UV curing resin based on E-DCPA monomer and preparation method thereof

Abstract

The invention relates to the field of resin, in particular to UV curing resin based on an E-DCPA monomer and a preparation method of the UV curing resin based on the E-DCPA monomer, and the UV curing resin based on the E-DCPA monomer comprises the following raw materials in parts by weight: 60-80 parts of the E-DCPA monomer, 20-30 parts of high-functionality acrylic ester, 2-4 parts of a photoinitiator and 5-10 parts of a nano toughening agent. The impact strength of the prepared finished product is not lower than 15 kJ / m < 2 > and exceeds that of existing UV resin, the finished product has high impact resistance, the tensile modulus is 1.2-1.5 GPa, the elongation at break is larger than 40%, the light transmittance is larger than 90%, the curing shrinkage rate is not larger than 2%, prepolymerization is not needed, the curing time is within 3 seconds, optical performance and processing performance are both considered, and the finished product is suitable for industrial production. The composite material is suitable for scenes with strict requirements on impact resistance and mechanical strength, such as automotive interior coatings, electronic equipment protective films, flexible display substrates and the like.

Description

Technical Field

[0001] The present invention relates to the field of resins, and in particular to a UV-curable resin based on an E-DCPA monomer and a preparation method thereof. Background Art

[0002] Resin generally refers to an organic polymer that softens or melts when heated, tends to flow under external force, and is solid, semi-solid, or sometimes liquid at room temperature. UV-curable resin based on DCPA monomer is a common example of this type of resin.

[0003] Existing UV-curable resins based on DCPA (dicyclopentene acrylate) monomers combine rigidity (from DCPA) and flexibility (from PUA, i.e. polyurethane acrylate) through physical blending. This usually has the following problems: 1. Separation risk: Physical blending leads to poor material uniformity, and the interface is prone to cracking after long-term use. 2. Performance compromise: When rigidity is increased, impact resistance will decrease (usually the impact strength of DCPA resin is less than 5kJ / m 2 3. Complex process: multiple steps of pre-polymerization and compounding are required, resulting in high cost and low curing efficiency. Summary of the Invention

[0004] To achieve the above objectives, the present invention aims to provide a UV-curable resin based on E-DCPA monomer, which can solve the problems existing in the background art. The present invention provides the following technical solutions: A UV-curable resin based on E-DCPA (ethoxylated DCPA) monomer comprises the following raw materials in parts by weight: 60-80 parts of E-DCPA monomer, 20-30 parts of high-functionality acrylate, 2-4 parts of photoinitiator and 5-10 parts of nano-toughener.

[0005] As a further embodiment of the present invention, the photoinitiator is TPO (phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide) or 184-type photoinitiator.

[0006] As a further scheme of the present invention: The preparation method of the E-DCPA monomer is as follows: DCPA monomer and ethylene oxide are subjected to a ring-opening reaction in the presence of an acidic catalyst, and the ethoxy chain length is precisely controlled to be 2-4 units (n=2-4) to obtain an intermediate, and the intermediate is esterified with acryloyl chloride at 0-5 degrees Celsius, and then subjected to reduced pressure distillation and purification to obtain the E-DCPA monomer. The acidic catalyst is p-toluenesulfonic acid, and the acidic catalytic temperature is 80-100 degrees Celsius.

[0007] As a further solution of the present invention: the nano toughening agent is a core-shell structured acrylic ester nanoparticle, the core of which is polymethyl methacrylate (PMMA) and the shell of which is polybutyl acrylate (PBA), and the particle size is 50-100 nm.

[0008] As a further embodiment of the present invention, the high-functionality acrylate is TMPTA (trimethylolpropane triacrylate).

[0009] A method for preparing a UV-curable resin based on E-DCPA monomer comprises the following steps: (1) Dispersing the E-DCPA monomer and the nano toughening agent at high speed shear at 40-60 degrees Celsius to obtain a mixture; (2) The remaining raw materials are added to the mixture and coated on the substrate, and then cured using a UV light source to obtain the finished product.

[0010] As a further solution of the present invention: the UV light source is a 385nm UV-LED light source, and the curing energy is 600-800mJ / cm 2 , oxygen inhibition is suppressed by nitrogen blanketing (oxygen concentration is less than 200ppm).

[0011] Performance tests were conducted on this product, existing products, engineering plastic PC, and engineering plastic PA66 using the ASTM D256 / D638 standard. The test results are shown in Table 1.

[0012] Table 1 Material <![CDATA[Impact strength (kJ / m 2 )]]> Elongation at break (%) Tensile modulus (GPA) This product 18.5 45 1.32 Existing products 4.8 8 2.1 PC 18-22 110-50 2.2 PA66 10-22 30-100 1.1-3.0 As can be seen from Table 1, the product's impact strength of 18.5 kJ / m² exceeds that of PA66 (≈85% improvement) and is close to the level of PC (84% of PC). Its elongation at break of 45% is 5.6 times that of existing products, meeting the toughness requirements of engineering plastics.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention introduces ethoxylated flexible segments into the rigid dicyclopentene skeleton of DCPA through precise ethoxylation of the molecular structure to form a rigid-flexible synergistic structure within a single molecule. The impact strength of the prepared finished product is not less than 15 kJ / m 2 , surpassing existing UV resins (usually less than 10kJ / m 2 ), with high impact resistance, tensile modulus of 1.2-1.5GPa, elongation at break greater than 40%, simultaneous optimization of modulus and toughness, adapted to dynamic load scenarios such as folding screen hinge coatings, achieving a balance of rigidity and flexibility, light transmittance greater than 90%, and curing shrinkage of no more than 2%. No pre-polymerization is required and the curing time is within 3 seconds. Taking into account both optical properties and processing performance, it is suitable for scenarios with strict requirements on impact resistance and mechanical strength, such as automotive interior coatings, electronic equipment protective films, and flexible display substrates. DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0015] In this invention, the E-DCPA monomer is the primary component of the rigid-flexible synergy; the high-functionality acrylate increases crosslink density. The ethoxy segments (flexible) and the dicyclopentene ring (rigid) are chemically bonded, achieving intramolecular rigid-flexible synergy and eliminating the risk of separation. The ethoxy segments of the E-DCPA monomer absorb impact energy, while the dicyclopentene ring provides rigid support, forming a dynamic crosslinked network that increases impact strength by 300%. The core-shell (hard core / soft shell) of the nanotoughener forms an interpenetrating network with the E-DCPA, further dispersing stress and achieving a synergistic nanotoughening effect.

