example 5

[0041] This embodiment provides a silicone-modified polyurethane acrylate, which is prepared through the following steps:

[0042] 500g of isocyanate-functionalized organosilicon prepolymer (Silmer NCO Di-50) was vacuum dehydrated at 65℃ until no bubbles were generated. After cooling to 40℃, 70g of pentaerythritol triacrylate and 0.8g of hydroquinone were added and stirred until homogeneous. Then, 0.6g of organotin catalyst was added dropwise and stirred for another 30 minutes until homogeneous. The mixture was then slowly heated to 60℃ and reacted for 3.5 hours to obtain organosilicon-modified polyurethane acrylate.

[0043] Example 6

[0044] This embodiment provides a silicone-modified polyurethane acrylate, which is prepared through the following steps:

[0045] 500g of isocyanate-functionalized organosilicon prepolymer (Silmer NCO Di-50) was vacuum dehydrated at 70℃ until no bubbles were generated. After cooling to 40℃, 71g of pentaerythritol triacrylate and 1g of hydroquinone were added and stirred until homogeneous. Then, 0.7g of organotin catalyst was added dropwise and stirred for another 30 minutes until homogeneous. The mixture was then slowly heated to 60℃ and reacted for 4 hours to obtain organosilicon-modified polyurethane acrylate.

[0046] Example 7

[0047] This embodiment provides an EB-cured matte skin-feel coating, which is prepared by the following steps:

[0048] According to the weight ratio, 20 parts of polyester modified polyurethane acrylate prepared in Example 1, 20 parts of organosilicon modified polyurethane acrylate prepared in Example 4, 30 parts of amine modified polyurethane acrylate (7683), 20 parts of 1,6-hexanediol diacrylate, 0.2 parts of leveling agent 5100, 0.5 parts of wetting agent 2405, 0.2 parts of defoamer 4016 and 1 part of silica matting powder were added to a disperser and mixed evenly to obtain EB-cured matte skin-feel coating.

[0049] Example 8

[0050] This embodiment provides an EB-cured matte skin-feel coating, which is prepared by the following steps:

[0051] According to the weight ratio, 30 parts of polyester modified polyurethane acrylate prepared in Example 2, 10 parts of organosilicon modified polyurethane acrylate prepared in Example 5, 30 parts of amine modified polyurethane acrylate (7683), 20 parts of 1,6-hexanediol diacrylate, 0.2 parts of leveling agent 5100, 0.5 parts of wetting agent 2405, 0.2 parts of defoamer 4016 and 1 part of silica matting powder were added to a disperser and mixed evenly to obtain EB-cured matte skin-feel coating.

[0052] Example 9

[0053] This embodiment provides an EB-cured matte skin-feel coating, which is prepared by the following steps:

[0054] According to the weight ratio, 30 parts of polyester modified polyurethane acrylate prepared in Example 3, 30 parts of organosilicon modified polyurethane acrylate prepared in Example 6, 10 parts of amine modified polyurethane acrylate (7683), 20 parts of 1,6-hexanediol diacrylate, 0.2 parts of leveling agent 5100, 0.5 parts of wetting agent 2405, 0.2 parts of defoamer 4016 and 1 part of silica matting powder were added to a disperser and mixed evenly to obtain EB-cured matte skin-feel coating.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 7 is that commercially available ordinary polyurethane acrylate (CR93636, produced by Guangdong Haohui New Materials Co., Ltd.) was used to replace the polyester-modified polyurethane acrylate prepared in Example 1 and the silicone-modified polyurethane acrylate prepared in Example 4 in equal amounts. All other raw materials and steps are the same.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 7 is that an equal amount of commercially available ordinary polyurethane acrylate (CR93636, produced by Guangdong Haohui New Materials Co., Ltd.) was used to replace the amine-modified polyurethane acrylate, while the other raw materials and steps were the same.

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 7 is that commercially available ordinary polyurethane acrylate (CR93636, produced by Guangdong Haohui New Materials Co., Ltd.) was used to replace the silicone-modified polyurethane acrylate prepared in Example 4 in an equal amount, while the other raw materials and steps were the same.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 7 is that the amount of silicone-modified polyurethane acrylate prepared in Example 4 is changed to 10 parts by weight, and the amount of amine-modified polyurethane acrylate (7683) is changed to 40 parts by weight. All other raw materials and steps are the same.

[0063] The amounts of each raw material component used in Examples 7-9 and Comparative Examples 1-4 are detailed in Table 1 below.

[0064] Table 1

[0065] raw material Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Polyester modified polyurethane acrylate 20 30 30 0 20 20 20 Organosilicon-modified polyurethane acrylate 20 10 30 0 20 0 10 Amine-modified polyurethane acrylate 30 30 10 30 0 30 40 Commercially available polyurethane acrylate CR93636 0 0 0 40 30 20 0 1,6-Hexanediol diacrylate 20 20 20 20 20 20 20 Leveling agent 5100 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Wetting agent 2405 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Defoamer 4016 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Silica matte powder 1 1 1 1 1 1 1

[0066] The coatings obtained in Examples 7-9 and Comparative Examples 1-4 were applied to the surface of a wooden board using a 30 μm wire rod. Initial curing was performed in an oxygen-rich environment using an electron beam with a voltage of 200 kV and an energy of 40 kGy. Then, curing was carried out in an oxygen-free environment using an electron beam with an energy density of 50 mW / cm². 2 The coating was cured by a 172nm excimer lamp and then finally cured again by an electron beam with a voltage of 200kV and an energy of 40kGy to obtain the coating.

