UV hardening liquid and preparation method and application thereof

Abstract

The application provides a UV hardening liquid and a preparation method and application thereof, the UV hardening liquid comprises a main agent and a photoinitiator; the main agent comprises the following raw materials in parts by weight: 5-15 parts of modified polyether polyol or modified polyester polyol, 5-10 parts of hydroxyl-terminated polyolefin and 0.25-0.35 parts of fluorocarbon alcohol monomer; the modified polyether polyol or the modified polyester polyol contains at least one of a cardanol structural unit and a cardol structural unit. The modified polyether polyol with a long-chain structure, the hydroxyl-terminated polyolefin and the fluorocarbon alcohol monomer are introduced into the UV hardening liquid, the UV hardening liquid can effectively improve the stain resistance and acid and alkali resistance of a cured film formed by the UV hardening liquid, and the protection effect on the surface of related products such as electronic products can be further improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of glue, and particularly relates to a UV hardening liquid and a preparation method and application thereof. BACKGROUND

[0002] 3C products (such as mobile phones, smart watches and tablet computers) need to be protected on the surface during preparation and use. PET film has good light transmission and mechanical properties and is widely used. To prevent the PET surface from being scratched, the most commonly used method is to coat a layer of hardening liquid on the surface to improve the scratch resistance, and even some products need to have certain stain resistance (low surface tension, not easy to stick to contaminants) and acid and alkali resistance during the preparation process. The UV hardening liquid has the advantages of fast curing speed, fast film forming speed and excellent scratch resistance, and is widely used in the industries of vacuum coating, PVC floor, car paint hardening coating, automobile headlamp and kitchen panel. Therefore, the UV hardening liquid has wide application prospects as a protective coating on the PET substrate.

[0003] Patent CN112980318A uses nano-aluminum oxide modified polyurethane acrylate oligomer, fluorine modified polyurethane acrylate oligomer, photoinitiator, polytetrafluoroethylene micro powder wax, modified polyurethane dispersant and ether and ester diluents to prepare a high wear-resistant and fingerprint-resistant matte UV hardening liquid. Although the wear resistance and stain resistance of the UV hardening liquid are excellent, the main UV resin has high functionality and a molecular weight of only about 1000-2500, and the cured coating has certain acid and alkali corrosion resistance, but has high shrinkage and is prone to wrinkling, affecting the appearance. Patent CN110606912A self-prepares a propylene acid resin, introduces fluorine element, and adds photoinitiator and other additives to prepare a UV hardening liquid that meets the requirements of hardness and wear resistance and also has anti-fingerprint and stain resistance, but the acid and alkali resistance is poor.

[0004] Therefore, in the prior art, there is little report on the UV hardening liquid that has excellent stain resistance and certain acid and alkali corrosion resistance. Therefore, it is of great significance to develop a UV hardening liquid that has good stain resistance and acid and alkali resistance to further improve the protection effect on the surface of related products such as electronic products. SUMMARY

[0005] To solve the problems and deficiencies in the prior art, the application provides a UV hardening liquid and a preparation method and application thereof. The modified polyether polyol with a long-chain structure, the hydroxyl-terminated polyolefin and the fluorocarbon alcohol monomer are introduced into the UV hardening liquid, which can effectively improve the stain resistance and acid and alkali resistance of the cured film formed by the UV hardening liquid, and further improve the protection effect on the surface of related products such as electronic products.

[0006] According to a first aspect of the present application, a UV hardening liquid is provided, comprising a main agent and a photoinitiator; the main agent comprises raw materials in the following weight proportions: modified polyether polyol or modified polyester polyol 5-15 parts, hydroxyl-terminated polyolefin 5-10 parts, fluorocarbon alcohol monomer 0.25-0.35 parts; the modified polyether polyol or modified polyester polyol contains at least one of cardanol structural unit and cardol structural unit.

[0007] The present application effectively improves the stain resistance and acid and alkali resistance of the cured film formed by the UV hardening liquid, and further improves the hardness of the cured film, optimizes the overall performance of the cured film, and effectively enhances the protection effect of the cured film on the surface of related products such as electronic products.

[0008] Firstly, the modified polyether polyol or modified polyester polyol of cardanol or cardol, the hydroxyl-terminated polyolefin all have long chain structures and good acid and alkali resistance, and the long chain structure can endow the UV resin with molecular chain activity after curing, improve the overall flexibility of the resin, and improve the impact resistance, so that the overall performance of the resin is further improved. The modified polyether polyol of cardanol has a benzene ring structure, which can further improve the rigidity of the resin and enhance the adhesion to the substrate, and optimize the acid and alkali resistance and adhesion of the resin.

[0009] Secondly, the modified polyether polyol or modified polyester polyol of cardanol or cardol, the hydroxyl-terminated polyolefin and the fluorocarbon alcohol monomer contain polar groups such as hydroxyl groups, which can form chemical bonds, hydrogen bonds or van der Waals forces with the surface of the adherend, so as to have a synergistic effect in improving the adhesion of the UV resin to the substrate, so that various interaction forces are formed between the resin and the substrate, including chemical bonds, hydrogen bonds and van der Waals forces, thereby greatly enhancing the adhesion of the resin to different material substrates, ensuring that the UV resin can be firmly adhered to the surface of the adherend during use. Moreover, the hydroxyl groups contained in the three substances are active groups, which can participate in the curing reaction of the UV resin, provide more additional active sites for the formation of crosslinked network, enhance the complexity and stability of the network, and further improve the rigidity and strength of the network, and improve the acid and alkali resistance of the cured resin.

