UV hardening liquid and preparation method thereof

Abstract

The invention provides a UV hardening liquid and a preparation method thereof, and the UV hardening liquid is prepared from the following materials: organic and inorganic hybrid resin, hyperbranched polyurethane acrylate, fluorine modified epoxy acrylate, isobornyl acrylate, tripropylene glycol diacrylate, a thiol diluent, a photoinitiator, nano aluminum oxide, benzotriazole, hindered amine and a silane coupling agent. The photoinitiator comprises a photoinitiator TPO-L and a photoinitiator 819; the benzotriazole comprises UV-1; and the hindered amine comprises HALS-2. The UV hardening liquid disclosed by the invention can be rapidly cured through low energy to form a UV hardening layer with high wear resistance, high hardness and yellowing resistance.

Description

TECHNICAL FIELD

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

[0002] As a core carrier of high-end anti-counterfeiting labels, the holographic anti-counterfeiting Patch film realizes dynamic optical effects through micro-nano structures (such as gratings, pixel arrays) formed by laser interference, and can be widely applied to fields such as financial cards (bank cards, credit cards), legal certificates (identity cards, passports) and traffic tickets (subway cards, access control cards). The Patch film is a double-PET structure, and its traditional structure includes, in sequence, a glue layer, a plating layer, an imaging layer, a PET base film, a UV hardening layer, a connecting layer and a PET carrier layer. In use, the glue layer is adhered to the card base material, and the connecting layer and the PET carrier layer are torn off, exposing the UV hardening layer.

[0003] Bank cards, identity cards, membership cards, work cards and the like have become an essential part of people's lives, and in daily use, the cards are inevitably subjected to various degrees of friction and light, and as the top layer directly contacting the external environment, the UV hardening layer needs to meet the requirements of mechanical protection, optical stability and long-term durability.

[0004] However, the prior art solutions have certain technical contradictions, such as the contradiction between hardness and flexibility: a high cross-linking density formula can achieve a hardness of ≥3H pencil, but it causes the film layer to be brittle, and micro-cracks occur when the card is bent. Insufficient wear resistance, such as the holographic pattern blurring caused by friction during the ATM machine feeding process; yellowing occurs after long-term ultraviolet irradiation, which causes distortion of the holographic color. SUMMARY

[0005] In view of this, the application provides a UV hardening liquid and a preparation method thereof, which can form a UV hardening layer with high wear resistance, high hardness and anti-yellowing through low-energy rapid curing.

[0006] To achieve the above-mentioned purposes, the application adopts the following technical solutions: On the one hand, the application provides a UV hardening liquid, and the materials for preparing the UV hardening liquid include: organic-inorganic hybrid resin, hyperbranched polyurethane acrylate, fluorine-modified epoxy acrylate, isobornyl acrylate, tripropylene glycol diacrylate, thiol diluent, photoinitiator, nano-alumina, benzotriazole, hindered amine, silane coupling agent, photoinitiator including photoinitiator TPO-L and photoinitiator 819; benzotriazole includes UV-1; hindered amine includes HALS-2.

[0007] Preferably, the organic-inorganic hybrid resin comprises 30-40 parts by weight, the hyperbranched polyurethane acrylate comprises 15-25 parts by weight, the fluorinated epoxy acrylate comprises 10-15 parts by weight, the isobornyl acrylate comprises 15-20 parts by weight, the tripropylene glycol diacrylate comprises 10-15 parts by weight, the thiol diluent comprises 3-5 parts by weight, the photoinitiator TPO-L comprises 3-4 parts by weight, the photoinitiator 819 comprises 1-2 parts by weight, the nano-alumina comprises 2-5 parts by weight, the benzotriazole UV-1 comprises 0.5-1 part by weight, the hindered amine HALS-2 comprises 0.3-0.5 parts by weight, and the silane coupling agent comprises 1-2 parts by weight.

[0008] Preferably, the thiol diluent comprises pentaerythritol tetra-3-mercaptopropionate.

[0009] Preferably, the particle size of nano-alumina is 20-50 nm.

[0010] Preferably, the silane coupling agent includes KH-570.

