A fluorescent rosin-based 3D printing UV resin, its preparation method and its uses

Abstract

The present invention discloses a fluorescent rosin-based 3D printing UV resin, its preparation method and uses. The molecular structure of the fluorescent rosin-based 3D printing UV resin is as follows: The present invention uses dehydroabietylamine as a raw material to synthesize the fluorescent rosin-based 3D printing UV resin. The synthesis method is simple and does not require any solvent. Under the excitation wavelength of 335 nm, it emits blue light at 400 nm and can be used as an anti-counterfeiting material or a safety marking material. The fluorescent rosin-based 3D printing UV resin of the present invention can be used for the preparation of photocurable materials. Through the design of a rosin-based hexaacrylate with a specific structure, while taking into account mechanical properties such as mechanical properties and adhesion and chemical resistance, the amount of diluent monomer is significantly increased, the operability is improved, and the production cost is reduced, enabling good shaping in photocurable 3D printing.

Description

Technical Field

[0001] The present invention relates to a fluorescent rosin-based 3D printing UV resin, a preparation method thereof, and uses thereof, belonging to the fields of forest chemical engineering and polymer materials. Background Art

[0002] Stereolithography 3D printing technology, also known as stereolithography or SLA 3D printing, is a common 3D printing technology. It is based on the principle of photocuring and prints a model layer by layer by using a specific photosensitive resin material and an ultraviolet light source. Stereolithography 3D printing technology has been widely used in many fields. For example, in the manufacturing industry, it can be used for rapid prototyping, product development, and customized manufacturing. In the medical field, stereolithography 3D printing technology can manufacture simulation organs, personalized medical devices, and orthopedic surgical instruments. In addition, it is also used in the fields of jewelry, artworks, architectural models, etc. However, most of the raw materials for current stereolithography 3D printing are petroleum-based synthetic resins, which are usually extracted or synthesized from petroleum by synthetic chemical methods.

[0003] Rosin is an important natural and environmentally friendly resin resource, which is inexpensive and easily available, and has characteristics such as high transparency and low toxicity. The present invention provides a fluorescent rosin-based 3D printing UV resin, a preparation method thereof, and uses thereof. Summary of the Invention

[0004] The present invention relates to a fluorescent rosin-based 3D printing UV resin, a preparation method thereof, and uses thereof. In this application, dehydroabietylamine is used as a raw material to synthesize a fluorescent rosin-based 3D printing UV resin, which emits blue light at 400 nm under an excitation wavelength of 335 nm and is used as an anti-counterfeiting material or a safety marking material; trimethylolpropane triacrylate has poor mechanical properties and difficult-to-control curing time after being photocured alone and cannot be applied to stereolithography 3D printing. The synthesized fluorescent rosin-based 3D printing UV resin in this application has good mechanical properties and thermal stability, short curing time and easy control, can be used for the preparation of photocurable materials, significantly increases the dosage of the diluent monomer while taking into account mechanical properties such as strength and adhesion, and chemical resistance, and the dosage of the diluent monomer can reach more than 50%, thereby significantly improving the operability of the photocurable material, reducing the cost, being able to be applied to stereolithography 3D printing, and clearly printing out loaded objects; it can reduce the dependence on limited resources and help reduce the negative impact on the environment.

[0005] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0006] A fluorescent rosin-based 3D printing UV resin, whose molecular structure is:

[0007]

[0008] The present invention uses trimethylolpropane triacrylate as an electrophilic reagent and ethanolamine and dehydroabietylamine as nucleophilic reagents to synthesize a fluorescent rosin-based 3D printing UV resin. Through the Michael addition reaction, it breaks through the solvent-free system and low reaction temperature, meeting the development requirements of green chemistry; the synthesis method of this fluorescent rosin-based 3D printing UV resin is simple. Under solvent-free conditions, the fluorescent rosin-based 3D printing UV resin is formed by the reaction of ethanolamine, dehydroabietylamine and trimethylolpropane triacrylate. It is simple, safe, easy to control, and low in cost, and can form a photocurable material under ultraviolet light curing.

[0009] The above-mentioned fluorescent rosin-based 3D printing UV resin emits blue light at 400 nm under an excitation wavelength of 335 nm and has obvious fluorescence properties. As one of its uses, it can be used as an anti-counterfeiting material or a safety marking material.