[0010] Thirdly, in the fluorocarbon alcohol monomer, the electronegativity of fluorine atom is strong, so that the fluorine atom in the fluororesin molecule tends to be far away from other atoms, and a relatively sparse structure is formed on the surface of the molecular chain. This structure leads to a low surface energy of the fluorine-containing resin, which is not easy to be absorbed by water or other liquids, and thus excellent anti-fouling performance is given to the resin. Moreover, the fluorocarbon alcohol monomer can participate in the reaction of the resin and be grafted into the resin molecule, avoiding the problem of separation and stratification that occurs over time after adding an appropriate amount of leveling agent (fluorine-containing small molecule) to the main resin, thereby further improving the cohesive strength of the resin and the acid and alkali resistance of the resin. Moreover, the fluorocarbon bond in the fluorocarbon alcohol has high chemical stability and can effectively resist the corrosion of acid, alkali, salt, organic solvent and other chemicals, so that the introduction of the fluorocarbon alcohol monomer can enhance the chemical corrosion resistance of the UV resin, so that the resin can still maintain good performance in some harsh chemical environments.

[0011] In addition, the above-mentioned cardanol, cashew phenolic modified polyether polyol or modified polyester polyol, hydroxyl-terminated polyolefin, fluorocarbon alcohol monomer can further cooperate with each other, especially the three can form a good mixed system, and further make the UV resin form a more uniform, dense and flexible cross-linked network structure, and improve the comprehensive performance of the resin. Moreover, the three substances can produce a certain synergistic effect, which can further improve the mechanical properties and acid and alkali resistance of the resin, and the synergistic effect will not significantly affect the surface anti-fouling performance of the resin and the adhesion to the substrate.

[0012] Preferably, the modified polyether polyol or modified polyester polyol comprises at least one of cardanol polyether polyol and cashew nut shell oil polyester diol.

[0013] Preferably, the modified polyether polyol or modified polyester polyol comprises cardanol polyether polyol.

[0014] Preferably, the fluorocarbon alcohol monomer comprises at least one of 2-perfluorobutyl ethyl alcohol, 2-perfluorohexyl ethyl alcohol and 2-perfluorooctyl ethyl alcohol.

[0015] Preferably, the fluorocarbon alcohol monomer comprises 2-perfluorobutyl ethyl alcohol. The introduction of this fluorocarbon alcohol monomer has a more obvious effect on the optimization of the overall performance of the UV resin, especially in the anti-fouling performance and acid and alkali resistance.

[0016] Preferably, in the main agent, the mass ratio of fluorine element in the solute is 0.30-0.40wt%. Here, it means that the mass ratio of fluorine element in the main agent (i.e. the sum of other materials except the solvent) is 0.30-0.40wt%. Controlling the mass ratio of fluorine element in the solute is conducive to balancing the resin surface performance (stain resistance), mechanical properties, acid and alkali resistance, and resin uniformity. If the fluorine element is too little, the improvement effect on the stain resistance, acid and alkali resistance, hardness and other properties of the resin is not good; if the fluorine element is too much, because the fluorocarbon alcohol monomer is relatively low in polarity, the compatibility with the main resin is relatively poor, and too much addition can easily cause uneven mixing of the glue, turbidity and even stratification, which is not conducive to forming a uniform and stable cross-linked network, and deteriorating the overall performance of the resin.

[0017] Preferably, the hydroxyl value of the cardanol-modified polyether polyol is 75-98mgKOH / g; and the hydroxyl value of the hydroxyl-terminated polyolefin is 60-200mgKOH / g. Ensuring that the hydroxyl value of the cardanol-modified polyether polyol and the hydroxyl-terminated polyolefin is within the above range is conducive to ensuring that the mixed system has a certain reaction activity, improving the curing efficiency, and at the same time, promoting the uniform mixing of each component, thereby improving the performance of the resin in all aspects. If the hydroxyl value is too high, the reaction activity is too strong, which can cause the curing reaction to be too fast, generate a large amount of heat, cause uneven shrinkage of the resin, increase internal stress and other problems, affect the curing quality, and further affect the overall performance of the resin.

[0018] Preferably, the average molecular weight of the hydroxyl-terminated polyolefin is 500-2000g / mol. Controlling the average molecular weight of the hydroxyl-terminated polyolefin within the above range is conducive to making the resin have a suitable molecular weight and a good molecular weight distribution, controlling the cross-linking degree before curing, making the resin have moderate hardness after final curing, and optimizing the overall performance of the resin.

[0019] Preferably, the hydroxyl-terminated polyolefin includes hydroxyl-terminated polybutadiene (HTPB), hydroxyl-terminated hydrogenated polybutadiene (HLBH), hydroxyl-terminated butadiene-styrene liquid rubber (HTBS), and hydroxyl-terminated polyisoprene (HTPI).

[0020] Preferably, the hydroxyl-terminated polyolefin includes hydroxyl-terminated polybutadiene.