[0011] Preferably, the organic-inorganic hybrid resin includes 601X-35. It should be noted that the organic-inorganic hybrid resin is Changxing Chemical's 601X-35, whose molecular structure contains a large number of siloxane bonds (Si-O-Si) providing inorganic rigidity, while the acrylate functional groups grafted onto the side chains or ends participate in the photocuring reaction. Preferably, the hyperbranched polyurethane acrylate includes CN964. It should be noted that the hyperbranched polyurethane acrylate is Sartoma's CN964. Due to its unique structure and the flexibility provided by the caprolactone segments, it effectively improves brittleness and balances stress while providing high crosslinking density (high hardness).

[0012] Preferably, the fluorinated epoxy acrylate includes KY-1203. It should be noted that the fluorinated epoxy acrylate is KY-1203 from Jiangsu Kangaite Chemical Co., Ltd., which combines the high adhesion and hardness of epoxy resin, the rapid curing characteristics of acrylate, and the low surface energy and excellent weather resistance of fluorinated compounds.

[0013] On the other hand, the present invention provides a method for preparing the UV curing liquid, comprising the following steps: S1. Mix organic-inorganic hybrid resin, hyperbranched polyurethane acrylate and fluorinated epoxy acrylate to obtain a mixed prepolymer; S2. Mix nano-alumina, silane coupling agent and ethanol to obtain pretreated nano-dispersion; S3. Mix isobornyl acrylate, tripropylene glycol diacrylate, thiol diluent, and photoinitiator to obtain the mixed diluent. S4, the pretreated nanodispersion, the mixed diluent are mixed with the mixed prepolymer in sequence, and then benzotriazole and hindered amine are added to obtain a UV hardening liquid.

[0014] Preferably, in step S1, the organic-inorganic hybrid resin, the hyperbranched polyurethane acrylate and the fluorine-modified epoxy acrylate are mixed, preheated at 60 DEG C, stirred until transparent, and a mixed prepolymer is obtained.

[0015] Compared with the prior art, the application has the following advantages: (1) The UV curing energy of the application is less than or equal to 380 mJ / cm 2 , the curing energy is significantly reduced, which is beneficial to improve production efficiency and reduce energy consumption.

[0016] (2) The nanometer alumina and the organic-inorganic hybrid resin provide a mechanical support of rigidity and toughness, and the hyperbranched polyurethane acrylate increases the crosslinking point density and reduces the brittleness; the non-yellowing TPO-L, the benzotriazole UV-1 and the hindered amine HALS-2 form a free radical scavenging synergistic effect, which significantly inhibits yellowing and aging. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The preparation method flow chart of the UV hardening liquid provided by an embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0018] The application will be further described in detail below with reference to specific embodiments, so that those skilled in the art can more clearly understand the application.

[0019] Embodiment 1 The UV hardening liquid provided by the embodiment includes the following raw materials: 35 parts of organic-inorganic hybrid resin (601X-35), 20 parts of hyperbranched polyurethane acrylate (CN964), 12 parts of fluorine-modified epoxy acrylate (KY-1203), 18 parts of isobornyl acrylate, 12 parts of tripropyleneglycol diacrylate, 4 parts of pentaerythritol tetra-3-mercapto propionate, 3.5 parts of photoinitiator TPO-L, 1.5 parts of photoinitiator 819, 3 parts of nanometer alumina, 1.5 parts of silane coupling agent KH-570, 0.7 parts of benzotriazole UV-1 and 0.4 parts of hindered amine HALS-2.

[0020] The preparation method of the UV hardening liquid comprises the following steps: adding organic-inorganic hybrid resin, hyperbranched polyurethane acrylate and fluorine-modified epoxy acrylate into a reaction kettle, preheating at 60 DEG C, stirring for 20 min to obtain a mixed prepolymer; then ultrasonic dispersing nano-alumina and silane coupling agent in ethanol solvent for 30 min, drying at 80 DEG C to remove the solvent, then adding into the mixed prepolymer, high-speed dispersing for 30 min to avoid agglomeration; then mixing isobornyl acrylate, tripropyleneglycol diacrylate and pentaerythritol tetra-3-mercaptopropionate in a light-proof container, then adding photoinitiator TPO-L and 819, stirring at 40 DEG C until completely dissolved to obtain a mixed diluent; finally adding the mixed diluent into the mixed prepolymer, stirring for 15 min, then continuously adding UV-1 and HALS-2, continuously stirring for 10 min, and then vacuum degassing to obtain a transparent UV hardening liquid.