[0010] To improve the yield, the preparation method of the above-mentioned fluorescent rosin-based 3D printing UV resin is as follows: Using p-methoxyphenol as an inhibitor, trimethylolpropane triacrylate, ethanolamine and dehydroabietylamine react at 40 - 50 °C for 8 - 18 h to obtain the fluorescent rosin-based 3D printing UV resin. No solvent is required in the foregoing reaction process.

[0011] The above-mentioned fluorescent rosin-based 3D printing UV resin does not require a complex reaction process, and the preparation method is very simple.

[0012] To facilitate operation, while taking into account environmental protection and product yield, the above reaction is carried out under the protection of nitrogen; the molar ratio of ethanolamine, trimethylolpropane triacrylate and dehydroabietylamine is 1:(2 - 2.1):0.5; the mass dosage of p-methoxyphenol is 0.05% - 0.1% of the sum of the masses of dehydroabietylamine and trimethylolpropane triacrylate.

[0013] To improve the reaction efficiency and product purity, when all the primary amines of ethanolamine and dehydroabietylamine react to become tertiary amines, that is, when the amine value of the product no longer changes, the reaction ends.

[0014] As one of the preferred specific schemes, the preparation method of the above-mentioned fluorescent rosin-based 3D printing UV resin is as follows: including the following steps:

[0015] 1) Dissolve the inhibitor p-methoxyphenol in trimethylolpropane triacrylate, then dropwise add ethanolamine at 40 - 50 °C. After the addition of ethanolamine is completed, react for 8 - 18 h under light-shielded conditions at 40 - 50 °C to obtain an intermediate product;

[0016] 2) Dropwise add dehydroabietylamine to the intermediate product obtained in step 1), and react for 6 - 10 h under light-shielded conditions at 40 - 50 °C to obtain the fluorescent rosin-based 3D printing UV resin.

[0017] The addition time of ethanolamine and dehydroabietylamine was controlled to be completed within 50 to 70 minutes.

[0018] Both steps were carried out in the dark (protected from light).

[0019] The present application first uses ethanolamine to prepare an intermediate, and then reacts it with dehydroabietylamine to obtain a fluorescent rosin-based 3D printing UV resin. The inventors found that the addition of ethanolamine can introduce polar groups into the photocurable resin, increase the adhesion between the resin and the printing platform, and enable the invented resin to be used for photocurable 3D printing.

[0020] A fluorescent rosin-based 3D printing UV resin photocuring material is prepared from the fluorescent rosin-based 3D printing UV resin and can be used for coatings or 3D printing, etc.

[0021] In order to improve the success rate of curing, the fluorescent rosin-based 3D printing UV resin, the diluent monomer 4-acryloylmorpholine and the photoinitiator TPO (diphenyl-(2,4,6-trimethylbenzoyl)phosphine) are mixed evenly, and after removing bubbles in an environment of 20-30°C, they are irradiated with ultraviolet light to form a rosin-based resin photocuring material, wherein the mass dosage of 4-acryloylmorpholine is 40-60% of the mass of the tetrafunctional rosin UV resin, and the mass dosage of the photoinitiator TPO is 1-3% of the mass of the tetrafunctional rosin UV resin.

[0022] Preferably, the mass dosage of 4-acryloylmorpholine is 50-55% of the mass of the fluorescent rosin-based 3D printing UV resin; the present application significantly increases the dosage of the diluent monomer. When the dosage of the diluent monomer reaches more than 50%, it can better balance the tensile strength and strain, and at the same time achieve a level 0 adhesion on plastic substrates such as polypropylene, which greatly improves the operability of the photocurable material and reduces the production cost.

[0023] In the prior art, the diluent monomer can generally only reach 6-8% of the mass of the UV resin, and at most 10%. If the diluent monomer is further increased, its strength and adhesion and other properties will not meet the use requirements. If the amount of diluent monomer is small, the operability will be poor, and it will be difficult to operate with more diluent monomer, which will affect the quality. In addition, the reduction of the amount of diluent monomer means the increase of the amount of UV resin, which will increase the cost.

[0024] The intensity of the ultraviolet light irradiation is 850 mJ / cm2, and the irradiation time is 1 to 5 seconds.

[0025] The technologies not mentioned in the present invention are all referred to the prior art.

[0026] The present invention achieves the following beneficial effects:

[0027] 1) The fluorescent rosin-based 3D printing UV resin of the present invention has a simple synthesis method and does not require any solvents. Rosin-based hexaacrylate is generated through the reaction, which has fluorescent properties. Under the excitation wavelength of 335 nm, it emits blue light at 400 nm and can be used as an anti-counterfeiting material or a safety marking material.