[0021] Preferably, the main agent further comprises the following raw materials by weight: 5-7.5 parts of active diluent, 5-10 parts of hydroxy acrylic monomer; the active diluent contains hydroxyl group. Further, the introduction of the above two materials containing hydroxyl group and other active groups in the main agent is beneficial to provide more active sites, further improve the density and structural stability of the cross-linked network, optimize the internal cohesive strength of the resin, and further improve the hardness and acid and alkali corrosion resistance of the resin. At the same time, the active diluent can be beneficial to the overall adhesion of the glue, promote the full dissolution of each material, improve the overall uniformity of the material, and be beneficial to the more uniform and smooth glue film after curing.

[0022] Preferably, the active diluent comprises a hydroxyl-containing multifunctional acrylate. Specifically, it can comprise at least one of dipentaerythritol pentaacrylate and pentaerythritol triacrylate.

[0023] Preferably, the active diluent comprises pentaerythritol triacrylate.

[0024] Preferably, the hydroxy acrylic monomer comprises at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0025] Preferably, the main agent further comprises the following raw materials by weight: 0.5-2.0 parts of chain extender, 10-25 parts of polyisocyanate. Further, the appropriate chain extender and polyisocyanate can increase the molecular chain length, improve the cross-linking density of the resin, and further improve the cohesive strength of the resin, thereby further improving the hardness and acid and alkali resistance of the resin. Moreover, the polyisocyanate is beneficial to improve the yellowing resistance of the resin and optimize the overall performance of the resin.

[0026] Preferably, the main agent further comprises the following raw materials by weight: 0.0025-0.005 parts of catalyst.

[0027] Preferably, the chain extender comprises at least one of ethylene glycol, butanediol, and diethylene glycol.

[0028] Preferably, the catalyst comprises at least one of bismuth carboxylate, organic mercury, organic tin, and organic zinc.

[0029] Preferably, the polyisocyanate comprises aliphatic polyisocyanate.

[0030] Preferably, the aliphatic polyisocyanate comprises at least one of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexyl methane diisocyanate, HDI trimer, HDI biuret, and IPDI trimer.

[0031] Preferably, the main agent further comprises the following raw materials by weight: 30-80 parts of first organic solvent.

[0032] Preferably, the first organic solvent comprises at least one of dimethylformamide, toluene, butanone, ethyl acetate.

[0033] Preferably, the first organic solvent is consistent with the second organic solvent.

[0034] Preferably, the photoinitiator comprises at least one of 1-hydroxy-cyclohexyl-phenyl ketone (184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropanone (907), benzoin dimethyl ether (BDK).

[0035] According to a second aspect of the present application, a preparation method of the above UV hardening liquid is provided, comprising the following steps: S1. mixing the modified polyether polyol, the hydroxyl-terminated polyolefin, the chain extender and the first part of the first organic solvent uniformly, and reacting at 50-60°C for 10-20 min to obtain a first mixed system; S2. adding the polyisocyanate to the first mixed system and mixing uniformly, and reacting at 80-90°C for 2-3 h to obtain a second mixed system; S3. when the mass content of isocyanate groups in the second mixed system is equal to 4.5-5.5%, cooling to 65-75°C, adding a mixed liquid of the catalyst, the pentaerythritol trimethylolpropane and the second part of the first organic solvent, and reacting at 65-75°C for 0.5-1 h to obtain a third mixed system; S4. adding a mixed liquid of the hydroxyacrylic monomer and the third part of the first organic solvent to the third mixed system, and continuing to react at 65-75°C for 0.5-1 h to obtain a fourth mixed system; S5. adding a mixed liquid of the fluorocarbon alcohol monomer and the fourth part of the first organic solvent to the fourth mixed system, and continuing to react at 65-75°C for 0.5-1 h to obtain a fifth mixed system; S6. after the isocyanate groups in the fifth mixed system are completely consumed, adding the fifth part of the first organic solvent, and cooling to obtain a main agent; and S7. mixing the main agent, the photoinitiator and the second organic solvent uniformly to obtain the UV hardening liquid.

[0036] By using the above preparation method, it is beneficial to obtain UV hardening liquid with suitable molecular weight and better molecular weight distribution, so that the UV cured film prepared therefrom also has suitable molecular weight and better molecular weight distribution, and it is beneficial to balance the mechanical properties (such as hardness), antifouling properties, and acid and alkali resistance of the resin, so that these properties are at a relatively high level. In S3, the content of isocyanate groups in the second mixed system needs to be equal to 4.5-5.5%, and then the catalyst and pentaerythritol trimethylol propane are further added, which is to enable grafting of the subsequent reactive substances pentaerythritol trimethylol propane and hydroxy acrylic monomer, and the content of isocyanate groups is ensured to be 4.5-5.5% in order to ensure that the main body of the prepolymer has a certain molecular weight and can graft a suitable amount of active acrylic monomer or other active substances, promote the full mixing of the components of the UV hardening liquid, and further solidify the resin after UV to obtain a resin with high crosslinking density, thereby optimizing the structural strength of the resin and further optimizing the hardness, antifouling properties, and acid and alkali resistance of the resin, etc. At the same time, the fluorocarbon alcohol monomer in S5 is introduced at the end of the polymer, which can maximize the optimization of the surface antifouling properties of the resin, and can avoid the problem that the addition of an appropriate amount of leveling agent (containing fluorine element small molecules) to the main resin will easily cause separation and stratification over time, thereby further improving the cohesive strength of the resin and improving the acid and alkali resistance and other properties of the resin.

[0037] Preferably, the second organic solvent includes at least one of dimethylformamide, toluene, butanone, and ethyl acetate.