[0021] Example 2 The UV hardening liquid comprises the following raw materials: 30 parts of organic-inorganic hybrid resin (601X-35), 15 parts of hyperbranched polyurethane acrylate (CN964), 10 parts of fluorine-modified epoxy acrylate (KY-1203), 15 parts of isobornyl acrylate, 10 parts of tripropyleneglycol diacrylate, 3 parts of pentaerythritol tetra-3-mercaptopropionate, 3 parts of photoinitiator TPO-L, 1 part of photoinitiator 819, 2 parts of nano-alumina, 1 part of silane coupling agent KH-570, 0.5 part of benzotriazole UV-1 and 0.3 part of hindered amine HALS-2.

[0022] The preparation method of the UV hardening liquid comprises the following steps: adding organic-inorganic hybrid resin, hyperbranched polyurethane acrylate and fluorine-modified epoxy acrylate into a reaction kettle, preheating at 60 DEG C, stirring for 20 min to obtain a mixed prepolymer; then ultrasonic dispersing nano-alumina and silane coupling agent in ethanol solvent for 30 min, drying at 80 DEG C to remove the solvent, then adding into the mixed prepolymer, high-speed dispersing for 30 min to avoid agglomeration; then mixing isobornyl acrylate, tripropyleneglycol diacrylate and pentaerythritol tetra-3-mercaptopropionate in a light-proof container, then adding photoinitiator TPO-L and 819, stirring at 40 DEG C until completely dissolved to obtain a mixed diluent; finally adding the mixed diluent into the mixed prepolymer, stirring for 15 min, then continuously adding UV-1 and HALS-2, continuously stirring for 10 min, and then vacuum degassing to obtain a transparent UV hardening liquid.

[0023] Example 3 The embodiment provides a UV hardening liquid, raw materials of which include: organic-inorganic hybrid resin (601X-35) 40 parts, hyperbranched polyurethane acrylate (CN964) 25 parts, fluorine-modified epoxy acrylate (KY-1203) 15 parts, isobornyl acrylate 20 parts, tripropylene glycol diacrylate 15 parts, pentaerythritol tetra-3-mercaptopropionate 5 parts, photoinitiator TPO-L 4 parts, photoinitiator 819 2 parts, nano-alumina 5 parts, silane coupling agent KH-570 2 parts, benzotriazole UV-1 1 part, hindered amine HALS-2 0.5 parts.

[0024] A preparation method of the UV hardening liquid comprises the following steps: the organic-inorganic hybrid resin, the hyperbranched polyurethane acrylate and the fluorine-modified epoxy acrylate are added into a reaction kettle, preheated at 60 DEG C, stirred for 20 min to be uniform and transparent, and a mixed prepolymer is obtained; then the nano-alumina and the silane coupling agent are ultrasonically dispersed in ethanol solvent for 30 min, dried at 80 DEG C to remove the solvent, and then added into the mixed prepolymer, and high-speed dispersed for 30 min to avoid agglomeration; then the isobornyl acrylate, the tripropylene glycol diacrylate and the pentaerythritol tetra-3-mercaptopropionate are mixed in a light-proof container, the photoinitiator TPO-L and 819 are added, and stirred at 40 DEG C until completely dissolved, and a mixed diluent is obtained; finally, the mixed diluent is added into the mixed prepolymer, stirred for 15 min, then the UV-1 and the HALS-2 are continuously added, and continuously stirred for 10 min, and a transparent UV hardening liquid is obtained after vacuum degassing.

[0025] Comparative Example 1 The comparative example provides a UV hardening liquid, raw materials of which include: organic-inorganic hybrid resin (601X-35) 35 parts, hyperbranched polyurethane acrylate (CN964) 20 parts, fluorine-modified epoxy acrylate (KY-1203) 12 parts, isobornyl acrylate 20 parts, tripropylene glycol diacrylate 14 parts, photoinitiator TPO-L 3.5 parts, photoinitiator 819 1.5 parts, nano-alumina 3 parts, silane coupling agent KH-570 1.5 parts, benzotriazole UV-1 0.7 parts, hindered amine HALS-2 0.4 parts.