[0028] 2) The fluorescent rosin-based 3D printing UV resin of the present invention can be used for the preparation of photocurable materials. The preparation is simple and easy to control. Through the design of rosin-based hexaacrylate with a specific structure, while taking into account mechanical properties such as mechanical properties and adhesion and chemical resistance, the dosage of the diluent monomer is significantly increased, the operability is improved, the production cost is reduced, and it can be well formed in photocurable 3D printing, promoting the high-value utilization of rosin. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a physical picture of the preparation of the fluorescent rosin-based 3D printing UV resin of the present invention;

[0030] Figure 2 It is the infrared spectrum diagram of the fluorescent rosin-based 3D printing UV resin of the present invention;

[0031] Figure 3 It is the fluorescence emission spectrum of the fluorescent rosin-based 3D printing UV resin of the present invention;

[0032] Figure 4 It is the fluorescence excitation spectrum of the fluorescent rosin-based 3D printing UV resin of the present invention;

[0033] Figure 5 It is the physical picture of the fluorescent rosin-based 3D printing UV resin of the present invention under white light (left picture) and ultraviolet light (right picture);

[0034] Figure 6 The influence of the mixture of different mass fractions of diluent monomers and the fluorescent rosin-based 3D printing UV resin of the present invention on the mechanical properties;

[0035] Figure 7 It is the TG diagram of different mass fractions of diluent monomers and the fluorescent rosin-based 3D printing UV resin of the present invention;

[0036] Figure 8 It is the 3D printing physical picture of the fluorescent rosin-based 3D printing UV resin of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] In order to better understand the present invention, the content of the present invention will be further clarified below with reference to the drawings and embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manner and specific operation process are given, but the content of the present invention is not limited to the following embodiments.

[0038] Example 1

[0039] Trimethylolpropane triacrylate (29.6 g, 0.1 mol) and inhibitor 4-methoxyphenol (0.0327 g) were added into a 250 mL three-necked flask. The mixture was heated to 70 °C and stirred at a speed of 200 rad / min for 10 min to completely dissolve the inhibitor. The temperature was adjusted to 50 °C, and the dropping rate was controlled using a dropping funnel to add ethanolamine (3.1 g, 0.05 mol). After the addition of ethanolamine was completed (dropped within 1 h), the reaction was carried out at 50 °C for 10 h in the dark (under light-shielded conditions) to produce an intermediate product. The progress of the reaction was monitored by detecting the amine value of the reaction. After confirming that the amine value no longer changed, the dropping rate was controlled using a dropping funnel to slowly add dehydroabietylamine (7.1 g, 0.025 mol). After the addition of dehydroabietylamine was completed (dropped within 1 h), the reaction was carried out at 50 °C in the dark (under light-shielded conditions) for 10 h to produce a fluorescent rosin-based 3D printing UV resin. At the same time, the progress of the reaction was monitored by detecting the amine value of the reaction. After confirming that the amine value no longer changed, the fluorescent rosin-based 3D printing UV resin was prepared. The physical object is as Figure 1 shown. The aforementioned reactions were all carried out under the protection of nitrogen. Figure 2 FT-IR spectra of raw materials ethanolamine MEA, dehydroabietylamine DHAA, trimethylolpropane triacrylate TMPTA, intermediate product TMEA, and product TMEADH. The peaks at wavenumbers 3350 cm -1 and 3167 cm -1 represent the characteristic peaks of primary amine —NH2. It can be seen that the characteristic peaks of primary amine in the intermediate product MEA have disappeared, confirming that the primary amine of ethanolamine participated in the reaction. The doublet at wavenumber 3373 cm -1 in DHAA also disappeared in the spectrum of TMEADH after the reaction ended, indicating that the primary amine of dehydroabietylamine also reacted with the double bond. The structure is as follows:

[0040]

[0041] Example 2

[0042] Anti-counterfeiting use of the fluorescent rosin-based 3D printing UV resin:

[0043] The excitation spectrum and emission spectrum of this fluorescent rosin-based 3D printing UV resin (prepared in Example 1) were tested using a fluorescence spectrometer (FLS920) produced by Edinburgh Instruments Ltd., UK. Figure 3 and Figure 4From the fluorescence emission spectrum and fluorescence excitation spectrum of the fluorescent rosin-based 3D printing UV resin, it can be seen that when the fluorescent rosin-based 3D printing UV resin is excited at 335nm, it can emit 400nm blue light. The inventor believes that the reason is that the fluorescent rosin-based 3D printing UV resin has the steric hindrance of the rosin enlarged molecule and a conjugated double bond system on the rosin skeleton, which makes the intramolecular rotation of the fluorescent rosin-based 3D printing UV resin highly restricted due to physical constraints, making the fluorescent rosin-based 3D printing UV resin fluorescent.