[0038] Preferably, the first organic solvent is consistent with the second organic solvent.

[0039] Preferably, in S3, the mixed solution of the catalyst, pentaerythritol trimethylol propane, and the second part of the organic solvent is added by dripping. Preferably, in S3, the mixed solution of the catalyst, pentaerythritol trimethylol propane, and the second part of the organic solvent is added by dripping, and the dripping time is not more than 2h. Preferably, the dripping time is 1-1.5h. The dripping method is more beneficial to control the progress of the polymerization reaction and obtain a resin with suitable molecular weight and better molecular weight distribution.

[0040] Preferably, in S4, the mixed solution of the hydroxy acrylic monomer and the third part of the organic solvent is added by dripping. Preferably, in S4, the mixed solution of the hydroxy acrylic monomer and the third part of the organic solvent is added by dripping, and the dripping time is not more than 2h. Preferably, the dripping time is 1.5-2h. The dripping method is more beneficial to control the progress of the polymerization reaction and obtain a resin with suitable molecular weight and better molecular weight distribution.

[0041] Preferably, in S5, the mixture of fluorocarbon alcohol monomer and the fourth part of organic solvent is added in one time.

[0042] According to the second aspect of the present application, a cured film is provided, which is obtained by curing the UV curing liquid or the UV curing liquid prepared by the preparation method of the UV curing liquid.

[0043] According to the third aspect of the present application, a polymer film is provided, which comprises the cured film obtained by curing the UV curing liquid or the UV curing liquid prepared by the preparation method of the UV curing liquid, or the cured film. The UV curing liquid can be cured on the polymer film to form a UV cured film with uniform, high cross-linking density, strong structural stability, good adhesion to the surface of the polymer film, and low surface properties, thereby providing good protection for the surface of the polymer film.

[0044] Preferably, the material of the polymer film comprises at least one of PET, PC, PVC, ABS, PE, PP, and BOPP.

[0045] Preferably, the material of the polymer film comprises PET. DETAILED DESCRIPTION

[0046] In order to make the personnel in the technical field better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all.

[0047] Embodiment 1

[0048] In the UV curing liquid prepared in this embodiment, the main agent and 1.0wt% of the total mass of the main agent of photoinitiator are included, and the photoinitiator is 184.

[0049] (1) Raw materials are as follows:

[0050] Cashew phenol modified polyether polyol: 9.34 parts of cashew phenol modified polyether polyol (NX-9203) with a hydroxyl value of 98 mgKOH / g;

[0051] Hydroxyl-terminated polyolefin: 6.04 parts of hydroxyl-terminated polybutadiene (R-20LM) with a hydroxyl value of 101 mgKOH / g;

[0052] Catalyst: 0.003 parts of K-KAT348 bismuth carboxylate;

[0053] Chain extender: 1.44 parts of diethylene glycol (DEG);

[0054] Polyisocyanate: 19.87 parts of HDI biuret;

[0055] Active diluent: pentaerythritol triacrylate (PET3A) 5.67 parts;

[0056] Hydroxy acrylate monomer: hydroxyethyl methacrylate (HEMA) 7.23 parts;

[0057] Fluorocarbon alcohol monomer: 2-perfluorobutylethyl alcohol (DAIKINA-1420) 0.28 parts;

[0058] First organic solvent: ethyl acetate 50 parts;

[0059] Second organic solvent: ethyl acetate, added as needed.

[0060] (2) Preparation method as follows:

[0061] S1. Mix NX-9203, R-20LM, DEG and 10 parts of ethyl acetate, heat to 50-60°C, stir for 10-20 min to obtain a first mixed system;

[0062] S2. To the above first mixed system, add HDI biuret and heat to 80-90°C to reflux for 2-3 h to obtain a second mixed system;

[0063] S3. When the content of isocyanate groups in the above second mixed system is ≤4.89%, cool to 65-75°C, and add a mixture of K-KAT348, PET3A and 12.5 parts of ethyl acetate dropwise within 1-1.5 h, maintain the reaction temperature at 65-75°C, and react for 0.5-1 h to obtain a third mixed system;

[0064] S4. To the third mixed system, add HEMA and 12.5 parts of ethyl acetate dropwise, the titration time is 1.5-2.0 h, maintain the reaction temperature at 65-75°C, and react for 0.5-1 h to obtain a fourth mixed system;

[0065] S5. To the fourth mixed system, add DAIKINA-1420 and 10 parts of ethyl acetate at once, maintain the reaction temperature at 65-75°C, and react for 0.5-1 h to obtain a fifth mixed system;

[0066] S6. After the isocyanate groups in the fifth mixed system are completely consumed, add 5 parts of ethyl acetate, and cool to obtain a main agent;

[0067] S7. Dilute the above main agent with a photoinitiator in the remaining ethyl acetate to obtain a UV hardening liquid. Specifically, dilute the above main agent with the above photoinitiator in ethyl acetate to a solute mass fraction of 35 wt% to obtain a UV hardening liquid.

[0068] (3) Preparation of UV hardening adhesive film (UV cured film)

[0069] The UV hardening liquid described above was coated on 50 μm corona PET, and the coating amount was controlled to be 3-5 g / m 2 After coating, the sample was baked at 110°C for 45 s, and the curing conditions were as follows: 365-395 nm wavelength LED light curing for 15 s.