[0026] The preparation method of the UV hardening liquid comprises the following steps: adding organic-inorganic hybrid resin, hyperbranched polyurethane acrylate and fluorine-modified epoxy acrylate into a reaction kettle, preheating at 60 DEG C, stirring for 20 min to obtain a mixed prepolymer; then ultrasonic dispersing nano-aluminum oxide and silane coupling agent in ethanol solvent for 30 min, drying at 80 DEG C to remove the solvent, and then adding into the mixed prepolymer and high-speed dispersing for 30 min to avoid agglomeration; then adding isobornyl acrylate and tripropylene glycol diacrylate into a light-proof container, and then adding photoinitiator TPO-L and 819, stirring at 40 DEG C until completely dissolved to obtain a mixed diluent; finally adding the mixed diluent into the mixed prepolymer, stirring for 15 min, and then continuously adding UV-1 and HALS-2, and continuously stirring for 10 min to obtain a transparent UV hardening liquid.

[0027] Comparative Example 2 The UV hardening liquid provided by the embodiment comprises the following raw materials: 35 parts of organic-inorganic hybrid resin (601X-35), 25 parts of hyperbranched polyurethane acrylate (CN964), 6 parts of fluorine-modified epoxy acrylate (KY-1203), 18 parts of isobornyl acrylate, 12 parts of tripropylene glycol diacrylate, 4 parts of pentaerythritol tetra-3-mercapto propionate, 3.5 parts of photoinitiator TPO-L, 1.5 parts of photoinitiator 819, 0.7 parts of benzotriazole UV-1 and 0.4 parts of hindered amine HALS-2.

[0028] The preparation method of the UV hardening liquid comprises the following steps: adding organic-inorganic hybrid resin, hyperbranched polyurethane acrylate and fluorine-modified epoxy acrylate into a reaction kettle, preheating at 60 DEG C, stirring for 20 min to obtain a mixed prepolymer; then ultrasonic dispersing nano-aluminum oxide and silane coupling agent in ethanol solvent for 30 min, drying at 80 DEG C to remove the solvent, and then adding into the mixed prepolymer and high-speed dispersing for 30 min to avoid agglomeration; then adding isobornyl acrylate and tripropylene glycol diacrylate into a light-proof container, and then adding photoinitiator TPO-L and 819, stirring at 40 DEG C until completely dissolved to obtain a mixed diluent; finally adding the mixed diluent into the mixed prepolymer, stirring for 15 min, and then continuously adding UV-1 and HALS-2, and continuously stirring for 10 min to obtain a transparent UV hardening liquid.

[0029] Comparative Example 3 The embodiment provides a UV hardening liquid, raw materials of which include: 35 parts of organic-inorganic hybrid resin (601X-35), 20 parts of hyperbranched polyurethane acrylate (CN964), 12 parts of fluorine-modified epoxy acrylate (KY-1203), 18 parts of isobornyl acrylate, 12 parts of tripropyleneglycol diacrylate, 4 parts of pentaerythritol tetra-3-mercaptopropionate, 3 parts of photoinitiator benzophenone, 2 parts of photoinitiator isopropyl thioxanthone, 3 parts of nano alumina, 1.5 parts of silane coupling agent KH-570, 0.7 parts of benzotriazole UV-10 and 0.4 parts of hindered amine HALS-2.

[0030] The preparation method of the UV hardening liquid comprises the following steps: the organic-inorganic hybrid resin, the hyperbranched polyurethane acrylate and the fluorine-modified epoxy acrylate are added into a reaction kettle, preheated at 60 DEG C, stirred for 20 min to be uniform and transparent, and a mixed prepolymer is obtained; then the nano alumina and the silane coupling agent are ultrasonically dispersed in ethanol solvent for 30 min, dried at 80 DEG C to remove the solvent, and then added into the mixed prepolymer, and high-speed dispersed for 30 min to avoid agglomeration; then the isobornyl acrylate, the tripropyleneglycol diacrylate and the pentaerythritol tetra-3-mercaptopropionate are mixed in a light-proof container, the photoinitiator benzophenone and the photoinitiator isopropyl thioxanthone are added, and stirred at 40 DEG C until completely dissolved to obtain a mixed diluent; finally, the mixed diluent is added into the mixed prepolymer, stirred for 15 min, then the UV-1 and the HALS-2 are continuously added, and continuously stirred for 10 min, and a transparent UV hardening liquid can be obtained after vacuum degassing.

[0031] Performance test and result Test condition: 1. Test curing energy: the UV hardening liquid is coated on a PET base film, and the minimum curing energy is tested by using a radiometer to test the tack-free after curing.

[0032] 2. Hardness test: ASTM D3363 pencil hardness (3H, i.e. 3kg load without scratch).

[0033] 3. Abrasion resistance test: referring to ISO 5470, the mass loss after friction for 1000 times under a load of 500g of steel wool #0000 type is tested. Five groups of effective data of each sample are averaged.