[0044] The fluorescent rosin-based 3D printing UV resin is encapsulated in a black container with a transparent top, such as Figure 4 As shown, this fluorescent rosin-based 3D printing UV resin is primary color under white light and has no fluorescence, but it exhibits blue fluorescence under 360nm ultraviolet light. This is used as an anti-counterfeiting mark attached to the genuine product or genuine product packaging, and users use it to determine whether it is genuine. If it exhibits blue fluorescence under 360nm ultraviolet light, it is genuine, otherwise it is a counterfeit.

[0045] The adhesion test in each case refers to the standard GB / T 9286-2021, and the best is grade 0.

[0046] Example 3

[0047] Preparation of light-curable materials:

[0048] Accurately weigh 2.388g of photoinitiator TPO with an analytical balance, add 79.6g of fluorescent rosin-based 3D printing UV resin prepared in Example 1, heat to 50°C, stir it thoroughly, mix it, pour it into a polytetrafluoroethylene mold, remove bubbles at 20-30°C, and evenly apply it on a corona-treated polypropylene film with a wire rod coater. The coating layer thickness is 10μm. Put the coating under an ultraviolet lamp for irradiation and curing for 2s (the ultraviolet lamp irradiation intensity is about 850mJ / cm2, and the distance is 21cm) to cure. The surface of the obtained coating is smooth and transparent, the adhesion is level 0, the impact resistance is greater than 50kg·cm, and the flexibility is ≤1mm. The water resistance test results: the coating is soaked in water for 48h, and the coating surface does not lose gloss, does not turn white, and there are no bubbles or shedding. At the same time, the same method was used to add different mass fractions of diluent monomer 4-acryloylmorpholine (ACMO) before adding the initiator TPO for comparison, and the mechanical properties were tested by uniaxial tensile test after curing. Figure 6 As shown by Figure 6It can be seen that the addition of 50% diluent monomer 4-acryloylmorpholine can well balance tensile strength and strain, showing better tensile strength. It can be seen that the application significantly increases the amount of diluent monomer, and the amount of diluent monomer can reach more than 50%, and can still better balance tensile strength (34Mpa) and elongation at break (up to 12%), while achieving 0-level adhesion, greatly improving the operability of the photocurable material. The existing diluent monomer can only reach 6-8% of the mass of UV resin, and can only reach 10% at most. If the diluent monomer continues to increase, its strength and adhesion and other properties will not meet the use requirements; and the amount of diluent monomer is small, the operability of the material will deteriorate, increase the difficulty of operation, and thus affect the quality, and the reduction of the amount of diluent monomer means an increase in the amount of UV resin, which in turn increases the cost. Figure 6 In the formula, TMEADH means that 4-acryloylmorpholine is added without any addition; TMEADH / ACMO10 means that the mass dosage of 4-acryloylmorpholine is 10% of the mass of the fluorescent rosin-based 3D printing UV resin, and the other similar expressions have similar meanings. TG tests were performed on diluent monomers with different mass fractions, such as Figure 7 shown.

[0049] Example 4

[0050] Testing the adhesion of light-curing materials on tinplate:

[0051] The preparation of the photocurable material refers to Example 3. As described in Example 3, the adhesion of the photocurable material on the plastic substrate can reach level 0. This example tests the adhesion of the photocurable material on tinplate. The photocurable material is attached to the tinplate. The coating layer thickness is 10μm, and the adhesion of TMEADH / ACMO50 reaches level 1. It can be seen that this photocurable material also has good adhesion on the metal substrate, so that it can better adhere to the photocurable 3D printing platform. The adhesion of 8wt ACMO on tinplate in application number 202310237017.8 was tested in the same way and was level 2.