[0070] Example 2

[0071] The UV hardening liquid prepared in this example includes a main agent and 1.0 wt% of a photoinitiator based on the total mass of the main agent, and the photoinitiator is 184.

[0072] (1) The raw materials were as follows:

[0073] Cashew phenol-modified polyether polyol: cashew phenol-modified polyether polyol (NX-9203) with a hydroxyl value of 98 mgKOH / g, 9.00 parts;

[0074] Hydroxyl-terminated polyolefin: hydroxyl-terminated polybutadiene (R-20LM) with a hydroxyl value of 101 mgKOH / g, 5.82 parts;

[0075] Catalyst: K-KAT348 bismuth carboxylate, 0.003 parts;

[0076] Chain extender: diethylene glycol (DEG), 1.39 parts;

[0077] Polyisocyanate: HDI trimer, 20.20 parts;

[0078] Active diluent: pentaerythritol triacrylate (PET3A), 5.47 parts;

[0079] Hydroxy acrylate monomer: hydroxypropyl methacrylate (HPMA), 7.72 parts;

[0080] Fluorocarbon alcohol monomer: 2-perfluorobutyl ethyl alcohol (DAIKINA-1420), 0.25 parts;

[0081] First organic solvent: ethyl acetate, 50 parts;

[0082] Second organic solvent: ethyl acetate, added as needed.

[0083] (2) The UV hardening liquid preparation method was the same as in Example 1.

[0084] (3) The UV hardening adhesive film was prepared in the same manner as in Example 1.

[0085] Example 3

[0086] The UV hardening liquid prepared in this example includes a main agent and 1.0 wt% of a photoinitiator based on the total mass of the main agent, and the photoinitiator is 184.

[0087] (1) The raw materials were as follows:

[0088] Cardanol-modified polyether polyol: cardanol-modified polyether polyol (NX-9203) with a hydroxyl value of 98 mgKOH / g 6.84 parts;

[0089] Hydroxyl-terminated polyolefin: hydroxyl-terminated polybutadiene (R-20LM) with a hydroxyl value of 101 mgKOH / g 5.43 parts;

[0090] Catalyst: K-KAT348 bismuth carboxylate 0.0025 parts;

[0091] Chain extender: butanediol (BDO) 0.98 parts;

[0092] Polyisocyanate: IPDI trimer 24.25 parts;

[0093] Active diluent: pentaerythritol triacrylate (PET3A) 5.66 parts;

[0094] Hydroxy acrylic monomer: hydroxyethyl acrylate (HEA) 6.44 parts;

[0095] Fluorocarbon alcohol monomer: 2-perfluorobutylethyl alcohol (DAIKINA-1420) 0.26 parts;

[0096] First organic solvent: ethyl acetate 50 parts;

[0097] Second organic solvent: ethyl acetate, added as needed.

[0098] (2) The UV hardening liquid was prepared according to the method of Example 1.

[0099] (3) The UV hardening adhesive film was prepared according to the method of Example 1.

[0100] Example 4

[0101] The UV hardening liquid prepared in this example includes a main agent and 1.0 wt% of the total mass of the main agent of a photoinitiator, and the photoinitiator is 184.

[0102] (1) The raw materials are as follows:

[0103] Cardanol-modified polyether polyol: cardanol-modified polyether polyol (NX-9203) with a hydroxyl value of 98 mgKOH / g 12.38 parts;

[0104] Hydroxyl-terminated polyolefin: hydroxyl-terminated polybutadiene (R-20LM) with a hydroxyl value of 101 mgKOH / g 8.01 parts;

[0105] Catalyst: K-KAT348 bismuth carboxylate 0.0041 parts;

[0106] Chain extender: ethylene glycol (EG) 1.12 parts;

[0107] Polyisocyanate: IPDI 14.00 parts;

[0108] Active diluent: pentaerythritol triacrylate (PET3A) 6.18 parts;

[0109] Hydroxy acrylate monomer: hydroxypropyl acrylate (HPA) 7.87 parts;

[0110] Fluorocarbon alcohol monomer: 2-perfluorobutyl ethyl alcohol (DAIKINA-1420) 0.26 parts;

[0111] First organic solvent: ethyl acetate 50 parts;

[0112] Second organic solvent: ethyl acetate, added as needed.

[0113] (2) The UV curing liquid preparation method is the same as in Example 1.

[0114] (3) The UV curing adhesive film is prepared in the same manner as in Example 1.

[0115] Example 5

[0116] This example differs from Example 1 in that the fluorocarbon alcohol monomer is adjusted to be a mixture of 2-perfluorobutyl ethyl alcohol and 2-perfluorooctyl ethyl alcohol, and the mass ratio of 2-perfluorobutyl ethyl alcohol to 2-perfluorooctyl ethyl alcohol is 1:1, and the total mass of the fluorocarbon alcohol monomer remains unchanged. The rest is the same as in Example 1.

[0117] Example 6

[0118] This example differs from Example 1 in that the fluorocarbon alcohol monomer is adjusted to be a mixture of 2-perfluorobutyl ethyl alcohol and 2-perfluorooctyl ethyl alcohol, and the mass ratio of 2-perfluorobutyl ethyl alcohol to 2-perfluorooctyl ethyl alcohol is 1:1, and the total mass of the fluorocarbon alcohol monomer remains unchanged. The rest is the same as in Example 1.