[0034] 4. UV resistance test: the PET base film coated with the UV hardening liquid is placed in a UV aging box (0.89W / m 2 , 500h), and then the yellowing index ΔYI is tested. Five groups of effective data are averaged. The result is shown in Table 1.

[0035] Table 1

[0036] It can be seen from Table 1 that the curing energy of Examples 1-3 is ≤380 mJ / cm2 due to the effect of mercaptan additives 2 The hardness of Examples 1-3 is ≥3H and the frictional weight loss is ≤22 mg, which is superior to the hardness and wear resistance of Comparative Example 2. This is mainly due to the synergistic effect of the nano-alumina in the formula and the organic-inorganic hybrid resin. The inorganic nanoparticles can improve the wear resistance, the siloxane (Si-O-Si) in the organic-inorganic hybrid resin provides inorganic rigidity, the acrylate segment provides organic toughness, the hyperbranched polyurethane acrylate increases the crosslinking point density with its three-dimensional structure, and the end group flexible chain reduces brittleness. The ΔYI of Examples 1-3 is ≤1.5, which is much lower than that of Comparative Example 3. This is mainly due to the use of non-yellowing TPO-L, the addition of benzotriazole UV-1 and hindered amine light stabilizer HALS-2, which forms a synergistic effect of free radical scavenging.

[0037] The specific raw materials in the present application are all existing substances, which can be directly purchased from the market.

[0038] The above is only a preferred embodiment of the present application, and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A UV curing liquid, characterized in that, The materials used to prepare UV curing solutions include: Organic-inorganic hybrid resin; Hyperbranched polyurethane acrylate; Fluorine-modified epoxy acrylate; Isoborneol acrylate; Dipropylene glycol diacrylate; Thiol diluent; Photoinitiators, including photoinitiator TPO-L and photoinitiator 819; Nano-alumina; Benztriazole, including UV-1; Hindered amines, including HALS-2; and, Silane coupling agent.

2. The UV curing liquid according to claim 1, characterized in that, The organic-inorganic hybrid resin comprises 30-40 parts by weight, hyperbranched polyurethane acrylate comprises 15-25 parts by weight, fluorinated epoxy acrylate comprises 10-15 parts by weight, isobornyl acrylate comprises 15-20 parts by weight, tripropylene glycol diacrylate comprises 10-15 parts by weight, thiol diluent comprises 3-5 parts by weight, photoinitiator TPO-L comprises 3-4 parts by weight, photoinitiator 819 comprises 1-2 parts by weight, nano-alumina comprises 2-5 parts by weight, benzotriazole UV-1 comprises 0.5-1 part by weight, hindered amine HALS-2 comprises 0.3-0.5 parts by weight, and silane coupling agent comprises 1-2 parts by weight.

3. The UV curing liquid according to claim 1, characterized in that, Thiol diluents include pentaerythritol tetra-3-mercaptopropionate.

4. The UV curing liquid according to claim 1, characterized in that, The particle size of nano-alumina is 20-50 nm.

5. The UV curing liquid according to claim 1, characterized in that, Silane coupling agents include KH-570.

6. The UV curing liquid according to claim 1, characterized in that, Organic-inorganic hybrid resins include 601X-35.

7. The UV curing liquid according to claim 1, characterized in that, Hyperbranched polyurethane acrylates include CN964.

8. The UV curing liquid according to claim 1, characterized in that, Fluorinated modified epoxy acrylates include KY-1203.

9. The method for preparing the UV curing liquid according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Mix organic-inorganic hybrid resin, hyperbranched polyurethane acrylate and fluorinated epoxy acrylate to obtain a mixed prepolymer; S2. Mix nano-alumina, silane coupling agent and ethanol to obtain pretreated nano-dispersion; S3. Mix isobornyl acrylate, tripropylene glycol diacrylate, thiol diluent, and photoinitiator to obtain the mixed diluent. S4. After mixing the pretreated nano-dispersion and the mixed diluent with the mixed prepolymer in sequence, benzotriazole and hindered amine are added to obtain the UV curing liquid.

10. The preparation method according to claim 9, characterized in that, In step S1, the organic-inorganic hybrid resin, hyperbranched polyurethane acrylate, and fluorinated epoxy acrylate are mixed, preheated at 60°C, and stirred until transparent to obtain a mixed prepolymer.

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