[0016] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0017] Example 1

[0018] Raw materials: 70 parts of E-DCPA monomer, 25 parts of TMPTA, 3 parts of TPO and 8 parts of nano-toughener. In the E-DCPA monomer, n=2 (the ethoxy chain length is 2 units).

[0019] Curing conditions: 385nm LED light source, energy 700mJ / cm 2 .

[0020] Comparative Example: Ordinary DCPA resin.

[0021] The finished product of Example 1 and the comparative example were subjected to performance tests, and the test results are shown in Table 2.

[0022] Table 2 Performance results index Example 1 Comparative Example <![CDATA[Impact strength (kJ / m 2 )]]> 16.2 4.8 Elongation at break (%) 45 8 Tensile modulus (GPa) 1.35 2.1 Transmittance (550nm) 92% 88% Curing shrinkage (%) 1.8 5.5 As can be seen from Table 2, this product (ethoxy chain length n=2) is the key breakthrough in achieving low shrinkage and high toughness: The impact strength is greatly improved (about 3.4 times that of the control); The elongation at break is significantly improved (about 5.6 times that of the control group); The tensile modulus decreased (about 64% of the comparative example); Light transmittance is slightly improved (4% increase); 5. The curing shrinkage rate is significantly reduced (reduced by about 67%).

[0023] Example 2

[0024] The only difference from Example 1 is that an ultraviolet absorber (Tinuvin 405) is added. The product of Example 2 was subjected to performance testing, and the results are shown in Table 3.

[0025] Table 3 Performance results index Example 2 After 1000 hours of QUV aging Effect <![CDATA[Impact strength (kJ / m 2 )]]> 16.0 14.6 (Retention rate 91.3%) Elongation at break (%) 44 40 (Retention rate 90.9%) Tensile modulus (GPa) 1.34 1.32 Transmittance (550nm) 88% 87% Curing shrinkage (%) 1.8 1.8 UV protection / Tinuvin 405 Impact strength retention rate>90% As can be seen from Table 3, the impact strength retention rate after 1000 hours of QUV aging is greater than 90%, which is suitable for anti-stone impact coating of new energy vehicle exterior parts.

[0026] This invention, for the first time, introduces ethoxylated flexible segments into DCPA, achieving controllable rigidity and flexibility within a single molecule. This results in impact strength and toughness comparable to engineering plastics (such as PC and PA) while maintaining UV curing efficiency, resulting in a significant performance improvement. The synthesis route is simple (requiring only two reactions), and the raw material cost is 40% lower than that of imported toughened resins, ensuring industrial feasibility. Through molecular-level rigidity-flexibility synergistic design, this invention overcomes the industry bottleneck of insufficient impact resistance in UV-curable resins. Combining high performance with low cost, this invention is widely applicable in the automotive, electronics, and high-end equipment manufacturing sectors.

[0027] It should be noted that, in the present invention, unless otherwise expressly specified or limited, the terms "fixed" and "disposed" should be understood in a broad sense. For example, they can refer to welded connections, bolted connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise expressly specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A UV curable resin based on E-DCPA monomer, characterized in that: The invention comprises the following raw materials in parts by weight: 60-80 parts of E-DCPA monomer, 20-30 parts of high-functionality acrylate, 2-4 parts of photoinitiator and 5-10 parts of nano toughening agent.

2. The UV curable resin based on E-DCPA monomer according to claim 1, characterized in that The photoinitiator is TPO or 184 type photoinitiator.

3. The UV curable resin based on E-DCPA monomer according to claim 1 or 2, characterized in that The preparation method of the E-DCPA monomer is as follows: DCPA monomer and ethylene oxide are subjected to a ring-opening reaction in the presence of an acidic catalyst to obtain an intermediate, the intermediate is esterified with acryloyl chloride at 0-5 degrees Celsius, and then vacuum distilled and purified to obtain the E-DCPA monomer.

4. The UV curable resin based on E-DCPA monomer according to claim 1, characterized in that The nano toughening agent is core-shell structured acrylic ester nanoparticles with a particle size of 50-100 nm.

5. The UV curable resin based on E-DCPA monomer according to claim 1 or 4, characterized in that The high-functionality acrylate is TMPTA.

6. A method for preparing a UV-curable resin based on E-DCPA monomer, characterized in that: The following steps are involved: (1) Dispersing the E-DCPA monomer and the nano toughening agent at high speed shear at 40-60 degrees Celsius to obtain a mixture; (2) The remaining raw materials are added to the mixture and coated on the substrate, and then cured using a UV light source to obtain the finished product.

7. The method for preparing a UV-curable resin based on E-DCPA monomer according to claim 6, wherein: The UV light source is a 385nm UV-LED light source with a curing energy of 600-800mJ / cm 2 .