[0119] Example 7

[0120] This example differs from Example 1 in that the mass fraction of 2-perfluorobutyl ethyl alcohol in the fluorocarbon alcohol monomer is adjusted to 0.32 parts, so that the mass percentage of fluorine element in the solute is 0.415wt%. The rest is the same as in Example 1.

[0121] Example 8

[0122] This example differs from Example 1 in that the mass fraction of 2-perfluorobutyl ethyl alcohol in the fluorocarbon alcohol monomer is adjusted to 0.14, so that the mass percentage of fluorine element in the solute is 0.182wt%. The rest is the same as in Example 1.

[0123] Example 9

[0124] The difference between this example and Example 1 is that the raw material cashew phenol modified polyether polyol is adjusted to cashew shell oil polyester diol NX-9201LP with a hydroxyl value of 70 mgKOH / g. The rest is consistent with Example 1.

[0125] Example 10

[0126] The difference between this example and Example 1 is that the hydroxyl value of the raw material hydroxyl-terminated polybutadiene is 40 mgKOH / g. The rest is consistent with Example 1.

[0127] Example 11

[0128] The difference between this example and Example 1 is that the pentaerythritol triacrylate is adjusted to dipentaerythritol pentaacrylate, and the fraction is adjusted to 9.89 parts. The rest is consistent with Example 1.

[0129] Example 12

[0130] The difference between this example and Example 1 is that the amount of hydroxyethyl methacrylate (HEMA) in the raw material hydroxyacrylic monomer is adjusted to 12 parts. The rest is consistent with Example 1.

[0131] Example 13

[0132] The difference between this example and Example 1 is that in the process of preparing the UV hardening liquid, in S3, the content of isocyanate groups in the second mixed system is controlled to be equal to 4% and then the temperature is lowered. The rest is consistent with Example 1.

[0133] Comparative Example 1

[0134] The UV hardening liquid prepared in this comparative example includes a main agent and a photoinitiator accounting for 1.0 wt% of the total mass of the main agent, and the photoinitiator is 184.

[0135] (1) Raw materials are as follows:

[0136] Hydroxyl-terminated polyolefin: hydroxyl-terminated polybutadiene (R-20LM) with a hydroxyl value of 101 mgKOH / g 13.63 parts;

[0137] Catalyst: K-KAT348 bismuth carboxylate 0.0027 parts;

[0138] Chain extender: diethylene glycol (DEG) 1.30 parts;

[0139] Polyisocyanate: HDI biuret 17.92 parts;

[0140] Active diluent: pentaerythritol triacrylate (PET3A) 7.31 parts;

[0141] Hydroxyacrylic monomer: hydroxyethyl methacrylate (HEMA) 9.31 parts;

[0142] Fluorocarbon alcohol monomer: 2-perfluorobutyl ethyl alcohol (DAIKINA-1420) 0.32 parts;

[0143] First organic solvent: ethyl acetate 50 parts;

[0144] Second organic solvent: ethyl acetate, added as needed.

[0145] (2) The UV curing liquid was prepared according to the method of Example 1.

[0146] (3) The UV curing adhesive film was prepared according to the method of Example 1.

[0147] Comparative Example 2

[0148] The UV curing liquid prepared in this comparative example comprises a main agent and a photoinitiator accounting for 1.0 wt% of the total mass of the main agent, and the photoinitiator is 184.

[0149] (1) The raw materials are as follows:

[0150] Cashew phenol modified polyether polyol: cashew phenol modified polyether polyol (NX-9203) with a hydroxyl value of 98 mgKOH / g 16.78 parts;

[0151] Catalyst: K-KAT348 bismuth carboxylate 0.0034 parts;

[0152] Chain extender: diethylene glycol (DEG) 1.55 parts;

[0153] Polyisocyanate: HDI biuret 21.42 parts;

[0154] Active diluent: pentaerythritol triacrylate (PET3A) 4.37 parts;

[0155] Hydroxy acrylate monomer: hydroxyethyl methacrylate (HEMA) 5.56 parts;

[0156] Fluorocarbon alcohol monomer: 2-perfluorobutyl ethyl alcohol (DAIKINA-1420) 0.31 parts;

[0157] First organic solvent: ethyl acetate 50 parts;

[0158] Second organic solvent: ethyl acetate, added as needed.

[0159] (2) The UV curing liquid was prepared according to the method of Example 1.

[0160] (3) The UV curing adhesive film was prepared according to the method of Example 1.

[0161] Comparative Example 3

[0162] The present comparative example differs from Example 1 in that, among the raw materials used, the cashew phenolic modified polyether polyol is adjusted to be a polypropylene oxide polyether polyol (PPG-1000) with a hydroxyl value of 112 mgKOH / g. The rest is consistent with Example 1.

[0163] Comparative Example 4

[0164] The present comparative example differs from Example 1 in that, among the raw materials used, the hydroxyl-terminated polybutadiene is adjusted to be a polybutylene adipate polyol (PBA-1000) with a hydroxyl value of 112 mgKOH / g. The rest is consistent with Example 1.

[0165] Comparative Example 5

[0166] The present comparative example differs from Example 1 in that, among the raw materials used, the fluorocarbon alcohol monomer, i.e. 2-perfluorobutyl ethyl alcohol, is not contained, i.e. the S5 step in the preparation method is not performed. The rest is consistent with Example 1.