[0052] Example 5

[0053] The following parameters were used for printing using the light-curing 3D printer CREATY SKY of Shenzhen Chuangxiang 3D Technology Co., Ltd.: initial exposure 40s, light-off delay 4s, printing exposure 2.2s, printing rise height 7mm, motor speed 1mm / s, bottom exposure layer number 3 layers, and TMEADH / ACMO50 composed of fluorescent rosin-based 3D printing UV resin and 4-acryloylmorpholine ACMO (prepared with reference to Example 3) was able to clearly print complex objects on the tinplate 3D printing platform, see Figure 8 .

[0054] Example 6

[0055] Determination of chemical resistance: The photocurable material was cut into pieces of 2 cm × 2 cm, weighed, and immersed in 10 wt% H2SO4 aqueous solution, 10 wt% NaOH aqueous solution, and 3 wt% NaCl aqueous solution at room temperature respectively. After soaking for 48 h, the samples were taken out, the surface solution was wiped dry, and weighed again. The mass before and after soaking was compared, and the mass retention rate of the photocurable material was used as an evaluation index for acid resistance, alkali resistance, and salt resistance. The acid resistance, alkali resistance, and salt resistance of TMEADH / ACMO50 (prepared according to Example 3 for reference) all reached over 99.9%.

Claims

1. A fluorescent rosin-based 3D printing UV resin, characterized in that: Its molecular structure is as follows:

2. A preparation method of the fluorescent rosin-based 3D printing UV resin according to claim 1, characterized in that: It is prepared from dehydroabietylamine, trimethylolpropane triacrylate and ethanolamine.

3. The preparation method according to claim 2, characterized in that: It includes the following steps: 1) Using p-methoxyphenol as an inhibitor, ethanolamine reacts with trimethylolpropane triacrylate at 40 - 50 °C for 8 - 18 h to obtain an intermediate product. 2) Adding dehydroabietylamine to the intermediate product obtained in step 1) and reacting at 40 - 50 °C for 6 - 10 h to prepare a fluorescent rosin-based 3D printing UV resin.

4. The preparation method according to claim 3, characterized in that: It includes the following steps: 1) Dissolving the inhibitor p-methoxyphenol in trimethylolpropane triacrylate, then dropping ethanolamine at 40 - 50 °C. After the addition of ethanolamine is completed, react for 8 - 18 h under light-shielded conditions at 40 - 50 °C to obtain an intermediate product. 2) Dropwise adding dehydroabietylamine to the intermediate product obtained in step 1) and reacting for 6 - 10 h under light-shielded conditions at 40 - 50 °C to prepare a fluorescent rosin-based 3D printing UV resin.

5. The preparation method according to claim 4, characterized in that: When all the primary amines of ethanolamine react to form tertiary amines, the reaction in step 1) ends; when all the primary amines of dehydroabietylamine react to form tertiary amines, the reaction in step 2) ends.

6. The preparation method according to any one of claims 2-5, characterized in that: The reaction is carried out under the protection of nitrogen; the molar ratio of ethanolamine, trimethylolpropane triacrylate and dehydroabietylamine is 1:(2 - 2.1):0.5; the mass dosage of p-methoxyphenol is 0.05% - 0.1% of the total mass of ethanolamine, trimethylolpropane triacrylate and dehydroabietylamine.

7. A use of the fluorescent rosin-based 3D printing UV resin according to claim 1, characterized in that: It is used as an anti-counterfeiting material or a safety marking material, and emits blue light at 400 nm under an excitation wavelength of 335 nm.

8. A use of the fluorescent rosin-based 3D printing UV resin according to claim 1, characterized in that: It is used to prepare a rosin-based resin photocuring material, and the prepared rosin-based resin photocuring material is used for coatings or 3D printing.

9. The use according to claim 8, characterized in that: The preparation method of the rosin-based resin photocuring material is as follows: Mix the fluorescent rosin-based 3D printing UV resin, the diluent monomer 4-acryloylmorpholine and the photoinitiator TPO evenly. After removing bubbles in an environment of 20 - 30 °C, irradiate with ultraviolet light to form a rosin-based resin photocuring material. Among them, the mass dosage of 4-acryloylmorpholine is 30 - 60% of the mass of the fluorescent rosin-based 3D printing UV resin, and the mass dosage of the photoinitiator TPO is 1 - 3% of the mass of the UV resin.

10. The use according to claim 9, characterized in that: The mass dosage of 4-acryloylmorpholine is 40 - 60% of the mass of the fluorescent rosin-based 3D printing UV resin.

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