[0067] The coatings prepared according to GB / T 17657-2013 were tested for performance in Examples 7-9 and Comparative Examples 1-4, and the results are shown in Table 2:

[0068] Table 2

[0069] Test Project Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Coating skin feel effect Fine sand texture Delicate skin texture Delicate skin texture Wrinkled, rough to the touch Wrinkled, rough to the touch Delicate skin texture Fine sand texture Hardness (750g) 4H 4H 5H 3H 4H 3H 3H Yellowing resistance △E 0.43 0.4 0.45 0.57 0.96 0.67 0.41 Durable marker pen Clean easily Clean easily Clean easily Cannot be wiped off Partially wiped off Cannot be wiped off Partially wiped off Scratch resistance No mark No mark No mark Mark Slight marks Mark Slight marks Adhesion rating Level 0 Level 0 Level 0 Level 0 Level 0 Level 0 Level 0 Gloss level ° 4.6 4.8 4.9 4.7 4.6 4.8 4.9

[0070] As can be seen from the data in Table 2, the coatings formed by the coatings of Examples 7-9 of the present invention not only exhibit excellent matte and delicate skin feel effects, but also have superior hardness, yellowing resistance, stain resistance, and scratch resistance. This indicates that the synergistic effect of the raw material formulation of the present invention is crucial for forming an ideal surface structure. Comparative Examples 1-4, due to the lack of the key modified polyurethane acrylate in the raw materials of the coatings of the present invention, as well as the dosage ratio of the key modified polyurethane acrylate, showed a decline in skin feel effect, hardness, yellowing resistance, stain resistance, and scratch resistance, which confirms the necessity and superiority of the synergistic combination of the raw material components of the present invention.

[0071] In summary, this invention, through the selection, proportioning, and synergistic effects of specific components, combined with an optimized curing process, successfully prepared an EB-cured coating that is non-yellowing, non-migrating, and possesses excellent matte finish and comprehensive performance.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0073] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An EB-cured matte skin-feel coating characterized in that, The following raw materials are included by weight parts: polyester modified polyurethane acrylate 20-30 parts, organosilicon modified polyurethane acrylate 10-30 parts, amine modified polyurethane acrylate 10-30 parts, 1,6-hexanediol diacrylate 20 parts, leveling agent 0.2 parts, wetting agent 0.5 parts, defoaming agent 0.2 parts and silica matting powder 1 part; the type of the amine modified polyurethane acrylate is 7683; The polyester modified polyurethane acrylate is prepared by the following steps: hydroxyethyl acrylate and hydroquinone are added into isophorone diisocyanate and stirred to mix uniformly, then organotin catalyst is added dropwise, and stirring is continued until mixing is uniform, the temperature is raised to 40-50℃, and reaction is carried out for 3-4h, then pre-dehydrated adipic acid polyester diol is added, and reaction is carried out at 60-70℃ for 2.5-3.5h, and after cooling to room temperature, polyester modified polyurethane acrylate is obtained; the dosage ratio of the isophorone diisocyanate, hydroxyethyl acrylate, hydroquinone, organotin catalyst and adipic acid polyester diol is 100g:58-60g:0.18-0.3g:0.2-0.3g:500g; the type of the adipic acid polyester diol is HP-1310; The organosilicon modified polyurethane acrylate is prepared by the following steps: isocyanate functionalized organosilicon prepolymer is vacuum dehydrated at 60-70℃ until no bubbles are generated, then the temperature is lowered to 40℃, pentaerythritol triacrylate and hydroquinone are added and stirred to mix uniformly, then organotin catalyst is added dropwise, and stirring is continued until mixing is uniform, then the temperature is slowly raised to 60℃, and reaction is carried out for 3-4h, and organosilicon modified polyurethane acrylate is obtained; the dosage ratio of the isocyanate functionalized organosilicon prepolymer, pentaerythritol triacrylate, hydroquinone and organotin catalyst is 500g:69-71g:0.6-1g:0.5-0.7g; the type of the isocyanate functionalized organosilicon prepolymer is Silmer NCO Di-50.

2. The EB-cured matte skin-feel coating of claim 1, wherein, The type of the leveling agent is 5100; the type of the wetting agent is 2405; the type of the defoaming agent is 4016.

3. The method of preparing an EB-cured matte haptics coating according to claim 1, wherein, The following steps are included: polyester modified polyurethane acrylate, organosilicon modified polyurethane acrylate, amine modified polyurethane acrylate, 1,6-hexanediol diacrylate, leveling agent, wetting agent, defoaming agent and silica matting powder are weighed according to the ratio respectively, then they are added into a dispersing machine and dispersed to mix uniformly, and EB curing matte skin feel coating is obtained.

4. Use of an EB-cured matte haptics coating according to claim 1, characterized in that, The following steps are included: EB curing matte skin feel coating is coated on the surface of a wooden board with a 30μm wire rod, preliminary curing is carried out in an oxygen environment by using electron beam, then curing is carried out in an anaerobic environment by using 172nm excimer lamp, and finally, final curing is carried out by using electron beam.

5. Use of an EB-cured matte haptics coating according to claim 4, characterized in that, The voltage of the preliminary curing and final curing is 200kV, and the energy is 40kGy.

6. Use of an EB-cured matte haptics coating according to claim 4, characterized in that, 172 nm excimer lamp with an energy density of 50 mW / cm 2 .