[0167] Comparative Example 6

[0168] The present comparative example differs from Example 1 in that, among the raw materials used, the fluorocarbon alcohol monomer 2-perfluorobutyl ethyl alcohol is adjusted to be perfluoro-2,5-dimethyl-3,6-dioxaoctanoic acid; and in the preparation method of the UV hardening liquid, the step of S5 is not performed, and in S7, the main agent, the photoinitiator and the above-mentioned perfluoro-2,5-dimethyl-3,6-dioxaoctanoic acid are directly mixed to obtain the UV hardening liquid. The rest is consistent with Example 1.

[0169] Test Example

[0170] 1. Experimental construction

[0171] The products obtained in (3) of all the above examples and comparative examples are taken as test objects, and the following performance tests are carried out:

[0172] a. Corona value test: first clean the surface of the test object and lay it flat on a horizontal table, draw a line on the surface of the primer layer of the test object with a corona pen, if the liquid does not shrink within three seconds, the corona pen selected daoyin value is reached, otherwise it is not reached. The lower the corona value, the smaller the surface tension of the substrate, and the better the surface stain resistance.

[0173] b. Adhesion test: according to GB / T9286-1998, coat the coating on a 50 μm PET original film, control the coating thickness to be 3-5 g / m 2 , draw 100 small squares with a 1 mm interval crosshatch knife, paste the M600 or 610 tape in the crosshatch, quickly pull up the 3M tape, and test the number of peeling.

[0174] c. Pencil hardness test: According to GB / T6739-2006 "Pencil method for testing the hardness of paint films", select the appropriate hardness pencil to test the prepared sample, if the paint film appears plastic deformation or cohesive failure during the test, use a lower hardness pencil to test, until the pencil is drawn, the paint film no longer appears to be damaged, repeat 3 times, the results are consistent, then determine the pencil hardness as the pencil with the same hardness.

[0175] d. Acid and alkali resistance test: Place the prepared paint film in 25% sulfuric acid and 25% NaOH solution, 80°C for 1 day, wipe off the surface of sulfuric acid or NaOH, and test the pencil hardness.

[0176] 2. Experimental results

[0177] The related properties of the UV-cured adhesive film after curing of the UV-curing liquid of all the above examples and comparative examples are shown in Table 1.

[0178] Table 1: Related property results of the UV-cured adhesive film after curing of the UV-curing liquid of examples and comparative examples

[0179]

[0180]

[0181] It should be noted that the calculation method of the fluorine element content in Table 1 above is: fluorine element content = [(fluorine element relative atomic mass x atomic number) / fluorine monomer relative molecular mass] x fluorine monomer mass / total amount of the system (excluding solvent). For example 1: fluorine element content = [(19 x 9) / 264 x 0.28] / (9.34 + 6.04 + 0.003 + 1.44 + 19.87 + 5.67 + 7.23 + 0.28) = 0.364%, the molecular formula of the fluorine monomer in example 1 is C6H5F9O, and the molar mass is 264 g / mol.

[0182] As can be seen from Table 1, the long-chain structure of the cashew phenol modified polyether polyol, the hydroxyl-terminated polyolefin and the fluorocarbon alcohol monomer introduced into the UV-curing liquid can effectively improve the stain resistance and acid and alkali resistance of the cured film formed by the UV-curing liquid, and can further improve the protection effect on the surface of related products such as electronic products. For specific reference, see examples 1-13.

[0183] No modified polyether polyol or modified polyester polyol was added in Comparative Example 1; no hydroxyl-terminated polyolefin was added in Comparative Example 2; the cashew phenol-modified polyether polyol in Example 1 was replaced by a polyoxypropylene polyether polyol in Comparative Example 3; the hydroxyl-terminated polybutadiene in Example 1 was adjusted to a polybutylene adipate polyester polyol in Comparative Example 4; no fluorocarbon alcohol monomer was contained in Comparative Example 5; and the fluorocarbon alcohol monomer in Comparative Example 6 was a commonly used leveling agent fluorine-containing small molecule perfluoro-2,5-dimethyl-3,6-dioxaoctanoic acid, which did not participate in the reaction and was directly mixed with other materials to obtain the UV hardening liquid. These factors caused the cured film in Comparative Examples 1 to 4 to have a significant decrease in adhesion or acid and alkali resistance, the cured film in Comparative Example 5 had a significant decrease in stain resistance, and the cured film in Comparative Example 6 was initially transparent but became hazy over time, which did not meet the standard of transparency required for the cured film and lost the significance of performance evaluation (the cured films of other examples and comparative examples were transparent). This indicates that the mutual matching of the modified polyether polyol or modified polyester polyol, the hydroxyl-terminated polyolefin, and the fluorocarbon alcohol monomer in the present application is crucial for the cured film obtained by curing the UV hardening liquid to have good stain resistance, adhesion, acid and alkali resistance, and other properties.

[0184] Further comparison of Example 1 with Examples 5 and 6 shows that the fluorocarbon alcohol monomer in Example 5 is 2-perfluorohexylethanol, the fluorocarbon alcohol monomer in Example 6 is 2-perfluorobutylethanol and 2-perfluorooctylethanol, the cured film in Examples 5 and 6 has a higher corona value (worse stain resistance), and the adhesion of the cured film is also decreased. This indicates that when the fluorocarbon alcohol monomer is 2-perfluorohexylethanol, it is more conducive to optimizing the stain resistance and adhesion of the cured film formed after curing the UV hardening liquid and further improving the overall performance of the cured film.

[0185] Comparison of Example 1 with Examples 7 and 8 shows that the content of the fluorocarbon alcohol monomer 2-perfluorobutylethanol in Examples 7 and 8 is too high and too low, respectively (the fluorine content is too high and too low, respectively), which causes the adhesion of the cured film in Example 7 to be decreased and the corona value of the cured film in Example 8 to be increased, i.e., the stain resistance is deteriorated. This indicates that further controlling the fluorine content within a specific range is conducive to balancing the adhesion and stain resistance of the cured film, i.e., it is more conducive to improving the overall performance of the cured film.

[0186] Comparison of Example 1 with Examples 9 and 10 shows that the cashew shell oil polyester diol used in Example 9 has a relatively low hydroxyl value, and the hydroxyl-terminated polybutadiene used in Example 10 has a low hydroxyl value, which causes the adhesion of the cured film in Examples 9 and 10 to be decreased. Therefore, it is necessary to ensure that the hydroxyl value is within a certain range, which is more conducive to improving the overall performance of the cured film.

[0187] Comparing example 1 with example 11 and 12, the kind of active diluent in example 11 is dipentaerythritol pentaacrylate, and the amount of hydroxyl acrylate monomer hydroxyethyl methacrylate in example 12 is higher, which causes the adhesion and acid and alkali resistance of the cured film in example 11 to decrease, and the alkali resistance of the cured film in example 12 to decrease, which shows that the appropriate active diluent needs to be selected and the amount of hydroxyl acrylate monomer needs to be controlled within a certain range, which is more conducive to the performance of the cured film in all aspects being taken into account.

[0188] Comparing example 1 with example 13, in example 13, in S3, the content of isocyanate groups in the second mixed system is controlled to be equal to 3%, and then the temperature is lowered, which causes there being not enough isocyanate groups to react with the hydroxyl groups of the active diluent and the hydroxyl acrylate monomer in the subsequent step, which leads to the adhesion of the cured film after the UV hardening liquid obtained in the subsequent step is cured to decrease obviously.

[0189] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the above examples, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently, but these modifications or replacements are within the protection scope of the present application.

Claims

1. A method for preparing a UV curing liquid, characterized in that, Includes the following steps: S1. Mix 5-15 parts by weight of modified polyether polyol, 5-10 parts by weight of hydroxyl-terminated polyolefin, chain extender and first organic solvent of the first part evenly, and heat to 50-60℃ and react for 10-20 min to obtain the first mixed system; S2. Add polyisocyanate to the first mixture, mix evenly, and heat to 80-90℃ for 2-3 hours to obtain the second mixture. S3. When the mass content of isocyanate groups in the second mixture is equal to 4.5-5.5%, the temperature is lowered to 65-75°C, and a mixture of catalyst, pentaerythritol triacrylate and the second part of the first organic solvent is added. The mixture is then reacted at 65-75°C for 0.5-1 h to obtain the third mixture. S4. Add the mixture of hydroxyacrylic acid monomer and the first organic solvent in the third part to the third mixture system, and continue the reaction at 65-75℃ for 0.5-1h to obtain the fourth mixture system. S5. Add 0.25-0.35 parts by weight of fluorocarbon alcohol monomer and the mixture of the first organic solvent in the fourth part to the fourth mixture system, and continue to react at 65-75°C for 0.5-1 h to obtain the fifth mixture system; S6. After the isocyanate groups in the fifth mixture are completely consumed, the first organic solvent in the fifth part is added to it, and the mixture is cooled to obtain the main agent; S7. Mix the main agent, photoinitiator and second organic solvent evenly to obtain a UV curing liquid; The modified polyether polyol contains at least one of the cashew phenol structural units and cashew diol structural units.

2. The method for preparing the UV curing liquid as described in claim 1, characterized in that: The fluorocarbon alcohol monomer includes at least one of 2-perfluorobutylethyl alcohol, 2-perfluorohexylethyl alcohol, and 2-perfluorooctylethyl alcohol.

3. The method for preparing the UV curing liquid as described in claim 1, characterized in that: The modified polyether polyol contains the cashew phenol structural unit and has a hydroxyl value of 70-98 mgKOH / g; The hydroxyl value of the terminal hydroxyl polyolefin is 60-200 mg KOH / g.

4. The method for preparing the UV curing liquid as described in claim 1, characterized in that: The average molecular weight of the terminal hydroxyl polyolefin is 500-2000 g / mol.

5. The method for preparing the UV curing liquid as described in claim 1, characterized in that: The amount of the hydroxyacrylic acid monomer used is 5-10 parts by weight.

6. The method for preparing the UV curing liquid as described in claim 1, characterized in that, The chain extender is used in an amount of 0.5-2.0 parts by weight, and the polyisocyanate is used in an amount of 10-25 parts by weight.

7. A UV curing liquid, characterized in that: It is prepared by the method for preparing UV curing liquid as described in any one of claims 1 to 6.

8. A cured film, characterized in that: The UV curing liquid is prepared by the method of any one of claims 1-6 or obtained by curing the UV curing liquid as described in claim 7.

9. A polymer film, characterized in that, The UV curing liquid prepared by the method of any one of claims 1-6, or the cured film obtained by curing the UV curing liquid as described in claim 7, or the cured film as described in claim 8.

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